Autoantibodies in COVID-19 correlate with anti-viral humoral responses and distinct immune signatures

BackgroundSeveral autoimmune features occur during coronavirus disease 2019 (COVID-19), with possible implications for disease course, immunity, and autoimmune pathology. In this study, we longitudinally screened for clinically relevant systemic autoantibodies to assess their prevalence, temporal trajectory, and association with immunity, comorbidities, and severity of COVID-19. MethodsWe performed highly sensitive indirect immunofluorescence assays to detect anti-nuclear antibodies (ANA) and anti-neutrophil cytoplasmic antibodies (ANCA), along with serum proteomics and virome-wide serological profiling in a multicentric cohort of 175 COVID-19 patients followed-up to one year after infection, eleven vaccinated individuals, and 41 unexposed controls. ResultsCompared to healthy controls, similar prevalence and patterns of ANA were present in patients during acute COVID-19 and recovery. However, paired analysis revealed a subgroup of patients with transient presence of certain ANA patterns during acute COVID-19. Furthermore, patients with severe COVID-19 exhibited a high prevalence of ANCA during acute disease. These autoantibodies were quantitatively associated with higher SARS-CoV-2-specific antibody titers in COVID-19 patients and in vaccinated individuals, thus linking autoantibody production to increased antigen-specific humoral responses. Notably, the qualitative breadth of antibodies cross-reactive with other coronaviruses was comparable in ANA-positive and ANA- negative individuals during acute COVID-19. In autoantibody-positive patients, multiparametric characterization demonstrated an inflammatory signature during acute COVID-19 and alterations of the B cell compartment after recovery. ConclusionHighly sensitive indirect immunofluorescence assays revealed transient autoantibody production during acute SARS-CoV-2 infection, while the presence of autoantibodies in COVID-19 patients correlated with increased anti-viral humoral immune responses and inflammatory immune signatures.

The Immunology of Multisystem Inflammatory Syndrome in Children with COVID-19

SARS-CoV-2 infection is typically very mild and often asymptomatic in children. A complication is the rare Multisystem Inflammatory Syndrome in Children (MIS-C) associated with COVID-19, presenting 4-6 weeks after infection as high fever, organ dysfunction and strongly elevated markers of inflammation. The pathogenesis is unclear but has overlapping features with Kawasaki disease suggestive of vasculitis and a likely autoimmune etiology. We apply systems-level analyses of blood immune cells, cytokines and autoantibodies in healthy children, children with Kawasaki disease enrolled prior to COVID-19, children infected with SARS-CoV-2 and children presenting with MIS-C. We find that the inflammatory response in MIS-C differs from the cytokine storm of severe acute COVID-19, shares several features with Kawasaki disease, but also differs from this condition with respect to T-cell subsets, IL-17A and biomarkers associated with arterial damage. Finally, autoantibody profiling suggests multiple autoantibodies that could be involved in the pathogenesis of MIS-C. HIGHLIGHTSHyperinflammation in MIS-C differs from that of acute COVID-19 T-cell subsets discriminate Kawasaki disease patients from MIS-C IL-17A drives Kawasaki, but not MIS-C hyperinflammation. Global autoantibodies profiling indicate possibly pathogenic autoantibodies

Systems-level immunomonitoring from acute to recovery phase of severe COVID-19

The immune response to SARS-CoV2 is under intense investigation, but not fully understood att this moment. Severe disease is characterized by vigorous inflammatory responses in the lung, often with a sudden onset after 5-7 days of stable disease. Efforts to modulate this hyperinflammation and the associated acute respiratory distress syndrome, rely on the unraveling of the immune cell interactions and cytokines that drive such responses. Systems-level analyses are required to simultaneously capture all immune cell populations and the many protein mediators by which cells communicate. Since every patient analyzed will be captured at different stages of his or her infection, longitudinal monitoring of the immune response is critical. Here we report on a systems-level blood immunomonitoring study of 39 adult patients, hospitalized with severe COVID-19 and followed with up to 14 blood samples from acute to recovery phases of the disease. We describe an IFN{gamma} - Eosinophil axis activated prior to lung hyperinflammation and changes in cell-cell coregulation during different stages of the disease. We also map an immune trajectory during recovery that is shared among patients with severe COVID-19. HIGHLIGHTSSystems-level immunomonitoring from acute to recovery in severe COVID-19 An IFN{gamma} - Eosinophil axis involved in lung hyperinflammation Cell-cell coregulation differ during four disease stages Basophils and hyperinflammation modulate humoral responses A shared trajectory of immunological recovery in severe COVID-19