Multisystem Inflammatory Syndrome of Children: Subphenotypes, Risk Factors, Biomarkers, Cytokine Profiles, and Viral...

Area of Science:

• Pediatric infectious diseases
• Immunology
• Genomics

Background:

• Multisystem inflammatory syndrome in children (MIS-C) is a serious post-infectious complication.
• Understanding MIS-C's diverse clinical presentations and underlying mechanisms is crucial for effective management.

Purpose of the Study:

• To characterize demographic, clinical, and biomarker features of MIS-C.
• To compare MIS-C sub-phenotypes and identify cytokine biosignatures.
• To analyze viral genome sequences in MIS-C patients.

Main Methods:

• Prospective observational cohort study of 124 children (63 MIS-C, 61 controls).
• Analysis of clinical data, cytokine levels (IL-2, IL-10, IL-6, TNF-α, IL-17), viral load (cycle threshold), and viral genome sequences.
• Comparison of MIS-C patients with controls and across MIS-C sub-phenotypes.

Main Results:

• Black and Latino children were over-represented in the MIS-C cohort, with Black children at higher risk.
• Critically ill MIS-C patients had more frequent cardiac complications, including systolic myocardial dysfunction and valvular regurgitation.
• Elevated cytokines (IL-2 receptor, IL-10, IL-6) were observed in MIS-C patients; specific cytokine patterns correlated with disease severity and cardiac involvement.
• Viral load was lower in MIS-C cases compared to primary SARS-CoV-2 infection; viral sequencing showed GH clade predominance without differences between MIS-C and COVID-19 patients.

Conclusions:

• This study provides a well-characterized cohort of MIS-C patients, detailing key clinical, biomarker, and cytokine features.
• Cytokine profiles and viral load offer insights into MIS-C pathogenesis and sub-phenotypes.
• Long-term follow-up is essential for understanding MIS-C sequelae.