Publication
Severe Coronavirus Disease 2019 (COVID-19) is Associated With Elevated Serum Immunoglobulin (Ig) A and Antiphospholipid IgA Antibodies
Journal Paper/Review - Jan 2, 2021
Hasan Ali Omar, Penninger Josef M, Bergthaler Andreas, Popa Alexandra M, Gómez-Mejia Alejandro, Schüpbach Reto A, Bühler Philipp K, Vernazza Pietro, Kahlert Christian, Kohler Philipp, Albrich Werner, Kern Lukas, Thiel Sarah, Weber Myriam, Paprotny Matthias, Brugger Silvio D, Risch Lorenz, Bomze David, Flatz Lukas
Units
PubMed
Doi
Citation
Type
Journal
Publication Date
Issn Electronic
Pages
Brief description/objective
BACKGROUND
Severe coronavirus disease 2019 (COVID-19) frequently entails complications that bear similarities to autoimmune diseases. To date, there are little data on possible immunoglobulin (Ig) A-mediated autoimmune responses. Here, we aim to determine whether COVID-19 is associated with a vigorous total IgA response and whether IgA antibodies are associated with complications of severe illness. Since thrombotic events are frequent in severe COVID-19 and resemble hypercoagulation of antiphospholipid syndrome, our approach focused on antiphospholipid antibodies (aPL).
METHODS
In this retrospective cohort study, clinical data and aPL from 64 patients with COVID-19 were compared from 3 independent tertiary hospitals (1 in Liechtenstein, 2 in Switzerland). Samples were collected from 9 April to 1 May 2020.
RESULTS
Clinical records of 64 patients with COVID-19 were reviewed and divided into a cohort with mild illness (mCOVID; 41%), a discovery cohort with severe illness (sdCOVID; 22%) and a confirmation cohort with severe illness (scCOVID; 38%). Total IgA, IgG, and aPL were measured with clinical diagnostic kits. Severe illness was significantly associated with increased total IgA (sdCOVID, P = .01; scCOVID, P < .001), but not total IgG. Among aPL, both cohorts with severe illness significantly correlated with elevated anticardiolipin IgA (sdCOVID and scCOVID, P < .001), anticardiolipin IgM (sdCOVID, P = .003; scCOVID, P< .001), and anti-beta 2 glycoprotein-1 IgA (sdCOVID and scCOVID, P< .001). Systemic lupus erythematosus was excluded from all patients as a potential confounder.
CONCLUSIONS
Higher total IgA and IgA-aPL were consistently associated with severe illness. These novel data strongly suggest that a vigorous antiviral IgA response, possibly triggered in the bronchial mucosa, induces systemic autoimmunity.