O3017: Clinical and Inflammatory Markers Response to Intravenous Immunoglobulin (IVIg) versus Ivig and Corticosteroids for Mild to Moderately Ill Hospitalized Multi-system Inflammatory Syndrome in Children (MIS-C)

Background: IVIg, corticosteroids and biological agents are used to treat all severities of MIS-C patients with discordant results. Objective of our study was to evaluate the effect of IVIg versus IVIg and corticosteroids on clinical outcomes and inflammatory markers in management of mild to moderately ill hospitalized MIS-C patients.

Methods: Single center retrospective observational study of all hospitalized mild and moderately ill MIS-C patients between April 2020 and December 2021 (IRB # 22-170). Previously reported definitions for MIS-C, mild illness (no vasoactive requirement, minimal respiratory support, minimal signs of organ injury, normal left ventricular function (LVEF) > 55%) and moderate illness (vasoactive inotrope score ≤ 10, significant supplemental oxygen requirement, mild or isolated organ injury, decreased LVEF: 30- 55%) were used. Demographic data, duration of symptoms and fever, number of systems involved were studied. Clinical outcomes were assessed by heart rate, mean blood pressure, LVEF at baseline (day 0) and absolute changes in these parameters after initiation of therapy and resolution of fever. Likewise, inflammatory makers (C-reactive protein, ferritin, fibrinogen, d-dimer, serum albumin, absolute neutrophil count, absolute lymphocyte count) were assessed at baseline (day 0) and absolute changes in these parameters after initiation of therapy. Patients were divided into Group A (who received only IVIg on day 0 of therapy) and group B (who received IVIg and corticosteroids within 24 hours of initiation of therapy on day 0). Statistical analysis included Wilcoxon rank sum test for continuous/ordinal variables and Pearson’s chi-square or Fisher’s exact test for categorical values. All tests were two-tailed.

Results: 39 (mild: 21 and moderate: 18) patients were included in our study. The median age was 8 [3, 11] years, median weight was 29.2 [11.9, 52.1] kilograms, 64% male gender, and 51% white race. The median duration of fever was 5 [4, 6] days with 79% having gastrointestinal symptoms and 56% having dermatological symptoms. Group A had 17 patients (mild: 11, moderate: 6) patients and Group B had 22 (mild: 10, moderate: 12) patients. There was no significant difference in demographic data, presenting symptoms, or severity of illness between the 2 groups. Group B patients had greater improvement in heart rate, mean blood pressure, LVEF and earlier resolution of fever as compared to group A (table 1). Likewise, Group B patients had greater improvement in most of the inflammatory markers after initiation of therapy as compared to group A (Table 2). 8 (47%) patients in Group A received additional corticosteroid therapy after 24 hours for persistent fevers, hypotension or low LVEF.

Conclusion: Our study results reveal that mild and moderately severe MIS-C patients treated with combined IVIg and corticosteroid therapy had greater improvement in clinical outcomes and inflammatory markers as compared to IVIg only.