Serum responses of children with Kawasaki Disease against SARS-CoV-2 proteins.

Recently, numerous reports have suggested association of pediatric Coronavirus Disease 2019 (COVID-19) cases and Kawasaki Disease (KD). KD is a major cause of childhood acquired heart disease and vasculitis in the pediatric population. Epidemiological patterns suggest KD is related to an infectious agent; however, the etiology remains unknown1. As past reports have considered other coronaviruses to be related to KD2,3, these reports of pediatric COVID-19 related inflammatory disorder cases leads to the hypothesis of potential cross-coronavirus reactivity that would account for the past controversial proposals of other coronaviruses and these new cases. We sought to address this hypothesis by assessing the antigen targeting of biobanked plasma samples of febrile children, including those with KD, against SARS-CoV-2 proteins.