Early combination therapy with immunoglobulin and steroids is associated with shorter ICU length of stay in Multisystem Inflammatory Syndrome in Children (MIS-C) associated with COVID-19: A retrospective cohort analysis from 28 U.S. Hospitals

Objectives: Suggested therapeutic options for Multisystem Inflammatory Syndrome in Children (MIS-C) include intravenous immunoglobulins (IVIG) and steroids. Prior studies have shown the benefit of combination therapy with both agents on fever control or the resolution of organ dysfunction. The primary objective of this study was to analyze the impact of IVIG and steroids on hospital and ICU length of stay (LOS) in patients with MIS-C associated with Coronavirus Disease 2019 (COVID-19).

Study design: This was a retrospective study on 356 hospitalized patients with MIS-C from March 2020 to September 2021 (28 sites in the United States) in the Society of Critical Care Medicine (SCCM) Discovery Viral Infection and Respiratory Illness Universal Study (VIRUS) COVID-19 Registry. The effect of IVIG and steroids initiated in the first 2 days of admission, alone or in combination, on LOS was analyzed. Adjustment for confounders was made by multivariable mixed regression with a random intercept for the site.

Results: The median age of the study population was 8.8 (Interquartile range (IQR) 4.0, 13) years. 247/356 (69%) patients required intensive care unit (ICU) admission during hospitalization. Overall hospital mortality was 2% (7/356). Of the total patients, 153 (43%) received IVIG and steroids, 33 (9%) received IVIG only, 43 (12%) received steroids only, and 127 (36%) received neither within 2 days of admission. After adjustment of confounders, only combination therapy showed a significant decrease of ICU LOS by 1.6 days compared to no therapy (exponentiated coefficient 0.71 [95% confidence interval 0.51, 0.97, p = 0.03]). No significant difference was observed in hospital LOS or the secondary outcome variable of the normalization of inflammatory mediators by Day 3.

Conclusions: Combination therapy with IVIG and steroids initiated in the first 2 days of admission favorably impacts ICU but not the overall hospital LOS in children with MIS-C.