Biased T cell receptor V gene usage in rheumatoid arthritis. Oligoclonal expansion of T cells expressing V alpha 2 genes in synovial fluid but not in peripheral blood.

OBJECTIVE: To analyze the T cell receptor (TCR) variable (V) region gene usage in the rheumatoid joint.
METHODS: Monoclonal antibodies (MAb) were used to determine the prevalence of selected V elements on T cells in synovial fluid (SF) from rheumatoid arthritis (RA) patients and in peripheral blood (PB) from RA patients and normal controls. V alpha 2-positive PB and SF T cells from 1 patient were cloned by immediate limiting-dilution and analyzed by restriction mapping.
RESULTS: In 9 of 14 RA patients, SF was enriched in at least 1 of the selected V elements, compared with PB. TCR genes of the V alpha 2 family were the most frequently overrepresented in the SF (4 patients). The expanded V alpha 2-positive cells were oligoclonal in SF but heterogeneic in PB.
CONCLUSION: Our data showing biased and clonally restricted TCR elements in the rheumatoid joint indicate major histocompatibility complex-restricted antigen recognition, rather than a "superantigen," in the pathogenesis of RA.