key: cord-0041371-ekxgpxv8
authors: nan
title: Oral Abstract Session OAS
date: 2017-08-30
journal: Allergy
DOI: 10.1111/all.13250
sha: 30feb1888b0a58c03c2f634eb1d55b9de4d31972
doc_id: 41371
cord_uid: ekxgpxv8

nan

Objectives: Using longitudinally collected samples from a population-based cohort of challenge-confirmed egg allergic infants with either persistent or transient egg allergy, we aimed to define the immune profiles associated with egg allergy and assess the immunological changes that occur with the development of natural tolerance in childhood.

Results: We show that egg allergy is characterised by a hyperactive innate immune phenotype in the first year of life. This is particularly evident in infants with egg allergy that persists into childhood, with significant increases observed in circulating monocytes and dendritic cells that naturally produce more inflammatory cytokines (IL-1b, IL-6, IL-8) and less regulatory (IL-10) cytokines. Follow up analysis revealed that infants with persistent egg allergy continue to show a hyperactive innate phenotype in childhood and that this is not observed in children who develop natural tolerance. Reductions in the number of circulating memory B cells were also associated with persistent egg allergy, and children who develop natural tolerance in childhood appear to recover this deficit over time.

Conclusions: We report the complete innate and adaptive cellular immune profiles of infants and children with carefully defined clinical phenotypes of egg allergy. We used longitudinally collected samples and clinical outcomes from the HealthNuts study to reveal that hyperactivation of the innate immune system in the first year of life is a biomarker of persistent egg allergy in childhood. 0002 | Genetic variation at the Th2 immune gene IL13 is associated with IgE -mediated paediatric food allergy Introduction: The introduction of whole new foods in a population may lead to sensitization and food allergy. This constitutes a potential public health problem and a challenge to risk assessors and managers as the existing understanding of the physiopathological processes and the currently available biological tools for prediction of the risk for food allergy development and the severity of the reaction are not sufficient.

There is a substantial body of in vivo and in vitro data describing molecular and cellular events potentially involved in food sensitization. However, these events have not been organized in a sequence of related events that is plausible to result in sensitization, and useful to challenge current hypotheses.

Objectives: The aim of the COST Action network FA1402, called 'ImpARAS', was to collect and structure the current mechanistic understanding of sensitization induction to food proteins by applying the concept of adverse outcome pathway (AOP).

Results: The proposed AOP for food sensitization is based on information on molecular and cellular mechanisms and pathways evidenced to be involved in sensitization by food and food proteins and uses the AOPs for chemical skin sensitization and respiratory sensitization induction as templates. Available mechanistic data on protein respiratory sensitization were included to fill out gaps in the understanding of how proteins may affect cells, cell-cell interactions and tissue homeostasis. Analysis revealed several key events (KE) and biomarkers that may have potential use in testing and assessment of proteins for their sensitizing potential.

Conclusions: The application of the AOP concept to structure mechanistic in vivo and in vitro knowledge has made it possible to identify a number of methods, each addressing a specific KE, that provide information about the food allergenic potential of new proteins. When applied in the context of an integrated strategy these methods may reduce, if not replace, current animal testing approaches.

The proposed AOP will be shared at the www.aopwiki.org platform to expand the mechanistic data, improve the confidence in each of the proposed KE and key event relations (KERs), and allow for the identification of new, or refinement of established KE and KERs. 0004 | Metabolomic phenotyping based biomarkers in food allergy linked to respiratory allergy Villaseñor A 1 ; Obeso D 1 ; Rosace D 1 ; Escribese M 1 ; P erez-Gordo M 1 ; Santaolalla M 2 ; Fern andez-Rivas M 3 ; Blanco C 4 ; Alvarado M 5 ; Dominguez C 5 ; Barbas C 1 ; Barber D 1 1 San pablo ceu university, Madrid, Spain; 2 Hospital universitario sanchinarro, Madrid, Spain; 3 Hospital clinico san carlos, Madrid, Spain; 4 Hospital universitario de la princesa, Madrid, Spain; 5 Hospital publico virgen del puerto, Plasencia, Spain Introduction: Allergies are increasing steadily worldwide, only current prevalence in western world is estimated for about 25% of total population. In recent decades there have been both; a progression and an increment in the severity of this kind of diseases including food and respiratory allergies. In the case of food allergy, the model using allergen profilin has shown that allergens may have an effective access to the body through the oral mucosa. This fact has created from profilin a unique model to study the evolution of allergic inflammation. Along with it Spain which is characterized by an extreme climatic variation, is an ideal place to study the correlation between allergen respiratory exposure and development of severe food allergy. To date, there is a huge lack of deep knowledge concerning the molecular mechanism involved in this pathology. To tackle down, metabolomics emerged as a science capable of managing complex multifactorial diseases thought the analysis of all possible metabolites in a biological sample obtaining a global interpretation of biological systems.

Introduction: Allergic asthma is an inflammatory disease of the airways, resulting from an inappropriate immune response to inhaled allergens, which involves multiple inflammatory cells and mediators that contribute to airway hyperresponsiveness. Omalizumab is a monoclonal antibody, specifically directed to the C-ɛ 3 domain of immunoglobulin E (IgE), indicated as an additional therapy in severe allergic asthma. Data on circulating CD4 + Foxp3 + CD25 + CD127 lo Treg related to asthma control are scarce, as are biomarkers linked to asthma control in general.

Objectives: To investigate whether the proportion of circulating CD4 + Foxp3 + CD25 + CD127 lo Treg could be used as a biomarker for asthma control in patients treated with omalizumab.

Results: We performed a prospective cross-sectional study in a tertiary care hospital. All the children were older than 6 years and had severe allergic asthma remaining uncontrolled for at least 6 months despite high-dose inhaled corticosteroids (ICS). Asthma control was assessed at baseline and after 16 weeks of omalizumab. We monitored in parallel blood eosinophils and the proportion of circulating CD4 + Foxp3 + CD25 + CD127 lo T cells. Twenty-one children aged 11.2AE3.5 years were recruited consecutively. The percentage of children with well or partly controlled asthma increased after 16 weeks of omalizumab from 0% to 42.9% and 52.4%, respectively. Dose of ICS was on average 1300 μg of equivalent budesonide (IQR 1000 (IQR -2000 and remained unchanged during the follow-up. The mean proportion of circulating CD4 + Foxp3 + CD25 + CD127 lo Treg increased from 4.6AE1.6% of CD4 + T cells at baseline to 5.7AE1.9% after omalizumab treatment (P=.02), whereas mean blood eosinophilia decreased from 460AE316 to 320AE200/mm 3 (P=.02). Proportions of CD4 + Foxp3 + CD25 + CD127 lo Treg significantly changed according to asthma control after treatment (P<.01). The proportion of CD4 + Foxp3 + CD25 + CD127 lo Treg was confirmed to be independently associated with disease control [OR 2.3;  P=.04].

Conclusions: Thus, circulating Tregs appear more as a marker of omalizumab-induced control. A more extensive analysis is warranted to validate the proportion of CD4 + Foxp3 + CD25 + CD127 lo Treg as a biomarker to assess omalizumab efficacy. If confirmed, these results also support the role of CD4 + Foxp3 + CD25 + CD127 lo Treg in controlling the inflammation process in asthma.

0068 | Quantification of histamine-secreting microbes from the gut differentiates obese vs non-obese asthma patients heart rate variability (HRV) indices were derived and found as well to associate with risk of persistent asthma (under review).

In the present study, recordings were successful in 34 young children (age 3-7 y) with recurrent or persistent lower airway symptoms.

Most of the children were without regular medication and were considered to have either high (n=14) or lower (n=13) risk of persistent asthma according to modified asthma predictive index (mAPI); additionally, 7 children were on inhaled corticosteroids due to asthma.

Signals for both TAFV and HRV analysis were collected with custom-made wearable recorders (design of Tampere University of Technology) through four skin electrodes at home during night sleep.

The airflow parameters of minimal curve shape correlation (CSR min ) and minimal noise limit (NL min ) reflect overnight change in expired flow-volume curve shape, and smallest detected respiratory chaoticity, respectively. HRV parameters represent high (HF) and normalised low (LFn) frequency power. HRV organisation index (OI) describes regularity of the HF components of HRV spectrum.

Objectives: The objective of this study was to assess the association between novel IP-derived indices of TAFV and HRV indices measured during sleep.

Results: HRV indices LFn and OI correlated significantly with NL min , but none of the HRV indices correlated with CSR min ( Table 1) .

Exclusion of the ICS group (n=7) did not change significances of the correlation analysis.

The results show that indices of TAFV and HRV are related in young children with asthmatic symptoms. Specifically, reduced NL min indicating lowered chaoticity in tidal breathing flows relates to reduced LFn indicating parasympathetic dominance and increased organization of the HF band of the HRV spectrum, which may suggest lack of adaptability of the parasympathetic nervous system. It is possible that the same neural mechanisms contribute to both heart rate and airflow variability, or changes in HRV spectrum reflect altered respiratory modulation in asthma. Objectives: Based on the published genome of the Pacific oyster (Crassostrea gigas) we aimed to identify the complete potential oyster allergen repertoire using bioinformatics analysis and to investigate identified protein allergenicity using a combination of immuno-chemical methods and proteomic analysis.

Results: Ninety-five potential allergenic proteins of the Pacific oyster were discovered using in silico analyses. These proteins shared over 50% amino acid identity with their homologous allergens. The allergenicity of these proteins was characterized using a combination of immunoassay and genome-derived proteomics analysis. The 2Dimmunoblotting using a serum pool from five shellfish-allergic patients showed twenty-two IgE-reactive spots in the raw extract of the Pacific oyster and five spots in the heated extract. The identity of these IgE-reactive proteins was investigated by mass spectrometry. Eighteen allergens were identified, some with two or more isoforms.

Conclusions: The combination of genomics coupled to proteomics and IgE-reactivity profiling is a powerful method for the identification of novel allergens from food sources. Using this combination approach we were able to expand the current knowledge on IgEreactivity to various proteins of the Pacific oyster. These newly iden- Results: The ligand carried by Pru p 3 was purified by organic extraction (methanol: formic acid) and chromatographic methods (LH20 exclusion chromatography). Mass spectrometry was employed to identify the chemical nature of the ligand which was then confirmed by commercial standards. The immunological

properties of the purified ligand of Pru p 3 were investigated by using monocyte cell line THP1 and monocyte-derived dendritic cells.

The ligand of Pru p 3 was identified as a mono-hydroxylated derivative of the alkaloid camptothecin linked to phytosphingosine. While the hydrophobic tail of the sphingoid moiety is inserted into the hydrophobic cavity of the LTP, the camptothecin derivative that bears a number of polar groups is exposed to the aqueous solvent.

The results obtained from several immunological assays showed that the ligand of Pru p 3 should be an important factor in the activation of the immune cells investigated.

Conclusions: The ligand of the major peach allergen Pru p 3 has been characterized and clear evidence of its immunological role has been found.

Introduction: Prenatal maternal stress affects the offspring's development of allergic diseases. No specific biomarker, however, has succeeded in evaluating the risk of allergic diseases development or the degree of exposure to the potential risks factors. Recently the shortening of leucocyte telomere lengths (LTL) begins to be highlighted as potential marker for the exposure to oxidative stress.

Objectives: We aimed to explore whether LTL shortening varies according to the high exposure to maternal stress and the later development of atopic dermatitis (AD).

We chose four groups of samples from the COCOA birth cohort according to the exposure to maternal prenatal distress and the later development of atopic dermatitis at 1 year. We measured the LTL from the cord-blood and 1-year peripheral blood of the sample populations. The LTL was shorter in 1-year samples than in the cord blood ones (P<.001), which was evident in the prenatally distressed and later AD-developed group (P=.004), the prenatally nondistressed and later AD-developed one (P=.026), and the prenatally distressed but later AD-undeveloped one (P=.003). However, the LTL was not different in the prenatally non-distressed and AD-undeveloped group. (P=.434). The LTL was shorter in prenatally-distressed groups than non-distressed the others (P=.002 in the cord blood and P=.015 in the 1-year peripheral blood), but the difference is not significant between the group of later AD-developed and non-developed ones (P=.310 in the cord blood and P=.154 in the 1-year peripheral blood).

We observed a significant difference in LTL according to the exposure to prenatal maternal distress but less significant trend according to the later AD development. The result implies that oxidative stress may partly be involved in the pathogenesis of prenatal stress exposure and the later AD development, but also implies that there might be other moderating factors. Objectives: To examine whether preterm birth predicts the risk of atopy in adulthood.

Methods: Young adults born during 1985-9 in Northern Finland participated in Ester preterm birth-cohort study at mean age of 23.5AE1.7 years. Participants were tested for atopy for common allergens (birch, timothy, mugworth, dpteron, cat, dog) , as part of a clinical health check and provided health details and history of atopic diseases (incl. physician-diagnosed asthma) via a questionnaire. Mean wheal diameter (largest + perpent/2) ≥3 mm and no reaction in the negative control, was considered a positive result. Participants were grouped into early preterm: GA≤34 weeks, n=134, late preterm: 34<37 weeks, n=235) and full-term-born (≥37 weeks, n=331).

Results: 43% of all participants were tested positive for any atopy and 22% to birch. Likelihood of birth pollen sensitisation was considered as uniform across the population and a good representative of a random sensitisation. Logistic regression analysis showed that latepreterm individuals had a significantly lower risk of any atopy (OR: 0.7, 95% CI: 0.5, 0.9, birch: 0.8, 95% CI: 0.7, 1.0) than full-term-born.

The association was not observed within the early-preterm-born (any atopy: 0.9, 95% CI: 0.6, 1.4, birch: 0.7, 95% CI: 0.4, 1.0). Parental educational attainment or maternal smoking during pregnancy, were not association with atopy in this population.

Conclusions: Preterm birth has a significant effect on the early development of immunity. Late preterm birth may expose individuals to environmental antigens earlier, possibly priming immunological maturation and protecting against atopy. Severity of early preterm birth may counterbalance this benefit.

Introduction: Asthma prevalence has increased in epidemic proportions along urbanization, while growing up on traditional farms offers protection. The protection in farms has been associated with rich indoor dust microbiota. It remains elusive whether compositionally similar microbiota predicts lower asthma risk in non-farm homes, independently of the farm environment and lifestyle.

Objectives: To determine compositional predictors of asthma protective microbial exposures in farm homes and whether similar microbiota is associated with lower asthma-risk also in homes away from farms.

We modelled the primary distinguishing features between indoor dust microbiota composition of farm homes and other rural homes in a prospective birth cohort of 204 children with half living on farms. The samples were collected when the children were 2 months old and microbiota analysed by DNA amplicon sequencing.

Living in a house with microbiota more similar to farm than non-farm homes was a stronger predictor of the farm-associated asthma protection by 6 years of age than living in an actual farm home. The microbiota feature distinct to farm homes was high proportion of livestock-associated taxa over those commonly found in human airways. Applying the approach to a second Finnish, mainly suburban, birth cohort of 182 children, showed that also in non-farm homes the risk of asthma was inversely associated with the similarity of the predominant microbiota in farm homes. The similarity was characterized by high abundance of bacteria associated with outdoor environment and associated with reduced proinflammatory cytokine responses against bacterial cell wall components ex vivo.

Conclusions: These results identify the phylogenetic composition of indoor dust microbiome as characterizable predictor of asthma-risk and a novel modifiable target for asthma preventive interventions.

Pekkanen J 1 ; Valkonen M 2 ; T€ aubel M 2 ; Lepp€ anen H 2 ; K€ arkk€ ainen P 2 ; Rintala H 2 ; Zock J 3 ; Casas L 3 ; Tischer C 3 ; Probst-Hensch N 4 ; Forsberg B 5 ; Holm M 6 ; Jahnson C 7 ; Pin I 8 ; G ıslason T 9 ; Jarvis D 10 ; Heinrich J 11 ; Hyv€ arinen A 2 1 University of Helsinki, Helsinki, Finland; 2 National Institute for Health and Welfare, Kuopio, Finland; 3 ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; 4 Swiss Tropical and Public Health Institute, Basel, Switzerland; 5 Umeå University, Umeå, Sweden; 6 Sahlgrenska University Hospital, Gothenburg, Sweden; 7 Uppsala University, Uppsala, Sweden; 8 CHU de Grenoble Alpes, Grenoble, France; 9 University of Iceland, Reykjavik, Iceland; 10 Imperial College, National Heart and Lung Institute, London, United Kingdom; 11 Ludwig Maximilians University, Munich, Germany Introduction: Both protective and adverse effects of indoor microbial exposure on risk of asthma have been reported, mainly among children. There are very few studies on adults.

Objectives: Xxxxxxxxx. Results: Altogether 37 different bands were detected in the bacterial DNA fingerprints with DGGE, of which 15 bands had at least a suggestive adjusted association (P<.25) with asthma. These 15 bands were sequenced for detection of specific microbes and based on the results, four qPCRs were developed or optimized. Of these four qPCRs, Clostridium cluster XI confirmed the protective association with asthma observed in the analyses of the DGGE bands. The association was dose dependent over the four quartiles of exposure for the fourth quartile vs first quartile) (p for trend 0.009) and independent of levels of other microbial markers.

In an exposure study, environmental in addition to human sources were found to be important determinants of mattress dust levels of Clostridium cluster XI.

Conclusions: In this large international study, using non-targeted DNA fingerprinting for detection of important bacteria together with targeted quantitative confirmation, cluster XI of Gram-positive ABSTRACTS | 15

Clostridium bacteria was independently associated with lower risk of prevalent asthma. Results suggest the importance of environmental bacteria also in adult asthma, but this needs to be confirmed in prospective studies. 0174 | Perinatal probiotics decreased eczema up to 10 years of age but at 5-10 years allergic rhino conjunctivitis was increased Objectives: We conducted a randomized double-blind, placebocontrolled trial to determine whether perinatally given probiotics prevent allergic diseases in high-risk children.

1223 pregnant women were randomized to receive probiotics (LGG ATCC 53103, L. rhamnosus LC705, Bifidobacterium breve Bb99) or placebo from 36 gestational week and their infants with a high allergy risk pro-and prebiotics or placebo from birth until 6 months.

At 10 years parents filled in questionnaires, based on the ISAACstudy. Our primary outcome was the prevalence of allergic diseases.

Results: Of intention-to-treat children´s parents 79.2% returned the questionnaire. The lifetime prevalence of any allergic disease (eczema, allergic rhinitis (AR) or asthma) was similar (64.4% vs 70.0%) in the probiotic and placebo group. However the lifetime prevalence of eczema was lower in the probiotic group (35.2% vs 41.7%, adjusted OR 0.74 (0.55-1.00 P<.05). The lifetime prevalences of any doctor-diagnosed allergic disease (eczema, AR or asthma) (49.4% vs 52.3%), eczema (33.0% vs 37.6%), AR (27.0% vs 24.5%) or asthma (14.3% vs 15.5%) were comparable between the probiotic and placebo groups, respectively.

Between age 5-10 years allergic rhino conjunctivitis occurred more frequently in the probiotic group (36.5% vs 29.3%; OR 1.39; 95% CI 1.03-1.86; P=.03). The prevalences of eczema (26.7% vs 31.9%) and asthma (9.4% vs 12.4%) were similar.

At age 5-10 years, Caesarean-born children in the probiotic group had less respiratory tract infections than the controls (13.0% vs 33.3%, OR 0.30; 95% CI 0.13-0.70; P<.01) and more often no use of antibiotics in the past 5 years (17.4% vs 6.7%, adjusted OR 0.31; 95% Cl 0.10-0.98; P<.05).

Conclusions: Perinatally received probiotics may reduce the cumulative incidence of eczema until age 10 years, but the prevalence of allergic rhino conjunctivitis at age 5-10 years increased. Objectives: In this study, we aimed to investigate the role of polymorphisms in cytokine genes such as IL-1alpha, IL-1b, IL-1RA, IL-2, IL-4R alpha, IL-4, IL-6, IL-10, IL-12, IFN-gamma, TGF-b and TNF-alpha, in insect venom allergy. Twenty-one patients who had a history of early systemic allergic reaction after a sting were included in the study. Nineteen male beekeepers and 18 non-atopic healthy subjects who did not experience any systemic allergic reaction despite insect sting were selected as control groups. Insect venom allergy was diagnosed by using skin prick and intradermal tests and/or specific IgE measurements. Cytokine genotyping and haplotyping were carried out from genomic DNA by polymerase chain reaction with sequence-specific primers (PCR-SSP) using a commercial kit.

Results: Frequency of IL-10-1082, -819 AT* (76.2%) in allergic patients was found significantly higher than both from non-allergic beekeepers (35.3%) and healthy controls (58.8%) (P=.042). On the other hand, tendency of lower frequency of IL-10-1082, -592 A*A in non-allergic beekeepers (46.7%) comparing to allergic individuals (75%) was shown. Frequency of IL4-1098, -590 TT* (43.8%) in allergic patients was found higher than both from non-allergic beekeepers (30.8%) and healthy controls (13.2%). Comparison of allergic individuals with non-allergic beekeepers resulted with significant P value for IL-10-1082,-819 AT* (P=.013, frequency; 76.2% and 35.3%, respectively). However, non-allergic beekeepers showed a tendency of higher frequency of IFN-gamma +874 A genotype than in the allergic patients (P=.062, 94.7% and 71.4%, respectively). Gene polymorphisms did not differ between non-allergic beekeepers and healthy controls. Furthermore, the presence of IFN-gamma +874 A genotype was correlated with the lower grade of severity of systemic sting reaction (P=.018).

