Activated T lymphocytes, rheumatoid factor and erythrocyte sedimentation rate assays in rheumatoid arthritis.

Activated T lymphocytes (Ia+ T-cells) in peripheral blood are associated with immune stimulation. We found the percentages of these cells significantly increased in 95% of rheumatoid arthritis (RA) patients. Our studies showed no relation between the percentages of these cells in peripheral blood and concurrent erythrocyte sedimentation rates or rheumatoid factor titers. Circulating immune complex titers determined in a small number of patients conjectured an association with Ia+ T-cell levels.