Activated T lymphocytes of the synovial membrane in rheumatoid arthritis and other arthropathies.
Immunohistological techniques were used to identify activated T lymphocytes within the synovial membrane of patients with rheumatoid arthritis, using the monoclonal antibody (MoAb) RFT2, which identifies a 40-k dalton molecule preferentially expressed by T blasts or activated cells. Using this reagent together with a monoclonal 'cocktail' that stains all T cells, cell counts on consecutive sections of rheumatoid synovium revealed that up to 50% T lymphocytes were RFT2+ (range 9.3-50.2%, mean 25.4). Subsequent analysis using combination immunofluorescence demonstrated that over 90% of these activated cells were of the T4+ subset. Furthermore all these cells appeared to be Leu8-, suggesting that the activated population were exclusively 'true helpers' and not suppressor inducers. Studies indicated that 50% of the RFT2+ cells were positive with anti-Tac MoAb. Comparisons with tissues from other arthropathies demonstrated that this relatively high proportion of RFT2+ cells was a feature restricted to rheumatoid arthritis, although biopsies from patients with psoriatic arthritis and ankylosing spondylitis also contained activated cells. Biopsies of Reiter's syndrome, osteo-arthritis, and pigmented villonodular synovitis contained no activated cells, nor were any seen in sections of normal synovium. The presence in rheumatoid synovial membrane of activated T cells which are only of the T4+, Leu8- subset adds weight to the suggestion that local immunoregulatory dysfunction contributes to the chronic inflammation of rheumatoid arthritis.
D000911:Antibodies, Monoclonal; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D002469:Cell Separation; D006801:Humans; D007592:Joint Diseases / Q000276:immunology*; D008213:Lymphocyte Activation; D010641:Phenotype; D013583:Synovial Membrane / Q000166:cytology / Q000276:immunology*
D000911:Antibodies, Monoclonal