CD8A and pulmonary emphysema: Subjects with lower CD4/CD8 ratio were more likely to have >10% emphysema: 43% of those with CD4/CD8 ratio <0.4 had emphysema, compared to 25% of those with CD4/CD8 ratio 0.4–1.0 and 21% of those with CD4/CD8 >1.0 (p = 0.03 for χ2 test).