Abstract:Objective:To investigate airway ciliary ultrastructure and mucociliary clearance(MCC) in COPD patients with heavy smoking. Methods:Bronchial biopsy from 10 patients and 6 healthy volunteers during fiberoptic bronchoscopy was performed and submitted to ultrastructural study of cilia.Using Emisson Computed Tomography of radioactive particles inhalation technique,MCC of 7 cases and 7 normal control subjects was evaluated. Rusults: The percentage of axonemal ultrastructure abnormalities(AUA) was markedly higher in patients group[(19.2±2.8)%] than that in control group[(11.6±2.3)%,P<0.01]. The half time of radioactivity aerosol particles being cleared(MCC marker) in right lung center-region of interesting(C-ROI) was significantly higher in patients group[(1943±629)s]than that in control group[(1207±276)s,P<0.05].There was a significant correlation between AUA and MCC (r=0.704 5,P<0.05). Conclusion: Heavy smoking and chronic airway infection cause significant increase in airway AUA percentage and decrease in MCC of respiratory tract, and Ciliary ultrastructure is coincided with mucociliary clearance of respiratory tract.