Abstract
To determine whether synovial mononuclear cells include a population of tumor necrosis factor α-producing T cells, we measured tumor necrosis a levels in culture supernatants of synovial mononuclear cells by ELISA and analyzed tumor necrosisα mRNA-positive cell frequencies. There were no significant differences in the spontaneous levels of TNF α between synovial mononuclear cells and peripheral mononuclear cells. The frequency of tumor necrosis factor a mRNA-positive cells in synovial mononuclear cells was higher than that of peripheral mononuclear cells. When stimulated with a superantigen, mononuclear cells from the synovial fluid of rheumatoid arthritis patients showed higher levels of tumor necrosis factor α production (1, 035±817pg/ml) than did mononuclear cells from their peripheral blood (236±180 pg/ml). In addition, we observed that a few T cell clones were resistant to superantigenic restimulation in vitro. We conclude that when these types of T cells persist in the synovium, they play a role in the development of rheumatoid arthritis via a mechanism involving tumor necrosis factor α production.
