CILIARY ABNORMALITIES IN BRONCHIAL EPITHELIUM OF SMOKERS, EX-SMOKERS,AND NONSMOKERS

Although respiratory changes induced by tobacco smoke have been extens ively described, no study has focused on ciliary abnormalities associa ted with chronic smoking. Ciliary ultrastructure was studied in 37 adu lts with chronic sputum production (CSP) consisting of 13 current smok ers (Group 1), 5 ex-smokers (Group 2), and 19 nonsmokers (Group 3). Fi ve healthy nonsmokers constituted the control group (Group 4). Clinica l and radiologic data and respiratory function tests were recorded. Ac ute respiratory infection was diagnosed by culture of tracheobronchial secretions obtained during bronchoscopy. Bronchial ciliated cells wer e obtained and processed for transmission electron microscopy. Within each group, the percentages of abnormal cilia were similar in patients with either chronic bronchitis or bronchiectasis and in patients with or without acute infection. The percentage of axonemal ultrastructura l abnormalities (AUA) was higher in smokers (16.5% +/- 2.7%) and ex-sm okers (17.5% +/- 7%) than in nonsmokers (5.2% +/- 1%) or control subje cts (0.7% +/- 0.2%) (p < 0.0002). The AUA were polymorphic, characteri stic of acquired ultrastructural changes. These results suggest that c hronic smoking may induce an increased number of abnormal cilia which could participate in impairment of tracheobronchial clearance and whic h appears to be independent of the etiology of CSP.