Nuclear factor κB activation in pulmonary leukocytes from infants with hyaline membrane disease:: Associations with chorioamnionitis and Ureaplasma urealyticum colonization

Unresolved pulmonary inflammation in hyaline membrane disease (HMD) may be a precursor to the development of chronic lung disease of early infancy. We investigated whether nuclear factor kappa B (NF-kappa B), a transcription factor that regulates the inflammatory process, is activated in pulmonary leukocytes in tracheal aspirates from premature infants with HMD. A total of 172 samples were obtained from 59 infants, two thirds of whom showed NF-kappa B activation in lung neutrophils and macrophages on at least one occasion. Infants who had activated NF-kappa B showed elevated tumor necrosis factor-a concentrations in their tracheal aspirates. These infants also required a longer period of mechanical ventilation support. Almost half of the infants with HMD had antenatal exposure to chorioamnionitis on the basis of placental histopathologic examination. These infants had evidence of activated NF-kappa B and elevated cytokines and were more likely to have Ureaplasma urealyticum colonization in their airways. Together, these observations suggest that NF-kappa B activation in pulmonary leukocytes may be involved in the lung inflammatory process in infants with HMD.