Demystifying the three different types of COVID-19 associated multisystem inflammatory syndrome in children: Experience from a tertiary care hospital

Background: Following the coronavirus disease-2019 (COVID-19) pandemic, a new entity emerged termed as multisystem inflammatory syndrome in children and adolescents temporally related to COVID-19 (MISC) by the World Health Organization (WHO). Infection with COVID-19 triggers the formation of antibodies to viral surface epitopes. It is believed that low titer non-neutralizing antibodies may accentuate virus-triggered immune responses. The study aimed to describe the various clinical presenting features, deranged laboratory parameters, echocardiographic findings, and immediate outcome and to categorize into 3 types of MISC and find any difference among the 3 types. Methodology: Children 29-days old to 12-years old who clinically satisfied the published WHO’s case definition for MISC were included in the study. All children were subjected to serological testing for total immunoglobulin to viral spike glycoprotein, relevant blood investigations, and echocardiography. Results: Out of 50 cases, we had 24(48%) cases of MISC without shock, 12(24%) cases of Kawasaki disease-like phenotype, and 14(28%) cases of MISC with shock. Fever (96%) and respiratory complaints (64%) predominate followed by gastrointestinal (45%) and red eye (32%). The inflammatory markers were notably elevated- the median CRP was 39.6mg/L, median ESR was 70mm 1sthr, median procalcitonin was 8.2 ng/ml. There is a significant drop in inflammatory markers post-treatment (p=0.019, p=0.000, p=0.016 respectively for CRP, ESR and procalcitonin). Abnormal echocardiographic findings were seen in 46% of cases in terms of decreased ejection fraction and coronary artery aneurysms (CAA). There were 7 deaths (14%), and 42(84%) patients were successfully discharged. Conclusion: Following the COVID-19 pandemic, MISC has emerged with its characteristic clinical pattern which needs early identification and prompt treatment to prevent mortality and morbidity. Keywords: MISC; non-COVID; Eastern India; Kawasaki disease; PIMS-TS; IVIG; immunity