Abstract:

Objective: To determine postnatal changes in neonatal serum concentrations of interferon-γ (IFN-γ), interleukin-4 (IL-4) and its soluble receptor (sIL-4R). Methods: Forty-five healthy term neonates, 25 of the neonates' mothers and 27 healthy adults (controls) participated in the study. Cytokine concentrations were measured in blood samples from the umbilical cord, from the neonates on the 1st and 5th day after birth, from mothers and from controls. Results: IFN-γ concentrations were significantly lower in the umbilical cord, compared to concentrations in the controls (p < 0.04), and increased significantly from the umbilical cord to levels in neonates on day 5 (p < 0.03). In mothers and the umbilical cord, IFN-γ concentrations were dependent on the mode of delivery, being higher after vaginal delivery than after elective Cesarean section (p < 0.005; p < 0.006, respectively). IL-4 concentrations in the umbilical cord for 1-day and 5-day neonates were significantly elevated compared to those in mothers (p < 0.001; p < 0.0007; p < 0.0001, respectively) and controls (p < 0.05; p < 0.01; p < 0.006, respectively). sIL-4R concentrations in all neonatal samples were significantly elevated compared to those in controls (p < 0.0001), the highest being found in 1-day-old neonates. A strong negative correlation was found between IL-4 and sIL-4R concentrations in 1- and 5-day-old neonates (r = -0.48, p < 0.002; r = -0.45, p < 0.0065, respectively). Moreover, IFN-γ/IL-4 ratio increased significantly from the umbilical cord to 5 days of life (p < 0.03). Conclusions: Our findings indicate an earlier development of IL-4 than IFN-γ, which could be viewed as a developmental characteristic in the ontogeny of the immune system.