T cell receptor expression and activation of synovial lymphocyte subsets in patients with rheumatoid arthritis. Phenotyping of multiple synovial sites.

Two-color flow cytometry analysis of peripheral blood and synovial lymphocytes from rheumatoid arthritis patients was performed using monoclonal antibodies directed against T cell subsets, T cell activation markers, and T cell receptors. The results showed an abnormally high percentage (>15%) of CD3+, CD4−, and CD8− T cells expressing a specific receptor containing a γ chain. Phenotypic analysis of lymphocytes infiltrating both knee joints of individual rheumatoid arthritis patients revealed very similar subset distribution and activation levels, despite strong differences in the clinical status between the 2 sites.