CD4 and rheumatoid arthritis: We found that the total T cell count (P<0.001), CD4+ T cell count (P<0.001), CD8+ T cell count (P<0.001), Th17 cell count (P<0.001) and percentage (P=0.019), Th1/Th2 ratio (P=0.032), and Th17/Treg ratio (P<0.001) were significantly higher in the RA-obstructive CAD group, while the Treg cell count (P=0.011) and percentage (P<0.001) were lower compared to the RA-non-obstructive CAD group (Tables 2A, B; Figures 1A, B; Supplementary Table 2).