Correlation of Immunological Biomarkers and Severity of Pneumonia in Pediatric Patients

Among children under five, pneumonia stands as a major contributor to both illness and death, creating a significant challenge for global health efforts. This study aimed to evaluate the correlation between radiological severity, clinical parameters (such as fever and oxygen saturation), and laboratory markers (including CRP levels, white blood cell count, and the neutrophil-to-lymphocyte ratio) in pediatric patients with pneumonia. A retrospective analysis was conducted on 51 hospitalized children with severe pneumonia admitted to Al Mansour Pediatric Hospital in Baghdad from July 2024 to February 2025. The results revealed a strong association between radiologic severity and clinical indicators, with higher fevers and lower oxygen saturation levels observed in more severe cases. CRP levels showed a moderate positive correlation with pneumonia severity, while bacterial infections were associated with significantly higher CRP levels compared to viral or unknown causes. White blood cell count progressively increased with disease severity, reinforcing its role as a supportive marker. Notably, the neutrophil-to-lymphocyte (N-L) ratio emerged as a highly effective predictor of pneumonia severity, with a cut-off value of 18.5 ensuring high sensitivity (84.6%) and specificity (93.0%). These findings underscore the importance of integrating these biomarkers into clinical assessments for early identification and timely intervention in severe pediatric pneumonia cases. The study highlights the potential of the N-L ratio as a simple yet powerful tool to improve patient outcomes and calls for further research to validate these findings in larger cohorts.