Helper T cell function of rheumatoid synovial tissue lymphocytes.

The helper cell profiles of rheumatoid peripheral blood (PBT-RA), synovial fluid (SyT-RA) and synovial tissue (SyN-RA) T lymphocytes were compared both before and after irradiation with similarly treated normal peripheral blood T cells (PBT-N). Deficient helper cell profiles were noted in SyN-RA and were correlated with increased numbers of activated T lymphocytes in culture. Moderately reduced helper cell profiles were seen in PBT-RA and were the result of a functional lack of a radioresistant helper T cell and/or radiosensitive suppressor T cell. SyT-RA, however, showed normal or enhanced T helper cell profiles and similar numbers of activated T cells compared with PBT-RA. Activated helper T cells therefore play an important role in the local immune response in inflamed rheumatoid synovium.