Conclusions: Our data suggest that polymorphisms which have negative effects on expression of IL-10 gene may affect susceptibility on the development of severe allergic reaction in hymenoptera venom allergy.

Schiener M 1 ; Eberlein B 2 ; Hilger C 3 ; Kuehn A 3 ; Pascal M 4 ; Moreno-Aguilar C 5 ; Biedermann T 2 ; Darsow U 2 ; Schmidt-Weber C 1 Polistes dominula being an invasive species, Polistes venom allergy is likely to evolve in northern regions of Europe. Amongst others, the diagnostic challenge is due to extensive cross-reactivity between the venoms. Additionally, for Polistes dominula only a small fraction of venom components is known. In this study, Polistes venom was analyzed for additional allergens, which were subsequently characterized in detail regarding their potential to trigger allergic reactions.

Objectives: Polistes venom was extensively analyzed by mass spectrometry and de novo peptide sequencing following 1D or 2D gel electrophoresis. Identified components were cloned from venom gland mRNA and expressed in insect cells. The resulting purified proteins, together with their homologues of different hymenoptera species, were characterized by immunoblotting and assessed for IgE cross-reactivity. Moreover, their capacity to activate basophils of either honeybee or wasp venom allergic patients was evaluated.

Results: Newly identified Polistes venom components and homologues from other hymenoptera species were successfully produced in Sf9 insect cells and thus were devoid of cross-reactive carbohydrate determinants. The analysis of sera from honeybee, Vespula and 0178 | Can tests distinguish between acute patients, VIT treated patients, and asymptomatically sensitized subjects? Schrautzer C; Arzt L; Bokanovic D; Schwarz I; Laipold K; Aberer W; Sturm G Department of Dermatology, Graz, Austria Introduction: Currently no reliable serological marker is known to predict tolerance to hymenoptera stings. Our aim was therefore to evaluate different parameters and methods (sIgE and IgG 4 levels, IgE/IgG 4 ratio, ELIFAB assay, BAT-Inhibition) in three different groups of sensitized subjects to identify possible differences.

Objectives: We included 41 subjects with acute systemic sting reactions grade 2 or higher. The subgroup of VIT treated patients consisted of 37 patients, and 40 asymptomatically sensitized subjects were included. We measured baseline levels of sIgE and sIgG 4 to bee venom, wasp venom, rApi m 1 and rVes v 5 immediately after acute sting reactions and before sting challenges in VIT treated and asymptomatically sensitized subjects. To determine the time courses of sIgE and sIgG 4 levels, blood was taken one month after the acute sting or sting challenge. Additionally, the inhibitory activity was determined by using the ELIFAB assay and BAT-Inhibition-tests.

Results: Baseline sIgE levels to bee venom, wasp venom, rApi m 1 and rVes v 5 did not differ between the groups. IgG 4 levels proofed to be significantly higher in VIT-patients (P ˂ .001), while IgE/IgG 4 ratios where consequently lower (P ˂ .001). At baseline, IgE/IgG 4 ratios in acute patients and asymptomatically sensitized subjects tended to be higher in acute patients, although the difference was not statistically significant. The ELIFAB assay correlated with the low IgE/IgG 4 ratios in VIT patients showing markedly higher allergenblocking capacity (P ˂ .001).

Four weeks after the sting, sIgE and IgG 4 levels increased in acute patients and asymptomatically sensitized subjects, but not in VIT patients. A clear inhibition of basophil response could be shown for patients treated with wasp venom, whereas inhibition failed in patients treated with bee venom.

Conclusions: Baseline IgG 4 values of all parameters were significantly higher (P ˂ .001) in VIT-patients, which reflects the immunological effect of VIT. In addition to this, the ELIFAB assay confirmed the results of the IgE/IgG 4 ratios in VIT patients. BAT inhibition was a promising tool at least to monitor VIT with wasp venom. Different responses of IgE and IgG levels after bee and wasp stings, and differences in the BAT inhibition implied that bee and wasp venom allergy may be immunologically different. Introduction: SIT is an established therapy for wasp venom allergy. The aim of our work is to investigate the progression of surface antigen CD63 and CD203c expression during SIT using BAT.

Objectives: We included 71 patients (61 wasp, 10 honey bee; 19 aborted) in our study, which was approved by the institutional ethical review board. Here we report on 40 adult patients with SIT against wasp venom after 3 years of SIT. Blood samples were collected before and 3 days (3d), 2 weeks (2w), 6 months (6 m) and repeatedly every 6 months until 3 years (3y) during SIT. For all samples we determined CD63 and CD203c expression using BAT after stimulation with various wasp venom concentrations. We evaluated the relative proportion of activated basophile granulocytes at 57 μg/ l venom concentration (a2) and the calculated concentration c50 to stimulate 50% of total activatable basophile granulocytes. Clinical evaluation of outdoor stings during SIT and final sting challenge tests after 3 years was obtained from patient charts.

Results: CD63 expression (and inversely c50) (n=36) decreased in 27 and increased in 4 patients, while it was constant in 5 cases.

Median changes to baseline at 3y were a2=À79% (P<.01) and c50=722% (P=.02). CD203c expression (and inversely c50) (n=40) decreased in 25, increased in 9 and did not change in 6 patients. Objectives: To recognize differences in health service delivery across European countries which may influence diagnosis and treatment of Hymenoptera venom allergy.

Results: A link to an online questionnaire was sent to a practicing allergy physicians or representative of each of the 36 national allergy societies associated to EAACI. Data collection is ongoing.

Twenty two responses have been received so far (61%). First aid following field insect sting is delivered in most countries in emergency department [ED] (77%), ambulance (68%), or by general practitioners [GPs] (59%). In over 50% of countries surveyed, help received in ED or ambulance is free of charge. In about 1/3 of countries GPs and ED staff are allowed to prescribe adrenaline autoinjector. The price of an autoinjector ranged between 40-116 across the surveyed countries, but in 23% of countries it is either free or fully reimbursed. In almost all countries (96%) GPs refer patients to an allergy specialist, although in 46% patients can selfrefer to specialists. Waiting times for a first appointment with an allergy specialist varied considerably between 1 week and 6 months. Diagnostic blood tests are performed at primary (55%) or secondary/tertiary level (70% both) whereas skin tests are performed mainly at tertiary level (82% Introduction: Diagnostic efficacy of the conjunctival provocation test (CPT) was shown in recent years, exploring the severity of allergic reaction by rhinoconjunctivitis in immunotherapeutic, placebo controlled dose-finding and safety studies. The CPT is based on the eye mucosa challenge, instilling the allergen solution onto the conjunctival sac. Assessing the allergic symptoms, which occur after the conjunctival provocation with experimental allergen, severity of the allergic rhinoconjunctivitis and success of the immunotherapy is evaluated. Among the allergic symptoms only redness can be documented for further reassessment by different methods.

Objectives: To estimate an influence of missing values in assessment of the conjunctival redness severity during the hyposensitisation of the allergic rhinoconjunctivitis.

Results: Current analysis processes the data, collected in five prospective, multicenter, double-blind, placebo-controlled, randomized, immunotherapeutic hyposensitization studies in inhalative allergies. The CPT was an essential diagnostic method to assess the therapeutic effect in all considered studies. After an assessment of the allergic reaction on the conjunctival provocation, the study investigators documented the high-resolution digital photos of the challenged eyes. The allergic redness, represented on the eyes photos, was first assessed by an external observer, using the grading score. Then the imaging software was applied to assess the eye redness independently from the investigators subjectivity. Missing values, which appeared because of incompleteness or bad quality photodocumentation, were imputed by multiple imputations and compared with the original data set. The therapeutic effect uncertainties, induced by missing values, were estimated. Diagnostic performance of the redness, estimated by the imaging software and external observer, was assessed with the receiver operating characteristic (ROC) curves and correlation analysis, before and after the missing value imputation.

Conclusions: Multiple imputations of the photodocumentation missing values were successfully applied to reveal an assessment accuracy of the conjunctival redness during the immunotherapeutic hyposensitization studies with conjunctival provocation challenge. Objectives: The objectives of this study were to (i) access AR expert consensus on the AR CDSS step-up, and step down treatment strategies, (ii) formulate specific treatment recommendations for each step and (iii) improve robustness of the AR CDSS. A survey monkey was sent to 70 AR experts. The first part posed questions about the AR CDSS approach itself; when to start, step-up and stepdown treatment. The second part asked in depth questions on specific AR treatment recommendations at each step. For each scenario, respondents indicated their level of agreement on a VAS ranging from 0 (strongly disagree) to 100 (strongly agree). Stepping down was essentially the same in reverse, with the proviso that patients with nasal congestion should be stepped down to an INS-containing regimen in preference to AH.

Step-up and step-down strategies remained the same irrespective of immunotherapy status.

Conclusions: Experts endorsed the AR CDSS approach, with good agreement achieved on treatment recommendations. The AR CDSS and expert treatment recommendations will be incorporated into the Allergy Diary Companion. When using this app healthcare providers benefit from the combined wisdom of world experts in AR.

Campo P 1 ; Rondon C 1 ; Plaza M 2 ; Prieto A 3 ; Galindo L 1 ; Mayorga C 2 ; Blanca M 1 ; Torres M 1 1 Allergy Unit, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain; 2 Research Laboratory, IBIMA, Regional University Hospital of Malaga, UMA, Malaga, Spain; 3 Pediatric Unit, Regional University Hospital of Malaga, Malaga, Spain Introduction: Prior methods used for measuring nasal specific IgE (NsIgE) in local allergic rhinitis (LAR) have shown a variable sensitivity: 22% for D. Pteronyssinus (DP) using the Greiff/Gr€ unberg method and lower with Naclerio method.

Objectives: In this study a novel method of detection of NsIgE in patients with confirmed LAR to DP was evaluated.

Methods: Sixteen LAR (positive nasal allergen provocation test to DP (NAPT-DP), negative skin testing/sIgE to DP), 10 allergic rhinitis (AR) as positive control (positive NAPT-DP and skin testing/sIgE to DP), and 12 healthy controls as negative control (negative NAPT-DP and skin testing/sIgE to DP) were recruited. DP-ImmunoCAP solid phase was applied directly in the lower turbinate of each nostril for 10 minutes before and 24 hours after NAPT-DP and analyzed following the manufacturer´s instructions. ROC curves were performed to obtain the optimal cut-off point of nasal sIgE value to calculate sensitivity (S) and specificity (SP), and outcomes were compared with NAPT-DP result (gold standard test). Study was approved by local ethics´committee.

Results: All LAR and AR subjects had a positive response to NAPT-DP, and none in the healthy control group. At 24 hours after NAPT-DP, mean NsIgE values were 0.119 kU/l in LAR, 1.600 kU/l in AR and 0.115 kU/L in healthy controls. ROC curves using NsIgE values obtained 24 hours after NAPT-DP were performed. In LAR subjects, the area under the curve (AUC) was 0.7277, P=.0054. The optimal cut-off point to discriminate LAR subjects from controls was 0.135 kU/l, obtaining a S=20.31% and SP=88.09%. In AR (positive control group) the AUC was 0.9798, P=<.0001, and the optimal cutoff point was 0.17 kU/l with S=95% and SP=100%.

Conclusions: Measurement of NsIgE by direct application of DP-ImmunoCAP in LAR shows similar sensitivity to other methods and good specificity, with the advantage of being non-invasive, easier to perform and faster. FIS PI14/00864. Introduction: Local allergic rhinitis (LAR) describes a phenomenon where patients with symptoms of allergic rhinitis who are negative in allergy testing with skin tests and specific IgE determination (sIgE) react positively to nasal allergen provocation (NPT). LAR has been described and confirmed by several groups but considerable uncertainty remains about its incidence and the correct methodology for its diagnosis.

In our department, NPT is performed routinely following the recommendations of the German Society for Allergology and Clinical Immunology. A combination of symptom scores and rhinomanometry is used to determine the outcome. As opposed to others we challenge with high and increasing doses of allergen.

Objectives: The aim of this study was to analyze the frequency of LAR in our patient population. We performed a retrospective analysis of routine nasal allergen provocations that were performed between 1990 and 2013 in our allergy clinic. Only patients with complete data sets were included. Allergens from one manufacturer in concentrations of 5.000 BE/ml, 25.000 BE/ml, and 50.000 BE/ml -corresponding to 0.22 lg, 1.1 lg, and 2.2 lg major allergen of D.

farinae per application -were used. Results: There was a comparable and significant reduction of Der p 1 levels with both the probiotics-impregnated covers and the untreated covers. Several symptom and quality of life scores improved significantly with the probiotics-impregnated covers, whereas no significant changes were observed with the untreated covers. The effects of the probiotics-impregnated covers on symptoms and quality of life scores however were not significant compared to the placebo covers (except for a subscore NRQLQ sleeptime Objectives: Herein, we report on the molecular basis of the novel PGM3-deficiency associated to a rare autosomal recessive HIES and the assessment of related intervention approaches.

Results: We identified in two consanguineous tunisian families with multiple affected individuals, who were wild type for STAT3 and DOCK8, two distinct homozygous mutations in Phosphoglucomutase 3 (PGM3). PGM3 catalyzes the reversible conversion of N-acetyl glucosamine 6P to N-acetyl glucosamine 1P required for biosynthesis of uridine diphosphate N-acetylglucosamine an essential precursor for protein glycosylation. PGM3 deficiency is likely to impair glycan mediated processes such as cell-cell recognition or immune signalling. Functional studies of the two mutations show that they lead to an aberrant glycosylation pattern in leucocytes with reduced (bi-), tri-, and tetra-antennary N-glycan branching in leucocytes from affected individuals. The mutations are one in-frame deletion and one amino acid substitution, both of them permit at least some expression and translation of the variant PGM3. Furthermore, these hypomorphic mutations did show dose-dependent increase of enzyme activity in vitro, so we hypothetized that supplementing with an excess of substrate might improve residual enzymatic activity in vivo and clinical condition of patients, at least partially. Two PGM3 deficiency patients suffering eczema with extremely severe itching were treated with GlucNAc supplement and results are discussed.

Conclusions: This is a novel and rare primary immunodeficiency due to a congenital disorder of glycosylation. The proof of principal to correct a glycosylation defect by supplementation, is available since e.g. individuals deficient in mannose-6-phosphate isomerase (Fru-6-P to Man-6-P conversion) lack sufficient Man-6-P for complete physiologic N-glycosylation and daily supplements of mannose can correct this glycosylation deficiency. In PGM3 deficient patients supplementation with excess enzyme substrate or by a compound that bypasses the block could be a therapeutic approach to improve, at least, their severe eczema. Introduction: Serum free light chains (sFLC) are widely used as a prognostic marker in B cells lymphoproliferative disorders; in these conditions a raise of either kappa or lambda chain represents a marker of clonality. Furthermore, polyclonal increase in serum FLC has been identified in many autoimmune conditions as a marker of disease activity. Diagnosis of Common variable immunodeficiency (CVID) is an exclusion process. In particular, differential diagnosis between CVID and lymphoproliferative disorders or nonsecreting multiple myeloma may be challenging in adult patients. We recently suggested a role of sFLC in the diagnostic work-up of CVID, in a small single-center cohort of adult patients.

Objectives: sFLC levels were determined in 344 adult patients with CVID, enrolled in 5 different Italian referral centers for Primary Immunodeficiencies. B cell phenotype was available, according to EUROCLASS Study, of a subgroup of 120 patients. All CVID patients fulfilled the ESID-PAGID diagnostic criteria.

Results: Mean age was 51 (range 18-82); diagnostic delay was 10.6 years, on average. In 255 out of 344 patients (76.3%) a reduction of either kappa or lambda light chains or both was observed.

166 patients (49.7%) showed a decrease of both k and l chains; 82 patients (24.5%) presented a reduction of k chain only, with normal l levels; 7 patients (2.1%) presented a reduction of l chain only, with normal k levels. According to our previous study, we defined "jk + " "j + k -" and "jk -" as "CVID-like patterns". Interestingly, in a subgroup analysis of 120 subjects, 47.5% of patients with CVID-like pattern presented switched memory B cells %<2%, while the % of SmB cells was normal in 81% of normal FLC patients. Moreover, CD21lo cells resulted increased in 35% of CVID-like pattern patients vs 14.3% of normal sFLC patients.

Conclusions: A CVID-like sFLC pattern is present in more than 75% of our CVID cohort. This confirms our previous data and the promising diagnostic value of sFLC in the initial work-up of primary hypogammaglobulinemia. Finally, the subgroup analysis suggests the need for further investigations on the relationship between a CVIDlike pattern and the impairment of B cell function, in order to assess a putative prognostic role of sFLC determination. 0189 | Sustained natural killer cell expansion in virologically suppressed HIV+ individuals on antiretroviral therapy: a phenotypic study 0191 | Different serum cytokine profiles reflect anti-neutrophil cytoplasmic antibodies (ANCA)-specificity in patients with ancaassociated vasculitis Introduction: Evidence supporting the classification of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) based on ANCA type is accumulating [1] .

Objectives: To evaluate serum cytokine profiles in patients with AAV classified by ANCA type (proteinase 3 (PR3)-ANCA vs myeloperoxidase (MPO)-ANCA) or by clinical diagnosis (granulomatosis with polyangiitis (GPA) vs microscopic polyangiitis (MPA)) or by clinical phenotypes.

Methods: A panel of 30 cytokines was tested in patients with active AAV at inclusion in the Rituximab in ANCA-Associated Vasculitis (RAVE) trial as previously described [2] [3] . We analyzed the association of levels of these cytokines with ANCA specificity, clinical diagnosis, and distinct clinicopathologic phenotype categories derived from the BVAS/WG items recorded at the time of enrollment (capillaritis, granulomatous manifestations, renal involvement and alveolar hemorrhage; new diagnosis and relapsing disease), as described [4] .

Results: All cytokines tested except for RANTES, ACE, bFGF and VCAM-1 were significantly increased in the RAVE cohort when compared to healthy controls (P>.05). Within ANCA type, levels of 9 mediators were significantly higher in PR3-AAV (IL-6, NGFb, GM-CSF, IL-15, IL-18, IL-18Bb, sIL-2Ra, IL-8, TARC), compared to 5 different cytokines that were higher in MPO-AAV (sIL6R, NGAL, sICAM-1, VCAM-1, sTNFR II). In contrast, only 4 (GM-CSF, IL-15, IL-18, sIL-2Ra) cytokines were higher in GPA than MPA, and 1 (NGAL) was higher in MPA than GPA. The association of the majority of cytokines was stronger with ANCA specificity than with clinical diagnosis (ANCA type: association with P≤.001 for 5 cytokines, association with .001≤P≤.01 for 3 cytokines, and with .01≤P≤.05 for other 6 cytokines. AAV diagnosis: association with .01≤P≤.05 for 5 cytokines). Similarly, the defined clinical phenotypes were also not separated by cytokine signatures as clearly as the ANCA specificity was (data not shown).

Conclusions: Cytokine signatures separate patients more clearly by ANCA specificity than by clinical diagnosis, suggesting important differences in underlying pathophysiology and validating stratification of patients by ANCA specificity for treatment trials.

References: [1] Cornec D et al. Nat Rev Rheumatol. 2016; 12(10) Introduction: Preterm birth may obscure immune system development and is e.g. associated with increased risk for infections and asthma. Type-1 diabetes (T1D), an autoimmune disease, may as well occur more often in those born at a lower gestational age. We aimed at studying this in young adults born in Finland, a country with a record high T1D prevalence.

Objectives: We assessed whether a shorter gestation increases the risk of T1D.

We followed all 235 622 children born in Finland from Jan 1987 to Sep 1990. The national unique person identity number linked our data (Medical birth register: best estimated gestational age (GA), The Finnish Care Register for Health Care HILMO: ICD-9 and ICD-10 Diagnoses and dates of hospitalizations and specialized care outpatient visits (1998) (1999) (2000) (2001) (2002) (2003) (2004) (2005) (2006) (2007) (2008) (2009) (2010) (2011) (2012) (2013) (2014) (2015) , Population Register: time of death and emigration, Statistics Finland: education). For adequate power, we ran Cox's regression analysis in six GA categories (Table) .

A total of 2422 individuals were coded as T1D in HILMO during the total 6.3 million person years of follow-up. We observed no pooled effect of all preterm births (Table) . However, early term birth categories with GA either 37 or 38 full weeks associated with a 13% to 35% increased hazard of developing T1D. Parental T1D clearly increased offspring's risk but left, also in model 3 with parental education, the effects of early term birth relatively unchanged.

