Evidence Of Microangiopathy In Children With Sars-Cov-2 Regardless Of Clinical Presentation

Introduction: During the Coronavirus Disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2), 3 distinct phenotypes have emerged in children. The majority of children have mild or no symptoms. Similar to adults, a minority of children can be severely affected with respiratory distress requiring intensive care. Finally, they may develop a phenomenon presumed unique to children termed Multisystem Inflammatory Syndrome in Children (MIS-C). MIS-C is a hyperinflammatory syndrome characterized by fever and organ dysfunction (particularly cardiac) in the setting of recent COVID-19 infection. Reports from the adult literature have invoked thrombotic microangiopathy (TMA) and complement activation as a potential cause for severe manifestations of COVID-19 (Zhang et al. NEJM. 2020; Campbell et al. Circulation 2020). Soluble C5b9 (sC5b-9), the terminal complement complex, has been implicated as a marker of hematopoietic stem cell transplant associated TMA (HSCT-TMA; Jodele et al. Blood 2014). We sought to elucidate the role of terminal complement activation and TMA in the different pediatric disease phenotypes.