Relationship between selective IgA deficiency and COVID-19 prognosis

Çölkesen, Fatih; Kandemir, Bahar; Arslan, Sevket; Çölkesen, Fatma; Yildiz, Eray; Korkmaz, Celalettin; Vatansev, Hülya; Evcen, Recep; Sadi Aykan, Filiz; Kilinç, Mehmet; Aytekin, Gökhan; Feyzioglu, Bahadir; Dogan, Metin; Teke, Turgut

The prevalence and mortality rates of coronavirus disease 2019 (COVID-19) vary widely among populations. Mucosal immunity is the first barrier to pathogens' entry into the body. Immunoglobulin A (IgA) is the main antibody of mucosal immunity. We explored the relationship between selective immunoglobulin A deficiency (SIgAD) and the severity of COVID-19. We included 424 patients (203 females) with COVID-19. Eleven patients had SIgAD. Laboratory data on patients with SIgAD and normal IgA levels were compared. The relationship between SIgAD and severe COVID-19 infection was explored by logistic regression analysis. In univariate logistic regression analysis, the risk of severe disease in COVID-19 patients with SIgAD was approximately 7.7-fold higher than in the other patients (odds ratio [OR], 7.789; 95% confidence interval [CI], 1.665-36.690, p = 0.008), while it was 4-fold (OR, 4.053; 95% CI, 1.182-13.903, p = 0.026) higher in multivariate logistic regression analysis. Serum IgA levels were positively correlated with total lymphocyte counts, and negatively correlated with C-reactive protein (CRP) levels, which were found as a risk factor for severe COVID-19.In SIgAD patients, the number of SARS-CoV-2 viruses that pass through mucosal membranes may be increased, leading to complications such as cytokine storm syndrome and acute respiratory distress syndrome.