Conclusions: In conclusion, those born early at term develop T1D more often. This may indicate that development towards autoimmunity may occur during fetal and perinatal periods. Infancy and child-hood conditions, such as birth intervals and infections, may also play mediating roles. Introduction: Allergies such as those to various foods are likely to result in increased costs of health care. Determination of this marginal cost allows for an appreciation of the potential cost saving of preventing the disease or condition, or by reducing its severity.

Objectives: Our aim was to evaluate the difference in resource use and the related financial costs of treating people with peanut allergy (PA) in the United Kingdom, compared with the costs of treating people who did not have a diagnosis of PA.

Results: Of 15 483 people with a diagnosis of PA, it was possible to match 13 609 cases in Cohort-1 and 9320 in Cohort-2.

The annual, mean cost of primary care contacts for cases and controls in Cohort-1 was: £288 per patient year (PPY) vs £183 PPY, respectively (D=£105, P<.001).

In Cohort-2, the costs were £263 vs £196 PPY, respectively (D=£67, P<.001).

The annual cost of hospital inpatient care for cases and controls in Cohort-1 was: £335 per patient year (PPY) vs £268 PPY, respectively (D=£67, P<.001).

In Cohort-2, the costs were £327 vs £207 PPY, respectively (D= £120, P<.001).

The annual, mean cost of drug prescribing for cases and controls in Cohort-1 was: £146 per patient year (PPY) vs £48 PPY, respectively (D=£98, P<.001).

In Cohort-2, the costs were £124 vs £53, respectively (D=£71,

Conclusions: Albeit a conservative estimate, treating people with PA resulted in an annual, average increase in direct, financial costs to the health service of between £270 (»318) and £258 (»304) for those simple matched and atopy-matched respectively. Introduction: Few studies have prospectively followed children with cow's milk-associated symptoms beyond school age, although tolerance is thought to occur by this age. We examined the prognosis of symptoms, including timing of onset, as well as repeated measures of Immunoglobulin E (IgE) reactivity to milk, focusing on gender differences from early life to adolescence in the BAMSE population-based birth cohort.

Objectives: This study included 2320 children with data on milkassociated symptoms in early life (to 4y), and at 8y and 16y. Children with parent-reported, doctor-diagnosed lactose intolerance (n=188) were excluded. Timing of onset was defined as persistent (early life and/or 8y and 16y), transient (early life and/or 8y only), or late onset (16y only). At 16y, information on symptoms involving the gastrointestinal, dermatological, respiratory and/or cardiovascular/neurological systems was collected. At this age, multiple symptoms were defined as involvement of two or more systems. Data on milk-specific IgE were available at 4, 8 and 16 y for children who were IgE positive (≥0.35 kU A /l) to the food mix fx5 at the respective ages.

Data were analysed using descriptive statistics, Chi-square, Fisher exact tests and t-tests.

Results: Milk-associated symptoms were most prevalent in early life (17.1%), but decreased at 8y (1.5%) and 16y (3.1%). Symptoms were equally distributed between genders until 16y, when more girls than boys were affected (4.0% vs 2.3%; P=.002). Regarding timing of onset, transient cases were most common (16.5%), followed by persistent (4.5%) and late-onset (3.0%). Compared to boys, late-onset symptoms were more common in girls (61/87; 70.1%), amongst whom the majority reported gastrointestinal symptoms (e.g. vomiting or stomach pain) as the only symptom. Multiple symptoms were common amongst persistent cases (24/34; 70.6%), but rare amongst late-onset cases (1/87; 1.1%). Sensitisation to milk-specific IgE at 16y was uncommon in all groups, although most prevalent among persistent cases (6/31; 19 Results: A total of 50 subjects were recruited; 35 subjects (80% female, mean age 37 years) born and residing in the UK, with a positive Pru p 3 and diagnosis of LTP allergy, and 15 with diagnosed PFS (60% female, mean age 34 years). All subjects completed general allergy questionnaires and the validated Food Allergy Quality of Life Questionnaire -Adult Form (FAQLQ-AF). They also underwent skin prick testing (SPT; ALK Abello) to a panel of aeroallergens and foods and had a serum sample analysed using the ISAC microarray (ThermoFisher). There were no differences in atopic history or foods reported to cause reactions, although the PFS group were more likely to report reactions to raw fruits and vegetables (P<.001).

Those with LTP allergy also reported significantly more severe symptoms, were more likely to carry adrenaline and have had an emergency hospital visit than those with PFS (P<.001). A positive SPT to peach, walnut, barley, mustard, cabbage, raspberry and lettuce occurred more frequently (P<.001) in LTP allergic subjects, who were also more likely to be sensitised to the LTP allergens in mugworth Objectives: We conducted a nationwide, cross-sectional, population-based study to evaluate the current prevalence of food allergy and the distribution of offending food groups in this populous country. The survey was implemented in 5 different provinces across Vietnam and targeted towards two different age groups: children of age 2-6 years old from local kindergartens and university students, aged from 16 years old (adult group).

Results: A total of 17659 responses were collected from 8127 children and 9532 adult participants. The average response rate in the two groups was 69.9% (children: 77.9%; adults: 66.2%). There were more female participants (59.3%) answering the questionnaires than male ones (40.7%). There were 47.3% participants reported adverse reactions due to food consumption, but only 12.4% sought medical services for diagnosis. In 1477 (8.4%) doctor-confirmed food allergy participants, crustacean (55.3%), fish (25.4%) and molluscs (20.3%) were the leading causes of food allergy, followed by beef (12.4%) and milk (10.7%). Hives was the most typical clinical symptom in food allergic patients in this study, after nausea and diarrhea. Adult participants demonstrated a higher risk of allergy to beef (17%) as compared to children (3.6%) . In contrast, allergy to egg was more frequent in children (12.2%) than adults (7.7%).

Conclusions: This is the first population-based study ever conducted on food allergy in Vietnam. The prevalence of food allergy in Vietnam from this study is about 5.9%. We discovered that seafood is the predominant cause of food allergy while peanut and tree nut allergy are much less frequent. Furthermore, the occurrence of beef allergy is surprisingly high. Food allergy was shown to manifest differently in different age groups in this population. Results: Both populations differed in terms of socioeconomic status, environmental determinants, and prevalence of allergic diseases.

Nevertheless, we found similar latent classes (LC) in both populations: an unsensitized LC, a food LC, two inhalant LCs, differentiating between seasonal and perennial aero-allergens, and a severe atopy class. The latter was characterized by high total and sIgE levels and strongest associated with wheeze (odds ratio 5.64 [3.07-10.52 Introduction: Allergic sensitization is our initial clue to link clinical reactivity to etiology. Establishing this relation, clinical practice is started. The first Brazilian Project of Allergy (PROAL I) was established in 2004 in order to assess the prevalence of sensitization of the main allergens among Brazilian allergic children. This knowledge allowed us to evaluate the best management practices for the allergic diseases of our country. Primary, secondary and tertiary prevention had been developed more effectively.

Objectives: After a 12-year interval, a new assessment was conducted to estimate the prevalence trends (PROAL II). This time, with advancement of technology, including molecular and structural biology through the availability of allergen molecules. Eleven Brazilian Pediatric Allergy centers enrolled 470 individuals (mean -40 children by center, randomly selected; age range 6 m-18y). Identical design, diagnostic criteria and in-vitro analytical methods were used in both surveys (ImmunoCAP®, positive >0.35 kUA/l). Low bacterial/archaeal richness and low amount of house dust were associated with increased risk of developing asthma. The first two axis scores of principal coordinate analyses of the weighted bacterial/archaeal beta-diversity matrix were inversely associated with asthma. The first axis mainly represented the relative abundance of Firmicutes and Proteobacteria, and the second Actinobacteria abundance and diversity. Among the most abundant 139 genera, 41 bacterial genera correlated (r>|.4|) with either axis score. Twelve genera were inversely (P<0.10) and Lactococcus genus (aOR 1.36, 95% CI 1.13-1.63 per IQR change, P=.001) positively associated with the risk of asthma. Only the association with the Lactococcus genus was independent of the other taxa, and also independent of the bacterial/archaeal richness, and the amount of dust. The Lactococcus finding was also emphasized when using an alternative statistical approach ((Multivariate Association with Linear Models (MaAsLin)).

No association with asthma development was found with between fungal diversity and only weak associations were observed with fungal genera.

Conclusions: Our data suggest that the risk of childhood asthma is affected by bacterial composition of the early-life home dust microbiota while fungal microbiota has less impact. The asthma risk was positively associated with relative abundance of Lactococcus genus. 0202 | Differences in the immune profiles and asthma risk in urban and rural children Physician-diagnosed asthma as well allergic diseases and symptoms were ascertained using the ISAAC questionnaire completed by the parents.

Results: A total of 8055 children aged 6-14 years participated in the study (response rate=76.87%). In the rural and urban areas, asthma prevalence in Belarus was 1.4% and 1.5%, respectively while in Poland it was 3.5% and 4.1%. Any allergy was lower (P<.05) in Introduction: Based on Th1/Th2-paradigm, the association between allergic diseases and type 1 diabetes, two immunemediated diseases, has been suggested to be inverse. However, evidence from observational studies is inconsistent: inverse, direct and null associations have been reported.

Objectives: The aim of the present study was to assess the association between asthma and type 1 diabetes in Finnish children and adolescents taking into account the time sequence of disease diagnoses and potential confounders in a large case-cohort study. Among the initial cohort of all children born between 1.1.1981-31.12.2008, those who were diagnosed with asthma (n=81473) or type 1 diabetes (n=9541) up to 16 years of age by the end of 2009 were identified from the Central Drug Register maintained by the Social Insurance Institution of Finland. A 10% random sample from each birth year cohort was selected as a reference cohort (n=171138).

The association between asthma and type 1 diabetes were studied using multistate modelling approach to estimate transition rates between healthy and disease states, asthma and type 1 diabetes. As the rates for a disease were modified similarly at different ages by the appearance of the other disease, a single hazard ratio with 95% confidence intervals (CI's) was calculated to represent the average change in transition rate between the disease states.

Results: Altogether 80871 children with only asthma, 8939 children with only type 1 diabetes, and 602 with both diseases were identified. After adjusting for sex and birth decade, prior diagnosis of asthma increased the risk of subsequent type 1 diabetes on average by 41% (95% CI's 1.28-1.54), while prior diagnosis of type 1 diabetes decreased the risk of subsequent asthma on average by 18% (95% CI's 0.69-0.98).

Conclusions: Results from the present study's novel approach to the association between asthma and type 1 diabetes indicate that the direction of the association between asthma and type 1 diabetes may depend on the sequential occurrence of the diseases. Thus, the association between the diseases is complex, not just inverse. Additional studies that take into account the sequential appearance of the diseases are warranted to further clarify the association between asthma, other allergic diseases and type 1 diabetes. Elucidation of biological mechanisms underpinning the association between asthma and type 1 diabetes may give further insights into pathogenesis of both of these diseases. were implicated in SJS/TEN with SOC and about 80% of our patients developed SJS/TEN with SOC after taking cold medicines a few days before disease onset (CM-SJS/TEN with SOC). Our genome-wide association study documented an association between CM-SJS/TEN with SOC and Ikaros Family Zinc Finger 1 (IKZF1). Few studies examined biological and pathological functions of IKZF1 in mucosal immunity. We hypothesized that IKZF1 contributes to the mucocutaneous inflammation of CM-SJS/TEN with SOC.

Objectives: To investigate the function of IKZF1 in mucocutaneous inflammation. Human skin and conjunctival tissues were obtained for immunohistological studies. Primary human conjunctival epithelial cells (PHCjECs) and adult human epidermal keratinocytes (HEKa) also used for gene expression analysis. We also generated K5-Ikzf1-EGFP transgenic mice (Ikzf1 Tg) by introducing the Ik1 isoform into cells expressing keratin 5, which is expressed in epithelial tissues such as the epidermis and conjunctiva, and then examined them histologically. Moreover, Ikzf1 Tg were induced allergic contact dermatitis.

Results: We found that human epidermis and conjunctival epithelium expressed IKZF1, and in PHCjECs and HEKa, the expression of IKZF1 mRNA was up-regulated by stimulation with polyI:C, a TLR3 ligand. In Ikzf1 Tg, we observed dermatitis and mucosal inflammation including the ocular surface. In contact dermatitis model, inflammatory infiltrates in the skin of Ikzf1 Tg were significantly increased compared with wild type.

Conclusions: Our findings support the hypothesis that Ikaros might participate in mucocutaneous inflammation. Results: In the comparisons of genotype frequencies of SNPs of CD28 (rs3116496), CTLA4 (rs5742909, rs231775, rs3087243, rs17268364), CD40 (rs1800686, rs1883832) and CD40LG (rs3092952), there was no significant difference between the patients with ATD-induced asthma and ATD-tolerant controls. Next, the haplotypes frequencies of CTLA4 and CD40LG genes were not different between case and control groups. 0009 | Biotinylated clavulanic acid as a tool for identifying serum proteins target of haptenation by clavulanic acid in the context of allergy studies Martín-Serrano A 1 ; Barbero N 2 ; Gonz alez-Morena J 3 ; S anchez-G omez F 3 ; Fern andez T 4 ; S anchez M 5 ; P erez-Inestrosa E 2 ; P erez-Sala D 3 Objectives: The objective was to study haptenation by CLV and develop tools to identify CLV target proteins. To achieve this aim, CLV was derivatized with biotin, then incubated with either human serum albumin (HSA) or sera and, finally, the resulting protein adducts were analyzed by different techniques. Introduction: Drug hypersensitivity reactions (DHRs) affect about 7% of the population. Nearly 15% of them have an underlying adaptive immunological mechanism, ranging from immediate to delayed hypersensitivity. Importantly, DHRs often imply the treatment withdrawal, which represents a major issue, particularly if the therapeutic compound is either life-saving or irreplaceable. In the case of DHR, rapid desensitization has proven to be effective in preventing treatment discontinuation. Indeed, rapid desensitization induces tolerance through the slow infusion of the offending drug, intravenously at increasing doses. Yet, tolerance is not sustained. Thus, a permanent modification of the administration scheme is required.

Objectives: We propose a novel approach of desensitization for DHR that can be called allergen immunotherapy-like desensitization (AILD). Conclusions: AILD is effective, safe and can be pursued for both immediate and delayed DHRs. AILD prevents the treatment withdrawal and, importantly, provides sustained tolerance allowing treatment resumption. Introduction: Although desensitization in immediate type hypersensitivity reactions due to chemotherapeutics is well described and standardized for many drugs, common protocols in delayed type hypersensitivity reactions are not standardized.

Objectives: To evaluate the effectiveness of the previously published slow desensitization protocol in the nonimmediate type hypersensitivity reactions (HR) induced by oral chemotherapeutics (OCs).

Method: Using our previously published slow desensitization protocol with capecitabine, we desensitized the patients who gave nonimmediate hypersensitivity reactions to different OCs. The protocol was started with the 1/100 of the culprit drug; then the doses increased slowly in order to complete the desensitization in 16 days.

Demographic and clinical features of the patients were appraised.

Results: Six patients (mean age was 54.5AE15.75 years, 4 female) were enrolled. The culprit drugs were lenalidomide (n=3), pazopanib (n=1), nilotinib (n=1) and temozolomide (n=1). The types of HR were maculopapular eruption (MPE, n=5) and eczematous rush (n=1) and the mean reaction time was 6.6AE2.1 days. The desensitization was successfully completed in 16 days in 2 patients. In 4 patients MPE developed in an average of 11.25AE3.3 days. In three of them desensitization was completed with a more slowly dose incrementation and the targeted doses were achieved in the average of 29AE5.5 days. However in one patient, only ¾ of targeted nilotinib dose could be given. Because this amount was under the therapeutic goal, treatment plan was changed.

Conclusions: Although 16-day desensitization with OC can work in some patients, longer periods can be necessary in some others.

Desensitization plans should be tailored for each patient. Introduction: We previously showed that patients with severe allergic asthma have higher numbers of ILC2s expressing the chemokine receptor CCR10 in the blood compared to allergic subjects without asthma or healthy controls.

Objectives: To confirm and extend these results, we analyzed circulating CCR10 + ILC2s by flow cytometry not only in allergic but also in non-allergic asthmatic patients (n=42). Phenotypic and functional properties of human CCR10 + and CCR10 -ILC2s were further characterized by multiparametric flow cytometry and intracytoplasmic staining of cytokines. The role of CCR10 + ILC2s in asthma pathophysiology was addressed in a mouse model of allergic asthma induced by birch pollen.

Results: CCR10 + ILC2s are significantly enriched in the blood of both allergic and non-allergic severe asthmatic patients. These cells are less activated than their CCR10counterpart, with a lower expression of CD25 and KLRG1 and a higher expression of CD27.

This subset exhibits ILC1-like properties including a capacity to produce IFN-y. Surprisingly, the depletion of lung CCR10 + ILC2s by anti-CCL27 and anti-CCL28 antibodies exacerbates the airway hyperreactivity of mice challenged with birch pollen. We confirmed that CCR10 + ILC2s are present in human lung samples. In agreement with the aforementioned results, plasma concentrations of the CCR10 ligand CCL27 are also significantly increased in severe asthmatics compared to non-asthmatic individuals. Objectives: We compared ILC2s from nasal polyps and peripheral blood phenotypically and functionally to identify differences between circulating and tissue resident cells. Based on this we analysed the expression of different activation and tissue homing markers on ILC2s in the blood of severe asthma patients and patients suffering from COPD as compared to those from healthy controls.

The effects of cytokine stimulation on the regulation of these markers was also studied.

Results: Nasal polyp ILC2s differed from blood ILC2s in their expression of CD45RO instead of CD45RA, lack of CD62L, but they do express CD69 and CCR10. These cells were more activated compared to blood ILC2s as they already produced IL-5 upon culture with only IL-2. In vitro we were able to reproduce this activated phenotype upon culture of blood ILCs with specific stimulating cytokines. In the blood of severe asthma patients we observed a population of ILC2s that displayed this activated phenotype. The same was observed for ex-ILC2s with an ILC1 phenotype in the blood of COPD patients. In this manner these cells resembled their tissue counterparts. Interestingly, in mild to moderate asthma patients we did not observe a population with this activated phenotype.

Conclusions: Taken together this is indicative that in severe forms of pulmonary inflammation there is also a systemic component which affects the ILCs. We propose that the activation state of peripheral blood ILCs can be used as a marker for disease severity.

Yu Q 1 ; Guo Y 2 ; Li X 3 ; Li C 1 ; Tan W 2 ; Fan X 1 ; Wen W 1 ; Fu Q 1 Objectives: The purpose of this study was to perform a prospective study and evaluate the ILC2 levels and function after systematic glucocorticoid therapy in asthma patients and the potential mechanisms.

Results: Glucocorticoid was used to treat the isolated ILC2s in vitro and the possible signalling pathways involved were also investigated.

The patients were well-controlled and the ILC2 levels were significantly decreased at 1 and 3 months. ILC2s were successfully sorted out from the asthma patients and were confirmed to be the predominant source of the large amounts of IL-5 and IL-13 in response to IL-25, IL-33 plus IL-2, and glucocorticoid significantly decreased their levels. Furthermore, p-STAT3 and p-STAT6 levels were highly increased in Lincells with the stimulation and were reversed with the glucocorticoid administration.

Conclusions: The data suggested that glucocorticoid administration could be effective in treating asthma by regulating ILC2s via STAT3 and STAT6 signalling pathways. This will provide an effi- Objectives: Our aim was to evaluate whether AIT could be more effective in the suppression of local inflammation, if it is applied in combination with a short-term non-specific immune-modulator, which interferes with the JAK pathways.

Results: Human naive CD4+ T cells were differentiated in vitro into induced regulatory T cells and the effect of Tofacitinib (TOFA, a

Rapamycin and Cyclosporine on T helper cell subset differentiation was assessed via flow cytometry. In C57BL/6J mice, an in vivo model of ovalbumin (OVA)-induced allergic airway inflammation and allergen-specific immunotherapy was combined with the administration of TOFA from 48 hours prior to 48 hours after therapeutic OVAinjection. Plasma-as well as broncho-alveolar lavage samples were investigated on cellular as well as on cytokine level. TOFA enhanced the induction of human FOXP3 + CD4 + T cells in contrast to other tested immune-modulators. In vivo, AIT combined with short-term TOFA administration was significantly more effective in suppressing total cell numbers and eosinophil infiltration into the lung, as well as local cytokine production including IL-1b and CXCL1. A trend for the reduction of IL-4, IL-13, TNF-a and IL-6 compared to AIT alone was also observed. Furthermore, TOFA co-administration was able to significantly reduce the level of systemic IL-1b, IL-6, and OVA-specific IgE and induced IgG1 to the same extent as AIT alone.

This proof of concept study shows that JAK inhibition via TOFA did not inhibit tolerance induction in vitro and in vivo, but amplified the positive effects of experimental AIT at the level of local inflammation. The improved control of local inflammation might extend the use of AIT in more severe conditions such as polysensitization, asthma and high-risk patients. 0020 | IgG4, but not IgG1, repolarizes proallergic M2a macrophages to a tolerogenic M2blike phenotype: implications for allergen immunotherapy-mediated immune tolerance Introduction: The induction of allergen-specific IgG4 antibody is a hallmark of allergen-specific immunotherapy (AIT), but the mechanism how IgG4 could be involved in the induced immune tolerance is still unknown. We investigated here whether IgG4 could convert M2a macrophages, which are predominant in allergy, into an immunoregulatory M2b-like phenotype as new concept of AITmediated immune tolerance.

