Performance of Interleukin-27 Cord Blood Level as A Biomarker Predicating Early Onset Neonatal Sepsis

Overview

Neonatal sepsis still considered as one of the major causes of mortality and morbidity during the neonatal period due to high vulnerability of that age group. The blood culture is considered as the gold standard for diagnosis of bacterial sepsis, however in early onset neonatal sepsis (EONS) the inability to isolate a microbial pathogen does not exclude sepsis. The reason behind the high number of culture-negative cases is not clear and might be attributed to low levels of bacteremia or small volumes of blood obtained from sick infants. Also maternal antibiotic treatment before or during delivery may theoretically mask detection of bacteremia in the newborn. In addition these cultures have a 48-72 hours delay to obtain results. Therefore, the combination of clinical assessment and laboratory biomarkers currently are the bases for diagnosis of neonatal sepsis. Recently interleukin-27 (IL-27) has been looked at as another candidate biomarker in the serum for diagnosis of sepsis in both adult and children. Interleukin-27 (IL-27), a novel member of the IL-12 family, was first discovered in 2002. IL- 27 is primarily synthesized by antigen-presenting cells, and it is widely expressed in a myriad of cells, including placental trophoblast cells. Although multiple studies have reported IL-27 as an essential regulator of immune response and inflammation, its precise role in the immune response is still disputable. Conventionally, IL-27 has been envisaged as a potent promoter of inflammation. When first discovered, it was characterized as a promoting factor in the rapid initiation of inflammatory responses, processing the ability to stimulate the rapid expansion of naïve CD4+T and then the production of IFN-?, which has been demonstrated by various subsequent studies. The aim of this study was to evaluate the usage of elevated IL-27 in cord blood as an early predictor biomarker for EONS.

A prospective study will be conducted in the neonatal intensive care unit (NICU), Mansoura University Children Hospital -over a period of one year. The study subjects will include all newborn infants born to pregnant women with one or more of antenatal risk factors for sepsis including maternal fever, prolonged rupture of membranes with leakage of amniotic fluid preceding the onset of labor for 18 hours or more, presence of chorioamnionitis or evidence of maternal colonization with group B streptococcus (GBS). Prematurity was defined as gestational age of 36+6 weeks and less. Blood samples for biomarkers detection will be collected from the umbilical artery after clamping the umbilical cords before delivery of the placenta. The blood will be collected in ethylene diamine tetra-acetic acid-containing tubes from each infant for immunological detection of IL-27, procalcitonin and C-reactive protein. For neonatal blood culture, blood samples will be collected from each neonate, before starting any antimicrobial treatment, by venous puncture from a peripheral vein for blood culture. About 1 mL of blood will be directly inoculated into a pediatric blood culture bottle and sent to the Medical Microbiology and Immunology Department, Mansoura University, Egypt for subsequent microbiological processing. Obtained bacterial isolates will be identified by standard microbiological techniques