Diagnostic biomarkers for late-onset sepsis in pediatric intensive care: a retrospective cohort study

This study explores the potential of various biomarkers to facilitate the differential diagnosis of late-onset sepsis (LOS) from non-LOS infections in hospitalized pediatric patients.

We conducted a retrospective cohort study using electronic medical records from our hospital from January 2022 to December 2023, and divided the patients into LOS (n = 178) and non-LOS (n = 159) groups. Data collected included demographic information, levels of inflammatory and metabolic biomarkers. Descriptive statistics were used for demographic data, and multivariable logistic regression followed by ROC curve analysis was used to assess the diagnostic value of these biomarkers.

Significant differences were observed in the levels of PCT, CRP, Lac, HBP, TNF-α, IL-6, IL-1β, IL-10, and IL-12 between the LOS and non-LOS groups (all p < 0.001). Multivariate logistic regression identified PCT, CRP, IL-6, IL-1β, IL-12, and Lac as independent predictors of LOS. ROC curve analysis showed high diagnostic values for PCT, Lac, and IL-1β. A combined diagnostic model of CRP, Lac, and IL-1β achieved the highest performance with an AUC of 0.958, sensitivity of 97.8%, and specificity of 91.8%. Additionally, Gram-negative LOS was associated with higher levels of PCT, CRP, and IL-6 compared to Gram-positive LOS. PCT levels demonstrated moderate diagnostic performance in differentiating LOS caused by Gram-positive vs. Gram-negative bacteria (AUC = 0.626).

The combination of CRP, Lac, and IL-1β serves as a robust set of biomarkers for the differential diagnosis of LOS in pediatric ICU settings. Furthermore, PCT also serves as a critical biomarker for differentiating between Gram-negative and Gram-positive bacterial causes, aiding in more targeted clinical management.