Role of ratios of neutrophil and monocyte to lymphocyte and red cell distribution width to platelet in the detection of early onset neonatal sepsis in comparison with serum C-reactive protein

Introduction and Aim: Early onset neonatal sepsis (EONS) is a preventable cause of neonatal mortality and morbidity. Blood culture, the current gold standard has a turn-around time of 48 to 72 hours and high false negatives. Thus, there is a need for reliable biomarkers for its early detection. The present study aims to find the utility of ratios derived from components of complete blood count in detecting EONS. Materials and Methods: The laboratory investigations of neonates with and without clinical sepsis were recorded using purposive convenience sampling technique. The total leucocyte count, absolute neutrophil count, C-reactive protein (CRP) and ratios of blood counts were compared by Mann Whitney test. Their performance was then analysed by receiver operating characteristic analysis. Results: A total of 196 neonates aged 0 to 3 days were considered for the study, out of which 98 cases were study group. Serum CRP and red cell distribution width to platelet (RPR) ratios were found to have statistical significance, albeit low sensitivity and specificity in detection of EONS. Positive correlation of RPR was found with CRP (p value=0.001). The area under the curve for CRP and RPR was 0.661 and 0.628 respectively. However, there was no statistical significant difference in neutrophil and monocyte to lymphocyte ratios between the study and comparative groups. Conclusion: In the background of low yield of culture positivity and its longer turnaround time, RPR can be used as a reliable biomarker in the diagnosis of EONS in conjunction with CRP.