Reduced apoptosis of CD8+ T-lymphocytes in the airways of smokers with mild/moderate COPD.

Chronic obstructive pulmonary disease (COPD) is characterised by chronic inflammation in airways and lung parenchyma. CD8+ T-lymphocytes, crucial effector and regulatory cells in inflammation, are increased in the central and peripheral airways in COPD. The aim of this study was to assess the role of apoptosis in the accumulation of CD8+ T-lymphocytes within the airway wall in COPD. We examined the submucosa of transverse sections of central and peripheral airways from post-operative tissues from non-smokers (n=16), smokers with normal lung function (n=16), smokers with mild/moderate COPD (n=16), and smokers with severe/very severe COPD (n=9). TUNEL and immunohistochemistry techniques were used to identify apoptosis and cell phenotype, respectively. The percentage of apoptotic CD8+ T-lymphocytes was significantly lower (p