Diagnostic Value of Immature to Total Neutrophil Ratio, C-reactive Protein and Clinical Parameters in Early Detection of Neonatal Sepsis: A Cross-sectional Study

Introduction: Neonatal sepsis remains a major cause of neonatal morbidity and mortality worldwide, particularly in resource-limited settings where advanced diagnostic facilities are not readily available. The condition often presents with subtle and non specific clinical features, making early recognition and timely initiation of treatment challenging. Although blood culture is considered the gold standard for diagnosis, its delayed reporting time and limited sensitivity may hinder prompt clinical decision-making. Therefore, readily available clinical and haematological markers are essential for early identification and risk stratification of affected neonates. Aim: To explore the relationship between Immature to Total neutrophil ratio (IT ratio), C-reactive Protein (CRP), clinical features, laboratory findings and blood culture positivity for early diagnosis of neonatal sepsis. Materials and Methods: A cross-sectional study was conducted in the Neonatal Intensive Care Unit (NICU) of the Department of Paediatrics at SMBT Institute of Medical Sciences and Research Centre (IMS & RC), located in Dhamangaon, Igatpuri, Nashik, Maharashtra, India from March 2025 to August 2025, including 92 neonates with suspected sepsis. Complete blood count (CBC), I/T ratio, CRP, and blood culture were evaluated. Chi-square test, Fisher’s-exact test, and logistic regression analysis were performed. A p-value <0.05 was considered statistically significant. Results: The study included 92 neonates, of whom 25 (27.17%) were female and 67 (72.83%) were male. Blood culture was positive in 36 neonates (39.13%). Significant associations with culture positivity were observed for I/T ratio >0.2 (p-value<0.001), CRP, abnormal Total Leucocyte Count (TLC), low Absolute Neutrophil Count (ANC), and thrombocytopenia. Among clinical parameters, abdominal distension (χ2=24.85; p-value<0.001), low birth weight (χ2=19.63; p-value=0.0002), prolonged Capillary Refill Time (CRT) (χ2=9.05; p-value=0.02), direct hyperbilirubinemia (χ2=16.02; p-value<0.001), and lower gestational age (χ2=22.2; p-value<0.001) were significantly associated with culture positivity. Hyperglycaemia, hypoglycaemia, increased gastric residue, need for inotropic support, metabolic acidosis, mottling, and sclerema also showed significant associations. On multivariate logistic regression, I/T ratio, CRP, Ionotropic support, Sclerema and TLC remained independent predictors of blood culture positivity. Conclusion: For early detection of sepsis IT ratio is useful parameter along with TLC, ionotropic support, sclerema and CRP and has significant association with culture positivity.