Cord blood interleukin-8 levels correlate with airway flow limitation at eight years of age in ex-very low birth weight infants

Background. Exposure to prenatal inflammation increases the risk for development of bronchopulmonary dysplasia. Aim. To evaluate the correlation between cord blood and gastric aspirate levels of interleukine-6 (IL-6) and interleukine-8 (IL-8) in preterm infants, and lung function at the age of 8 years. Methods. Between 2000-2002 we recruited 129 infants of gestational age < 30 wks. The concentration of IL-6 and IL-8 were measured in gastric aspirate and cord blood. At the age of 8 years, 30 ex-preterm infants, with mean gestational age of 27 wks and mean birth weight of 955 g, returned for pulmonary function measurement. To exclude major bias, a comparison between the study group and non-responder group was done and showed no statistically significant difference with respect to perinatal characteristics, ventilation days, bronchopulmonary dysplasia and cytokine concentration. Results. Pulmonary function test measurments in children born preterm were lower than in their term pairs. However, only the difference in forced mid-expiratory flow (FEF25-75%) was statisticaly significant. The concentration of IL-6 and IL-8 in cord blood and in gastric aspirate inversely correlated to all parameters of lung fuction at the age of 8 years, however only correlations between the concentration of IL-8 in cord blood and forced expired volume in one second/forced vital capacity (FEV1/FVC) (r = -0.38, p = 0.04) and FEF 25%-75% (r = -0.44, p = 0.02) were statistically significant. Conclusion. These results show a negative correlation between the concentration of IL-8 in cord blood and FEF25%-75% and FEV1/FVC, which suggests the important role of IL-8 in early airway remodeling. IRENA ŠTUCIN GANTAR ( ) LILIJANA KORNHAUSER CERAR •