Diagnostic Accuracy of Presepsin, sMR, and Established Inflammatory Biomarkers in Critically Ill Children with Sepsis or Systemic Inflammatory Response Syndrome

Background: Pediatric sepsis is a life-threatening emergency and remains complex to diagnose promptly due to the absence of universally reliable biomarkers. C-reactive protein (CRP) and procalcitonin (PCT) are widely used but have limited effectiveness. We evaluated the diagnostic reliability of presepsin and soluble mannose receptor (sMR) and identified optimal biomarker combinations for distinguishing sepsis from non-infectious systemic inflammatory response syndrome (SIRS) in children. Methods: A total of 80 children were enrolled in this prospective study, including 53 consecutive admissions to the pediatric intensive care unit (PICU) (sepsis, n = 42; non-infectious SIRS, n = 11) and 27 healthy controls. The serum levels of new biomarkers presepsin and soluble mannose receptor (sMR) levels were quantified by ELISA methods and their diagnostic reliability (both individually and combined with CRP and PCT) was assessed using receiver operating characteristic (ROC) curves and multivariate logistic regression. Results: Significantly higher concentrations of all measured markers were found both in septic and other critically ill patients than in healthy controls (p < 0.05). No single biomarker reliably differentiated sepsis from non-infectious SIRS. The sMR + CRP + PCT combination demonstrated the highest diagnostic accuracy (AUC = 0.78, p = 0.0007), surpassing the CRP + PCT model (AUC = 0.71, p = 0.0087). Conclusions: The addition of sMR to the established markers CRP and PCT improves the diagnostic effectiveness in pediatric sepsis. Larger multicenter studies are warranted to confirm clinical utility.