Study of some biological markers in cord blood of preterm and term infants and their association with neonatal sepsis

Introduction
Neonatal sepsis is the third leading cause of neonatal mortality, which occurs due to bacterial infection and is a major public health problem, especially in developing countries. Efforts to reduce the rates of infection in this vulnerable population are one of the most important interventions in neonatal care. This study aimed to compare the levels of biomarkers such as presepsin, procalcitonin, interleukin 6 (IL-6), fetuin, and CRP in cord blood between preterm and term infants and evaluate their association with neonatal sepsis.

Material and methods
A total of 176 infants were included in this study. Cord blood samples were collected from preterm (gestational age < 37 weeks) and term (gestational age ≥ 37 weeks) infants immediately after delivery. Umbilical cord blood was assessed for C-reactive protein (CRP), presepsin, procalcitonin, IL-6, and fetuin by using enzyme-linked immunosorbent assay (ELISA). The Pearson correlation coefficient test (r) was used to test for a positive or negative relationship between 2 (presepsin and fetuin) variables with CRP and procalcitonin. A receiver operating characteristic (ROC) analysis was executed to describe a cutoff value of the studied biomarkers.

Results
When compared to term newborns, preterm infants have considerably higher values for CRP, presepsin, procalcitonin, and IL-6. Elevated levels of presepsin, procalcitonin, and IL-6 in cord blood were significantly associated with an increased risk of neonatal distress in both preterm and term infants (p < 0.05). Fetuin levels showed a trend towards association with neonatal distress but did not reach statistical significant. A Pearson correlation study between CRP and presepsin and fetuin shows that CRP is positively correlated with presepsin; however, procalcitonin shows positive correlation with fetuin. Further, these results were confirmed with ROC analysis.

Conclusions
In early diagnosis of neonatal sepsis, compared with procalcitonin, presepsin and IL-6 seems to provide better early diagnostic value with consequent rapid therapeutic decision making and possible positive impact on neonatal prognosis. Elevated levels of these biomarkers are associated with risk of neonatal distress, highlighting their potential utility as early markers for identifying at-risk infants.