CD28 and rheumatoid arthritis: CD8 + CD28 − T cells with immunosuppressive role might be favorable to RA disease to control the severity of the inflammatory response; however, a subset of these cells with defects in its regulatory suppressor function in RA patients has been demonstrated.28 In our findings, we observed no changes in the total percentages of CD8 + T cells among RA groups and CS; thus, the diminished frequency and expression of CD8 + T cells positive to CD28 could reflect an inversely proportional increase of CD8 + T cells negative for CD28 in chronic RA patients.