key: cord-0046047-ic584g2y
authors: Yue, Junqing; Qin, Lu; Zhang, Cong; Xie, Min
title: Reply
date: 2020-06-22
journal: J Allergy Clin Immunol
DOI: 10.1016/j.jaci.2020.06.002
sha: d465297e777156381b3c0c7d7b2dba75f3eab640
doc_id: 46047
cord_uid: ic584g2y

nan

Reply Q 1 To the Editor:

The article by Marco et al 1 titled ''Asthmatic patients in COVID-19 outbreak: few cases despite many cases'' discusses the prevalence of asthma in patients with coronavirus disease 2019 in the Northeast of Italy. The low prevalence of asthma in patients with COVID-19 in Italy 1 was consistent with what we observed in our study, 2 but was much lower than those from the United States 3 and Dublin. 4 The reasons behind the regional difference in asthma with COVID-19 are worth discussion.

We searched PubMed and Medline database for articles published up to May 20, 2020, using the keywords ''SARS-COV-2,'' ''COVID-19,'' and ''asthma.'' As shown in Table I ½T1 , 1-7 the prevalence of asthma with COVID-19 in each country was listed as well as the prevalence of asthma in the general population of the corresponding region.

The studies from China, Italy, and Mexico confirmed the lower rates of asthma with patients with COVID-19 when compared with the prevalence of asthma in the corresponding general population (0.9%, 1.92%, and 3.6%, compared with 6.4%, 6.1%, and 5.0%, respectively). 1,2,5 However, recent data released from New York and Dublin indicated the high rates of asthma in COVID-19, which were similar or a little higher than the prevalence of asthma (9.0% and 8.8%, compared with 10.1% and 7%, respectively). 3, 4 The other 2 small cohorts from France and Australia also manifested the high rates of asthma in pediatric patients with COVID-19. 6, 7 The reasons for these regional differences may partially be attributed to the variety in the strictness of prevention and control measures, the public awareness of self-protection, and the detection strategy of SARS-COV-2. However, we also notice that the risk of patients with asthma to COVID-19 in the regions with a low prevalence of asthma seems lower than that in regions with a high prevalence of asthma. The recent study suggested that T H 2 cytokine may decrease the expression of angiotensin-converting enzyme 2 (ACE2) in epithelial cells, but increase another SARS-COV-2 receptor transmembrane protease serine 2 (TMPRSS2) gene expression. The regulation on the expressions of ACE2 and TMPRSS2 in T H 2-high patients with asthma differed from that in T H 2-low patients with asthma. Therefore, we may speculate that the difference in phenotype and genotype of asthma may contribute to the differential regulation of ACE2 and TMPRSS2 and is partially responsible for the variety in susceptibility of patients with asthma to COVID-19 among different regions.

The other concern is the various clinical characteristics of patients with asthma in the different regions; for example, high body mass index in patients with asthma is more common in the United States than in China and Italy. Obesity is related to an increased risk of COVID-19. Obese patients are also prone to have hypertension, which is a predisposing factor for COVID-19. The different comorbidities with patients with asthma may also be one of the reasons for the regional differences in the prevalence of asthma in COVID-19.

Asthma is a disease with marked heterogeneity. It would be intriguing to investigate and understand how the heterogeneity of asthma is attributable to the variability in susceptibility and clinical course of asthma with COVID-19. 1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42  43  44  45  46  47  48  49  50  51  52  53  54  55  56  57  58  59  60 

Asthmatic patients in COVID-19 outbreak: few cases despite many cases

Risk factors for severity and mortality in adult COVID-19 inpatients in Wuhan

Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19 in the New York City area

Prevalence of comorbid asthma in COVID-19 patients

COVID-19 fatality and comorbidity risk factors among confirmed patients in Mexico

Acute heart failure in multisystem inflammatory syndrome in children (MIS-C) in the context of global SARS-CoV-2 pandemic

SARS-CoV-2 testing and outcomes in the first 30 days after the first case of COVID-19 at an Australian children's hospital