Markers of activated T cells on synovial fluid lymphocytes in rheumatoid arthritis.

Membrane markers of activated T lymphocytes of synovial fluid of two groups of patients with various forms of arthritis were studied. The first group (group A) concerns patients affected by rheumatoid arthritis (RA), and the other (group B) includes those affected by not immunologically-mediated arthropathies as osteoarthrosis, crystal synovitis, post-traumatic arthritis. Some other arthropathies included in a third group (group C) have been considered separately. Both the receptor for human group O Rh negative erythrocytes (H rosettes forming cells) and the receptor able to bind at 37 degrees C sheep red blood cells (stable-E-rosette forming cells) respectively were used as markers for the identification of activated T lymphocytes. The results show a marked increase of activated T cells in group A in comparison to group B. So the possible causes of this lymphocyte activation in rheumatoid patients are suggested.