Relationship between Selective IgA Deficiency and COVID-19 Prognosis

Abstract

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.

SARS-CoV-2-specific nasal IgA wanes 9 months after hospitalisation with COVID-19 and is not induced by subsequent vaccination

“…This is in keeping with one Turkish study of 424 COVID-19 patients which found only 11/424 had SIgAD. 39 Given that Turkey has a higher incidence of SIgAD than the UK (0.52% in Turkey and 0.11% in the UK) we anticipate even lower prevalence in our study. 40 …”

SARS-CoV-2-Neutralizing Humoral IgA Response Occurs Earlier but Is Modest and Diminishes Faster than IgG Response

“…There are reports that individuals with selective IgA deficiency tend to have higher risks of severe COVID-19 ( 36 , 37 ). Thus, we initially hypothesized that individuals with moderate symptoms would possess greater neutralizing activity of serum IgA than those with severe COVID-19.…”

SARS-CoV-2-neutralizing humoral IgA response occurs earlier but modest and diminishes faster compared to IgG response

“…There are reports that individuals with selective IgA deficiency tend to have higher risks of severe COVID-19 [37,38]. Thus, we initially hypothesized that individuals with moderate symptoms would possess greater neutralizing activity of serum IgA than those with severe COVID-19.…”