PM2041: A Descriptive Study of Patients with Multisystem Inflammatory Syndrome in Children

Background: Multisystem inflammatory syndrome in children (MIS-C) occurs 2-6 weeks after infection with SARS-CoV-2. It is characterized by fever, GI symptoms, rash, conjunctivitis, cardiorespiratory symptoms, neurocognitive symptoms, and laboratory evidence of systemic inflammation. Infection with different COVID variants can result in MIS-C however it is unknown whether severity of MIS-C differs between the variants.

Methods: A retrospective chart review was performed to compare laboratory values for patients based on their level of care, treatments received, and length of hospitalization. The study included 55 patients (26 males, 29 females, mean age 8.5 years) with a diagnosis of MIS-C admitted to a single center between May 2020 and March 2022. The patients were diagnosed based on the CDC’s case definition for MIS-C. Patients were also compared according to the COVID variant that was dominant at the time of their infection (Table 1). The dominant variants were defined by the CDC's reported infection rates.

Results: Comparison of mean CRP, ESR, and ferritin values between patients admitted to the PICU (n=27) and those who were not revealed a significant elevation in ferritin values for patients admitted to the PICU (p=0.001) (Table 2). CRP and ESR values were not statistically significant (p=0.18 for CRP and p=0.29 for ESR). The proportion of patients admitted to the ICU did not differ by COVID variant, p=0.23 (Chi-Square).

Patients who required hemodynamic support (n=22) had a significant elevation in BNP compared to patients who did not require vasopressor support (p=0.006). The proportion of patients who required vasopressors did not differ by COVID variant, p=0.12 (Chi-Square). There was no significant difference in troponin value between patients who required hemodynamic support compared to those who did not (p=0.05). The proportion of patients with an elevated troponin did not differ by COVID variant, p=0.25 (Chi-Square).

There was a significant difference between the length of hospitalization for patients who received steroids within 24 hours of admission (n=35) compared to those that received steroids after 24 hours or did not receive steroids at all (p=0.02). The mean length of hospitalization was 6.3 days for patients who received steroids within 24 hours of admission and 9.0 days for those who did not.

Conclusion: This cohort of patients showed a significant elevation of serum ferritin in patients with more severe disease (admitted to the PICU) and patients treated early with steroids had a statistically significant shorter length of hospitalization. There was also a significant difference in elevation of BNP between patients who required hemodynamic support and those who did not. Biomarkers of disease severity did not differ by predominant COVID variant. This study is limited by small sample size and further research is required to evaluate differences in MIS-C severity between the COVID variants.