Background Cigarette smoke induces an acute but persisting inflammation in peripheral blood and airway in chronic obstructive pulmonary disease (COPD),and CD8+ Tc-lymphocytes are considered as a key role in this process.We aimed to investigate the Tc-lymphocytes immunodeviation in system and local airway of COPD patients and changes of the immunodeviation after short-term smoking cessation.Methods Peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) were collected from 42 patients (14 COPD patients,16 smokers with normal lung function and 12 nonsmokers),while PB and induced sputum (IS) were obtained from other 19 patients (10 quitting smokers and 9 continuing smokers) at baseline and follow-up respectively of 4-week smoking cessation.Percentages of CD8+ Tc-lymphocytes (％CD3+) and Tc1/Tc2 ratios were measured by flow cytometry.Results Percentages of CD8+ Tc-lymphocytes were higher in COPD patients than those in smokers and nonsmokers in both PB and BALF.Tc1/Tc2 ratio in PB and in BALF from COPD patients was greater than that from smokers and nonsmokers and negatively correlated with FEV1％pre.When comparing the ratios between PB and BALF,significantly positive correlation was found in COPD patients.Furthermore,after 4-week smoking cessation,percentages of CD8+ Tc-lymphocytes in PB and IS in quitting smokers were decreased compared to that in baseline and continuing smokers,whereas Tc1/Tc2 ratios were not influenced.Conclusions CD8+ Tc1-trend immunodeviation profiles occurred in both system and local airway of COPD patients.This exceptional immunodeviation could not be relieved by short-term smoking cessation.