CD8A and chronic obstructive pulmonary disease: Specifically, a significantly higher proportion of CD8+ T-lymphocytes from both current smokers with COPD (88.2%, 70.6–97.1; p<0.001) and ex-smokers with COPD (69.3%, 64.3–79.7; p<0.005) were activated ex vivo compared to healthy non-smokers (26.1%, 16.2–28.2).