CD8A and pulmonary emphysema: In adjusted models, a decrease in ratio of 1.0 (i.e. a decrease in CD4/CD8 ratio from 1.5 to 0.5) was associated with 4.1 (95% CI 1.5–12) times the odds of emphysema and remained statistically significant when current CD4 and HIV viral load were added to the model (OR 4.6, 95% CI 1.2–17).