Evaluation of Neutrophil-To-Lymphocyte Ratio, Platelet-To-Lymphocyte Ratio and Procalcitonin in Early Onset Neonatal Sepsis At A Tertiary Care Center In India

Abstract

Background:
Early-onset neonatal sepsis (EONS) is a major cause of neonatal morbidity and mortality, particularly in low- and middle-income countries where early diagnostic facilities are limited. Simple and rapid biomarkers are needed for early identification of neonatal sepsis. The present study aimed to evaluate the predictive role of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and procalcitonin (PCT) in diagnosing EONS.

Materials and Methods:

This prospective observational cross-sectional study was conducted in the Department of Pediatrics, of a tertiary care hospital of North India. A total of 120 neonates with suspected early-onset sepsis within the first 72 hours of life were enrolled. Clinical evaluation, complete blood count, blood culture, and procalcitonin levels were assessed. NLR and PLR were calculated from routine hematological parameters.

Results:
Among the 120 neonates studied, 14 (11.7%) were diagnosed with EONS. Septic neonates showed significantly higher mean NLR (4.62 ± 1.48) and PLR (84.0 ± 53.0) compared to non-septic neonates (1.92 ± 0.87 and 61.9 ± 26.1 respectively). Mean procalcitonin levels were also significantly elevated in the sepsis group (7.2 ± 3.4 ng/mL) compared with the non-sepsis group (4.64 ± 7.66 ng/mL). ROC analysis demonstrated that PCT had the highest diagnostic accuracy with an area under the curve (AUC) of 0.788, followed by NLR (AUC 0.678) and PLR (AUC 0.644). The optimal cut-off values identified were 6.49 ng/mL for PCT, 3.23 for NLR, and 67.2 for PLR. At these thresholds, PCT showed sensitivity of 71.4% and specificity of 79.2%, while NLR and PLR demonstrated moderate diagnostic performance.

Conclusion:
Neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and procalcitonin are useful biomarkers for early detection of neonatal sepsis. Among these, procalcitonin showed the highest diagnostic accuracy, while NLR and PLR offer inexpensive and easily available screening tools derived from routine blood tests.