Background: Early-onset sepsis remains a common and serious problem for neonates. The neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) are easily accessible biomarkers that have been reported to have meaningful correlations with inflammatory markers and some diseases severity in adult trials.
Objectives: We aimed to evaluate the neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and procalcitonin as a diagnostic adjunct tests for early detection of neonatal early-onset sepsis (EOS).
Patients and Methods: This study was carried out on 60 term infants at the Neonatal Intensive Care Unit (NICU) of Al-Hussien University Hospital. They were divided into two groups: Group A (patients group) which included thirty term AGA neonates, suffering from EOS and group B (controls group) which included thirty healthy term AGA neonates. Neonates with prematurity, postmaturity, small for gestational age (SGA), large for gestational age (LGA), multiple pregnancies, major congenital anomalies, cyanotic congenital heart disease, negative values of together C-reactive protein (CRP), and procalcitonin, and neonates who had mothers with hypertension or preeclampsia, diabetes mellitus (pre-existing or gestational)and tobacco use during pregnancy were excluded. History-taking, complete clinical examination, chest x-ray, blood culture, complete blood count (CBC), C-reactive protein (CRP), procalcitonine level, immature to total neutrophil ratio (I/T ratio), neutrophil/lymphocyte ratio ( NLR) and platelet/lymphocyte ratio (PLR) were done.
Results: There were no significant differences between the study groups regarding age, gender, mode of delivery, GA, BW, length and HC. As regard vital data, patients group had higher RR, HR and SPO2. Respiratory distress and tachycardia were the most common clinical signs of EOS. There was a significant difference between patients and controls as regard platelet count and I/T ratio. Patients group had significantly higher absolute neutrophil counts, NLR, PLR, C-reactive protein, and procalcitonin levels compared with the controls group. As regard blood culture, Klebsiella was the most common organism followed by Staphylococcus aureus. An NLR of 2.52 was determined as the predictive cutoff value of neonatal EOS (sensitivity 96.7%; specificity 100%; P=0.001). A PLR of 47.4 was determined as the predictive cutoff value of neonatal EOS (sensitivity 90.0%; specificity 100%; P=0.001). Procalcitonin (PCT) showed a sensitivity of 96.7 % and specificity 100% at a cut-off point of 1.04 ng/mL. I/T ratio, at a cut-off value at (0.12), had sensitivity of 76.7% and specificity of 96.7%. CRP, at a cut-off value at (5), had sensitivity of 100% and specificity of 96.7%.
Conclusion: Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), I/T ratio, serum CRP and procalcitonin levels had high sensitivity and specificity as diagnostic markers for early-onset neonatal sepsis.