Increased bronchoalveolar granulocytes and granulocyte/macrophage colony-stimulating factor during exacerbations of chronic bronchitis

Although inflammatory changes are found throughout the airways of patients with chronic bronchitis, the mechanisms of the pathogenesis of chronic bronchitis are still unclear. The aim of this study was to investigate airways inflammation in patients with and without an exacerbation of bronchitis. Thirteen chronic bronchitic patients and nine normal subjects were studied. Eight of the patients were studied under baseline conditions (B), and five during an exacerbation of bronchitis (E). Bronchoscopy and bronchoalveolar lavage (BAL) with cytological analysis were performed, and the levels of granulocyte/macrophage colony-stimulating factor (GM-CSF) were determined in sera and in BAL supernatants by a solid phase enzyme immunoassay. Compared with patients under baseline conditions, chronic bronchitic patients with an exacerbation had increased numbers of BAL neutrophils (10+/-3 and 83+/-18x10(3) cells x mL(-1), respectively; p