[Pathogenesis of bronchopulmonary dysplasia].

Bronchopulmonary dysplasia of preterm infants has a multifactorial etiology. Pulmonary immaturity, oxygen toxicity, formation of oxygen radicals and mechanical lung trauma as well as additional factors (pulmonary hyperhydration, infection a.o.) may contribute to pulmonary damage. A pulmonary inflammatory reaction is thought to play a central role in the pathogenesis of chronic lung disease. It is characterized by the presence of inflammatory cells and various inflammatory mediators including proteases, chemoattractants, cytokines, leukotrienes and others. Due to the immaturity of several protective systems (antiproteases, antioxidants, surfactant system) the inflammatory response seems to be aggravated. Moreover, the magnitude and persistence of inflammation may eventually lead to pulmonary fibrosis.