Assessment of serum interleukin-35 as a diagnostic biomarker of neonatal early-onset sepsis

Neonatal sepsis is a life-threatening disorder among infants, which is associated with high morbidity and mortality. In recent years, although the management of newborns has improved, early diagnosis and treatment of neonatal early-onset sepsis (NEOS) are the major challenges for neonatologists in Neonatal intensive care units (NICUs). We assessed the diagnostic value of interleukins-35 (IL-35) in diagnosis of NEOS. A prospective process evaluation study was carried out in the NICU of Akbar-Abadi and Ali-Asghar Hospitals affiliated to Iran University of Medical Sciences from 2017 to 2018. Eighty hospitalized neonates with clinical suspicion of sepsis in the first 72 h of life entered the study by convenience or accidental sampling. Routine hematology tests regarding sepsis diagnosis were performed after admission. All subjects were assigned into two groups: newborns with proven sepsis and newborns with suspected sepsis. IL-35 levels in septic and unlikely infected hospitalized newborns were measured using Elisa Kit (ZellBio GmbH. Cat. No; ZB-10042C-H9648, Human Interleukin 35), and the results were compared. The mean IL-35 in serum samples from septic neonates was significantly higher than this variable in samples from unlikely infected newborns (13.41 ± 2.4 vs. 9.02 ± 2.6 pg/ml; p < 0.0001). The area under receiver-operating characteristic (ROC) curve for IL-35 was 0.895 (CI 95% = 0.826–0.963; p = 0.0001). The result of study showed serum IL-35 had a moderate accuracy (AUC = 0.895) for the diagnosis of NS. Therefore, serum IL-35 could be suggested as a predictive biomarker in neonatal early-onset sepsis. Further studies with larger sample size are strongly suggested.