Monocyte cytotoxicity in connective tissue diseases. Correlation with disease groups.

The proportion of antibody-dependent cytotoxic plaque-forming cells (PFC) with monocyte characteristics was estimated in peripheral blood mononuclear leukocyte suspensions from 40 patients with rheumatoid arthritis (RA), (29 seropositive and 11 seronegative), 7 with ankylosing spondylitis (AS), 14 with juvenile rheumatoid arthritis (JRA) and 7 with systemic lupus erythematosus (SLE). In RA and also in AS patients, higher mean proportions of PFC were found when compared with those of normal adult blood donors. Seropositive RA patients had a significantly higher proportion of PFC than seronegative RA patients. SLE patients showed values equal to those of the controls. Patients with JRA had a lower percentage of these cells than age-matched healthy children.