CD8A and rheumatoid arthritis: Compared to healthy volunteers, RA patients exhibited higher HLA-DR expression percentages and MFI on CD8+ T cells (43.8 (24.8), (N = 31) vs. 15.4 (13.85), (N = 17), p < 0.0001; MFI: 672 (265), (N = 31) vs. 537 (100), (N = 17), p = 0.0013).