CD8A and chronic obstructive pulmonary disease: For HLA-DR expression in CD3+CD8+ Tc cells (Figure 2D), levels were significantly elevated in the COPD-only group (1591 ± 531 MFI) as opposed to the HS group (1360 ± 477 MFI, adjusted p = 0.036) or the asthma group (1438 ± 385 MFI, adjusted p = 0.008).