Interactions between Cigarette Smoking and the Natural History of Idiopathic Pulmonary Fibrosis: Results (Part 2)
Cigarette Smoking and BAL Cell Populations
The mean retrieved volume percentage of BAL fluid was similar in smokers (48.7 ±20 percent) and nonsmokers (47.2 ±16 percent). The alveolar macrophage cell population, either expressed in percentage (p<0.02) or number of cells per milliliter (p<0.01), was significantly higher in smokers than in nonsmokers (Fig 2). Noticeably the number of macrophages per milliliter and the number of cigarettes smoked per day at time of BAL procedure were correlated (rs = 0.64; p<0.01). In contrast, the lymphocyte cell population was higher in nonsmokers, either expressed in percentage (p<0.01) or number of cells per milliliter (p<0.05). Moreover the lymphocyte cell counts were negatively correlated with dyspnea duration (rs= —0.55, p<0.01 for percentage and rs= —0.51, p<0.01 for number of cells per milliliter). No difference in neutrophil cell populations was observed between smokers and nonsmokers. Eosinophil counts, when expressed in number per milliliter, were higher in smokers than in nonsmokers (p<0.05). flovent inhaler
Figure 2. Comparison of BAL cell populations in smokers and nonsmokers. Percentage of cells (top), absolute cell numbers (bottom). M: alveolar macrophages; L: lymphocytes; N: polymorphonuclear neutrophils; E: eosinophils.