Differentiating Multisystem Inflammatory Syndrome in Children (MIS-C) from Acute COVID-19 Using Biomarkers: Toward a

Carmen Loredana Petrea Cliveți1,2, Diana-Andreea Ciortea1,3, Gabriela Gurău1,2

  • 1Faculty of Medicine and Pharmacy, Research Center in the Medico-Pharmaceutical Field, "Dunarea de Jos" University of Galati, 800008 Galati, Romania.

Biomedicines
|February 27, 2026
PubMed

Insights

Multisystem inflammatory syndrome in children (MIS-C) has a distinct inflammatory signature compared to COVID-19. Routine biomarkers like CRP, NLR, and PLR can help differentiate these conditions in children.

Area of Science:

  • Pediatric immunology
  • Infectious disease diagnostics
  • Biomarker discovery

Background:

  • Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children presents with varied clinical symptoms.
  • Multisystem inflammatory syndrome in children (MIS-C) is a distinct hyperinflammatory condition.
  • Early differentiation between MIS-C and COVID-19 in pediatric patients is crucial.

Purpose of the Study:

  • To identify routine laboratory biomarkers for early discrimination between MIS-C and COVID-19 in children.
  • To establish a panel of biomarkers with high diagnostic accuracy.

Main Methods:

  • Retrospective comparative study of 144 pediatric patients.
  • Analysis using classical statistics, FDR correction, penalized regression, and machine learning.
  • Focus on routine laboratory tests for biomarker identification.

Main Results:

  • MIS-C exhibits a distinct inflammatory profile (elevated CRP, NLR, PLR; lymphopenia; electrolyte disturbances) compared to COVID-19.
  • Machine learning models (Random Forest) achieved high discrimination (AUC = 0.95) using a core set of biomarkers.
  • Key discriminatory thresholds identified: CRP ~3.7 mg/dL, NLR ~3.3, PLR ~376, potassium ~4.2 mmol/L.

Conclusions:

  • MIS-C is characterized by a specific and reproducible immunological signature differentiating it from COVID-19.
  • Identified biomarkers form a basis for developing simple clinical algorithms for pediatric triage and risk stratification.
  • A simplified scoring tool for emergency settings is a potential application.