Neutrophil-to-Lymphocyte Ratio as an Alternative Marker of Neonatal Sepsis in Developing Countries

Abstract

Objectives: We sought to analyze the neutrophil-to-lymphocyte ratio (NLR) as an alternative marker of neonatal sepsis. Methods: In this cross-sectional study, we undertook consecutive sampling in all inborn neonates admitted to the Neonatal Intensive Care Unit with clinical manifestations of neonatal sepsis. Neonates with congenital anomalies and referred neonates were excluded. Complete blood count, C-reactive protein (CRP), and blood culture were carried out as the septic workup examinations based on the local Clinical Practical Guidelines. NLR is obtained by dividing the absolute count of neutrophils from lymphocytes manually. A cut-off value of NLR is obtained using a receiver operating characteristic curve. Results: The median NLR value of the 104 neonates who met the inclusion and exclusion criteria was 3.63 (2.39–6.12). Neonates with NLR of 2.12 have the area under the curve of 0.630 (95% confidence interval (CI): 0.528–0.741) and 0.725 (95% CI: 0.636–0.814) when combined with CRP = 2.70 mg/dL. Neonates with NLR ≥ 2.12 in clinical neonatal sepsis had almost double the risk of providing positive blood culture results (relative risk = 1.867, 95% CI: 1.077–3.235; p = 0.011). Conclusions: NLR, calculated from complete blood count, can be used as an alternative marker of easy and relatively inexpensive neonatal sepsis, especially in developing countries, and detection of proven neonatal sepsis to be better when combined with CRP.

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