Some children present with severe secondary effects in response to COVID-19, similar to Kawasaki disease, termed multisystem inflammatory disease in children (MIS-C). MIS-C patients present with higher frequencies of CD4+ and CD8+ T cells and lower levels of IL-17A, ESDN and TNF-β (1, 2, 3, 4). Additionally, children with MIS-C demonstrate an increase in IgG antibodies but low IgM antibodies (2). Data suggests that binding of autoantibodies to proteins involved in immune cell signalling and in within the vasculature might explain the autoimmune reactivity contributing to MIS-C pathology (2, 4).

1)Verdoni L, Mazza A, Gervasoni A, Martelli L, Ruggeri M, Ciuffreda M, et al. An outbreak of severe Kawasaki-like disease at the Italian epicentre of the SARS-CoV-2 epidemic: an observational cohort study. Lancet. 2020;395(10239):1771-8.

2)Consiglio CR, Cotugno N, Sardh F, Pou C, Amodio D, Rodriguez L, et al. The Immunology of Multisystem Inflammatory Syndrome in Children with COVID-19. Cell. 2020;183(4):968-81 e7.

3) Vella L, Giles JR, Baxter AE, Oldridge DA, Diorio C, Kuri-Cervantes L, et al. Deep Immune Profiling of MIS-C demonstrates marked but transient immune activation compared to adult and pediatric COVID-19. medRxiv. 2020.

4) Gruber CN, Patel RS, Trachtman R, Lepow L, Amanat F, Krammer F, et al. Mapping Systemic Inflammation and Antibody Responses in Multisystem Inflammatory Syndrome in Children (MIS-C). Cell. 2020;183(4):982-95 e14.