Interleukin-8 and neutrophils in the tracheobronchial aspirate at birth and the risk for the development of chronic lung disease of prematurity

We tested the hypothesis that preterm infants who develop chronic lung disease (CLD) have higher concentrations of interleukin-8 (IL-8) and higher neutrophil counts in the tracheobronchial aspirate at birth than those who do not develop CLD. The relationship between concentrations of IL-8 and neutrophil counts in the tracheobronchial aspirate at birth and the development of CLD was examined in 27 preterm infants. Concentrations of IL-8 were measured by specific immunoassay and neutrophil counts by cytospin analysis. Median concentrations of IL-8 and neutrophil counts in the tracheobronchial aspirate at birth were higher in preterm infants who developed CLD than in those who did not develop CLD (p < 0.005 for each). These differences persisted significantly after adjustments were made for the effects of gestational age at birth, the presence of respiratory distress syndrome and patent ductus arteriosus (p < 0.05 for each). The fetal pulmonary inflammatory response, as measured by increased IL-8 concentrations and neutrophil counts in the tracheobronchial aspirate at birth in preterm infants, might be a risk factor for the development of CLD. These results support the hypothesis that the lung impairment responsible for CLD in preterm infants might begin in the prenatal period.