key: cord-0784592-4xy7smxc
authors: De Lorenzo, Rebecca; Sciorati, Clara; Lorè, Nicola I.; Capobianco, Annalisa; Tresoldi, Cristina; Cirillo, Daniela M.; Ciceri, Fabio; Rovere-Querini, Patrizia; Manfredi, Angelo A.
title: Chitinase-3-like protein-1 at hospital admission predicts COVID-19 outcome: a prospective cohort study
date: 2022-05-09
journal: Sci Rep
DOI: 10.1038/s41598-022-11532-x
sha: addd6f595fb704cf96dcd0d8e4e9044832d9e6f9
doc_id: 784592
cord_uid: 4xy7smxc

Infectious and inflammatory stimuli elicit the generation of chitinase-3-like protein-1 (CHI3L1), involved in tissue damage, repair and remodeling. We evaluated whether plasma CHI3L1 at disease onset predicts clinical outcome of patients with Coronavirus 2019 (COVID-19) disease. Blood from 191 prospectively followed COVID-19 patients were collected at hospital admission between March 18th and May 5th, 2020. Plasma from 80 survivors was collected one month post-discharge. Forty age- and sex-matched healthy volunteers served as controls. Primary outcome was transfer to intensive care unit (ICU) or death. CHI3L1 was higher in COVID-19 patients than controls (p < 0.0001). Patients with unfavorable outcome (41 patients admitted to ICU, 47 died) had significantly higher CHI3L1 levels than non-ICU survivors (p < 0.0001). CHI3L1 levels abated in survivors one month post-discharge, regardless of initial disease severity (p < 0.0001), although remaining higher than controls (p < 0.05). Cox regression analysis revealed that CHI3L1 levels predict primary outcome independently of age, sex, comorbidities, degree of respiratory insufficiency and systemic inflammation or time from symptom onset to sampling (p < 0.0001). Kaplan–Meier curve analysis confirmed that patients with CHI3L1 levels above the median (361 ng/mL) had a poorer prognosis (log rank test, p < 0.0001). Plasma CHI3L1 is increased in COVID-19 patients and predicts adverse outcome.

Over one year after the onset of Coronavirus disease 2019 (COVID-19) pandemic, substantial progress has been made in patient management and in understanding disease mechanisms. Several signals have been proposed as putative players in the disease natural history [1] [2] [3] [4] [5] [6] [7] [8] . As such, they may be interesting candidates as biomarkers of clinical outcome, helping inform management strategies and minimize the risk of disease progression. The ideal biomarkers should not just reflect the overall inflammatory burden but disclose the events responsible for adverse disease evolution, such as vascular inflammation and lung remodeling 9, 10 . Moreover, since the interplay of antigen-presenting cells and T cells is crucial determinant of COVID-19 outcome, molecules involved in this process could be suitable candidates 11 . Chitinase-3 like-protein-1 (CHI3L1), a member of the glycoside hydrolase family 18, meets these requirements 12 . CHI3L1 binds to chitin, although being devoid of the ability to cleave the protein. It also binds to other substrates such as hyaluronic acid and heparin. Various signals that are activated in the early phases of COVID-19, including extracellular matrix (ECM) alterations, cell and tissue injury and response to cytokines and growth factors, elicit its synthesis by tissue cells and inflammatory leukocytes 12 . In turn, CHI3L1 stimulates the expression of angiotensin-converting enzyme 2 (ACE-2) and viral spike protein priming proteases in pulmonary epithelial and vascular cells 13 . ACE-2 is the functional receptor of SARS-CoV-2 and mediates viral entry through the viral spike protein 14 . After binding, the spike protein is cleaved by proteases into two subunits that mediate the fusion between viral envelope and cell plasma membrane 14 . ACE is expressed by several cells including enterocytes, renal tubular cells, cardiomyocytes and male reproductive and vascular cells 15 . ACE expression in the respiratory system is limited, in physiological conditions, to regions of the sinonasal Fig. 1 panel B) Fig. 1 panel C) , although remaining higher than HC (p < 0.05). CHI3L1 levels at admission were inversely correlated with respiratory function, as reflected by the PaO 2 /FiO 2 (R coefficient − 0.31, p < 0.0001, Fig. 2 panel A) . On the contrary, CHI3L1 levels positively correlate with CRP levels (R coefficient 0.49, p < 0.0001, Fig. 2 panel B) , NLR (R coefficient 0.34, p < 0.0001, Fig. 2 panel C) and LDH levels (R coefficient 0.29, p < 0.0001, Fig. 2 panel D) .