Objectives: Because macrophages, in the presence of immune complexes, can be polarized in vitro into M2b, we investigated whether it would make a difference whether the allergen would be complexed by IgG1 or IgG4.

Methods: Monocyte-derived macrophages (MDMs) were treated with M-CSF, followed by IL-4/IL-13 to induce the M2a allergic phenotype. To mimic immune complexes, culture plates were either directly coated with myeloma IgG1 or IgG4, or first coated with grass pollen major allergen Phl p 5 (for control Bet v 1 from birch), followed by incubation with recombinant human Phl p 5-specific 

Our results indicate that the IgG4 subclass can redirect the pro-allergic M2a macrophages to an immunosuppressive phenotype, characterized by IL-10. IL-6, and CCL-1, secretion and down-regulation of activation markers. We propose that this implies the involvement of macrophages in tolerance induction and could be a novel mechanism of AIT. Introduction: Allergic disease prevalence in developed countries is estimated between 10-30% of population with significant increase in progression and severity in last decades. Sublingual administration of Phleum pratense allergy immunotherapy (SLIT) tablets represents one of the most recent approaches of tolerance induction by way of the oral mucosal route aiming to a long-term allergen-specific immunomodulation in patients with allergic rhinoconjunctivitis, with or without moderate asthma. We have documented a "disease-modifying" effect of SLIT-tablets for at least two years after stopping the treatment.

Objectives: We now aim to elucidate the mechanisms responsible for these effects and to identify novel biomarkers useful for follow up and efficacy measurement.

Results: 32 patients allergic to grass pollen, were enrolled in a double blind clinical trial for two years based on either placebo or immunotherapy treatment using a standardised grass SLIT-tablet.

from all the patients were used to perform metabolomic and transcriptomic analysis. Samples for metabolomics were analysed using high throughput Liquid Chromatography-Mass Spectrometry (LC-MS) technique. The gene expression profile of all the samples was analysed using the GeneChip WT PLUS Reagent Kit and two specific softwares. Results from metabolomics showed there were statistically significant differences between the two groups after two years of immunotherapy. However, the time was the most significant factor observed in the trial. Significant metabolites were tentative identified using online databases. Transcriptome analysis suggests significant differences in gene clusters associated with immunological response between placebo and active group.

Conclusions: These findings in relation to immune response metabolism were joined to the transcriptomic outcomes in order to have more information that may elucidate the biological changes implied.

In the light of the above, this is the first study of its kind that showed first insights into the effect of immunotherapy in patients allergic to pollen using SLIT-tablets.

Ramos T 1 ; Blanco C 1 ; Varona R 2 ; Jimeno L 3 ; Gal an A 3 ; Wurtzen PA 4 ; Vega F 1 ; Mar ın A 5 ; Mart ın S 5 ; Escribese MM 6 ; Carrera AC 2 ; Barber D 7 Introduction: Sublingual administration of Phleum pratense allergen immunotherapy (SLIT) tablets is a clinically efficient treatment for grass pollen-induced allergic rhinoconjunctivitis. However, kinetics of immunological changes in patients undergoing grass tablet SLIT treatment has not been adequately studied.

Objectives: A 5-yr prospective clinical trial was designed, including a 3-yr grass tablet SLIT treatment period followed by 2 additional years after SLIT discontinuation. Systemic effects of SLIT on both humoral and cellular immune responses were evaluated in peripheral blood samples, in order to try to identify key immunological parameters that could explain sustained clinical benefit.

Results: Thirty patients completed the 5-yr protocol. Grass tablet SLIT administration induced a 2-phase systemic humoral and cellular response that mostly persisted 2-years after therapy discontinuation.

The Th2 response was initially exacerbated, detected as an increase in both allergen-specific IgE (sIgE) levels and IL-4 producing cells; followed by downregulation of the Th2 response, with a shift toward a Th1 cytokine profile, measured as an increment in IFN-gamma producing cells. A progressive increase in specific IgG4 (sIgG4) levels and IgE-facilitated allergen binding (FAB) blockage, as well as ABSTRACTS | 41 reduced grass-pollen-season eosinophil counts, were also relevant findings. sIgE/sIgG4 ratios at the end of trial were lower than preimmunotherapy in 70% of patients, meanwhile IgE-FAB remained lower in 83% of them. At the same time, a progressive development of a regulatory T cell response was observed in two thirds of the patients. Interestingly, there was a statistical association between this regulatory response, the maintenance of lower eosinophil counts during grass pollen seasons, and sIgE titers lower than before immunotherapy treatment, being the last ones significantly associated with clinical response.

Conclusions: Our results suggest that the maintained clinical improvement observed in patients 2-years after finishing a 3-yr treatment period with grass tablet SLIT is linked to acquisition of a regulatory T cell response, which in turn is associated with lower eosinophil counts and sIgE levels.

González M 1 ; Doña I 2 ; Palomares F 1 ; Campo P 2 ; Rodriguez MJ 1 ; Rond on C 2 ; Gomez F 2 ; Galindo L 2 ; Perkins J 1 ; Torres M 2 ; Mayorga C 1 1 Research laboratory IBIMA-UMA, M alaga, Spain; 2 Allergy unit IBIMA-UMA, M alaga, Spain Introduction: Specific immunotherapy is currently the only allergen-specific treatment with long-lasting effects and efficacy against allergens like house dust mites (HDM). Subcutaneous specific immunotherapy (SCIT) has shown to modify the HDM allergic response characterized by a Th2 pattern, towards Th1 patterns, with a generation of specific Treg cells that may produce IL-10 and TGFb, both important in tolerance induction. However, many works have reported no changes in Treg percentage, indicating the regulatory effects produced during immunotherapy can be due to modifications in their regulatory activities.

Objectives: We aimed to determine changes on Treg functionality and the mechanism involved during HDM-SCIT in patients who had a clinical improvement. To achieve this goal, 16 HDM-SCIT allergic patients and 8 non-treated allergic patients were included in the study. HDM-specific IgE and IgG4 were determined by ImmunoCAP from serum at both before and 12 months after HDM-SCIT. Treg (CD4 + CD25 + CD127 LOW FoxP3 + ) and T effector cells (CD4 + CD25 -) before and after 12 months of HDM-SCIT were isolated. Cells were cocultured in different combinations, without and with a-IL-10, a-TGF-b and both inhibitors (10 μg/ml) in presence of nDer p 1 (10 μg/ml). Cellular phenotyping, proliferative response and inhibition assays were evaluated by flow cytometry.

Results: Treg cells obtained after 12 months of HDM-SCIT increased Th1 (CD4 + IFNc + ) proliferation (P=.004) and decreased Th2 (CD4 + CD27 -CD294 + ) and Th9 (CD4 + CD294 -IL-9 + ) proliferation (P=.04 and P=.04). Moreover, Treg after 12 months enhanced IL-10 producing cells (CD4 + IL-10 + ) (P=.028) and diminished IL-4 and IL-9producing cells (CD4 + IL-4 + and CD4 + IL-9 + ) (P=.033 and .049). The presence of a-IL-10 blocking antibody (both alone or combined with a-TGFb) inhibited the Treg activity only on those obtained after 12 months of HDM-SCIT. Finally, the increase of HDM-specific IgG4 after 12 months was correlated with the increase of Treg percentage (P<.0001) and the IL-10 production (P=.023) and Treg percentage was correlated with IL-10 production (P=.036). Objectives: To explore how adolescents with eczema use emollients and topical glucocorticoids in relation to sex and eczema severity. In addition, to assess how topical treatment are dispensed from the pharmacy.

The study population consisted of adolescents participating in the BAMSE birth cohort 16-year follow-up (n=3108). Eczema (atopic dermatitis) was defined as dry skin in combination with itchy rash on typical localizations the previous 12 months. Severity of eczema was assessed according to BAMSE Eczema Severity Score (BESS) based on self-reported symptoms. Information about dispensed topical glucocorticoids was obtained from The Swedish Prescribed Drug Register.

Results: In total, 10% (n=297) fulfilled the study definition of eczema. According to BESS, 73% had mild, 17% moderate and 10% severe eczema. Almost all adolescents used emollients, 75% regularly and 21% less than 1 month a year, whereas only 55% used topical glucocorticoids. The latter were used more often among those with moderate or severe eczema than in those with mild eczema (84%, 84% and 44%, respectively). The use of topical glucocorticoids did not differ between sexes (girl 53% vs boy 61%, P=.179). The odds to treat with glucocorticoids increased when the adolescents had symptoms of current eczema, OR5.96 (95% CI 1.92-18.5) adjusted for self-rated severity of eczema, gender, family history of eczema, IgE sensitization, socioeconomic status and adolescents smoking. Of those with eczema, 24% (n=70) had any topical glucocorticoid (i.e. weak to potent) dispensed the last year. In the group with doctor's diagnosis of eczema ever (n=169), 32% had any topical glucocorticoid dispensed; 75% with a package of 100 grams and 25% with a smaller amount.

Conclusions: Almost all adolescents with eczema used emollients regularly. Girls and boys treated themselves equally with topical glucocorticoids, but one out of five adolescents with moderate or severe eczema had not used any topical glucocorticoid. Of adolescents with doctor's diagnosis of eczema, 7 of 10 had not had any glucocorticoid dispensed. 0027 | Immuno-modulatory effects of prebiotics, probiotics and active microbial structures on human primary epithelial cells Introduction: The human skin is one of the largest immunologic organs and represents the interface between the body and the environment. To achieve an effective defense barrier against environmental insults a crosstalk between epithelial and immune cells as well as the skin´s microbiota has to be maintained.

Besides direct cell-cell contact also indirect contact via the exchange of soluble mediators is used to transfer information. The release of these mediators is assumed to be potentially influenced by "beneficial intervention factors" such as prebiotics, probiotics or active microbial structures. However, the underlying mode of action as well as a direct contribution to skin health is not clear to date.

Objectives: To gain deeper insight in this field we investigated whether pre-/probiotics or active microbial structures have a direct effect on immune regulation as well as barrier function of human primary epithelial cells. For this purpose human primary keratinocytes and nasal epithelial cells from healthy or atopic donors were stimulated with a specific mixture of non-digestible short-chain galactooligosaccharides (GOS) and long-chain fructooligosaccharides (FOS) alone or in a combination with either lactic acid bacteria or lactocepin. Subsequently, the immunomodulatory effect of epithelial cell supernatants on dendritic cells (DCs) was tested by analyzing changes in DC cytokine release. Furthermore, prebiotics were tested regarding their direct effect on epithelial barrier function in an airliquid interface model. (Table) .

The most common treatment-emergent adverse events in these studies were nasopharyngitis, AD exacerbations, and injection site reactions. Conjunctivitis rates were numerically higher in the dupilumab groups than in the PBO group (subset A: 3.9%, 6.3%/8.4%

PBO, dupilumab q2w/qw; subset B: 0.5%, 5.4%/4.6). Similar efficacy ( Introduction: Atopic dermatitis (AD) is a chronic inflammatory skin disease that may persist for decades requiring systemic therapy for extended periods of time. Cyclosporine (CsA) provides a rapid and broad immunosuppressive effect but its long-term use is limited due to safety concerns including hypertension and impaired renal and hepatic function. Dupilumab, a fully human monoclonal antibody directed against interleukin (IL)-4 receptor alpha, inhibits type 2 cytokines IL-4 and IL-13. Long-term safety and efficacy of dupilumab was investigated in the phase 3 CHRONOS trial (NCT02260986).

Objectives: To compare the efficacy and safety of dupilumab vs placebo (PBO) at 52 weeks in two patient (pt) subsets of the CHRONOS population: pts who responded inadequately or were intolerant to CsA (subset A; n=114) and the remaining study population (subset B; n=509). CHRONOS was a 1-year, double-blind, randomized, PBO-controlled, parallel-group study in adults with moderate-to-severe AD and a history of inadequate response to topical corticosteroids (TCS). Pts were randomized 3: Introduction: Asthma is a chronic inflammatory disease of great importance given the social impact and the enormous health costs.

The most prominent phenotype is Th2-driven inflammation, which is mainly associated with eosinophilic inflammation. Our group demonstrated that eosinophils are capable to secrete exosomes to extracellular medium.

Objectives: The aim of this study is to investigate the effect of eosinophil-derived exosomes from asthmatic patients in structural Results: In BSMC studies, we observed proliferation was significant increased after 72 hours of exosome addition. Due to this process can be regulated by MAPK signalling pathway (p-ERK), we determined that the relative quantity of p-ERK in cells cultured in presence of exosomes at 72 hours was higher than in cells without exosomes; and this effect was reverted when BSMC were cultured in presence of p-ERK inhibitor. Moreover, the pattern of cytokine expression was different between cells in presence or absence of exosomes. Respect to SAEC, we noted that these cells need higher time to close the wound when they are in presence of exosomes.

Besides, gene expression pattern was modified due to the action of exosomes from asthmatics and this pattern was different when an artificial wound on monolayer was made. Also, alterations in phosphorylation of MAPK (p-ERK), p-AKT and p-STAT3 were observed in cells cultured with asthmatic exosomes. By contrast, when exosomes from healthy subjects was added to the culture no significant effects were observed in cell functionality.

airway epithelial cells is affected by the presence of eosinophilderived exosomes from asthmatics. 0032 | Impaired fibrinolysis and lower levels of plasma a2-macroglobulin are associated with an increased risk of severe asthma exacerbations Conclusions: Impaired fibrinolysis and lower levels of a 2 -macroglobulin might predispose to a higher rate of asthma exacerbations, suggesting new links between disturbed hemostasis and asthma.

Keywords: asthma, thrombin generation, fibrinolysis, asthma exacerbation, thromboembolic complication. Objectives: This study sought to investigate the expression of SOCS1 in atopic asthmatic BECs and airway immune cells and investigate the induction of SOCS1 in response to viruses and Th2 cytokines.

Results: SOCS1 mRNA expression in BECs and BAL-acquired cells from the lungs of atopic asthmatics was measured by qPCR. SOCS1 mRNA was induced in response to RV16 and RSV infection in BECs, with a trend toward increased induction in asthmatics. RV16 and RSV-induced SOCS1 positively correlated with number of positive skin prick tests (SPT; P<.05); RSV-induced SOCS1 was also associated with Serum IgE and serum eosinophilia (P<.01). In BAL cells, SOCS1 but not SOCS3 was induced following viral infection (P<.05).

In BEAS-2B cells, combined application of IL-4 and RV were found to strongly induce SOCS1 mRNA in an additive manner. IL-4 and IL-13 were found to activate the SOCS1 promoter, as measured by luciferase reporter assay, although RV did not. Furthermore, RV was found not to enhance SOCS1 mRNA stability. Chromatin immunoprecipitation-sequencing (CHIP-seq) was used to assess histone H3K27 acetylation in BECs obtained from atopic asthmatic patients and healthy controls, which has identified a region of H3K27ac enrichment 30Kb distal to the SOCS1 gene. This region appears to function as a distal enhancer for SOCS1 and we are currently investigating this a potential mechanism for viral-induced SOCS1.

Conclusions: SOCS1 expression in asthmatics appears to be related to atopy. Virus-induced SOCS1 is enhanced by pre-treatment with IL-4 or IL-13, although virus induced SOCS1 appears to be independent of the proximal promoter, and may involve epigenetic mechanisms. Results: At acute exacerbation, 78.6% of the children were virally infected and the dominant agent was rhinovirus (71.4%). The children were characterised by leukopenia (P=.0002) and lymphopenia (P<.0001) at acute exacerbation, and the ratio of total monocytes (acute:convalescent per ml blood) was elevated (1.25AE0.36; meanAESEM) . In contrast, other subsets were reduced (CD4 + Tcells 0.39AE0.10, CD4 + Tregs 0.43AE0.10, CD8 + Tcells 0.46AE0.16, B cells 0.71AE0.12, pDC 0.08AE0.02 and cDC 0.59AE0.17), consistent with migration from blood to infection sites. Network analysis identified 6 coexpression modules that were upregulated in association with exacerbations, 3 of which were related to myeloid activation and migration. Prominent amongst the list of upregulated genes was CCR2, the principal chemokine receptor associated with lung homing. The immunoregulator TGFB1 was the dominant molecular driver of the myeloid-associated modules and lower in rank were IFNG, TNF, IL-6, IL-10RA and IL-4.

Conclusions: Our study demonstrates that components of the inflammatory cell activation process associated with acute asthma exacerbations are triggered prior to their recruitment into the lung.

This suggests that therapeutic targeting of relevant precursor cells during acute exacerbations in their tissues of origin as opposed to only after their recruitment to the airways may be a viable approach towards asthma control. Introduction: In addition to their well described immunomodulatory properties in atopic asthma, allergens can also induce other pathological processes in the airways through their protease activities. Not much is known about the consequences of the protease activities of the allergens.

Objectives: We aimed to investigate the effects of allergen proteases on the airway epithelium obtained from healthy and asthmatic individuals.

Results: The antigens used in the study were Der p1, Der p serine proteases, Bla g2, and Lolium perenne extract. Effects of allergen derived proteases on cytokine/chemokine genes expressed in epithelial cells were determined by qPCR and multiplex ELISA. includes the prenatal period, as maternal environmental exposures, maternal diet and maternal asthma status (more so than paternal asthma status) strongly influence a child's risk for developing asthma.

Objectives: Herein, we explore the capacity of in utero exposures Results: We demonstrate that compared to animals exposed to PBS in utero, in utero HDM exposure resulted in more severe AHR, airway inflammation, Th2 cytokine production, and immunoglobulin levels following induction of experimental asthma. While transmission of allergen-specific immunoglobulins from mother to child was also evident, offspring of B cell deficient mothers exposed to HDM during pregnancy demonstrated similarly exacerbated experimental asthma, suggesting that transfer of maternal immunoglobulins was not required. Interestingly, while maternal exposure to antibiotics similarly increased the severity of allergen-induced AHR compared to offspring of control mothers, exacerbated AHR was not associated with an increased magnitude of cytokine production (either Th2 ABSTRACTS | 51 or Th17-associated) from T cells. This suggests that T cell-independent factors were regulating the development of more severe experimental asthma in offspring of antibiotic exposed animals.

Conclusions: Collectively, these data suggest that maternal exposure to a variety of factors known to influence asthma risk in humans (aeroallergens, antibiotics) have a profound influence on the severity of asthma that develops in offspring. These data lend support to developmental origins of allergic disease hypothesis and suggest that these observations may be successfully modeled in experimental models of allergic asthma.

Introduction: Epidemiological studies suggested an association between atopic dermatitis (AD) and cardiovascular diseases (CVD).

Objectives: Therefore, we investigate associations and potential There were more patients with AD having history of AID (5.4 vs 3.2%; P<.024), RD (7.8 vs 5.0%; P<.022) and IBD (1.9 vs 1.1%; n.s.).

They also reported on more PY of smoking (P<.008), but had decreased WHR (P<.035) and less frequent history of MI (1.1 vs 2.6%; P<.087) than controls. CHD (3.3 vs 3.5%; n.s.) and stroke (1.9 vs 2.2%; n.s) showed similar frequencies in both groups. After multivariate logistic regression, only age was significantly lower in patients with AD than in controls, while all other parameters turned out to be not significantly different.

Conclusions: Data confirmed frequent association of allergic rhinitis and asthma in subjects with AD. In contrast to some previous reports, we did not find any significant association of AD with other comorbidities investigated. One limitation of our study is the restriction to patients being mainly aged ≥40 years. Also, one might speculate that patients with severe comorbidities did not follow invitation to participate in this investigation. 0039 | Is there an increased risk of nonmelanoma skin cancer in patients with atopic dermatitis treated with oral immunosuppressive drugs? Objectives: Patch tests reactions to nickel on the upper arms were followed for two weeks and positive prick test reactions to birch tree pollen on lower arms were followed for 5 h. Skin biopsies, taken at four intervals (control, day 3, day 7 and day 14) after nickel provocation were analyzed immunohistologically with respect to occurrence and distribution of CD 3 + T cells/IL 17, IL 33, langerin, toll-like receptors (TLR-5 and TLR -7) and mast cell markers tryptase and chymase. Skin prick tests were biopsied after 20 min, 1 hours and 5 hours and compared with control skin using the same biomarkers.

Results: In control skin, Langerin-immunoreactivity (IR) was found in dendritic cells in epidermis. IL 33-IR was mainly confined to keratinocytes of the suprabasal layer of epidermis and some in endothelial cells of blood vessels scattered in dermis. TLR-5-IR was found on the surface of keratinocytes in epidermis, while TLR-7-IR was very sparse. CD3 + T cells/IL-17-IR was almost nonexistent. Mast cell tryptase/chymase-IR was also absent in epidermis and found in mast cells of the deeper part of dermis.

