[Proteins of bronchial secretions in mucoviscidosis. Role of infection].

The protein composition of sputum collected by a protected method in 17 children with cystic fibrosis (CF) was analysed. The severity of the disease was assessed using the Shwachman score and the degree of bronchial superinfection was determined by a quantitative cyto-bacteriological study. The main proteins with antibacterial activity (IgA, IgG, IgM, lysozyme and lactoferrin) or reflecting the degree of bronchial inflammation (serumalbumin and alpha 1-antitrypsin) were determined by immunological methods. In the presence of severe superinfection (11 cases out of 17), the concentrations of antibacterial activity proteins are unchanged. On the other hand, the bronchial superinfection is accompanied by a marked local inflammation. In sputa, the increased concentrations of serum-derived proteins are closely correlated to the severity of the disease. This study confirms the importance of bronchial inflammation in CF.