Abstract
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.
Keywords: COVID-19; antiphospholipid syndrome; autoimmunity; immunoglobulin A; thromboembolisms.
【저자키워드】 COVID-19, Autoimmunity, immunoglobulin A, Antiphospholipid syndrome, thromboembolisms., 【초록키워드】 coronavirus disease, IgG, IgM, severe COVID-19, Antiviral, antibody, hospital, diagnostic, Cohort, Immunoglobulin, IgA, Patient, Complication, Autoimmune diseases, Switzerland, similarity, mucosa, systemic, clinical record, retrospective cohort study, Clinical data, syndrome, mild illness, IgA response, approach, independent, thrombotic event, autoimmune responses, collected, Sample, significantly, elevated, determine, correlated, induce, triggered, excluded, were measured, Total, IgA antibody, patients with COVID-19, 【제목키워드】 IgA,