Diagnostic Value of Umbilical Cord Blood Interleukin-6 Level in Premature Infants with Early-Onset Sepsis

Objective: Early-onset sepsis (EOS) is a serious, grave, and frequently fatal condition in premature infants. This study aimed to assess the diagnostic value of interleukin-6 (IL-6) levels in umbilical cord blood for identifying EOS in preterm infants. Methods: This prospective cohort study was conducted on preterm infants between May 2019 and April 2021. Based on the diagnostic criteria for EOS, the participants were divided into EOS and non-EOS groups. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic efficacy of cord blood IL-6 levels for EOS. Results: The levels of IL-6 were significantly higher in the EOS group (n = 10) compared to the non-EOS group (n = 178) [617.5 pg/mL (323.3, 1579.8) vs. 49.7 pg/mL (15.8, 142.8), respectively; p = 0.000]. ROC curve analysis demonstrated that a cutoff value of 250.5 pg/mL for cord blood IL-6 yielded a sensitivity of 90%, specificity of 82%, and area under the curve of 0.876, with a confidence interval of 0.753-0.999, indicating its high accuracy as a diagnostic marker for EOS among preterm infants (p < 0.001). Conclusions: The detection of IL-6 in the umbilical cord blood offers convenience and exhibits significant diagnostic potential for EOS in preterm infants, thereby providing valuable support for clinical decision-making.