Selective T cell receptor decrease in peripheral blood T lymphocytes of patients with polymyalgia rheumatica and giant cell arteritis.

OBJECTIVES: To investigate the phenotype and T cell receptor (TCR) use in peripheral blood T cells in patients with polymyalgia rheumatica (PMR) and giant cell arteritis (GCA). METHODS: Circulating T lymphocyte phenotype and TCR repertoire were studied by flow cytometry using specific monoclonal antibodies in 23 healthy controls and 37 patients with PMR/GCA. RESULTS: Patients with active PMR/GCA showed an inverse relation between naive and memory CD4+ T cells and unchanged expression of activation surface markers compared with controls. CD4+ TCR BV expansions were seen in 12 (52%) controls and in 8 (22%) patients with active disease (p = 0.03). Within the CD8+ subset, the frequency of expansions was similar between groups. Most T cell expansions remained stable over time. Seventeen of the 23 patients with active PMR/GCA disclosed a simultaneous CD4+ and CD8+ T cell depletion for at least one particular BV family with a clear predominance of BV5S2/S3. CONCLUSIONS: The phenotype of circulating T cells in patients with PMR/GCA is similar to that found in aged healthy subjects, except for the surface markers of naive and memory cells and a striking non-activated phenotype. Specific BV expansions in CD4+ and CD8+ T cells, which remain stable over time, are frequent in aged subjects, including patients with PMR/GCA. TCR BV changes in patients with active disease seem to be also age related, except for the significant decrease in certain BV families in both CD4+ and CD8+ T cell subsets, which may favour the participation of a superantigen stimulation in PMR/GCA.

Reactive arthritis after BCG immunotherapy: T cell analysis in peripheral blood and synovial fluid.

OBJECTIVE: To investigate the pathogenic mechanism of reactive arthritis after instillation of Calmette-Guérin bacillus (BCG). Although the clinical features of reactive arthritis after BCG therapy are well described, only a few reports have studied the possible pathogenic mechanisms. METHODS: We analysed by flow cytometry the phenotype and T-cell receptor (TCR) expression of peripheral blood (PB) and synovial fluid (SF) T cells in a patient who developed reactive arthritis (ReA) following intravesical BCG immunotherapy for bladder cancer. The proliferative response of short-term T-cell lines (TCL) from PB of this patient to mycobacterial antigens was tested by bromodeoxyuridine incorporation. RESULTS: CD4(+) and CD8(+) SF T cells with activated and memory phenotype were observed at the onset of arthritis. We were able to detect BV-restricted expansion of CD8(+) T cells in PB (BV17) and in SF (BV5S1 and BV12). The percentage of PB and SF CD8(+) T cells that expanded diminished when the symptoms remitted. The strongest response of CD4(+) TCL from the patient in vitro was obtained for human hsp-60 in an inversely dose-dependent manner. Very important was the finding that CD8(+) TCL from the patient demonstrated no proliferative response to any antigenic challenge that was reversed after the addition of exogenous interleukin 2. CONCLUSION: Although the identity of the stimulating antigen that led to the expansions observed in this patient is not clarified by the present data, both CD4(+) and CD8(+) T cells might play a role in the development of ReA following intravesical administration of BCG.