Serum IL-6, IL-10, TNF-α and IFN-γ bio-signature for neonatal sepsis diagnosis and treatment outcome

BackgroundDiagnosing sepsis in preterm neonates is a significant challenge, underscoring the urgent need for timely and accurate methods. Serum inflammatory protein signatures show promising potential for early and precise disease diagnosis. MethodsIn this study, a cohort of preterm neonates (n=50, 25-35 weeks gestation, female 40%) at the time of suspicion and follow-up were enrolled along with healthy neonates. Based on clinical presentation and blood culture or MALDI results, the sepsis suspicion cases were categorized into culture-positive (CP)/culture-negative (CN) sepsis (n=13 each) or no-sepsis (NS, n=12) and compared with healthy controls (HC, n=12) from similar settings. These sub-groups (CP, CN, and NS) were followed up till completion of antibiotic therapy. Serum inflammatory proteins and trace elementals (57Fe, 66Zn, 63Cu, 77Se, 44Ca, 24Mg) were profiled using the Olink(R) Target 96 inflammation panel and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Serum proteins with log2fold changes>{+/-}1.3 and p<0.05 were identified as differentially expressed proteins (DEPs) and monitored in the follow-up samples receiving treatment. Elements showing significant differences (p<0.05) between the study groups were also identified for correlation analysis. ResultsSerum inflammatory protein levels showed group-specific trends. Significantly higher serum IL-6, IL-10, TNF- and LIF levels with low IFN-{gamma} and CCL28 were observed in the CP sepsis group compared to HC. CN group also showed reduced serum IFN-{gamma} along with CXCL10 and CCL11 levels when compared to HC. Also, the serum IL-6 level in CP cases was positively correlated with IFN-{gamma} and IL-10 levels (r<0.77, p<0.05), and an increased IL6:IFN-{gamma} was observed in the CP, CN and NS groups compared to the HC. Serum of NS patients showed higher FGF-23 levels with lower IFN-{gamma} and CCL11 than HC. Upon recovery, the serum IL-6 levels reached normal levels in CP, whereas the CN group showed IFN-{gamma}, CXCL10, and CCL11 levels returned to normal. Serum iron levels were significantly reduced in both the CP and CN groups, while serum selenium was low in the CP group and serum copper was lower in the CN group, with all levels returning to normal upon recovery. ConclusionsAbsolute levels of IL-6, IL-10, IFN-{gamma}, and TNF- in serum can be used as biosignatures for neonatal sepsis, offering the potential for early disease diagnosis and monitoring therapeutic response. Additionally, these markers implicated in disease resolution mechanisms might serve as therapeutic targets in sepsis treatment.