Isolation of YERSINIA‐Specific T Cell Clones from the Synovial Membrane and Synovial Fluid of a Patient with Reactive Arthritis

Synovial fluid (SF) mononuclear cells from patients with reactive arthritis (ReA) proliferate in vitro when challenged with ReA‐associated bacteria, the maximal response being for the organism causing the triggering infection. We report the results of a study of the antigenic specificity of synovial T lymphocytes from an HLA–B27 positive ReA patient whose SF mononuclear cells responded preferentially to Yersinia antigens. This is the first report of the isolation of Yersinia‐specific T cell clones from synovial membrane (obtained by closed‐needle synovial biopsy). We present a detailed analysis of these clones, together with others obtained from the SF.