Natural surfactant combined with beclomethasone decreases lung inflammation in the preterm lamb.

Background: Natural surfactant combined with beclomethasone decreases pulmonary oxidative stress in preterm lambs with respiratory distress syndrome (RDS). Objectives: To test the hypothesis that this occurs through a decrease in pulmonary inflammation. Methods: Preterm lambs received 200 mg/kg of natural surfactant or 200 mg/kg of natural surfactant combined with 400 or 800 g/kg of beclomethasone. Interleukin 8 (IL-8) and macrophage migration inhibitory factor (MIF) were assayed in bronchial aspirate samples and lung mechanics were evaluated. Results: IL-8 increased in all the groups, but the increase was lower in the groups treated with surfactant plus 400 and 800 g/kg of beclomethasone. MIF decreased in the surfactant group, did not vary in the surfactant plus 400 g/kg beclomethasone group, and decreased in the surfactant plus 800 g/kg beclomethasone group. MIF concentration was higher in the surfactant plus 800 g/kg beclomethasone group than in the other groups. Conclusions: Natural surfactant combined with beclomethasone at 800 g/kg is effective in reducing lung inflammation in an animal model of RDS, thus explaining the associated decrease in lung oxidative stress. The increase in MIF in animals treated with surfactant plus 800 g/ kg of beclomethasone might be an important maturative and protective factor for neonatal lungs.