Serum zinc dynamics as a diagnostic and immunomodulatory biomarker in neonatal sepsis

This study aimed to investigate serum zinc levels in term neonates with sepsis, evaluate its correlation with immune parameters, and assess zinc's diagnostic efficacy in identifying neonatal sepsis. A prospective cohort study was conducted, involving two groups: 52 neonates diagnosed with sepsis who were admitted to the neonatal intensive care unit (NICU) of our hospital between January 2022 and June 2023, and 50 healthy controls matched for gestational age and birth weight. Serum zinc levels, cytokine profiles, and C-reactive protein (CRP) were measured in both cohorts. No statistically significant differences were observed in baseline characteristics between the sepsis group (n = 52) and the healthy controls group (n = 50). Neonates with sepsis exhibited significantly lower serum zinc levels compared to controls (52.6 ± 17.4 µg/dL vs. 83.2 ± 21.4 µg/dL, P < 0.05), alongside markedly elevated pro-inflammatory cytokine levels (interleukin-6 [IL-6], interleukin-8 [IL-8], interleukin-10 [IL-10], and interleukin-12 [IL-12]). Spearman correlation analysis revealed significant associations: serum zinc levels showed a strong negative correlation with IL-6 (r = -0.510, P < 0.05) and IL-8 (r = -0.625, P < 0.05), while a positive correlation was observed with IL-12 (r = 0.627, P < 0.05). Receiver Operating Characteristic (ROC) curve analysis demonstrated serum zinc's moderate diagnostic utility for neonatal sepsis (area under the curve [AUC] = 0.812, P < 0.0001), with a sensitivity of 78% and a specificity of 76.9%, respectively. These findings highlight zinc's potential role in sepsis pathophysiology and diagnostic utility, despite its inferior performance compared to CRP (AUC = 0.865, P < 0.0001). Our findings demonstrate an inverse correlation between serum zinc levels and inflammatory response intensity in neonatal sepsis. Zinc deficiency may serve as a diagnostic biomarker, given its significant negative association with pro-inflammatory cytokine profiles (IL-6, IL-8, and IL-12) and its moderate predictive accuracy for disease detection.