Changes in lymphocyte infiltration of the synovial membrane and the clinical course of rheumatoid arthritis

Multiple samples of synovial membrane were obtained by needle biopsy from 24 patients with rheumatoid arthritis (RA) before, and 1 year after, standard antirheumatic drug therapy was given. Changes in the immunohistologic features of the synovial membrane (read blindly) were compared with the clinical course of RA in each patient. A composite clinical index of disease activity (IDA) and spontaneous in vitro synthesis of IgM rheumatoid factor (IgM‐RF) by blood mononuclear cells were also measured before and after treatment. In 16 patients (group A), the IDA indicated 26–69% improvement, and the values for spontaneous IgM‐RF decreased substantially. In 8 patients (group B), the IDA indicated deterioration or no improvement, and the values for spontaneous IgM‐RF were unchanged. In group A patients, the intensity of the T cell infiltrate decreased from a mean score of 1.3 to a mean score of 0.8 (P = 0.025). The ratio of T helper cells to T suppressor/cytotoxic cells was ⩽2:1 in 90% of group A patients before treatment, compared with 20% of these patients after treatment (P = 0.016), and the number of biopsy samples that contained identifiable B cells decreased from 36% before treatment to 7% after treatment. In group B patients, there were no changes in the intensity of T cell infiltration, the ratio of T helper cells to T suppressor/cytotoxic cells, or the number of biopsy samples with identifiable B cells.