PIMS-TS Innate Cell Signature and Immunophenotype, Description and Comparison with a Cohort of Healthy Children, Kawasaki Disease, Severe Viral and Bacterial Infections.

Abstract A new clinical syndrome named as Pediatric Inflammatory Multisystem Syndrome Temporally Associated with SARS-CoV-2 (PIMS-TS) has been described. This new disease is a main cause of hospital and pediatric intensive care unit (PICU). We made a prospective-retrospective observational study to describe the innate cell signature and immunophenotype of children admitted to PICU because of PIMS-TS (from March 2020 to September 2020). They were compared with previous cohorts of healthy controls and children admitted to PICU because bacterial infection, viral infection and Kawasaki disease (KD). Two hundred and forty seven children were studied: 183 healthy controls, 25 viral infections, 20 bacterial infections, 6 KD and 13 PIMS-TS. PIMT-TS showed the lowest percentage of lymphocytes and monocytes with higher relative numbers of CD4+ (p =0,000). Monocytes and neutrophils in PIMS-TS showed higher levels of CD64 expression (p = 0,000). Also, CD11a and CD11b were highly expressed compare to other severe viral or bacterial infections (p = 0,000). In conclusion, we describe and compare for the first time the innate cellular response of children with PIMS-TS with other severe forms of viral or bacterial infection and KD. These data should be further studied and may facilitate the diagnosis and management of these patients.