T lymphocyte subpopulations in synovial fluid of patients with rheumatic disease

Abstract

The proportion of T lymphocytes with receptors for the Fc portion of IgG (T_G cells) or IgM (T_M cells) was determined in synovial fluid and blood of 16 patients with various rheumatic diseases including rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis. The percentage of T_G cells was low in all synovial fluid samples, whereas in the patients' blood the percentage was higher than or equal to the level found in the blood of healthy subjects. Eight patients also had a lower level of T_M cells in synovial fluid as compared to the percentage found in the blood of healthy donors. In the patients' blood the percentage of T_M cells was usually within the normal range. Thus the proportion of T cells lacking either receptor (T_null cells) was higher in synovial fluid than in blood. This pattern of low T_Gcell and high T_null cell percentages was found in the synovial fluid of patients with various rheumatic diseases and thus seems to be a general feature of chronic inflammatory joint exudates.