Phenotypic characterization of lymphocytes infiltrating synovial tissue from patients with rheumatoid arthritis: analysis of lymphocytes isolated from minced synovial tissue by dual immunofluorescent staining.

The phenotypic markers of mononuclear cells in synovial tissue from 19 patients with active rheumatoid arthritis (RA) were identified by a dual immunofluorescent method. The mononuclear cells were isolated from synovial tissue by mechanical disaggregation and an enzymatic digestion technique. The results revealed a marked reduction in CD4+2H4+ cells (suppressor inducer T cells) and an increment in CD4+4B4+ cells (helper T cells) among CD4+ cells in synovial tissue. The percentage of CD8+CD11b+ cells (suppressor effector T cells) was significantly lower in synovial tissue than in peripheral blood from patients with RA, resulting in an increased percentage of CD8+CD11b-- cells (cytotoxic T cells). The synovial tissue had higher percentages of pan B cells (B1+ cells), differentiated B cells (B1+B2-- cells) and plasma cells (PCA-1+ cells). These findings suggest that a combination of the increment in helper T cells, the reduction in suppressor T cells, and the increment in differentiated B cells may lead to excessive production of autoantibodies.