Langerin-immunoreactivity (IR) increased twofold on day 7, occurring not only in epidermis but also in upper dermis. Also IL-33-IR and TLR-5-IR increased twofold in epidermis on day 7. A dense TLR-7-IR appeared on the cell surfaces in epidermis and in upper dermis. The increase of TLR-7 -IR was tenfold compared to control skin. The T cells CD 3 + /IL 17 were only few in control skin, their number increasing fifteen fold on day 7. The occurrence of mast cells in dermis remained unchanged for the time followed. The density of all biomarkers was mainly unchanged in prick test reactions followed over time.

Conclusions: Our findings suggest that TLR-7 and IL 17 may serve as potential targets for treatment of allergic contact dermatitis. Conclusions: Our results provide evidence that IL-5-activated eosinophils directly contribute to BP blister formation in the presence of BP autoantibodies. DES by IL-5 -activated eosinophils depends on adhesion and Fcg receptor activation, requires elevated ROS production and degranulation, and involves EET formation. Thus, targeting eosinophils may be a promising therapeutic approach for BP. Introduction: Numerous epidemiological studies show an inverse relation between raw cow's milk consumption and the development of asthma. This protective effect seems to be abolished by milk processing. Evidence for a causal relationship is however still lacking and also direct comparisons between raw and heat treated milk are hardly studied. In the present study we therefore investigated the preventive capacity of raw milk and heated raw milk on the development of house dust mite (HDM)-induced allergic asthma in mice.

Objectives: Six-to seven-week-old, male BALB/c mice were intranasally (i.n.) sensitized with 1 μg HDM or PBS on day 0, followed by an i.n. challenge with 10 μg HDM or PBS on days 7 to 11. In addition, mice were orally treated with 0.5 ml raw cow's milk, heated raw cow's milk (10 min, 80°C) or PBS three times a week throughout the study, starting one day before sensitization. At the end of the study (day 14), airway hyperresponsiveness (AHR) in response to increasing doses of methacholine was measured in order to assess lung function and bronchoalveolar lavage fluid (BALF) was examined to study the extent of airway inflammation. T helper (Th) cell subpopulations were quantified in lung cell suspensions using flow cytometry and chemokine and cytokine concentrations were determined in lung homogenates and supernatants of ex vivo HDM re-stimulated lung cells.

Results: Sensitization and challenge with HDM resulted in AHR and pulmonary eosinophilic inflammation. Raw milk prevented both typical features of allergic asthma, whereas heated raw milk did not.

Epithelial-and DC-derived mediators, IL-33, CCL20, CCL17 and 

The results showed that two types of fungal allergen significantly induced typical features of bronchial asthma; Interestingly, the NLRP3 inflammasome activation indicators, NLRP3, capase-1, and IL-1b were dramatically increased in lung tissues of both murine models. TCA assay showed that mature IL-1b levels were significantly increased in BALF from two types of fungal allergen induced asthma models. When dexamethasone was administered to these fungal allergen-inhaled mice, interestingly, Aa-inhaled mice showed the dramatic improvement of all asthmatic features, while the asthmatic features of Af-inhaled mice including NLRP3 inflammasome activation was not affected by the treatment with dexamethasone.

Meanwhile, the administration of MCC950 dramatically reduced the airway inflammation, pathologic changes, bronchial hyperresponsiveness, NLRP3 inflammasome activation, and mature IL-1b in Aainhaled mice. In case of Af-inhaled mice, the anti-inflammatory effects of MMC950 on asthmatic features including mature IL-1b appeared to be modest.

Conclusions: These findings suggest that NLRP3 inflammasome is one of critical pro-inflammatory contributors in the pathogenesis of fungal allergen-induced asthma, however, a single targeted inhibition for NLRP3 activation or assembly has some limitation to overcome steroid-resistant severe allergic airway inflammation. Results: We found that mucin induction and mucus-related pathologies such as airway hyper-reactivity, were IL13 dependent, while eosinophilia was more sensitive to IL5 activity. Blocking IL33 in addition to either IL5 or IL13 led to a total abrogation in these Type-2 related pathologies, emphasizing the role of IL33 in regulating these factors. However, co-blockade of IL33 and IL25 in this system led to only a partial suppression of these parameters.

Conclusions: These results highlight the distinct functions of IL5 and IL13 in disease pathophysiology, but also suggest there is a level of crosstalk between pathways which ultimately manifests in a reduction in overall inflammation when a single cytokine is blocked.

These results also indicate additional efficacy over single axis therapies alone in patients with severe asthma may be achievable using approaches to dampen multiple Type-2 cytokines. Given many systems can regulate IL5 and IL13 production in vivo, attention needs to be paid to the types of combinations used. Our studies indicate blocking a central regulator of Type-2 cytokines, such as IL33, in combination with a key pathological effector, such as IL13 or IL5, will lead to the greatest reduction in lung inflammation. 0047 | The metabolite D-tryptophan from probiotic bacteria ameliorates allergic airway disease and influences the gut microbiome Bartel S 1 ; Jatzlauk G 1 ; Kepert I 2 ; Fonseca J 3 ; M€ uller C 3 ; Milger K 4 ; Hochwind K 5 ; Kostric M 6 ; Eickelberg O 2 ; Schloter M 6 ; Hartmann A 7 ; Schmitt-Kopplin P 7 ; Krauss-Etschmann S 8 Objectives: This study aimed at identifying regulatory mechanisms of IL-17 producing NK cells during experimental asthma exacerbation. Therefore, poly (I:C) was applied intratracheally to mice with already established experimental allergic asthma to trigger acute exacerbation. Lung function, airway inflammation, cytokine expression, and mucus production was assessed in wild-type (WT) mice and mice deficient for IL-6, IL-23p19, and RORct. FACS staining for different leukocyte populations were performed.

Results: Poly (I:C)-induced exacerbation of experimental asthma in WT mice is characterized by aggravation of airway inflammation, mucus production and airway hyperresponsiveness, which was associated with infiltration of IL-17 producing NK cells and increased production of IL-6. Such an exacerbation of experimental asthma could also be evoked in IL-23p19 deficient mice, but not in animals lacking IL-6. It was not possible to induce experimental allergic asthmatic in RORct deficient mice.

Conclusions: These results indicate a critical role for IL-6 but not for IL-23 in poly (I:C) induced IL-17 production in NK cells and, thus, acute exacerbation of experimental asthma. Furthermore, our study suggests IL-6 as a potential target for the therapy of acute asthma exacerbations. Results: Unsupervised clustering identified 3 microbial endotypes in the nasal microbiome with a CH index of 0.20. We found several associations of these endotypes with respiratory symptoms. Endotype I and II were associated with wheezing and asthma. They con- Results: The prevalence of allergic rhinitis at the age of 12 was 22% and 57% were boys. Mean onset age was 7.8 years. Boys had a significantly earlier onset than girls (P=.005). The most common trigger factors were pollen (85%), furry animals (34%) and mites (17%). In a multivariate analysis, parental allergic rhinitis (adjusted odds ratio, Objectives: Detailed data on food diversity during the first year of life as well as allergic outcomes and potential confounders up to 15 years were collected prospectively within the population-based multicentre German birth cohort LISAplus (n=2518, recruited in 1998 LISAplus (n=2518, recruited in -1999 . 8 food groups and 48 food items were categorized into quartiles and treated as exposures. 6 atopic outcomes were considered: doctor diagnosed (1) eczema, (2) asthma and (3) allergic rhinitis, (4) nose and eyes symptoms, sensitization to (5) food allergens and (6) inhalant allergens. Longitudinal associations were analyzed using generalized estimation equations. As in the earlier study we found clear evidence for reverse causality between early skin symptoms and introduction of solids, all analyses were run for whole study population as well as stratified by whether a child had early skin symptoms.

Results: A lower prevalence of eczema and sensitization to inhalant allergens was associated with an increased diversity of food groups introduced during the first year of life (odds ratio=0.67 (95% confidence interval=0.48-0.94) and 0.61 (0.44-0.85) in the highest vs the lowest quartile, respectively). These associations were driven by the participants with early skin symptoms, whereas in participants without early skin symptoms, association with lower asthma prevalence was observed (0.21 (0.05-0.82)). Similar protective associations for sensitization to inhalant allergens were observed with food item diversity.

However, in children without early skin symptoms, higher diversity of food items was associated with higher prevalence of allergic rhinitis. Objectives: The study was a single-center, randomized, doubleblind, placebo-controlled, parallel-group study, with a treatment duration of 10 months. In total 168 patients (18-65 years of age) suffering from grass pollen induced ARC, were randomized to treatment with one of three different dosages of a liquid Phleum Pratense extract or placebo. For this post-hoc analysis, data from the 150 patients that completed the study were analyzed. The TSS was assessed at baseline, before the start of the grass pollen season and at the end of the study in the pollen exposure chamber. For the TSS assessment, the patients were exposed to grass pollen at an average concentration of 3500AE500 ppm 3 in a mobile EEC for 6 h. For this post-hoc analysis only the TSS at the end of the study was evaluated. The CSMS was assessed during the grass pollen season, which was defined based on actual pollen counts.

The TSS score was assessed in the EEC at the end of the study between August and September 2016, which was 1-2 months after the CSMS which was assessed during the grass pollen season (June/July 2016). The results showed a strong positive and statistically significant correlation between the CSMS during the pollen season evaluated after 8-9 months of treatment and the TSS measured in the EEC after 10 months of treatment (r=0.62 and P<.0001).

Conclusions: These study results support that after pollen SLIT with a liquid Phleum Pratense extract, TSS during controlled exposure to grass pollen in an EEC is a predictive surrogate parameter for CSMS measured during the grass pollen season for patients suffering from grass pollen induced ARC. 0056 | A randomized clinical trial of passive immunotherapy with single-dose anti-Fel d1 monoclonal antibodies REGN 1908 REGN -1909 

The GAP trial showed that treatment with a standardized grass SLIT-tablet for 3 years provided sustained reduction of ARC symptoms and ARC pharmacotherapy use 2 years after end of treatment. Additionally, the proportions of subjects with persistent ARC or with moderate/severe ARC were statistically significantly lower in the active group compared to placebo. Thus, for the first time, the disease-modifying effect of allergy immunotherapy treatment has been demonstrated in a large, long-term, randomised, double-blind, placebo-controlled trial in children. Objectives: To study efficacy and prognostic factors in omalizumab facilitated OIT among severely peanut allergic adolescents monitored with CD-sens (basophil allergen threshold sensitivity).

Results: Open phase 2 study in which 23 severely peanut allergic adolescents started peanut OIT after 8-24 weeks on omalizumab.

Omalizumab dosing was guided by CD-sens. Starting at 1 g of peanut, equivalent to 280 mg of peanut protein, the OIT dose was increased every 2 weeks up to the 2800 mg (protein) maintenance dose. After 8 weeks on maintenance dose, CD-sens was measured ABSTRACTS | 65 and omalizumab was reduced by 50 % if CD-sens was still suppressed and the patient had nothing but mild symptoms. The same procedure was repeated every 8 th week until omalizumab was dis-

continued. An open peanut challenge was performed >12 weeks after the final omalizumab dose.

Patients were grouped as good responders (GR); able to discontinue omalizumab and subsequently pass a 2800 mg peanut protein provocation (n=8) or poor responders (PR); still treated or drop outs.

All patients reached maintenance dose in median after 10 weeks, Objectives: The objective of this study was to validate Strasbourg EEC by determining the airborne concentration of Der p1 which induces 60% of immediate and/or late phase bronchial reactions in asthmatic patients sensitized to mite. This was a single-center, randomized, double blind, 3-way cross-over study, including 2 groups: group A: 24 asthmatic patients allergic to mites and group B: 20 asthmatic patients allergic to another allergen. All the subjects were first exposed to placebo (PCB). The group A was exposed at random to 3 airborne Der p1 concentrations: 63, 76 and 105 ng/m 3 (n=45).

The number of airborne particles and the particles size were also recorded on line during the exposure (n=90). The group B was exposed to the concentration of airborne Der p1 which fulfills the objective of the study determined after a first statistical analysis.

Results: The mean age of subjects was 28.2 years (AE7.27) For the 3 airborne concentrations of Der p1 we obtained more than 60% of late phase reactions (LR). The mean time necessary to obtain an immediate reaction (IR) was: 78.6AE56 minutes (n=69) and 304.2AE115 min (n=44) for the late phase. The optimal dose to obtain an IR and LR was 70 ng/m 3 with 100% of occurrence of IR and/or LR. The mean fall in FEV1 during IR and LR was 24.53% and 18.90 % respectively. We did not observe any severe reaction during 

We have validated Strasbourg EEC in patients with asthma sensitized to mite. We also demonstrated its specificity.

More than 60% of our selected patients had a late phase reaction.

That is of interest for future clinical studies with mite asthmatic treatments. Introduction: The majority of children with cow's milk allergy (CMA) tolerate baked-milk products. However, reactivity to fermented milk products like yogurt and cheese has not been previously evaluated. A novel LPA was used to identify IgE binding to allergenic epitopes in milk-allergic Turkish children who tolerated different forms of milk products in oral food challenges (OFCs). We sought to determine whether LPA results could distinguish patients' clinical reactivity to different forms of milk, e.g. baked-milk (muffin), yoghurt-cheese, and whole unprocessed milk.

Objectives: Milk-allergic children were identified by OFC outcome:

Reactive to baked-milk (n=16), Reactive to yogurt-cheese (n=18), Reactive to whole milk (n=23), and Outgrown milk allergy (n=32).

Milk, casein, and b-lactoglobulin sIgE and sIgG4 levels were determined by UniCAP; IgE and IgG4 binding to milk protein epitopes were assessed by LPA.

Results: Overall, levels of IgE-specific epitope binding were strongly associated with varying degrees of milk protein denaturation, with consistently increasing allergenic epitope binding diversity from Outgrown to Baked-milk subjects. Similar associations were observed for milk, casein and b-lactoglobulin sIgE, assayed by Uni-CAP. Using machine-learning techniques, we sought to develop models that could predict different degrees of CMA. Data were randomly divided in two groups with 75% of the data retained for model development (n=68) and 25% for testing (n=21). The predictive ability of LPA data was compared with that of models using serum component proteins (UniCAP), both using a random forest algorithm. All 68 children used for training were correctly classified for models using IgE or IgE plus IgG4 epitopes. The average crossvalidation accuracy was much higher for models using IgE and IgG4 epitopes (84.8%), twice the performance of the serum component proteins assayed by UniCAP (41.9%). The 21 children whose data were not used for modeling, were then used to test the performance of the model on 'unseen' data. The model including IgE peptides ABSTRACTS | 69 correctly predicted 86% of the patients (AUC=0.89) while the accuracy of IgE plus IgG4 model was 81% (AUC=0.94).

Conclusions: Using a novel high-throughput LPA, we were able to distinguish the reactivity and diversity of IgE/IgG4 binding to allergenic epitopes in varying CMA endotypes. LPA may be useful in distinguishing different degrees of CMA in clinical settings without using oral food challenges. 0065 | Using IgG4 for cow's milk proteins to define risk of eosinophilic esophagitis in the community Objectives: All sera were assayed for specific IgG4 antibodies to the CM proteins Bos d 4 (alpha-lactalbumin), Bos d 5 (beta-lactoglobulin) and Bos d 8 (caseins), as well as total IgG4 using the Immuno-CAP 250 instrument (units=lg/ml). Sera were collected from 71 children enrolled at either the University of Virginia (Charlottesville, Virginia) or Nationwide Children's Hospital (Columbus, Ohio) after being diagnosed with EoE by esophageal biopsy (≥15 eosinophils per high-power field). To obtain an estimate of the IgG4 response to CM in the community (i.e., a mixture of allergic and non-allergic children), sera from 210 out of 616 children (referred to as random controls hereafter) were chosen at random from an unselected birth cohort.

Results: Preliminary studies confirmed that the IgG4 assays for CM proteins are specific for the individual antigens and that they are quantitatively accurate. Despite being quite common in the community, specific IgG4 antibodies to CM proteins were dramatically higher in titer among children with EoE compared to random controls (P<.001 for each). In addition, ROC analysis revealed a strong association between EoE diagnosis and specific IgG4 antibodies to and immunoblot experiments were conducted using mono-and polyclonal antibodies specific to the major fish and shellfish allergens (parvalbumin and tropomyosin, respectively), as well as serum of patients with confirmed seafood allergy. IgE-reactive proteins were subsequently identified and the protein composition was further analysed by mass spectrometry. Special focus was given to cod, salmon, tuna, crab, and shrimp. Besides expected species-specific allergens and antibody recognition patterns, we found a great variance between SPT preparations for the same species from different manufacturers. Commonly used cod SPT preparations, for example, showed great differences in the content of allergens, resulting in over 4-fold difference in IgE reactivity.

Introduction: Early gut-mediated microbial stimulation appears central to normal development of functional immunoregulation and may thus influence the risk of allergies and asthma. Breast-milk is an early-life source of millions of microbes per day but its relevance prospectively on child health has not been studied.

Breast-milk microbiota were characterized from 637 breast-milk samples collected by mothers of 2 month old PASTURE birth cohort children from Finland, France, Germany and Switzerland using quantitative PCR and 16S rDNA amplicon sequencing by Illumina MiSeq platform. Asthma development was followed until the age of 6 years.

Objectives: To determine whether the breast-milk microbiota may, depending on its composition, reduce or increase the risk of developing asthma in childhood.

Results: Based on preliminary data the median (IQR) total bacterial concentration in breast-milk samples was 9.5 9 10 4 (3.4 9 10 4 -2.9 9 10 5 ) cell equivalents (ce) per ml with median 2 to 1 ratio of gram-positive to gram-negative bacteria. The median operational taxonomic unit (OTU) richness, at 97% sequence similarity level, was Conclusions: Our data supports breast-milk as a considerable source of early-life microbial exposure and provides first indication that breast-milk microbiota may affect the risk of asthma and thus have prolonged impact on child health. 0074 | Sex-shift of respiratory multimorbidity prevalence during adolescencepooled analyses of longitudinal european birth cohort data from medall Introduction: Allergy prevalence in childhood is higher in boys than girls. For the separate diagnoses of rhinitis and asthma, a shift to a female predominance in adolescence has been suggested, but evidence for patients with respiratory multimorbidity is scarce. We examined the sex-specific multimorbidity of rhinitis and asthma before and after puberty onset in European birth cohorts.

Objectives: We harmonized data from self-/parent-completed questionnaires from population-based birth cohorts (PIAMA, BAMSE, LISAplus, GINIplus, DARC and MAS) from the EU Project MeDALL to assess rhinitis, asthma (ISAAC) and puberty status (before vs after puberty onset). We used generalized estimating equations to analyse the associations of sex, age, puberty (yes/no), and possible confounders with respiratory multimorbidity (rhinitis with coexisting asthma). Additionally, we analysed IgE-and non-IgE-associated respiratory multimorbidity separately, whereby IgE-associated disease was defined by specific serum antibodies against one or more common allergens. We combined data of all cohorts with one stage Individual Participant Data meta-analysis.

Results: We included data from 18 852 children from birth to age 14-20 years. The prevalence of respiratory multimorbidity was lower in girls before puberty onset: adjusted odds ratio (females vs males) 0.55, 95%-CI 0.46-0.64, this male predominance shifted to a sexbalanced prevalence after puberty onset (0.89, 0.74-1.07). This shift was statistically significant, interaction sex*puberty P<.001.

The prevalence of IgE-associated respiratory multimorbidity showed similar results with a strong male predominance before (0.56, 0.44-0.71) and no sex differences (0.91, 0.73-1.13) after puberty onset, P<.001. In non-IgE-associated respiratory multimorbidity, we found a slightly smaller male predominance before puberty onset (0.63, 0.47-0.85) also shifting to a sex-balanced prevalence after puberty onset (1.04, 0.71-1.53), P=.019. These shifts in sex differences from before to after puberty onset showed to be stronger than those from earlier analyses in the same cohort data in patients with only rhinitis or asthma, where we found no significant sex-specific changes.

Conclusions: Analysing birth cohort data we found a clear male predominance in respiratory multimorbidity prevalence before puberty and a sex-shift towards a sex-balanced prevalence in adolescence. This shift was stronger than in rhinitis or asthma only. Introduction: Rhinovirus (RV) -induced bronchiolitis has been linked to increased risk of asthma. Over 160 different rhinovirus types have been identified and divided into three species: RVA, RVB and RVC. RVA and RVC have been shown to cause more severe acute illness but the relation of species to risk of future asthma remains unknown. In this study, we evaluated the association between rhinovirus species causing severe bronchiolitis and the need for asthma medication 4 years later.

Objectives: We enrolled 408 children hospitalized for bronchiolitis at age of <24 months (attending physician's diagnosis) over two consecutive winter seasons, from November 2008 to March 2010, in three university hospitals in Finland. The viruses were detected from nasopharyngeal aspirates at index hospitalization and clinical symptoms and background information were recorded. Follow-up was performed as a mailed questionnaire 4-5 years after hospitalization.

