The Use of Absolute Neutrophil Count and Neutrophil-Lymphocyte Ratio as Predictors of Early Onset Neonatal Sepsis.

Background: Neonatal sepsis contributes to significant morbidity and mortality. Blood culture, the gold standard in its diagnosis, has low sensitivity and is affected by multiple factors. Hence the need for markers derived from routine tests to improve diagnosis deserves further studies. Objectives: This study aims to determine the association and optimal cut-off value and diagnostic performance of absolute neutrophil count (ANC) and neutrophil lymphocyte ratio (NLR) with early-onset neonatal sepsis in term neonates. Methodology: This was a retrospective, analytical, single-center study of admitted patients from January 2016 to December 2021. Clinical factors were analyzed and NLR and ANC were derived from CBC and interpreted using the Manroe chart. Results: Included were 200 neonates with a median birth AOG of 38 weeks. Microorganisms were isolated from nine of 154 neonates with blood culture, corresponding prevalence of 5.84% (95% CI 2.71–10.80). Initial CBC showed elevated mean WBC and 76.5% of neonates were considered to have elevated ANC. Optimal cut-off point of NLR for detecting culture-proven sepsis was 2.86, with a sensitivity of 88.89% (95% CI, 51.75–99.72%) and specificity of 36.55% (95% CI, 28.72–44.95%). The ANC gave the best balance of sensitivity and specificity with an accuracy of 75.50%. Conclusions: The NLR demonstrated good discriminative ability for predicting clinical neonatal sepsis based on ANC. However, individually or simultaneously, these markers demonstrated poor discriminative ability for culture-proven neonatal sepsis in term neonates. ANC and NLR can be used to aid in the diagnosis of clinical neonatal sepsis.