biostudies-literatureUnknown4(5)Pfeifer J<h4>Background</h4>Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious complication of infection with SARS-CoV-2. A possible involvement of pathogenetically relevant autoantibodies has been discussed. Recently, neutralising autoantibodies against inflammatory receptor antagonists progranulin and interleukin-1 receptor antagonist (IL-1Ra) were found in adult patients with critical COVID-19. The aim of this study was to investigate the role of such autoantibodies in MIS-C.<h4>Methods</h4>In this multicentre, retrospective, cohort study, plasma and serum samples were collected from patients (0-18 years) with MIS-C (as per WHO criteria) treated at five clinical centres in Germany and Spain. As controls, we included plasma or serum samples from children with Kawasaki disThe Lancet. Rheumatologye329-e337https://www.ebi.ac.uk/biostudies/studies/S-EPMC8963770biostudies-literatureAutoantibodies against interleukin-1 receptor antagonist in multisystem inflammatory syndrome in children: a multicentre, retrospective, cohort study.PMC8963770Keren AThurner BJakob AKheiroddin PGerling SAbdul-Khaliq HWittkowski HDetemple MCMeyer SAnton JRegitz ESauer HLohse SBirk EThurner LMasjosthusmann KBecker SLRoemer KFoell DKos IAHeyne KPreuss KDSmola SBewarder MPfeifer JKessel CRohrer TFischer YHoffmann MCFedlmeier MPino-Ramirez RMBals RKabesch MBohm MFadle NJuenger HfalseAutoantibodies against interleukin-1 receptor antagonist in multisystem inflammatory syndrome in children: a multicentre, retrospective, cohort study.<h4>Background</h4>Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious complication of infection with SARS-CoV-2. A possible involvement of pathogenetically relevant autoantibodies has been discussed. Recently, neutralising autoantibodies against inflammatory receptor antagonists progranulin and interleukin-1 receptor antagonist (IL-1Ra) were found in adult patients with critical COVID-19. The aim of this study was to investigate the role of such autoantibodies in MIS-C.<h4>Methods</h4>In this multicentre, retrospective, cohort study, plasma and serum samples were collected from patients (0-18 years) with MIS-C (as per WHO criteria) treated at five clinical centres in Germany and Spain. As controls, we included plasma or serum samples from children with Kawasaki dis2022-01-01T00:00:00Z2022 May2025-06-01T01:33:42.005Z2025-06-01T01:33:42.005ZS-EPMC89637703536838710.1016/S2665-9913(22)00064-9