Behaviour of effector cells, synovial fluids, and sera from rheumatoid arthritis patients in antibody-dependent cell-mediated cytotoxicity.

Antibody-dependent cell-mediated cytotoxicity (ADCC) was examined in patients with rheumatoid arthritis (RA). The cytotoxicity of peripheral blood leucocytes from patients with RA was similar to that found in normal persons, whereas ADCC was less effective in RA synovial fluid cells. It is possible that the activity in these cells is lower because of immune complexes and other factors being absorbed from the synovial fluid itself. Although patients' sera had little effect on normal peripheral blood leucocytes, synovial fluid from RA patients was markedly inhibitory in ADCC. The degree of inhibition correlated significantly with the clinical status of the patients.