[Antigenic markers of immunocompetent cells in rheumatoid synovial membrane]

Immunologic characteristics of cells present in rheumatoid synovium from 15 patients were analyzed either "in situ" on frozen sections or after elution. Monoclonal antibodies directed against T cell subpopulation antigens and anti-Ia-like were used. T cells bearing the phenotype T3+, T4+, Ia+ are numerous, and they appeared gathered in lymphoid follicles and in perivascular areas. They are in close relationship with large Ia+ cells probably macrophagic in nature. Numerous dendritic cells as well as intimal cells are also Ia+. Some ratios T8+/T4+ cells are higher than results previously reported. This discrepancy could be related to drugs received by the patients before surgery.