Influence of Cigarette Smoking on Bronchoalveolar Lavage Cellularity in Asbestos-induced Lung Disease

Abstract

To investigate the influence of cigarette smoking on bronchoalveolar lavage (BAL) cellularity in asbestos-induced lung disease, we compared BAL cells in asbestos-exposed, nondiseased subjects (n = 20) with those with either asbestosis (n = 25) or asbestos-induced pleural fibrosis (n = 28). Patients with asbestosis (ILO greater than or equal to 1/0) had higher concentrations of BAL macrophages (p = 0.04), neutrophils (p = 0.003), and eosinophils (p = 0.01), while patients with asbestos-induced pleural fibrosis (circumscribed plaques and diffuse pleural thickening) had higher concentrations of BAL lymphocytes (p = 0.02). Within our study population, however, cigarette smoking (smoking status or pack-years of smoking) was strongly associated with BAL macrophages, neutrophils, and eosinophils but was not associated with the concentration of BAL lymphocytes. Using multivariate analysis, we found that although asbestosis remained associated with higher concentrations of BAL macrophages, neutrophils, and eosinophils, cigarette smoking had a far greater contribution to the concentrations of BAL macrophages and eosinophils than did asbestosis. Although cigarette smoking accounted for 17 to 18% of the variance of BAL macrophages and eosinophils, asbestosis was associated with approximately 6% of the variance associated with these cells. In contrast, the concentration of BAL neutrophils remained associated with asbestosis and was not influenced by smoking behavior. We conclude that cigarette smoking strongly influences BAL cellularity (macrophages and eosinophils) in our patients with asbestosis but does not appear to affect the type or concentration of BAL cells in patients with asbestos-induced pleural fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)