Airway inflammation and lymphocyte subset analysis in patients with chronic obstructive pulmonary disease and healthy smokers

Chronic airway inflammation is reported to have an important role for the development of chronic obstructive pulmonary disease (COPD), in addition to smoking, genetic and environmental factors. The present study was aimed to investigate whether the airway inflammation differed in subjects with stable COPD and healthy smokers. A total of 35 subjects (18 patients with COPD and 17 healthy smokers) were enrolled in this study. Bronchoalveolar lavage (BAL) was performed via fiberoptic bronchoscope in all subjects and cell counts and profiles and lymphocyte subset were analyzed in BAL fluids. The number of neutrophils in BAL of subjects with stable COPD was significantly higher than that of the healthy smokers (p< 0.001), and the number of macrophages was significantly lower than that of the healthy smokers (p< 0.001). Although CD4+ T:CD8+ T lymphocyte ratio was higher in healty smokers, the difference was not significant (p> 0.05). As a result, the most marked cellular change in BAL of subjects with stable COPD is the increase in neutrophils and decrease in macrophages, suggesting a very important role in the chronic airflow limitation.