CD8A and rheumatoid arthritis: Since some autoimmune diseases targeted by T cells are predominantly CD4-mediated (for example, SLE [28]) or CD8-mediated (for example, multiple sclerosis [29]) or both CD4- and CD8-mediated (for example, RA [30]), we examined the ratio of CD20+ CD4+ and CD8+ cells in a small sample of healthy control subjects (n = 4).