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

Background: Sepsis in children is a life-threatening condition that continues to be a serious challenge in emergency and intensive care medicine due to the lack of universal, rapid, and highly reliable diagnostic methods. Although C-reactive protein (CRP) and procalcitonin (PCT) are widely used in clinical practice, their effectiveness is limited. Objective: To evaluate the diagnostic reliability of presepsin and soluble mannose receptor (sMR) by determining the most effective combinations of biomarkers for distinguishing sepsis from non-infectious systemic inflammatory response syndrome (SIRS) in children. Methods: A prospective study was conducted among 80 children hospitalized in a pediatric intensive care unit and divided into three groups: septic (n=42), critically ill with non-infectious SIRS (n=11), and control (n=27). Presepsin and sMR levels were assessed using standard and ELISA methods. ROC analysis and multiple logistic regression were used to determine the diagnostic efficacy of each marker and their combinations, including the established biomarkers CRP and PCT. Results: All biomarkers studied showed a statistically significant increase in septic and critically ill patients compared to the control group (p<0.05). None of them showed a statistically significant advantage in distinguishing between patients with sepsis and those with non-infectious SIRS. The combined model sMR + CRP + PCT (AUC=0.78, p=0.0007) showed the highest discriminatory ability. In comparison, CRP + PCT showed lower efficacy (AUC=0.71, p=0.0087), but retained its established diagnostic value. Conclusion: The combined biomarker approach demonstrates an advantage over the use of individual markers alone. The addition of sMR to the established markers CRP and PCT improves diagnostic accuracy in pediatric sepsis. Further validation in larger cohorts is needed.