Umbilical cord blood level of interleukins used as a predictor of early-onset neonatal sepsis: a comprehensive review.

Neonatal sepsis (NS) is a major cause of morbidity and mortality in both preterm and term infants; early-onset NS (EONS) occurs in newborns within the first 72 h of life. Cytokines are messengers with low molecular weight that are produced by macrophages and lymphocytes in response to antigenic stimulations or products of inflammation. Different interleukins (IL) have higher values in EONS, when detected from peripheral venous blood. This review aims to analyze if the cytokines determined from the umbilical cord blood (UCB) of newborns may help in the rapid and accurate diagnosis of EONS in newborns originating from pregnancies with maternal-fetal infectious risk. Three databases, namely, PubMed, Scopus, and Web of Science, were searched for original research articles that assessed the relationship between interleukins and EONS. The search results retrieved a number of 18 articles that complied with the inclusion and exclusion criteria. Some studies report that neonates with EONS had higher umbilical plasma levels of cytokines such as IL-1ß, IL-6, IL-8, IL-10, IL-18, and IL-27. However, results are controversial, as many authors failed to establish the cut-off values of cytokines detected from UCB that may predict EONS. The main limitations of the current studies remain the small study samples, the heterogeneous population, and the lack of stratification of the studied population according to gestational age (GA). The cytokines that seem to be more accurate in the early diagnosis of EONS, as reported by the majority of the studies, are IL-6 and IL-8. The level of these cytokines may guide clinicians in the careful administration of antibiotics, thus aiding in the overall reduction of antimicrobial resistance.