CD8A and chronic obstructive pulmonary disease: Several factors have been implicated in the increased susceptibility to COPD in this population including higher prevalence of smoking among HIV+ individuals, exaggerated lung inflammation (e.g., mediators released by alveolar macrophages and CD8+ T cells), adverse effects of long-term anti-retroviral therapy and the direct effect of HIV-related proteins such as Tat and Env (gp120) on lung cells13–19.