Neutrophil CD64 index (CD64in) is the best individual marker for bacterial sepsis in children, while in neonates the highest diagnostic accuracy at the time of suspected sepsis was achieved by LBP and 24 h later by CD64in.

In critically ill neonates aged under 48 h LBP on the first day of suspected infection is a better marker of sepsis than IL-6 and PCT, and is similar to CRP. In critically ill neonates aged over 48 h and children LBP is a better marker than IL-6 and CRP, and is similar to PCT.

In critically ill neonates and children LBP concentration on the first day of suspected sepsis is a better marker of sepsis than lipopolysaccharide, soluble CD14, procalcitonin, and in neonates younger than 48 h and children, also a better marker than C-reactive protein. Lipopolysaccharide and soluble CD14 are not suitable markers for the differentiation of infectious and noninfectious SIRS.

The physiological increase in PCT after birth and the impact of underlying disease make the interpretation of postoperative values in the immediate postnatal period difficult. IL-6 is a very sensitive marker of neonatal surgical injury with considerable variation between different types of surgery. IL-8 response after neonatal surgery is similar after all types of surgery, very rapid and transient with relatively low concentrations. CRP response to surgery is slow with persistence of elevated levels throughout the study period. IL-8 could potentially be a useful marker for monitoring infection in the immediate postoperative period in neonates.

Background: Intra-amniotic inflammation with preterm premature rupture of membranes (PPROM) is a risk factor for fetal inflammatory response syndrome (FIRS) and adverse neonatal outcome. Objectives: To evaluate the diagnostic accuracy of lipopolysaccharide-binding protein (LBP) for detecting FIRS in preterm neonates born after PPROM. Methods: This was a prospective study in the level III neonatal intensive care unit (42 neonates; 23 + 6 to 31 + 6 weeks' gestation) of mothers with PPROM. Umbilical cord blood concentrations of LBP, C-reactive protein (CRP), interleukin (IL)-6 and white blood cell count with differential were measured at delivery and 24 h after birth. Neonates were classified into FIRS (n = 22) and no FIRS (n = 20) groups according to clinical criteria and IL-6 level (≥17.5 pg/ml). Histological examination of the placenta and umbilical cord was performed. Neurological examination at 12 months' corrected age was performed. Results: Umbilical cord blood concentration of LBP was significantly higher in the FIRS group than in the no FIRS group at delivery (median 21.6 mg/l vs. median 2.3 mg/l; p < 0.0001) and 24 h after birth (median 17.2 mg/l vs. median 20.0 mg/l; p < 0.001). The area under the ROC curve for FIRS at delivery was 0.98 (95% CI 0.88-1.0) for LBP, 0.92 (95% CI 0.80-0.99) for CRP and 0.82 (95% CI 0.64-0.94) for immature to total neutrophil ratio. Similar results were obtained if FIRS was defined by funisitis. Umbilical cord blood concentration of LBP at delivery was significantly higher in neonates with abnormal neurological exam at 12 months than in those with normal exam (median 19.5 mg/l vs. median 3.75 mg/l; p < 0.015). Conclusions: In preterm neonates born to asymptomatic women with PPROM, LBP in cord blood at delivery is an excellent diagnostic biomarker of FIRS/funisitis with prognostic potential.