analysis revealed that CHI3L1 plasma levels (ng/mL) at admission predict the risk of adverse outcome (transfer to ICU/death) independently of age, sex, comorbidities, degree of respiratory insufficiency and systemic inflammation (CRP) at admission, and time from symptom onset to blood draw (p < 0.01, Table 2 ). Risk of www.nature.com/scientificreports/ adverse outcomes was increased by 0.5% per increase of 10 ng/mL of CHI3L1 plasma levels. Kaplan-Meier curve analyses confirmed that patients with plasma levels of CHI3L1 above the median value of 361 ng/mL had a significantly higher risk of adverse outcome (transfer to ICU or death, log rank test, p < 0.0001, Fig. 3 ) and of death (log rank test, p 0.0036, Supplementary Fig. 1 ) than those with lower levels. Multivariable Cox regression analyses were performed to investigate whether the ability of CHI3L1 to predict adverse outcome was independent of patient characteristic. CHI3L1 levels (ng/mL) predict transfer to ICU or death independent of HTN, COPD, CAD, DM, active neoplasia, CKD, NLR at admission, hospitalization, length of stay in hospital, steroid therapy and LMWH administration during hospitalization (Supplementary Table 1 ). 

We report that CHI3L1 accumulates early in COVID-19 patients. Patients with higher CHI3L1 levels had higher CRP levels and NLR values, reflecting a high inflammatory burden. These results agree well with those recently reported by 17 , who retrospectively compared serum levels of CHI3L1 in hospitalized COVID-19 patients, healthy subjects, patients with chronic obstructive pulmonary disease and with unrelated interstitial lung disease. We found that plasma levels of CHI3L1 were reduced in COVID-19 survivors four weeks after clinical remission, at a time when systemic inflammation had returned to baseline levels 25 . Interestingly, CHI3L1 levels at this point were still significantly higher than in healthy subjects, suggesting that stimuli sustaining CHI3L1 production are still present. The crosstalk between the ECM and CHI3L1 12 is intriguing since ECM remodeling occurs during acute COVID-19 26 , and may persist following disease resolution given the evidence of autoantibodies against ECM components in COVID-19 patients 27 .

High levels of CHI3L1 were associated with an increased risk of adverse outcome, including transfer to the ICU or mortality, independently of age, sex, comorbidities, degree of respiratory insufficiency and systemic inflammation at admission, and time from symptom onset to blood draw, all known to be associated with COVID-19 clinical outcome 28, 29 . This observation indicates that the early generation of CHI3L1 is integral to the response initiated by the host recognition of SARS-CoV-2 and does not only reflect the magnitude of the inflammatory response or the clinical status. CHI3L1 is a recognized biomarker of kidney injury 30, 31 , which makes it tempting to speculate that CHI3L1 levels may at least in part reflect kidney damage 32 . To verify this possibility, data on larger groups of patients are needed. Further studies are warranted to identify the stimulus involved in the persistent generation of CHI3L1 in patients with COVID-19 and the reasons of its preferential early accumulation in patients who will experience adverse outcomes. This might prove valuable to dissect at the molecular level the heterogeneity of the disease, possibly allowing a better understanding of the mechanisms responsible for COVID-19 complications.

Our study has limitations. First, the monocentric nature of the cohort implies that conclusions need to be further validated in larger independent cohorts. Second, although patients were prospectively followed, blood specimens at follow-up were available for only eighty of them. Third, a longer follow-up might add information, especially after stratifying survivors based on long-term sequelae 19, 33 . In addition, the limited sample size may hamper the generalizability of results. Validation of our findings in larger cohorts support the routine use of CHI3L1 for prognostic and patient management purposes. Although quantification of CHI3L1 plasma levels is easy to perform through ELISA technique, it remains more expensive and time-consuming than measuring conventional biomarkers such as CRP, LDH or NLR, whose specificity for COVID-19 is however limited. Altogether, our data indicate that plasma levels of CHI3L1, a major player in the host response to inflammatory threats, are increased in patients with more severe COVID-19 patients and predicts adverse outcome independently of systemic inflammation and clinical indicators of severity. CHI3L1 may play a role in the progression of COVID-19 through mechanisms not directly related to the extent of the host inflammatory response. Further studies are needed to verify this claim. Kaplan-Meier curves depicting rates of adverse autcome (transfer to ICU or death) in patients with CHI3L1 levels below (low) or above (high) the median value of 361 ng/mL. Log rank test, p < 0.0001.

