Pulmonary Nonspecific Defense Mechanisms in Cystic Fibrosis: I. Phagocytic Capacity of Alveolar Macrophages and Neutrophils

摘要

Summary: Cystic fibrosis (CF) is the commonest cause of chronic obstructive lung disease within the first three decades of life. Because patients suffer from repeated pulmonary infections, we were interested in studying the nonspecific antibacterial mechanisms of the lungs of CF children. Fifteen CF children, 13 nontuberculous pulmonary-infected (I) children and 4 noninfected (N-I) children, who were diagnosed as having a foreign body in the air passages, were submitted to a bronchopulmonary washing. The absolute number, viability, and differential count of the cells were determined, and the phagocytic assay using the Lehrer's technique was carried out on the harvested cells.The materials obtained from CF and I patients were mucopurulent, whereas the ones from the N-I patients were not mucopurulent. The number of cells retrieved from CF and I patients was higher than that from the N-I patients. This was attributed to an increase in the absolute number of polymorphonuclear leukocytes. The phagocytic capacity of polymorphonuclear leukocytes was not different for the three groups studied, whereas that of alveolar macrophages was higher for the CF and the I patients than for the N-I ones. Inasmuch as there was no significant difference between the CF and the I patients, we conclude that the nonspecific phagocytic behavior of alveolar macrophages and pulmonary polymorphonuclear leukocytes of CF patients might be similar to the one coming from other bacterial infectious states of the lung.Speculation: Although cystic fibrosis children suffer from chronic progressive pulmonary infections, they show the normal population risk for other infections outside the lungs. Inasmuch as the immune system appears to be intact in these patients, a failure in one of the nonspecific antibacterial defense mechanisms of the lung may be considered.