Abstract

Background: Pediatric pneumonia remains a leading cause of childhood morbidity and mortality worldwide. Traditional biomarkers have limitations in predicting disease severity and outcomes. This study evaluated the diagnostic and prognostic value of non-classic biomarkers in pediatric pneumonia.

Objective: To assess the utility of  neutrophil CD64 expression, neutrophil-to-monocyte CD64 ratio, neutrophil-to-lymphocyte CD64 ratio in pediatric pneumonia diagnosis and prognosis.

Methods: A case-control study was conducted at Assiut University Children's Hospital including 60 children with pneumonia and 60 age-matched healthy controls. Clinical assessments, routine laboratory investigations, and flow cytometric analysis were performed. Cases were evaluated using the Clinical Respiratory Score and followed for outcomes including ICU admission, mechanical ventilation, and mortality. Receiver operating characteristic (ROC) curve analysis determined diagnostic performance.

Results: The non-classic biomarker showed significant differences between cases and controls (p<0.001). Neutrophil CD64 (692.67±326.26 vs. 359.84±57.48), and CD64 ratios were significantly elevated in cases. Biomarkers correlated significantly with disease severity, prolonged hospitalization, ICU admission, and mechanical ventilation. Fatal cases demonstrated markedly elevated inflammatory markers. ROC analysis revealed excellent diagnostic performance, with neutrophil-to-lymphocyte CD64 ratio showing superior accuracy (AUC=0.97, sensitivity=90%, specificity=99%).

Conclusion: Non-classic biomarkers demonstrate significant diagnostic and prognostic utility in pediatric pneumonia. These findings support their integration into clinical practice for improved risk stratification, treatment decision-making, and outcome prediction in children with pneumonia.