The effect of allergy and asthma as a comorbidity on the susceptibility and outcomes of COVID-19. International immunology Gao, Y., Agache, I., Akdis, M., Nadeau, K., Klimek, L., Jutel, M., Akdis, C. A. 2021


The coronavirus disease 2019 (COVID-19) pandemic causes an overwhelming number of hospitalization and deaths with a significant socioeconomic impact. The vast majority of studies indicate that asthma and allergic diseases do not represent a risk factor for COVID-19 susceptibility nor cause a more severe course of disease. This raises the opportunity to investigate the underlying mechanisms of the interaction between an allergic background and SARS-CoV-2 infection. The majority of patients with asthma, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, food and drug allergies exhibit an overexpression of type 2 immune and inflammatory pathways with the contribution of epithelial cells, innate lymphoid cells (ILC), dendritic cells, T cells, eosinophils, mast cells, basophils and the type 2 cytokines interleukin (IL)-4, IL-5, IL-9, IL-13, and IL-31. The potential impact of type 2 inflammation-related allergic diseases on susceptibility to COVID-19 and severity of its course have been reported. In this review, the prevalence of asthma and other common allergic diseases in COVID-19 patients is addressed. Moreover, the impact of allergic and non-allergic asthma with different severity and control status, currently available asthma treatments such as inhaled and oral corticosteroids, short- and long-acting beta2 agonists, leukotriene receptor antagonists and biologicals on the outcome of COVID-19 patients is reviewed. In addition, possible protective mechanisms of asthma and type 2 inflammation on COVID-19 infection, such as the expression of SARS-CoV-2 entry receptors, antiviral activity of eosinophils, cross-reactive T cell epitopes are discussed. Potential interactions of other allergic diseases with COVID-19 are postulated, including recommendations for their management.

View details for DOI 10.1093/intimm/dxab107

View details for PubMedID 34788827