Multisystem inflammatory syndrome in European White children – study of 274 cases

Abstract

Despite the growing literature on multisystem inflammatory syndrome in children (MIS-C), the data in European White population is limited. Our aim was to capture MIS-C emergence in Poland (central Europe) and to describe its characteristics with a focus on severity determinants. Patients who met the MIS-C definition (fever, multiorgan failure, inflammation, and proven SARS-CoV-2 infection or contact) were reported retrospectively and prospectively in an online survey. Study definitions fulfilment was automatically evaluated by a dedicated software. For the assessment of univariate relationships, either directed or divided by sex, age, or disease severity, we used the test for two categorical variables and the Kruskal-Wallis test for categorical-continuous variable pairs. The analysis involved 274 children, 62.8% boys, median age 8.8 years. Besides one Asian, all were European White. Merely 23 (8.4%) required paediatric intensive care treatment (PICU). They were older (11.2 vs. 8.4 years), and at hospital admission had higher respiratory rate (30 v. 20/minute), lower systolic blood pressure (89 vs. 100 mmHg), prolonged capillary refill time (40% vs. 11%), and decreased consciousness (22% vs. 5%). Teenage boys had more common cardiac involvement (fraction 25.9% vs. 14.7% ) and macrophage activation syndrome (31.0% vs. 15.2%) than others. Boys were also more often hospitalised in PICU with age (from median 11.2 years to 9.1). The severity of MIS-C is not as uniform as it seemed, ethnicity and sex may affect MIS-C phenotype. Management might not be universally applicable and should rather be adjusted to the specific population.

Recurrent assessment of lymphocyte subsets in 32 patients with multisystem inflammatory syndrome in children (MIS‐C)

“…cellular immunity, COVID-19, immune cells, MIS-C, PIMS-TS, prognostic markers, subsets Multisystem inflammatory syndrome in children (MIS-C) is a severe systemic disease manifested by persistent fever, substantially elevated inflammatory markers, and multiorgan failure, most commonly occurring in otherwise healthy, school-aged children. [1][2][3][4][5] Temporal association with coronavirus disease 2019 (COVID-19) is well established: MIS-C prevalence culminates 4-5 weeks after the COVID-19 wave in the local society, and the majority of children with MIS-C have either recent COVID-19 exposure or antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). [1][2][3][4][5] In Poland, isolated MIS-C cases were observed in May 2020, and the first substantial MIS-C wave was noted in autumn 2020.…”

“…[1][2][3][4][5] Temporal association with coronavirus disease 2019 (COVID-19) is well established: MIS-C prevalence culminates 4-5 weeks after the COVID-19 wave in the local society, and the majority of children with MIS-C have either recent COVID-19 exposure or antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). [1][2][3][4][5] In Poland, isolated MIS-C cases were observed in May 2020, and the first substantial MIS-C wave was noted in autumn 2020. 5 The pathophysiology of MIS-C remains largely unknown.…”

“…One of its characteristic laboratory features is lymphopenia. 1,[4][5][6][7][8] Deep depression of CD4, CD8, and γδT cells was described in the course of MIS-C, with some unique discrepancies distinguishing it from both acute COVID-19 and Kawasaki disease. 6,9 We aimed to describe lymphocyte subsets in patients with MIS-C and their possible associations with other typical aberrations of MIS-C.…”

“…Cytokine storm observed during the acute phase of the disease, without virus replication, but with the presence of anti‐SARS‐CoV‐2 antibodies, suggests that MIS‐C is a postinfectious aberrant hyperinflammatory reaction of the immune system. One of its characteristic laboratory features is lymphopenia 1,4–8 . Deep depression of CD4, CD8, and γδT cells was described in the course of MIS‐C, with some unique discrepancies distinguishing it from both acute COVID‐19 and Kawasaki disease 6,9 …”

“…[1][2][3][4][5] In Poland, isolated MIS-C cases were observed in May 2020, and the first substantial MIS-C wave was noted in autumn 2020. 5 The pathophysiology of MIS-C remains largely unknown. Cytokine storm observed during the acute phase of the disease, without virus replication, but with the presence of anti-SARS-CoV-2 antibodies, suggests that MIS-C is a postinfectious aberrant hyperinflammatory reaction of the immune system.…”