Association between anti-interferon-alpha autoantibodies and COVID-19 in systemic lupus erythematosus.

Abstract Objectives Anti-type I interferon (IFN) autoantibodies have been reported in patients with systemic lupus erythematosus (SLE). Recently, an association of these autoantibodies with severe COVID-19 was reported in the general population. We assessed whether having pre-existing anti-IFNα autoantibodies was associated with COVID-19 infection in SLE patients. Methods Patients with SLE who developed COVID-19 between April 1st to October 1st, 2020 were studied. Biobanked pre-COVID-19 plasma from these SLE subjects and healthy controls were tested for anti-IFNα IgG autoantibodies by ELISA. The ability of plasma anti-IFNα autoantibodies to block signal transducer and activator of transcription 1 (STAT1) phosphorylation by recombinant human IFNα in vitro was assessed by flow cytometry. Results Ten SLE subjects with COVID-19 were identified. A 40% of these subjects had stable autoantibodies against IFNα for up to three years preceding COVID-19 diagnosis. A 50% of the subjects with these autoantibodies neutralized IFNα induced STAT1 phosphorylation.None of the other SLE samples blocked IFNα signaling. Conclusions We noted an increased prevalence of pre-existing anti-IFNα autoantibodies in SLE patients with COVID-19 compared to the reported prevalence in lupus patients and the general population with severe COVID-19. Autoantibodies against IFNα in SLE patients may be pathogenic and patients with them maybe at-risk of developing COVID-19. Key Messages What is already known about this subject? -Anti-type I interferon (IFN) autoantibodies have been reported in patients with systemic lupus erythematosus (SLE) and have recently been associated with severe COVID-19 in the general population. What does this study add? -SLE subjects with COVID-19 had an increased prevalence of pre-existing anti-IFNα autoantibodies compared to the reported prevalence in lupus patients and the general population with severe COVID-19. -Plasma from 50% of subjects with these autoantibodies were able to block in vitro activity of IFNα. -SLE patients with pre-existing anti-IFNα autoantibodies had more severe COVID-19 manifestations. How might this impact on clinical practice or future developments? -Anti-IFNα autoantibodies may be pathogenic and could prove to be a helpful prognostic marker to predict which SLE patient may develop COVID-19 and inform preventive measures and management of this subset of patients.