AUTHOR=Burbelo Peter D. , Castagnoli Riccardo , Shimizu Chisato , Delmonte Ottavia M. , Dobbs Kerry , Discepolo Valentina , Lo Vecchio Andrea , Guarino Alfredo , Licciardi Francesco , Ramenghi Ugo , Rey-Jurado Emma , Vial Cecilia , Marseglia Gian Luigi , Licari Amelia , Montagna Daniela , Rossi Camillo , Montealegre Sanchez Gina A. , Barron Karyl , Warner Blake M. , Chiorini John A. , Espinosa Yazmin , Noguera Loreani , Dropulic Lesia , Truong Meng , Gerstbacher Dana , Mató Sayonara , Kanegaye John , Tremoulet Adriana H. , Pediatric Emergency Medicine Kawasaki Group , Eisenstein Eli M. , Su Helen C. , Imberti Luisa , Poli Maria Cecilia , Burns Jane C. , Notarangelo Luigi D. , Cohen Jeffrey I. , Abe Naomi , Bryl Amy , Donofrio-Odmann J. Joelle , Ekpenyong, Atim , Gardiner, Michael , Gutglass David J. , Nguyen Margaret B. , Ulrich Stacey TITLE=Autoantibodies Against Proteins Previously Associated With Autoimmunity in Adult and Pediatric Patients With COVID-19 and Children With MIS-C JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.841126 DOI=10.3389/fimmu.2022.841126 ISSN=1664-3224 ABSTRACT=

The antibody profile against autoantigens previously associated with autoimmune diseases and other human proteins in patients with COVID-19 or multisystem inflammatory syndrome in children (MIS-C) remains poorly defined. Here we show that 30% of adults with COVID-19 had autoantibodies against the lung antigen KCNRG, and 34% had antibodies to the SLE-associated Smith-D3 protein. Children with COVID-19 rarely had autoantibodies; one of 59 children had GAD65 autoantibodies associated with acute onset of insulin-dependent diabetes. While autoantibodies associated with SLE/Sjögren’s syndrome (Ro52, Ro60, and La) and/or autoimmune gastritis (gastric ATPase) were detected in 74% (40/54) of MIS-C patients, further analysis of these patients and of children with Kawasaki disease (KD), showed that the administration of intravenous immunoglobulin (IVIG) was largely responsible for detection of these autoantibodies in both groups of patients. Monitoring in vivo decay of the autoantibodies in MIS-C children showed that the IVIG-derived Ro52, Ro60, and La autoantibodies declined to undetectable levels by 45-60 days, but gastric ATPase autoantibodies declined more slowly requiring >100 days until undetectable. Further testing of IgG and/or IgA antibodies against a subset of potential targets identified by published autoantigen array studies of MIS-C failed to detect autoantibodies against most (16/18) of these proteins in patients with MIS-C who had not received IVIG. However, Troponin C2 and KLHL12 autoantibodies were detected in 2 of 20 and 1 of 20 patients with MIS-C, respectively. Overall, these results suggest that IVIG therapy may be a confounding factor in autoantibody measurements in MIS-C and that antibodies against antigens associated with autoimmune diseases or other human proteins are uncommon in MIS-C.