Long-term follow-up of anti-IFN-α2 autoantibody levels in hospitalized individuals with COVID-19

Anti-type-I interferon (IFN) autoantibodies have been associated with severe COVID-19. Their association with long COVID, however, is unclear.

Anti-IFN-α2 antibody levels were followed-up for one year in individuals hospitalized for acute COVID-19 (n=97). Specific anti-IFN-α2 antibodies were detected in 5/97 patients. High anti-IFN-α2 antibody levels during acute infection were only detected in patients admitted to ICU (3/42), of whom 2 had persistent high levels and residual changes on chest computed tomography 12 months post-infection. Two patients not admitted to ICU had undetectable antibodies during acute infection, but had low detectable antibody levels 12 months post-infection; one of whom suffered from long COVID.

In conclusion, anti-IFN-α2 antibodies during acute infection are not associated with post-SARS-CoV-2 residual sequelae. Two patients with initially undetectable anti-IFN-α2 autoantibodies showed increased autoantibody levels 12 months post-infection. Additional large studies are needed to study the potential role of loss of tolerance after SARS-CoV-2 infection in long COVID.