CD4 and rheumatoid arthritis: In contrast, in early, untreated RA patients the distribution of MAIT cells shifted from predominantly CD8+ (median RA 32.6%) to mainly CD4+ MAIT cells (Fig. 2a middle panel; median CD4+ MAIT controls 8.3%, SpA 12.3%, RA 52.6%; p < 0.001, controls vs RA p < 0.001, SpA vs RA p = 0.0073).