COVID-19 and multisystem inflammatory syndrome in children: A systematic review and meta-analysis

Background: Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 has been increasingly recognized. However, the clinical features of MIS-C and the differences from Kawasaki disease remain unknown. The study aims to investigate the epidemiology and clinical course of MIS-C. Methods: PubMed and EMBASE were searched through August 30, 2020. Observational studies describing MIS-C were included. Data regarding demographic features, clinical symptoms, laboratory, echocardiography and radiology findings, treatments, and outcomes were extracted. Study-specific estimates were combined using one-group meta-analysis in a random-effects model. Results: A total of 27 studies were identified including 917 MIS-C patients. The mean age was 9.3 (95% confidence interval [CI], 8.4–10.1). The pooled proportions of Hispanic and Black cases were 34.6% (95% CI, 28.3–40.9) and 31.5% (95% CI, 24.8–38.1), respectively. The common manifestations were gastrointestinal symptoms (87.3%; 95% CI, 82.9–91.6) and cardiovascular involvement such as myocardial dysfunction (55.3%; 95% CI, 42.4–68.2), coronary artery aneurysms (21.7%; 95% CI, 12.8–30.1) and shock (65.8%; 95% CI, 51.1–80.4), with marked elevated inflammatory and cardiac markers. The majority of patients received intravenous immunoglobulin (81.0%; 95% CI, 75.0–86.9), aspirin (67.3%; 95% CI, 48.8–85.7), and corticosteroids (63.6%; 95% CI, 53.4–73.8) with a variety of anti-inflammatory agents. Although myocardial dysfunction improved in 55.1% (95% CI, 33.4–76.8) at discharge, the rate of extracorporeal membrane oxygenation use was 6.3% (95% CI, 2.8–9.8) and the mortality was 1.9% (95% CI, 1.0–2.8). Conclusion: Our findings suggest that MIS-C leads to multiple organ failure, including gastrointestinal manifestations, myocardial dysfunction and coronary abnormalities, and has distinct features from Kawasaki disease.