1 www.gjmedph.com Vol. 15, No.4, 2026 ISSN# 2277-9604 Role of serum inflammatory biomarkers in diagnosis and therapeutic follow-up of neonatal sepsis: a longitudinal study from eastern India

Abstract

Objectives: The study aimed to compare levels of serum inflammatory biomarkers (CRP, PCT and IL-6) on Day 0,1 and 7 of intravenous antibiotic administration. It also measured their sensitivity, specificity, and predictive values in relation to blood culture in clinically suspected patients of neonatal sepsis.
Methods: An institution based, descriptive study with longitudinal study design was conducted over a period of 12 months at a tertiary care institute in eastern India. Neonates presenting with clinically suspected neonatal sepsis, fulfilling the inclusion criteria were included after informed written consent from parents. The study population was divided into 4 categories according to sepsis score and median levels of serum biomarkers were compared across the groups on day 0,1 and 7. Diagnostic accuracy: The data was tabulated in Microsoft excel and analysed with SPSS V.24 software. Sensitivity, specificity, positive predictive value, negative predictive value, and Receiver operating characteristic (ROC) curve analysis were done. A p-value of <0.05 was considered statistically significant for all tests performed. Therapeutic follow-up: The data was tabulated in Microsoft excel spreadsheets and analysed with Jamovi 2.7.3. The normality of data was tested by Shapiro-Wilk test. As the data was not normally distributed, Friedman Rank by Analysis of variance (ANOVA) was applied for statistical analysis of biomarkers (on Day 0, Day 1 and Day 7). Chi-square/ Fischer exact test was done for statistical analysis of categorical variables. A p value of <0.05 was considered statistically significant.
Results: IL-6 was found to have higher sensitivity and specificity than PCT and CRP. ROC curve analysis showed statistically significant association (p value < 0.001). The median score of each biomarker was decreased with administration of antibiotics. Friedman Rank by ANOVA test showed significant statistical association (p value
<0.05) of biomarkers (IL-6, PCT, CRP) at Day 0, Day 1 and Day 7 with antibiotic administration. Significantly higher median values of biomarkers (p value < 0.001) on day 7 were recorded in patients requiring any intervention- antibiotic upgradation, inotropes, mechanical ventilation, NICU transfer.
Conclusion: Procalcitonin and Interleukin-6 help in early diagnosis of neonatal sepsis and facilitate timely initiation of antibiotics. C-reactive protein should be used in conjunction with PCT/IL-6 in cases with clinical symptoms of sepsis but negative CRP to prove sepsis. IL-6 and PCT levels help in monitoring response to therapy, thus they can be used to avoid prolonged use of unnecessary antibiotics and reduce hospital stay.