Quantitative analysis of sputum cytologic differences between smokers and nonsmokers

An exploratory analysis of sputum cytology was conducted to determine the extent and nature of cytomorphologic differences between smokers and nonsmokers. Specifically, alveolar macrophages, pigmentation of macrophages, neutrophils, mucus, mucous spirals, columnar cells, metaplastic cells, and dysplastic cells were analyzed and compared in 349 smokers and 93 nonsmokers. Results indicate that smokers have significantly higher scores on all components than do nonsmokers. Pigmentation of macrophages, alveolar macrophages, and mucous spirals were the major components discriminating between smokers and nonsmokers. A comparison of the nonsmoking sample with a different group of smokers (n = 466) revealed similar findings. Using the cytomorphologic parameters as the basis for classification, discriminant function analysis was able to classify correctly 94 percent of the nonsmokers and 91% of the smokers, a finding confirmed in the second group of smokers. These data indicate that smokers differ reliably from nonsmokers with respect to their cytomorphologic profile.