Increased levels of plasma cytokines and correlations to organ failure and 30-day mortality in critically ill Covid-19 patients

IP-10 and MCP-1 as biomarkers associated with disease severity of COVID-19

Biobanking for COVID-19 research

A meta-analysis of potential biomarkers associated with severity of coronavirus disease 2019 (COVID-19)

Longitudinal analyses reveal immunological misfiring in severe COVID-19

Predictors of mortality in hospitalized COVID-19 patients: A systematic review and meta-analysis

Plasma IP-10 and MCP-3 levels are highly associated with disease severity and predict the progression of COVID-19

Uncontrolled innate and impaired adaptive immune responses in patients with COVID-19 acute respiratory distress syndrome

COVID-19 tissue atlases reveal SARS-CoV-2 pathology and cellular targets

COVID-19 and cardiovascular disease: From bench to bedside

Adaptive immunity to SARS-CoV-2 and COVID-19

Chitinase-3 like-protein-1 function and its role in diseases

Chitinase 3-like-1 is a Therapeutic target that mediates the effects of aging in COVID-19. bioRxiv: the preprint server for biology

SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2 and is blocked by a clinically proven protease inhibitor

The protein expression profile of ACE2 in human tissues

Heterogeneous expression of the SARS-Coronavirus-2 receptor ACE2 in the human respiratory tract

YKL-40 as a new promising prognostic marker of severity in COVID infection

Early predictors of clinical outcomes of COVID-19 outbreak in

Residual clinical damage after COVID-19: A retrospective and prospective observational cohort study

COVID-19: Pharmacology and kinetics of viral clearance

Post-COVID-19 follow-up clinic: Depicting chronicity of a new disease

Evaluation of inactivation methods for severe acute respiratory syndrome coronavirus in noncellular blood products

Blood neurofilament light chain and total tau levels at admission predict death in COVID-19 patients

The systemic inflammatory response and clinicopathological characteristics in patients admitted to hospital with COVID-19 infection: Comparison of 2 consecutive cohorts

Longitudinal monitoring of laboratory markers characterizes hospitalized and ambulatory COVID-19 patients

COVID-19 generates hyaluronan fragments that directly induce endothelial barrier dysfunction

Long COVID or Post-acute sequelae of COVID-19 (PASC): An overview of biological factors that may contribute to persistent symptoms

Predicting outcomes of COVID-19 from admission biomarkers: a prospective UK cohort study

IL-6 and other biomarkers associated with poor prognosis in a cohort of hospitalized patients with COVID-19 in Madrid

Urinary chitinase 3-like protein 1 for early diagnosis of acute kidney injury: A prospective cohort study in adult critically ill patients

Chitinase-3-like 1 is a biomarker of acute kidney injury and mortality in paediatric severe malaria

Role of blood pressure dysregulation on kidney and mortality outcomes in COVID-19. Kidney, blood pressure and mortality in SARS-CoV-2 infection

Physical and psychological sequelae at three months after acute illness in COVID-19 survivors

This work was supported by a COVID-19 program project grant from the IRCCS San Raffaele Hospital and the grant COVID-2020-12371617 from the Italian Ministero della Salute. The authors wish to thank the Institutional Biobank, whose support made it possible to carry out this study in a very difficult situation for the Institution and for the country, Fabio Saliu and the Bio Angels for COVID-BioB Study Group composed of Nicola 

The authors declare no competing interests.

Supplementary Information The online version contains supplementary material available at https:// doi. org/ 10. 1038/ s41598-022-11532-x.Correspondence and requests for materials should be addressed to P.R.-Q.Reprints and permissions information is available at www.nature.com/reprints.Publisher's note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/.