A Minority of Patients with Rheumatoid Arthritis Show a Dominant Rearrangement of T‐Cell Receptor β Chain Genes in Synovial Lymphocytes

The clonality of T lymphocytes isolated from the synovial fluid and peripheral blood of patients with rheumatoid arthritis was investigatcd by restriction enzyme fragment mapping of the rearrangement is of the β chain gene of the T-cell antigen receptor. Three patients showed a dominant rearrangement amongst their synovial fluid T cells which was not seen in their peripheral blood T-cell population, suggesting the prescnce of a predominating T-cell clone. However, most of the patients examined (8 out of 11) demonstrated polyclonal T-cell populations in both their synovial fluid and peripheral blood. Of four synovial fluid T-cell lines investigated, one showed evidence of a dominant T-cell clone.