Those not responding were interviewed by phone. The main outcome was current (i.e. during the last 12 months) use of asthma control medication (i.e. inhaled corticosteroid or leucotriene receptor antagonist). Analyses were repeated using a strict definition for bronchiolitis (age <12 months and first episode of wheezing). Objectives: We hypothesized that, using cells from peanut allergic donors, STAT6-IP treatment during in vitro exposure to peanut protein would result in decreased responsiveness to food allergens.

Using peripheral blood mononuclear cells (PBMC) from allergic human donors we studied STAT6-IP treatment of dendritic cells (DC) on T and B cell responsiveness to food allergen challenge in vitro.

Human PBMCs were obtained from peanut allergic and non-allergic volunteer donors. Monocytes, peripheral T and B cells were isolated.

Monocytes were differentiated into DC. Mature DCs were then exposed to purified peanut extract (PPE)AESTAT6-IP. The DCs were then co-cultured with T or B cells and assayed for proliferation and cytokine expression/production. Introduction: Egg allergy is among the most common food allergies in European children below the age of three. Oral immunotherapy (OIT) using whole egg white (EW) appears as a potential treatment option for egg allergy, although its major drawback is the high risk of severe side effects. This obstacle has prompted the investigation of allergen-derived immunomodulating peptides to be used in OIT to induce oral tolerance, or even as a strategy to prevent allergic sensitisation, once assured they lack sensitising potential. In this respect, hydrolysis of egg white proteins appears as an attractive and safe alternative for a reproducible and standardized production of immune-active peptides with low associated costs.

Objectives: The aim of this work was to evaluate the preventive and therapeutic properties of ovalbumin (OVA) hydrolysed with pepsin (OP) in an in vivo model of egg allergy.

The sensitising and eliciting capacities of OP were evaluated in BALB/c mice orally administered either EW or OP. In addition, mice sensitised to EW were used to assess the preventive and curative potential of OVA and OP, orally administered before or after sensitisation. At the end of the experimental periods, mice were orally challenged with EW and anaphylactic responses were evaluated by scoring clinical signs and rectal temperature. Blood and faecal samples were collected to study the antibody production at different time points throughout the experiments. Furthermore, the intestinal gene expression profile was analysed by RT-qPCR and T cell subsets were phenotyped using flow cytometry.

OP did not show sensitizing or eliciting potential in BALB/c mice. In addition, this hydrolysate was able to reduce the production of EW- Introduction: Peanut allergy in children is often associated with allergies to tree nuts and/or legumes. The aim of the present study was to analyze in cluster a cohort of children allergic to peanuts and assessed for cross-reactivity to nuts and legumes and to identify different phenotypes. Conclusions: The three phenotypes highlighted by the present study could be useful to identify children with high risk of crossallergic reaction to TNs and legumes early after PA diagnosis. Introduction: Accidental allergic reactions to food are frequent and can be severe and even fatal.

Objectives: Analyze the food products causing accidental reactions and the levels of undeclared allergens.

A prospective cohort study was conducted with adults (n=157) with a physician-diagnosed food allergy. All patients reported accidental allergic reactions and sampled the culprit food products for 1 year.

Food samples were analyzed for suspected non-ingredient allergens and quantification of risks.

Results: In 118 of 151 accidental reactions, allergic individuals were able to attribute their symptoms to a specific product. A large variety of food products was involved. More than half (53%) of the products were from a relative small/limited selection: bread (rolls), cookies, chocolates, meat products and fruits. Food samples received were analyzed for 28 different allergens, ranging from 1-15 allergens per product, and on average 5 -6 measurements per product. Analysis confirmed up to 4 undeclared allergens in 19 (37%) of the 51 received products. Concentrations varied from 0.01 ppm to even 5000 ppm protein of the allergenic food and were highest for peanut, milk and sesame. There was no correlation with the presence or absence of precautionary warning. In most of the unexpected allergic reactions, the allergen intake by patients was in (extreme) excess of Reference Doses as proposed by Taylor et al (2014) . For each product at least one undeclared allergen presented an estimated risk for >1% up to 64% of the allergic users of the products. Undeclared milk proteins posed the highest risk in the analysed products.

In part of the accidental reactions it was difficult to attribute the reaction to a specific food product or allergen. Reasons could be that meals consisted of multiple products, allergens might be not equally distributed through the food, or the wrong product was provided by patients.

Conclusions: A variety of food products and undeclared allergens cause accidental allergic reactions, for which a limited number of product categories was responsible for the majority of accidental reactions. Undeclared allergens make choosing a safe food problematic for allergic patients, especially for those with multiple allergies.

As there was no correlation with the presence or absence of a precautionary warning, guidance and harmonization of precautionary allergen labelling is warranted. Results: Clinico-histological active EoE patients (n=88) randomly received 6-weeks double-blind treatment with either 1 mg budesonide orodispersible tablets twice daily (BID) (n=59) or placebo BID (n=29). Budesonide 1 mg orodispersible tablets BID were highly statistically superior to placebo in achieving clinico-histological remission and improvements in inflammatory as well as fibrotic subscores in the endoscopy (see Table 1 ). formed. This is a great disadvantage for networking and community services purposes. As such, we undertake the task of updating, maintaining and disseminating an inventory of pollen monitoring stations in the world (task force TF-40108 sponsored by the EAACI).

Objectives: The aim of this work is to create an updated inventory and to provide comprehensive information on the pollen monitoring networks worldwide. To document the exact location, person responsible and their contact information as well as the methodologies and type of data that each station is collecting was our major goal.

Results: A team formed by working and advisory members defined the criteria needed to be recorded. We then constructed a database with detailed information about the existing national/regional net- Objectives: The aim of this study was to disseminate airborne pollen measurements using a novel automatic, real-time pollen sampler, so as to provide timely and accurate warning alerts to allergic patients throughout the duration of the pollen season. To achieve this, airborne pollen have been monitored in Augsburg, Germany, since 2015, using a novel automatic Bio-Aerosol Analyser (BAA 500), together with a network of conventional 7-day recording Hirst-type volumetric traps. Both techniques provided measurements on an hourly scale. The yearly pollen abundance of all recorded pollen types was estimated, as well as the start, peak and end of each pollen season. Moreover, the daily pollen abundance was assessed so as to differentiate between high-risk hours within each day. Comparisons have been made between the sampling methods so as to decide on the performance of the novel automatic pollen sampler. Dissemination methods for the widest possible informing of allergic patients and relevant health organisations have been investigated for use in daily practice.

Results: It was found that both sampling means detected comparable diversity and amount of pollen yearly. In most cases, the start, peak and end of the pollen season were satisfactorily predicted, especially for the allergenic Betula (birch) and Poaceae (grasses). The automatic pollen sampler sometimes overestimated the amount of pollen in the air, however, this corresponded to systematic error and was possible to fix appropriately. Training of the automatic pollen sampler improved the performance of the identification algorithms and further increased the performance. All measurements have been broadcasted real-time via the Institute's webpage (www.unika-t.de/ pollenflug/) on an hourly and daily scale.

Conclusions: Automatic, real-time information on concentrations of airborne allergenic pollen will significantly contribute to the implementation of accurate, timely, personalised management of allergies in the future. Towards this direction, novel, user-friendly health service infrastructure is needed, like mobile apps providing exposure risk alerts. Conclusions: Our findings suggest that neighbouring environment around schools influence lung function. Moreover, neighbourhood walkability appeared to affect autonomic nervous system.

Introduction: Nitrogen dioxide (NO 2 ) is associated with childhood asthma. Exposure time of NO 2 might be important for childhood asthma. However, vulnerable time of NO 2 exposure on airway hyperresponsiveness (AHR) and asthma in schoolchildren are unclear.

Objectives: To investigate the effect of NO 2 on AHR and asthma development according to several time aspects, from prenatal period to current exposure. From 2005, 3,570 elementary schoolchildren were enrolled to a prospective 4-year follow-up survey. Individual NO 2 exposure was estimated by using an ordinary kriging method from prenatal period to 7 years of age. Information on asthma diagnosis was collected by ISAAC questionnaire. Children were considered to have "new development of asthma" for a "no" response to "asthma diagnosis ever" at the first survey but "yes" at the follow-up survey. AHR was measured by methacholine challenge test at 7 years of age and defined as methacholine PC20 ≤ 8 mg/dL. We have also demonstrated that IL-1b plus IL-12 induced a conversion of NP-derived ILC2s into IFN-c-producing ILC1s, which was reversed by IL-4. Here, we identify epithelium-derived TGF-b, IL-1 b,

into IL-17-producing ILC3 and their role in neutrophil recruitment and maintenance in the local tissue.

Objectives: We seek to characterize all ILC subsets in CF-CRSwNP and non-CF CRSwNP. We identify which cytokines govern the ILC2 plasticity towards ILC3 in CF nasal polyps and determine their source. We analyse functional consequences of the elevated IL-17 producing ILC3 frequencies in CF.

Results: IL-17 producing ILC3 are enriched in NP of CRSwNP in CF (72% of ILC), whereas ILC2 are almost absent (0.9%), in contrast to non-CF CRSwNP (22% and 62% respectively). Increased frequencies of IL-17 producing ILC3 in CF may be a consequence of ILC2 plasticity. We show that key cytokines in CF: TGF-b, IL-1b, and IL-23 govern ILC2 transdifferentiation towards ILC3. ILC2 from non-CF CRSwNP exposed to the combination of TGF-b plus IL-1b plus IL-23 produced IL-17 and displayed a down-regulation of CRTH2 expression. Conversely, ILC3 from CRSwNP in CF exposed to IL-4 restored the CRTH2 marker expression and a subsequent stimulation with TSLP/IL-33 led to IL-5 production. This was not the case for ILC3 from non-CF CRSwNP. The major source of TGF-b, IL-1 b, and IL-23 may be epithelium as co-cultures of ILC2 with P. aeruginosa-challenged nasal epithelium resulted in IL-17 production by ex-ILC2s.

These ex-ILC2 IL17 producers may enhance neutrophil recruitment and maintenance, as ILC2/ILC3 ratio in NP correlates with eosinophil/neutrophil ratios. (P<.05). SNOT-20 and VAS score and levels of cytokines were also higher in patient group than healthy controls.

Our results showed the IL2s ratio were correlated with clinical features of allergic airway patients, type 2 innate immune responses were higher in CRS and asthma,ILC2 maybe a good marker of airway eosinophilic inflammation and peripheral blood is useful for evaluating type 2 innate immunity in human. Introduction: SMAD7 is a known negative feedback regulator of Transforming growth factor-b1 (TGF-b1). Overexpression of SMAD7 enhances Th1 and Th2 cytokine production in asthma models and inhibition of SMAD7 restores TGF-b1 signalling in human inflammatory related diseases. Previously, we reported the decreased expression of TGF-b1 and SMAD2 in persistent allergic rhinitis nasal mucosa. We sought to determine the expression of SMAD7 in the local nasal mucosa of severe persistent allergic rhinitis patients.

Objectives: Specific immunohistochemical staining was performed on inferior turbinate biopsy specimens to measure the expression of SMAD7 in subjects with severe persistent allergic rhinitis (seasonal and perennial; n=46) and healthy controls (n=19). [Correction added on 16 October 2017, after first online publication:

Name of the author "Qiu S" has been corrected to "Qiu CS".] 0094 | Targeted metabolomics reveals novel lipid and amino acid metabolism alterations in aspirin-exacerbated respiratory disease Introduction: Aspirin-exacerbated respiratory disease (AERD) is characterized by asthma, chronic rhinosinusitis with polyposis and aspirin/nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity.

To date, the pathomechanisms of AERD remain obscure, although disturbances in the metabolism of arachidonic acid seem to contribute to the disease.

Objectives: We hypothesized that AERD patients show distinct overall metabolic profiles compared to healthy individuals and aimed to identify metabolic pathways that may play a role in AERD patho- (CRSwNP). Toll-like receptors (TLRs) are thought to regulate epithelial barrier integrity, though its function has not been studied in CRSwNP thus far. In this study, we aimed at investigating whether TLR2 and TLR4 signalling is involved in regulating epithelial barrier function in CRSwNP.

CRSwNP patients (n=5) were isolated and grown in air-liquid interface on transwell inserts for 21 days. Epithelial integrity was evaluated by measuring transepithelial electrical resistance (TER), together with the expression of occludin and zonula occludens 1. TLR2 and TLR4 expression was evaluated using qRT-PCR. Introduction: Allergic rhinitis is a common allergic reactions and related diseases, with the incidence in the normal population generally higher. In recent years, more and more evidence suggests that the incidence of allergic rhinitis involves regulations of multiple genes. In this research, through exploring the gene expression profiles of allergic rhinitis by RNAseq technology, the differences of gene expression profiles was analyzed, providing a research basis on the mechanism of allergic rhinitis.

Objectives: To construct related gene expression profile of allergic rhinitis (AR) and screen the pathogenic genes.

Results: Compared AR group to the control group, there 89 related genes were found and 19 genes were up-regulated, 70 genes were down-regulated. Furthermore, there 2 genes (BCL6, STAT6) differentially expressed. Results: Proteotypic peptides suitable for MS assays were selected following isoallergen characterization of both grass pollen group 1 and HDM group 2 allergens. Subsequently, the MS quantification assays were developed and validated according to ICH topic Q2 (R1) as well as FDA bioanalytical method validation (2001) . Validation data confirmed that both assays are selective, linear (R²>0.98), accurate (recovery~100%) and sensitive (limit of detection <0.5 ng/ml).

Moreover, intra-run precision, inter-run precision and repeatability were below 20% for both assays. Besides, allergen contents quantified by LC-MS/MS were up to 100-fold higher as compared with the results obtained using ELISA.

Conclusions: Overall, MS-based assays can provide accurate, precise and robust major allergen quantification for both grass pollen and mite extracts intended for AIT. Such highly specific methods may be applied to other major allergens, especially when facing issues linked to restricted antibody specificity or reduced affinity because of allergen denaturation and/or absorption. 0100 | Improvement of symptoms and allergen tolerance in local allergic rhinitis patients treated with depigmented polymerized Phleum pratense extract immunotherapy, a double-blind placebocontrolled trial 

Phleum pratense in LAR patients. Objectives: The data from the pivotal Phase III study were used after pre-and co-seasonal birch SLIT administration in 406 patients suffering from moderate to severe birch pollen induced ARC. Previously, a MCID of 23% in CSMS compared to placebo was justified based on clinical and statistical criteria and accepted by regulators.

Pearson's correlation coefficient was calculated between the secondary RQLQ-S and CSMS and the MCID for CSMS was estimated using linear regression based on the consideration that an improvement of 0.5 points in the validated RQLQ-S score is accepted to be clinically relevant.

Results: A strong positive correlation was observed between the CSMS and the RQLQ-S scores during the pollen season (r=0.68 and P<.0001). Based on regression analysis using the study results, a clinically relevant 0.5 point improvement in RQLQ-S corresponds to an MICD for CSMS of 21% (95% CI: 19-23%).

Conclusions: This is the first validation of the CSMS as proposed by the EAACI as primary endpoint in a Phase III field trial. Using the validated RQLQ-S score as anchor, the post-hoc results show that a 21% improvement in CSMS may be considered clinically relevant.

Moreover, these results emphasize the clinical relevance of the 31% ABSTRACTS | 89 CSMS improvement realized after SLIT with a liquid birch pollen extract, the first pivotal Phase III study in ARC which used CSMS score as primary endpoint. Moreover, these results provide important guidance and support for the external validation of CSMS as primary outcome measure in allergen immunotherapy trials for ARC. Introduction: The prevalence of respiratory allergic sensitisation has increased over the last decades yet there is only limited understanding of the immunological processes involved. Our previous experimental studies have shown that reduced allergen uptake by airway mucosal dendritic cells is linked to a deficient regulatory T cell response and failure to induce mucosal tolerance to innocuous allergens.

Objectives: To provide insights into the immunological processes, modulating development of tolerance vs sensitisation during natural respiratory aeroallergen exposure, we used flow cytometry, confocal microscopy and in vitro cultures to analyse phenotypes of airway mucosal dendritic cell subsets and their functional capacity to take up and present allergen in two rat strains, these rats strains are either genetically resistant or susceptible to sensitisation and chronic airway disease when repeatedly exposed to allergen. Objectives: To investigate whether monocytes are recruited to the lungs in paediatric asthma.

Methods: Tissue samples obtained from children and adolescents with fatal asthma attack (n=12), age-matched non-atopic controls (n=9), and allergen-challenged AR patients (n=8) were subjected to in situ immunostaining.

Results: Monocytes, identified as CD68+S100A8/A9+ cells, were significantly increased in the lower airway mucosa and in the alveoli of fatal asthma patients compared with control individuals. Interestingly, aggregates of CD68+S100A8/A9+ monocytes obstructing the lumen of bronchioles were found in asthmatics (8 out of 12) but not in controls. Analysing tissue specimens from challenged AR patients we confirmed that co-staining with CD68 and S100A8/A9 was a valid method to identify recently recruited monocytes. We also showed that the vast majority of accumulating monocytes both in the lungs and nasal mucosa expressed matrix metalloproteinase 10, suggesting that this protein may be involved in their migration within the tissue. Objectives: The aim of this study was to compare the prevalence of CVD as well as cardiovascular risk factors in patients with SM and age-and sex-matched controls.

Results: Participants of this study were 50 adults diagnosed with SM according to WHO criteria and 50 age and sex-matched controls. The primary endpoint, CVD, was determined by carotid ultrasound (carotid intima-media thickness (C-IMT) and the presence of carotid plaques and CVD events.

Secondary endpoints were cardiovascular risk factors; dyslipidaemia, diabetes, hypertension, obesity and smoking.

CVD events were more prevalent in patients with SM compared to controls (20% vs. 6%, P=.04). CVD events were significantly associated with SM (P=.02) and hypertension (P=.01) in multivariate analysis The prevalence of diabetes, hypertension, obesity and smoking was similar between SM patients and controls. The prevalence of C-IMT and carotid plaques was similar between patients with SM compared to controls (54% vs 38%, P=.11 and 0.65AE0.11 mm vs. 0.64AE0.13 mm, P=.65 respectively).

Levels of total cholesterol and LDL-C were significantly lower in the SM patients than in the control group (5.1AE1.1 vs. 5.9AE0.9 mmol/l, P<.05 and 2.9AE0.8 vs. 3.5AE0.7 mmol/l, P<.05, respectively).

Conclusions: Despite lower plasma total cholesterol and LDL-C, the prevalence of CVD is higher in patients with SM compared to healthy controls. This study supports the evidence that mast cells contribute to atherosclerosis and CVD events in patients with SM.

Therefore cardiovascular screening in patients with SM seems warranted. 0108 | RNA is the key element of the th1promoting and allergy-protective activation of dendritic cells by the cowshed bacterium lactococcus lactis G121 Results: Overall, 26% (n=1118) of patients with chronic urticaria (N=4226) were diagnosed with CIndU at study entry. Of these patients, 31% had angiooedema at study entry or within the past 6 months and 77% had CIndU comorbid to chronic spontaneous urticaria (CSU). The rate of CIndU diagnoses was higher in C/SA than in EU (33% vs. 26%), but the rate of angiooedema and rate of CIndU comorbid to CSU was similar in both regions. Rates of light/ solar, vibratory, aquagenic, and contact urticaria were low (range: 0.7%-6.2%). Patients in C/SA had a higher rate of symptomatic dermographism (53% vs. 44%) and delayed pressure urticaria (30% vs. 25%) but a lower rate of cold urticaria (10% vs. 18%) and cholinergic urticaria (8% vs. 18%) compared with EU patients. Differences were also identified within subregion comparisons. UCT scores identified poor disease control in 77% of CIndU patients (C/SA 84% vs. EU 76%). Most patients reported a moderate (25%), very large (26%), or extremely large effect (7%) of CIndU on QoL (DLQI); ratings were comparable between regions.

Conclusions: CIndU is commonly associated with CSU, is uncontrolled in most patients, and can be severely disabling (as shown by angiooedema rates and the effect on QoL). Objectives: To explore baseline demographic and clinical characteristics of protocol-defined responders (randomized patients) and

protocol-defined non-responders (nonrandomized patients) identified following 24 weeks of participation in XTEND-CIU.

Methods: XTEND-CIU is an ongoing, Phase IV, multicenter, ran- Table) ; however none of these differences were large enough to suggest a distinguishing characteristic.

Conclusions: After examining baseline factors independently, it appears that there were no real differences between those who responded to omalizumab and those who did not. Additional classification analyses should be considered to determine if the interplay of a combination of factors might predict eventual response to omalizumab in this population of patients. Objectives: Plasma was collected in plastic sodium citrate tubes (BD Biosciences) from healthy volunteers (N=20), HAE patients during symptom-free periods (N=20), and during an acute attack (N=20).

Plasma samples from the three groups were analyzed using a mass spectrometry approach to compare relative levels of metabolites (50 -~1500 Da) by Metabolon (Durham, NC).

