Early is superior to late plasma exchange for severe multisystem inflammatory syndrome in children

Background Multisystem inflammatory syndrome in children (MIS-C) can be life threatening in severe cases because of uncontrolled inflammation and multi-organ failure. In this study, we report the effect of plasma exchange in the treatment of MIS-C and to emphasize the effect of its early application on outcome. Method In this retrospective observational study, the medical records of children with severe MIS-C admitted to pediatric intensive care unit (PICU) between April 2020 and January 2021 were reviewed. Severe MIS-C patients were treated according to protocol consisting of plasma exchange (PE), intravenous immune globulin, steroids, and anakinra which we called the "PISA" protocol referring to the initials. The patients were divided into two groups as early plasma exchange (E-PE) and late plasma exchange (L-PE) according to the elapse time between hospital admission and the administration of PE. Groups were compared in terms of outcome variables. Primary study outcome was 28-day mortality. Secondary outcome variables were acute phase response time, length of immunomodulatory treatment, frequency of patients requiring mechanical ventilation (MV) and inotropic support, length of inotropic support and MV, length of hospital and PICU stays. Results Eighteen pediatric patients with MIS-C were included in the study. Seventeen (95%) of the patients presented with decompensated shock and required inotropic support. One of the 17 patients needed extracorporeal membrane oxygenation support (ECMO) PISA protocol was used in all patients. There was no mortality in the E-PE group while the mortality rate was 20% in the L-PE group. Acute phase reactant response was faster in the E-PE group and immunomodulatory treatments could be reduced earlier; the frequency of patients requiring inotropic and mechanical ventilation (MV) support was lower in the E-PE group; the duration of inotropic support, duration of MV, and length of stay in hospital and PICU were significantly shorter in the E-PE group. Conclusion We suggest that in selected cases, timely administration of PE is a beneficial rescue therapy for MIS-C related hyperinflammation presenting with severe cardiovascular collapse.