Reduced COVID-19 susceptibility in persons with bronchial asthma
Published online: February 1, 2021
Certain demographic and clinical characteristics, such as older age, male sex, pre-existing hypertension, and chronic pulmonary or cardiovascular diseases may predispose patients with the coronavirus disease 2019 (COVID-19) to more severe manifestations.
Bronchial asthma is associated with significant reductions in Angiotensin-converting enzyme 2 receptors expression, which is the entry receptor for COVID-19. Previous epidemiological reports from several countries revealed that few patients with COVID-19 had asthma. However, all prevalence data were derived from the COVID-19 inpatient population. Therefore, the prevalence of asthma may be different in outpatient patients with COVID-19, and it is still unknown whether asthma contributes to the protection of individuals from COVID-19.
In a recent research article in The Journal of Allergy and Clinical Immunology: In Practice, Magen et al. analyzed whether people with bronchial asthma had a lower predisposition to COVID-19 than those without asthma and whether COVID-19 predisposition differed by asthma severity or anti-asthmatic medications. They conducted a population-based study using data from Israeli primary care electronic healthcare records from February to June 2020 with linked information about demographic, clinical features, medications, and hospitalization rates. Both pediatric and adult persons with asthma were included.
A total of 37,469 persons were tested for COVID-19, and 2,266 of them were positive for the virus. Most patients with asthma had mild asthma. Magen et al observed a 29.8 % lower risk to be infected by COVID-19 in persons with pre-existing asthma than in those without asthma. Asthma severity and treatment with anti-asthmatic medications, such as anti-leukotrienes, inhaled corticosteroids, and long-acting beta-agonists, did not have a significant impact on the COVID-19 susceptibility. The study revealed a negative association between blood eosinophil levels and COVID-19 risk. The authors did not find any difference in hospitalization rates between COVID-19 persons with and without asthma.
The study supports the recommendation that during the COVID-19 pandemic physicians should continue to treat asthma according to the existing asthma guidelines
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.
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