Exogenous Lung Surfactant Decreases Interleukin-8 Production and Increases Leukocytes Population and Total Immunoglobulins in Rabbits

Background and Objectives: Exogenous lung surfactant (ELS) obtained from extraction of bronchoalveolar lavage fluid, is prescribed in some respiratory disorders, which could affect production of lung-related cytokines. Interleukin-8 (IL-8) is a major cytokine that could affect severity of lung diseases. In this study, we investigate the possible impact of ELS on IL-8 expression, hematological parameters and IgG and IgM levels in rabbits. Methods: ELS solution obtained from fresh calf’s lung bronchoalveolar lavage was infused into the lungs of five rabbits via tracheal tube. Blood samples were collected before and after ELS treatment for 30 days. Results: Serum IL-8 levels decreased over time following ELS administration. IL-8 expression also decreased after exposure to ELS, but leukocytes count increased significantly 24, 48 and 72 hours after ELS therapy compared to baseline values (P<0.05). IgM level increased significantly 72 hours after the ELS therapy and returned to normal range at the end of study. Conclusion: Our findings suggest that ELS could down-regulate IL-8 expression in mononuclear cells while increasing leukocytes population and total immunoglobulins level, which can trigger immune responses without lung damage. However, further studies should be performed to confirm the regulatory effects of ELS on inflammatory responses in lung diseases.