MIS-C: early lessons from immune profiling

Multisystem inflammatory syndrome in children (MIS-C) is a rare complication of SARS-CoV-2 infection that can result in serious illness in the paediatric population but our understanding of this syndrome is in its infancy. Translational studies in 2020 leveraging immune profiling have laid the foundation to enable further discovery in MIS-C. Key advances The immune response in multisystem inflammatory syndrome in children (MIS-C) seems to be distinct from that during acute SARS-CoV-2 infection 8 , but has both shared and distinct features compared with Kawasaki disease 7 , 10 . The immune landscape shifts during the course of MIS-C, with the acute phase being characterized by activated innate immune cells and T cell and B cell lymphopenia, which normalize during recovery, and appropriate anti-viral antibody responses detected to SARS-CoV-2 (ref. 6 ). MIS-C and Kawasaki disease might share plasma protein profiles but differ in autoantibody targets 9 , 10 ; whether they are distinct or represent a continuum of the same clinical syndrome remains to be determined.