Bronchoalveolar inflammation following airway infection in preterm infants with chronic lung disease

Chronic lung disease (CLD) of the newborn is associated with pulmonary inflammation. However, the origin of this inflammation is not known. We evaluated the impact of airway infection on bronchoalveolar inflammation in mechanically ventilated preterm infant at risk for CLD (n = 68). Mean and maximum concentrations of the inflammatory mediators (IM) interleukin-1 and interleukin-8 were assayed in the tracheobronchial aspirate fluid (TAF) of neonates with perinatal airway infection (Ureaplasma urealyticum, or bacteria), postnatal nosocomial airway infection, or respiratory disease without airway infection from days 1-10 of postnatal age. Patients with CLD (n = 23;) exhibited increased levels of IM in TAF compared to neonates without CLD. Within the three subgroups, concentrations of IM were increased in CLD patients with perinatal infection and in CLD patients with respiratory disease without airway infection, but not in CLD patients with nosocomial airway infection. Although airway colonization with Gram-negative bacteria was more frequently found in CLD patients within the first month of life, there were no differences between levels of IM in patients colonized with Gram-negative bacteria or coagulase-negative staphyloccoci. We conclude that perinatal infections with Ureaplasma urealyticum or bacteria and respiratory disease without infection, but not nosocomial airway infection, contribute to the bronchopulmonary inflammatory response in neonates with CLD.