New insights into the pathogenesis of pulmonary inflammation in preterm infants.

Chronic lung disease (CLD) and bronchopulmonary dysplasia are associated with a significant inflammatory response of the airways and the interstitium of the lungs. Besides inflammatory cells, various cytokines, lipid mediators, proteolytic enzymes and toxic oxygen radicals may play an essential role in the pathogenesis of this disease. Intrauterine exposure to chorioamnionitis or proinflammatory cytokines has been shown to induce a pulmonary and systemic inflammatory response in the fetus. In this subgroup, antenatal infection may prime the lung such that minimally injurious postnatal events provoke an excessive inflammatory response in the airways and the pulmonary tissue. Inflammation and lung injury most certainly affect normal alveolization and pulmonary vascular development in preterm infants with CLD.