Results: Only a few metabolites displayed a difference in levels between attack and basal samples, which included elevation of antiinflammatory lipid precursors during attack and reduction of corticosteroids during attack. In contrast, a random forest statistical analysis of the aggregate metabolomic data indicated good separation of healthy and HAE subjects (basal or attack) as indicated by a 78% classification accuracy. Differences in metabolites were also noted between plasma from HAE patients and healthy volunteers (P < .05, matched pairs t-test and Welch's two sample t-test). Metabolites significantly increased in HAE plasma compared to that of healthy volunteers included serotonin, lipid amides, methionine sulfone, and c/ b-tocopherol. In contrast, oxidative lipids (13-HODE and 9-HODE, and DiHOME) and steroids (eg, cortisol) were decreased in HAE plasma.

Conclusions: A method for the metabolomic analysis of contact system activation based on the comparison of plasma from HAE patients, a disease known to be mediated by contact system, has been proposed. The further analysis and validation using orthogonal analytical methods may lead to new insights on the pathobiology of HAE and the identification of novel biomarkers of contact system activation.

Hofman ZL Results: We developed a heavy-chain-only antibody fragment (nanobody) specific for cHK. During assay development, we established that serine protease inhibitors in the assay buffer fully prevented pre-analytical cHK generation. Furthermore, we found that addition of a polyanionic compound to the assay buffer greatly improved the assay sensitivity in plasma samples, by increasing the avidity of the binding interaction. Kallikrein activation in plasma with b-FXIIa resulted in rapid cleavage of the total pool of HK (confirmed by immunoblotting), cHK remained stable for up to 90 min. Activation of plasma with plasminogen activator streptokinase also generated cHK. Both plasmin and kallikrein share affinity for the HK R389-S390 cleavage site, which mediates bradykinin release.

Further cleavage of (c)HK by plasmin eliminated nanobody recognition. Next, we went on to investigate the levels of cHK in plasma of HAE patients. We expressed cHK levels as % increase from baseline in pooled healthy control plasma (~2-6%). HAE patients in remission have a median cHK level of 13% above baseline (n=138; range 0-73%) which is higher than healthy controls (n=68; range 0-14%; P < .0001 by Mann-Whitney t-test). During attacks, the median cHK level was 25% above baseline (n=40; range 0-65%), higher than both healthy control and remission levels (P < .0001 Mann-Whitney ttest). effective treatments for a number of conditions due to their potency, specificity, and extended dosing intervals compared to conventional medications. They are increasingly being used to treat conditions associated with allergy/immunology. Immunogenicity is often associated with mABs, although this has improved with the emergence of fully human mABs. Lanadelumab is a mAB that is a potent inhibitor of plasma kallikrein to prevent bradykinin release. It is currently in Phase 3 clinical development with potential as a prophylactic treatment against HAE attacks.

Objectives: Here we describe data obtained to-date indicating the low immunogenicity risk for lanadelumab. Conclusions: Repeated administration is a risk factor for immunogenicity. In an ongoing pivotal Phase 3 study, patients will receive up to 13 doses of up to 300 mg lanadelumab and in the follow-on open-label extension study, patients will receive up to 26 doses of 300 mg lanadelumab. The risk of immunogenicity for lanadelumab is considered to be low and will continue to be evaluated during extended treatment in these Phase 3 studies. Results: 64 of 126 randomized pts in the extension study continued from the pivotal study and were randomized equally between the 2 treatment doses. In the pivotal study, the median (interquartile range, IQR) HAE attacks/month in these pts were 0.29 (0.00, 1.19) and 0.29 (0.00, 0.60) on 40 IU/Kg and 60 IU/Kg doses, respectively.

The median (IQR) within-pts differences for HAE attacks/month between the 2 studies (extension study minus pivotal study) were very small and not clinically relevant [40 IU/Kg: n=15, 0.20) ; 60 IU/Kg: n=14, 0.00 (-0.10, 0.20) ]. 12 of 15 (80%) pts on the 40 IU/Kg dose were maintained at the assigned dose. 3 pts were up-titrated to 60 IU/Kg and 1 of the 3 pts was further up-titrated to 80 IU/Kg. All pts assigned to the 60 IU/Kg dose were maintained at this dose. Efficacy for these pts was analyzed by the dose they were randomized to, independent of the dose they were receiving at the time of the attack. Safety results were comparable to those noted in the pivotal study. Introduction: About 20% of young children reacting to peanut will outgrow their allergy, but there is no laboratory test that accurately identifies this subset. Utilizing a cohort of 240 subjects from the CoFAR natural history study (Sicherer et al, 2010) , we monitored the development of IgE and IgG4 binding to sequential allergenic peanut epitopes in high risk infants from 3-15 mos to 8 yrs of age and determined their utility to predict clinical peanut allergy at age 5 years.

Objectives: A novel high-throughput luminex-based assay (Genisphere LLC) was used to quantitate IgE and IgG4 antibody binding to 50 sequential epitopes found on Ara h1-3. Sera from 240 subjects were evaluated for IgE and IgG4 epitope-specific antibodies at baseline, 2 and 5 yrs. At 5 yrs of age, 126 subjects were non-allergic whereas 48 had confirmed allergy and 66 had food-specific IgE>15 kU A /l. Epitope-specific binding (EB) scores were obtained from fluorescence intensities. Machine learning algorithms were used to build models that based on EB profiles (EBPs) at 2 years of age could predict whether an individual would be allergic to peanut or not at age 5 years.

Results: While the baseline EBPs of peanut allergic children at 5 years was no different from those without allergy, significant differences in EBPs were evident at 2 years and profound differences were observed at 4-5 years of age; 5 y/o subjects with peanut allergy had a marked increase in IgE epitope binding while non-allergic did not. One hundred eighty subjects were randomly selected for "model development" and 60 for "testing." Of strategies evaluated, the random forest algorithm performed best, accurately predicting the allergy status of all 180 children; with an average AUC>88.3% (Accuracy>81%, Balanced Accuracy>81%) in cross-validation. Models combining EBPs at baseline and Yr-2 together were not more predictive than models using Yr-2 alone. The model obtained during model development was then tested using the Yr-2 profiles of the 'unseen' 60 children. Using only IgE epitopes 51/60 (85.4%) children were correctly classified, for a balanced accuracy of 85%, AUC=87.5%, Sensitivity=73.1%, Specificity=96.5%, PPV=95%,

Conclusions: Evaluation of the peanut allergenic epitope repertoire at~2 yrs of age is predictive of peanut allergy status at 5 years. If confirmed in other studies, this assay should enable physicians to identify infants with persistent peanut allergy for initiating early immunotherapeutic interventions.

0124 | Peanut, tree-nut and sesame seed allergies: do children allergic to a nut or sesame seed need to avoid all nuts? Introduction: There is a large cross-sensitivity by IgE testing among tree nuts, peanut and sesame seed; however, rate of challenge proven co-allergy has not been proven. The introduction of 'safe' selective nuts and seeds in children already allergic to one nut is gaining momentum, especially following studies showing that oral peanut exposure prevents peanut allergy.

Objectives: The Pronuts study recruited children up to 16 years of age with at least one confirmed nut or seed allergy. Based on sequential challenge to 11 nut/seeds, our objective was to determine the true rate of co-existent peanut, tree-nut and sesame seed allergy. Patients were then asked to introduce all 'safe' nuts/seeds regularly into the diet to determine the feasibility and safety of this approach.

Results: Ninety three children completed over 800 food challenges performed according to the PRACTALL guidelines. Up to three nuts/ seeds were performed in a single challenge. Monoallergy was present in 45% of children and 2 nut allergies were present in 61%. The UK had a younger population and had a 52% rate of monoallergic children. In the UK peanut allergy was the most common index nut allergy followed by walnut and hazelnut; in Geneva it was cashew followed by peanut then pistachio. All 32 children with pistachio nut allergy had cashew nut allergy, but 6 cashew allergic children could tolerate pistachio. We noted clusters of other nut allergies, most notably between pecan, walnut and hazelnut allergy.

Conclusions: This is the first prospective study to establish the rate of challenge proven co-existent allergy among peanut, all treenuts and sesame seed allergy. The majority of participants were able to introduce up to 9 additional nuts and seeds into their diets. The differences between Geneva and London in the prevalence of monoallergy, specific nut allergies and clusters may be due to difference in age and/or dietary or environmental exposure to nuts. 0125 | Long-time evolution of oral immunotherapy in highly sensitized milk allergy children Introduction: Oral immunotherapy (OIT) with milk is an alternative treatment for children with persistent milk allergy. It could be a risky procedure, especially in highly sensitized patients. The aim of this study was to evaluate long-time evolution of milk allergic patients with milk/casein-specific IgE>100 KU/l who underwent OIT.

Objectives: Oral immunotherapy (OIT) with milk is an alternative treatment for children with persistent milk allergy. It could be a risky procedure, especially in highly sensitized patients. The aim of this study was to evaluate long-time evolution of milk allergic patients with milk/casein-specific IgE>100 KU/l who underwent OIT. Results: Circulating NETs and EETs were evaluated in 190 asthmatic patients (N=100 atopic asthma, N=90 non atopic asthma) from the national cohort COBRA, using two complementary approaches: cell free DNA quantification by fluorimetry and DNAenzyme complex quantification by ELISA: DNA-MPO (myeloperoxydase) for NET evaluation, and DNA-EMBP (eosinophil major basic protein) for EET evaluation. Local production of these extracellular traps (ETs) was assessed by evaluating these markers in 22 BAL supernatants (eosinophil count median, 2%; IQR, 0-5.5%; neutrophil count median 8%; IQR, 3.1-25.6%) and by imaging ETs in bronchial biopsies using immunofluorescence confocal microscopy.

We found higher circulating NET levels in severe asthma compared to moderate asthma whereas NET levels were similar between the atopic and the non atopic groups. In particular, NET levels correlated with some severity and poor control markers like persistence of symptoms between exacerbation, exertional dyspnea or wheezing.

When analyzing local production of NETs, we evidence an association between NET levels in BAL and bronchial neutrophilia. Surprisingly, while detecting circulating DNA-EMBP complexes in some patients, we failed to detect them in any of the 22 BAL supernatants available. To date, the visualization of NETs and EETs in bronchial biopsies is under evaluation.

Conclusions: NETs are associated with the clinical severity, the poor control and the neutrophilic phenotype of asthma independently of atopy, whereas EETs seem to be less important in this setting. Conclusions: In summary, we could show that the seasonal immune response to specific immunotherapy involves the local induction of B cells carrying immunoregulatory functions. We postulate that this increase leads to a shift of Th17 cells towards a rather regulatory phenotype, as not only the Th17 population, but also the intermediate IL-17 + FoxP3 + Treg subset was significantly increased out of the season. In conclusion, the frequency of Th17 cells and IL-17-producing regulatory T cells in the peripheral blood and induced sputum may represent early biomarkers of immunotherapy efficacy. Objectives: Here, we analyzed the role of TGF-b before and after RV challenge of PBMCs from preschool healthy and asthmatic children and in experimental asthma.

Results: In PBMCs from asthmatic children as well as in murine lung cells from asthmatic mice, after RV challenge ex vivo, TGF-beta is maintained and inhibited by LAP3 and IDO production in RV infected host cells leading to T-bet driven and CD8+IFN-gamma+ cell mediated anti-viral immune responses. However, administration of active exogenous mature TGF-beta to lung cells from asthmatic mice, after RV infection ex vivo, reduced an antiviral immune responses as shown by reduction of T cells producing IFN-gamma.

Conclusions: These data suggest that RV uses active TGF-b present in the environment to replicate and to inhibit effective antiviral immune responses. Moreover, during acute RV infections, endogenous TGF-beta is retained and inactivated in RV infected host cells, resulting in a CD4+T-bet+ and CD8+IFN-gamma+ T cell mediated acute immune response. Objectives: This post hoc analysis reports the effect of DPL on the rate and risk of severe asthma exacerbations in various subgroups. Severe exacerbations in the 24-week treatment period are reported for the intent-to-treat (ITT) population receiving DPL 200 and 300 mg every 2 weeks (q2w), doses currently being assessed in phase 3 (NCT02414854), and placebo (PBO). Subgroups are defined by: BMI, FEV 1 , FEV 1 % predicted, ACQ-5 score, severe exacerbations in the year prior to study, ICS+LABA dose, and age at asthma onset at baseline.

Results: DPL q2w (P < .001 vs PBO) reduced severe exacerbations in the ITT population (À70.0 to À70.5%; P < .001 vs PBO) and in all subgroups examined (numerically/significantly; Table) . A significant treatment-by-subgroup interaction was observed for the subgroup defined by baseline FEV 1 % predicted receiving DPL 300 mg q2w.

Numerically better reductions in severe exacerbations were observed with DPL 300 mg q2w in patients with baseline FEV 1 predicted <60% vs those with FEV 1 predicted ≥60%. Objectives: CD69 upregulation on CD3 + , CD3 + CD4 + and CD3 + CD8 + T cells was analysed by flow cytometry after stimulation and incubation for 4 hours with 25 lg/ml and 100 lg/ml amoxicillin in 13 patients with confirmed amoxicillin hypersensitivity.

PBMC were also incubated for 48 hours with 25 lg/ml and 100 lg/ ml amoxicillin. IL-2, IL-5, IL-13 and IFN-c concentrations were measured in supernatants with multiplex flow cytometry CBA Flex Array.

To evaluate predicted normal values the same measurements were done in 7 patients in whom hypersensitivity to amoxicillin was excluded and 5 healthy controls that were exposed to amoxicillin in the past and had no adverse events. Conclusions: In our sample the frequency of positive DPT was low. There were no statistically significant differences in relation to positivity of DPT between protocols. These results suggest that both protocols may be valid options in the work-up of NIR, however more studies with a larger population are needed. Results: Basophils were characterized as 2D7 + /FceRI + /CD117 -/ HLADR -. The optimum maturation window was between day 16-21.

This was further confirmed with BB1 expression (a marker of basophils) and activation tests using anti-IgE. Within this window, we usually get 1-4x10 7 cells where 30-50% are basophils.

Activation tests performed on cells passively sensitized with peanutallergic sera or grass-allergic sera showed significant association between the percentages of activated basophils (CD63) and sera Ara Objectives: 27 house dust mite (HDM) allergic patients and 30 patients with anaphylactic reactions to honey bee venom (HBV) (n=24) or yellow jacket venom (YJV) (n=6) were included. We also tested 6 healthy controls. Some HBV allergic patients were also followed during immunotherapy. Allergenic activity of HBV or HDM allergens was evaluated with basophil CD63 testing on heparinized whole blood with serial dilutions of nDer p 1, rDer p 2, rDer p 5, rDer p 7, rDer p 10, rDer p 21 and rDer p 23 allergens (from 10 À35 -100 ng/ml), or rApi m 1, nApi m 1, rApi m 2, rApi m 3, rApi m 5, rApi m 10, rApi m 11 allergens (from 0.001-10 lg/ml). IgE reactivity of the same recombinants was determined with dot blots or ELISA.

Results: For HDM allergens the protocol was performed in two steps. First, in sera of all HDM allergic patients IgE reactivity was determined and in next step, positive recombinants were tested with BAT and quantified with CDsens. Unfortunately, CDsens results showed extremely wide range and as such different allergens could not be combined and compared in individual patients. For HBV allergens, we measured IgE reactivity and BAT for all recombinants in all patients. Recombinant BAT was analyzed as area under the curve (AUC). On the level of individual patient, we developed a 3D-plot of AUCs to all tested HBV allergens, which represent multiparameter features of allergenic activity, including quantification for single allergens and summary for all tested allergens. This analysis represents a patient's fingerprint of allergenic activity of selected allergen source, and was successfully tested to evaluate clinical reactivity or follow up immunotherapy. Overall, both in HDM and in HBV models the IgE reactivity did not correlate with allergenic activity.

Conclusions: Fingerprint modeling of allergenic activity pointing out the actual allergens from the offending allergen source that eliciting the allergic response in individual patients. This approach offers ABSTRACTS | 115 a new tool to address patient's individual clinical reactivity at the molecular level and to monitor allergen immunotherapy.

Abadalkareem R 1 ; Skipp P 1 ; Parkinson E 1 ; Johnston D 1 ; Lau L 1 ; Zhou X 1 ; Eren E 2 ; Pedersen J 3 ; Idriss N 1 ; Khedr M 1 ; Walls AF 1 1 University of Southampton, Southampton, United Kingdom; 2 University Hospital Southampton, Southampton, United Kingdom; 3 Unizyme, Horsholm, Denmark Introduction: Activated mast cells orchestrate inflammatory events through the explosive release of diverse inflammatory mediators.

Dipeptidyl peptidase I (DPPI) has been implicated in the activation of several proteases prior to their secretion from mast cells, but its subcellular location is not clear.

Objectives: Our aim has been to examine the subcellular location of DPPI and investigate if it can be released following mast cell degranulation.

Results: Localization of organelle protein by isotope tagging (LOPIT) was employed on cells of the LAD2 mast cell line to investigate subcellular compartments in which DPPI and other proteases are located. This involved fractionation of organelles using density gradient centrifugation which allowed proteins from the same organelle to co-fractionate. The protein distribution in the fractions was analysed by mass spectrometry. Immunocytochemistry was performed on LAD2 cells with specific monoclonal antibodies we have developed against DPPI, tryptase, carboxypeptidase A3 (CPA3) and chymase. LAD2 Cells were stimulated experimentally, and the presence of DPP1 along with the other mast cell products in cell supernatants were investigated by specific enzyme immunoassays; and alterations in gene expression studied by quantitative polymerase chain reaction.

LOPIT analysis indicated that DPPI, tryptase, CPA3 and chymase were clustered in a fraction distinct from nuclear and mitochondrial fractions. DPPI was also co-localised with these mast cell proteases in immunostained preparations, though relative amounts of each protease differed between cells. Stimulation of the cells resulted in the secretion of DPPI in parallel with b-hexosaminidase and other mast cell proteases. DPPI gene expression was increased after cell activation accompanied by a similar increase in that for other mast cell proteases.

The presence of DPPI in mast cell granules and its release from activated cells indicates the potential for DPPI to have an extracellular role and it deserves consideration as a new marker of mast cell degranulation. 0148 | Specific ige to alpha-Gal in cow's milk allergic children: prevalence, quantification and relationship with meat allergy Introduction: Specific IgE to animal-derived carbohydrate determinants Gal-alpha-1,3-Gal-bêta-1,4-GlcNAc (alpha-Gal, AG) has been associated to cetuximab and red meat-induced allergic reactions.

Human glycoproteins lack AG. As a result, the most abundant (around 1%) specificity of naturally occurring IgG, IgM and IgA antibodies in humans is directed against AG epitopes. Isotype switch leading to production of IgE to AG has been reported only in association with tick bites. Thus, meat allergy is associated with specific IgE to AG, but may also occur in milk-allergic children.

Objectives: We sought to describe specific IgE to AG in a cow's milk-allergic pediatric population and its possible relationship with meat allergy and cow's milk main allergens.

Methods: Specific IgE to AG, cow's milk extract, beef extract, and cow's milk proteins casein, alpha-lactalbumin, beta-lactoglobulin, serumalbumin, and lactoferrin were measured in 50 cow's milk-allergic children (median age 2.7 years, range 15 days-18 years, 33 boys) among whom 14 reported clinical reactions to beef.

Results: 25 children (50%) displayed IgE to AG, but none before the age of 10 months (n=16). From 10 months to 18 ans, prevalence of IgE to AG was stable (mean 74%, 60-82% depending on age). The median level of detectable IgE to AG was 0.76 kUA/ (0.11-13 kUA/ l) and represented on an average 21% of the level of IgE to cow's milk extract in the corresponding serum.

We found a strong correlation (0.97) between IgE levels to AG and to beef extract in children with a history of clinical reaction to beef.

No such correlation was found between IgE levels to AG and to cow's milk extract or individual milk allergens.

Follow-up data over a period of one year or more were available in two patients : a 2-year old girl displayed increasing levels of IgE to AG despite a 50% decrease of lgE levels to beef, and a 5-year old boy whose IgE to AG were undetectable on two samples, despite novel sensitization to beef evidenced during the follow-up.

We report here that specific IgE to AG in cow's milk allergic children are highly prevalent but only after the age of 10 months. The level of IgE to AG represents on an average 21% of the level of IgE to cow's milk extract in a given patient. IgE to AG and to beef extract are strongly correlated, but an independent evolution seems possible. Pathophysiology of IgE sensitization to AG in cow's milk allergic children and its clinical significance need further work. Introduction: Little is known on the clinical relevance of Ara h 7, the third 2S albumin acting as an allergen in peanut allergy.

Objectives: To investigate the discriminative ability of Ara h 7 in diagnostics of peanut allergy and assess the role of cross-reactivity between Ara h 2, Ara h 6 and Ara h 7 isoforms.

Results: IgE binding to recombinant peanut storage proteins Ara h 1, 2, 3, 6 and 7 was assessed in sera from food challenged confirmed 40 peanut tolerant (40) and peanut allergic patients (40). The area under the receiver operating characteristic (ROC) curve (AUC) was determined to evaluate the ability of the tests to discriminate between allergy and tolerance. A dose-dependent ELISA inhibition experiment was performed with recombinant Ara h 2, 6 and Ara h 7.0101, 0201 and 0202 isoforms.

For Ara h 7.0201 an AUC value was found of 0,83, comparable to Ara h 2 (AUC 0,81) and Ara h 6 (AUC 0,85). Ara h 7 levels strongly correlated with those from Ara h 2 and 6 (both Spearman's r=.81).

The majority sensitized to 2S albumins Ara h 2, 6 or 7 was co-sensitized to all three (n=24, 68%), although mono-sensitization to single 2S albumins was also observed in selected patients (Ara h 2: n=6, 17%; Ara h 6: n=2, 6%; Ara h 7: n=2, 6%). Binding to Ara h 7.0101 and Ara h 7.0202 could be potently inhibited by the other isoforms, but not for Ara h 7.0201. IgE binding to Ara h 2 and 6 was variably inhibited with Ara h 7.0201. These findings indicate the presence of both cross-reactive and unique epitopes on Ara h 7.0201.

Conclusions: Ara h 7.0201 is the third clinically relevant peanut 2S albumin, with a discriminative ability for peanut allergy comparable to Ara h 2 and 6. While co-sensitization to all three 2S albumins is most common, mono-sensitization to either Ara h 2, 6 or 7 occurs in selected patients, leading to a risk of misdiagnosis when testing for a single 2S albumin. The Ara h 7.0201 isoform possesses cross-reactive epitopes, but also unique IgE epitopes, not present on the other Ara h 7 isoforms as well as Ara h 2 and 6. 0150 | Introducing a multiplex IgE diagnostic test, a new nanobead-based tool for allergy diagnosis: reporting on IgE reactivity of single allergen preparations and reproducibility performances Mari A 1 ; Mitterer G 2 ; Rafaiani C 1 ; Ciancamerla M 1 ; Bernardi ML 1 ; Alessandri C 1 ; Tuppo L 3 ; Giangrieco I 3 ; Ferrara R 1 ; Zennaro D 1 ; Tamburrini M 3 ; Ciardiello MA 3 ; Harwanegg C 2 1 CAAM -Centri Associati di Allergologia Molecolare, Rome, Italy; 2 Macro Array Diagnostics GmbH, Vienna, Austria; 3 Istituto di Bioscienze e Biorisorse -IBBR-CNR, Naples, Italy Introduction: Allergy diagnosis is currently based on the use of purified allergenic proteins and protein extract. Diagnosis can be performed in vivo using a limited number of extracts, whereas all allergenic preparations can be tested in vitro by measuring specific IgE.

In addition to third generation singleplex lab tests, multiplex testing tools are available since 10 years, allowing to have many IgE results from a single sample by testing allergens as micro spots on a rigid surface. Recently a new generation of lab diagnostic device has been released, the FABER test, adopting modern nanotechnologies, namely nanobeads, for allergen immobilization.

Objectives: To report the general set up of a multiplex test and the evaluation of some of its performances.

The test is based on 244 molecules (122) and extracts (122), coupled to nano-particles. Particles are arrayed to a solid phase matrix, to form a one-step comprehensive array-based testing solution, using 120 ll of serum per test. Each allergen particle population can be individually optimized to achieve the maximum testing performance. The proof of the IgE binding for the 244 allergen preparations has been obtained by using routine serum samples from the sera bank. The evaluation of the IgE binding was obtained by using a standard polyclonal commercial preparation obtained by pooling human sera. The test was used on 22 consecutive batches. 243 allergen preparations, even the rarest one in term of prevalence in the general population, gave positive IgE result using single serum samples. Negative results are recorded for HSA which is the negative control test. 174 out of 244 allergens gave positive IgE results. Average CV values were between 15 and 25%. Allergen specificities having values in the lower IgE range had a lower reproducibility rather than those in the higher range, anyhow never dropping to negative IgE detection. The multiplex test reproducibility performance was not related to the kind of allergen preparations, namely purified molecule or verified extracts.

Conclusions: This test is a new lab test for multiplex specific IgE detection using allergenic molecules and extracts at the same time showing good performances. All steps in assembling the test are verified and the present study reports that all allergens bind IgE. Evaluation of missing allergen specificities is performed with in-house made serum pools and performances could be further improved. Introduction: Respiratory allergic disease (RAD) is a growing concern in our population. Allergen immunotherapy (AIT) is, currently, the only approach to IgE-mediated allergic disorders that can induce specific immune tolerance, and is well established, mostly in adults.

New polymerized extracts, more immunogenic and less allergenic, are emerging. The safety and efficacy assessment of this new extracts in children is important.

Objectives: Evaluate safety and efficacy of the subcutaneous immunotherapy (SCIT) with polymerized extracts in children.

Material and methods: Children with RAD, to whom SCIT was proposed, were included and followed during 24 to 60 months (lAESD 39.28AE8.23). Amount of pharmacotherapy needed to achieve RAD control, skin prick test (SPT), specific IgE (sIgE) and adverse reactions were analysed in 2 moments, initial (IE) and final (FE) evaluation, and compared between two groups, with SCIT (y-SCIT) and without SCIT (n-SCIT). For the statistical analysis was used SPSS

Results: 36 patients with ages between 6 to 17 years were included; 25 y-SCIT, 11 n-SCIT, age groups (lAESD) 10.84AE3.24 and 8.55AE2.67, respectively. In the IE, there is a significant (Monte Carlo p .002) and very high (V 2 0.54) association between y-SCIT and a higher pharmacologic step to achieve asthma control. It was found a significant association (Monte Carlo p .001) and of high intensity (V 2 0.36) between SCIT and less rhinitis pharmacotherapy needs in FE.

The final sIgE was lower in y-SCIT group (t test; p .038). No difference was found between the two groups concerning SPT dimensions. 3 patients had a local reaction; none have had systemic reactions.

Conclusions: SCIT is safe in children. The higher pharmacotherapy step to achieve asthma control in IE of y-SCIT group may have been the reason to patients choose SCIT. AIT is associated with lower sIgE, and less preventive pharmacologic treatment needed to control RAD (consistent with previous studies). Our goal is to continue following these patients and increase the sample to improve this work accuracy. Objectives: Here, the pooled safety data from these trials are presented.

Results: A total of 1816 subjects were included; 922 were treated with the grass SLIT-tablet and 894 were treated with placebo.

The proportion of subjects who experienced adverse events (AEs) were similar in the active treatment group (71%) and the placebo group (70%). In the active group, the percentage of subjects who experienced treatment-related AEs (48%) was larger than in the placebo group (18%). However, most treatment-related AEs were mild or moderate of intensity and few were severe (grass SLIT-tablet: 79%, 19%, and 2%; placebo: 84%, 14%, and 2%, respectively). Further, most subjects who experienced at least one treatment-related AE continued the trial uninterruptedly and with no additional medication (grass SLIT-tablet: 89%; placebo: 87%) and recovered (both groups: 99%). Although the frequency was higher in the active group (7%) compared with placebo (<1%), few subjects discontinued the trial due to treatment-related AEs.

The most commonly reported treatment-related AEs in the active group were oral pruritus, throat irritation, tongue pruritus, and ear pruritus, occurring in 25%, 16%, 5%, and 5% of subjects treated with grass SLIT-tablet and in 2%, 1%, <1%, and <1% in subjects treated with placebo, respectively. The most commonly reported treatmentrelated AEs typically occurred within the first days or weeks of initial treatment with the grass SLIT-tablet and were recovered within days. Three treatment-related AEs in the active group involved use of adrenaline. Fewer than 1% of subjects treated with the grass SLIT-tablet experienced serious treatment-related AEs and none of these included constricted airways. All but one subject with immune thrombocytopenic purpura recovered. No anaphylactic shocks or deaths occurred in any of the trials. Objectives: The objectives of this prospective study were to investigate how children and adolescents with allergic asthma and allergic rhino-conjunctivitis undergoing AIT estimated HrQoL and allergy related symptoms before and after one-year treatment. Besides the effects on allergen specific IgE, IgG and IgG4 antibody-levels were evaluated.

Results: 116 children /adolescents, 69 boys and 47 girls, median age 11 (6-17) years were included. A majority (n=86, 74%) were treated with birch pollen allergen extract, 21 (18%) were treated with grass pollen allergen extract, the rest were treated with cat (n=4), dog (n=3) or mite (n=2) allergen extract.

Changes between base-line and one-year follow-up were analyzed with Wilcoxon signed ranks test. General HrQoL, measured with DISABKIDS, were improved (P<.001) after one year of treatment.

Besides, self-assessment of allergic symptoms showed improvements (P<.001), allergen specific IgE decreased and IgG and IgG4 increased (P<.001) between the start of treatment and one year follow-up.

The study shows that HrQoL in children and adolescents with respiratory allergies improves already after one year of AIT and is combined with reduction in allergic airway symptoms and in favorable changes in the immunoglobulin profile. Objectives: Here, we present pooled safety data from an adult population with HDM respiratory allergy, with a particular focus on the impact of asthma on the safety profile of the HDM SLIT-tablet.

Results: Safety data from 2 randomised DBPC phase III trials (MT-04 and MT-06) were pooled.

MT-04: 834 adults with HDM allergic asthma not well-controlled by inhaled corticosteroids and with HDM allergic rhinitis (EudraCT no.

MT-06: 992 adults with moderate-to-severe HDM allergic rhinitis despite use of allergy pharmacotherapy with or without asthma (EudraCT No. 2011-002277-38) Subjects with FEV 1 <70% at randomisation or a severe asthma exacerbation within the last 3 months prior to randomisation were not eligible.

The proportion of subjects experiencing adverse events (AEs) was greater in the active treatment group (73% of subjects) compared to placebo (53%). Most AEs were mild in both groups (70% in active; 66% in placebo), and the proportion of subjects reporting severe AEs was similar for active (5%) and placebo (4%). The most frequent treatment-related AEs were local allergic reactions, most of which occurred within the first few days of treatment and subsided with continued use. No systemic allergic reactions were reported.

Subgroup analysis by asthma status revealed no statistically significant difference in the risk of moderate or severe treatment-related AEs between subjects with asthma and subjects without asthma (N asthma =863, N no asthma =352; P=.88). Among subjects on active treatment, 12% with asthma and 11% without asthma reported events. Likewise, the proportion was 12% regardless of GINA treatment step at screening. Further, subjects with partly or uncontrolled asthma at treatment initiation were no more likely to experience moderate or severe treatment-related AEs than subjects with controlled asthma (11% and 14% of subjects on active treatment, respectively).

The HDM SLIT-tablet was well tolerated in adults with HDM respiratory allergic disease and most treatment-related ABSTRACTS | 119

AEs subsided with continued treatment. The safety profile was comparable for subjects with HDM allergic rhinitis with and without asthma, and GINA treatment step and asthma control level had no impact on the safety profile of the HDM SLIT-tablet. 0156 | Intralymphatic immunotherapy (ilit) with both grass and birch allergen-a randomized double-blind placebo controlled trial Introduction: Allergen specific immunotherapy is an effective but time-consuming treatment for allergic rhinitis. In order to shorten treatment duration, the use of three intralymphatic injections (ILIT) have been studied with diverging results.

Objectives: This study assessed safety, clinical effects and immunological changes after ILIT with two allergens given simultaneously.

Method: 58 patients with moderate to severe birch and grass pollen allergy were randomized 1:1 to receive three ultrasound-guided intralymphatic injections with placebo or Birch and Grass 1000 SQ/ U in each groin at one-month intervals. Patients were followed for one year and the study was conducted 2012-2015.

Results: Baseline characteristics were the same in both groups. 56 patients received all three injections. 52 patients fulfilled the follow up-visits. Side effects reported were mild or moderate.

The primary outcome measure was symptom score after nasal grass allergen, which decreased after active treatment. Skin prick test reactions were reduced and the Juniper Quality of Life Questionnaire scores improved in the active group during the birch pollen season, as compared to placebo. The consumption of nasal steroids and b-2agonists increased during the birch pollen season in the placebo group, but was unchanged in active group.

Immunological investigations showed that levels of S-IgG4 Timothy increased after active treatment. Allergen specific S-IgE levels remained stable or increased in the active group whereas the levels in placebo group decreased outside the pollen season. Analysis of lymph node aspirates and peripheral blood revealed an increased proportion of CD4 + effector memory cells in the active group but not in the placebo group. CD4 memory Th1-cells increased in the active group in blood; this was not seen in the placebo group.

Conclusions: We show for the first time that ILIT with two allergens appears to be a safe procedure with only limited side-effects.

Allergen challenge indicates that ILIT reduces rhinitis-symptoms. Several secondary outcomes also point favorably toward ILIT, including improved quality of life and reduced need for rescue medication.

The immunological results show that local administration of allergen in lymph nodes generates systemic changes in lymphocytes, further supporting the rationale for this alternative administration route. Results: We studied 113 children who experienced symptoms indicative of NSAID hypersensitivity. The 59% were males and the 41% females. Mean age 7,6 (0.5-14 y o). Atopic status occurred in the 46%. Drugs involved were: ibuprofen (81% of the episodes), paracetamol (10%), ASA (4.8%) and metamizol (1%). Cross intolerant were the 27%, selective immediate responders 1,7% and 74% had good tolerance. The clinical entities were urticaria/angioedema in 32% and isolated angioedema in 32%. Anaphylaxis occurred in 11.8% and asthma accompanied with facial angioedema in 17.6%. Cases were older (P<.0001), and had more episodes (P<.05) than those tolerant. Total IgE and atopy did not show significant differences. Results: Drug specific sensitization to AMX/CLV in the LTT was observed in five patients, two of whom showed also positive intradermal tests. Seven out of ten patients were positive to the TCLs. Moreover four out of ten patients were tested after a second AMX-CLV reaction following the first episode within EBV infection.

Conclusions: These data showed that a real sensitization to AMX-CLV may occur during infectious mononucleosis and in vitro investigations may help in the diagnostic work-up. 0159 | Vaccine allergy is extremely rare: a decade of experience from two large UK allergy centres Methods: SCAR cases between 2010 and 2015 were retrospectively analyzed using a web-based Korean SCAR Registry database.

SCARs caused by CAIs were compared with other drug-induced SCARs.

Results: Of the 783 patients with SCARs, 15 (1.9%) cases were reported CAIs including methazolamide and acetazolamide as major culprit drugs. They all developed SJS or TEN, but no Drug Reaction with Eosinophilia and Systemic Symptoms. More than half the CAIsinduced SCAR cases developed TEN (n=8, 53.5%), followed by SJS/ TEN overlap (n=4, 26.7%) and SJS (n=3, 20%). The period of hospitalization was 24.5AE14.1 days, which was longer than SJS/TEN cases caused by other drugs. The mean duration of exposure and latent period was 9.1AE8.0 days and 11.3AE5.7 days. CAIs-induced SJS/TEN cases had higher than average rate of complications (20% vs. 8.4%). Objectives: We prospectively enrolled 57 patients with frequent (IA) after informed consent, >3 episodes/year and analyzed mast cells cultured from peripheral blood CD34+ cells for rate of growth and releasibility following FceRI aggregation. Patients also underwent a bone marrow procedure to rule out clonal disease and the bone marrow mast cell compartment was analyzed by multi-parameter flow cytometry after bone marrow aspirates were processed and stained with antibodies for CD2, CD25, CD45 and CD117. Activation markers were identified with additional antibodies for CD11c, CD35, CD59, CD63, CD69 and CD203c in 52 subjects. Objectives: We hypothesize that in patients with severe anaphylaxis regardless the elicitor an underlying mastocytosis should be considered.

Methods: Between January 2015 and January 2016, 50 subjects with a severity grade III or IV according to Ring&Messmer were subjected to the analysis of KIT D816V mutation in peripheral blood. All subjects were registered in the anaphylaxis registry (Network for Online Registration of Anaphylaxis -NORA). Written informed consent was obtained.

Results: In 47 of 50 subject the KIT D816V analysis was successfully performed. The subjects comprise 29 females and 18 males with a median age of 48 (17-76) years. The elicitors were insect venom (n=21, mainly yellow jacket), food (n=17, various food) or unknown (n=8). One anaphylaxis was triggered during specific immunotherapy to bee. In 26 subjects, the elicitor was known and in 13 reasonably suspected.

Four out of 47 subjects (9%) were positive for KIT D816V mutation.

These 4 patients were females and experienced an anaphylactic reaction of grade III severity. The elicitors were yellow jacket (2x), shrimps (1x) and one reaction was idiopathic. In one case mastocytosis was already diagnosed and an elevated tryptase level was known prior the reaction. In the other 3 cases the mastocytosis was not considered beforehand.

Conclusions: Our data suggests that in adult patients who experienced a severe anaphylactic reaction a mastocytosis should be considered as an underlying disease. This seems to be important not only in venom induced anaphylaxis but in rather all cases, however more data is needed to better define the target population for the genetic analysis. Results: Methods: A total of 1513 patients enrolled in the ECNM registry were analyzed. In these patients, BMI, malnutrition, weight loss >10%, malabsorption, osteopenia/osteoporosis, and the variant of SM were analyzed.

Results: Malnutrition was observed in 1.4% of all subjects. In most patients the BMI was >=21. Weight loss >=10% was found in 6.7% of all patients, and . malabsorption was reported in 2.9% of all cases.

Osteopenia/osteoporosis were found in 28.2% of the patients examined.

Weight loss, malnutrition, and malabsorption were most prevalent in patients with advanced forms of SM (ASM, AHNMD), while low BMI and osteopenia/osteoporosis were found in all forms of the disease.

Conclusions: Weight loss, malnutrition, and malabsorption are indicators of an advanced form of mastocytosis. ABSTRACTS

Kasujee I 3

Sau Paulo, Brazil; 5 Service de Dermatologie

Vall D'hebron Hospital

Chronic inducible urticaria (CIndU) is characterised by itchy wheals and/or angiooedema that only appears when triggered by a specific stimuli. The real-world rate of CIndU across Europe (EU) and Central/South America (C/SA) is currently unknown. Objectives: To examine diagnosis, perceived disease control (measured by the Urticaria Control Test [UCT]data were split into regions for comparison

Kwon Y 22

Despite the seriousness of these conditions, epidemiologic and clinical information is still not sufficient due to their sporadic occurrence. Therefore, a nationwide surveillance system is required to gather epidemiologic data of SCARs. Objectives: To investigate the nationwide occurrence and clinical outcomes of SCARs in Korea. Results: We built a retrospective SCARs registry which comprised of 34 tertiary referral university hospitals in order to recruit SCAR cases occurred from 2010 to 2015. The demographic information, culprit agents, and clinical outcomes were assessed. A total of 745 SCAR cases were enrolled; 384 cases of SJS or TEN and 361 cases of DRESS. Median age was 55 years and the male proportion was 49%. Patients with SCARs were hospitalized for average 22 days; 51 patients (6.8%) were transferred to intensive care units. Overall mortality rate was 6.6% and long-term sequelae were reported in 8.2%. While 92.2% of patients with DRESS completely recovered, only 76.6% of patients with SJS/TEN recover their health. Aging was the most important risk factor of fatality. For 745 cases, 1,393 drugs were suspected as culprit drugs

| Basophil activation using synthetic antigenic determinants for diagnosing immediate hypersensitivity to clavulanic acid

Mayorga C 1 ; Perez-Inestrosa E 2

Liabeuf V 4 ; Cabon-Boudard I 5 ; Cleach I 1

Klingebiel C 6 ; M ege

Multidisciplinary Pediatrics Department

hepatitis B (14%) and measles, mumps and rubella (MMR) vaccines (13%) (31%), angioedema (14%) and vasovagal syncope (11%)

Other reactions: respiratory (8%), gastrointestinal (5%) and fever (7%)

United Kingdom; 3 Observational and Pragmatic Research Institute Pte Ltd

Adrenaline auto-injector (AAI) prescriptions are not keeping pace with the increasing anaphylaxis hospitalization rate, and, even when prescribed, AAIs are frequently not used. Objectives: In this environment

Continued training, further simplification and wider dissemination of guideline messages are required

food allergy syndrome 0164 | Significant improvement in diagnosing anaphylaxis over time: A major factor compounding time-trend data?

Objectives: The aim of this study was to investigate the extent of anaphylaxis miscoding, how this changed after intensified training programs and new anaphylaxis guidelines, and whether this contributed to apparent changes in prevalence over a 10-year period. Results: We conducted a retrospective chart examination of all cases coded as anaphylaxis presenting to the main tertiary Pediatric Emergency Department (PED

and 177/71822 ED presentations in 2012 were coded as anaphylaxis (ICD-10) with significantly more coding errors in

Sub-analysis sug

We also examined for potential underdiagnosis of anaphylaxis analyzing 400 randomly selected cases of ED presentations attributed to conditions with an associated diagnosis. Based on the estimate of total anaphylaxis cases for both time periods we found an underdiagnosis rate of 37% (63% correctly diagnosed

Acknowledgements: Authors would like to thank Prof. DBK Golden for his valuable comments and to all Respondents for their comprehensive answers.

Conclusions: We developed a detection method for cHK and found that these levels are increased in HAE patients. We propose that cHK constitutes a promising surrogate biomarker for bradykinin release that should prove useful for HAE and potentially other bra-