Lymphokines in the rheumatoid joint.

Joint fluids and culture supernatants of synovial tissue were examined for the presence of two lymphokines. Migration inhibitory activity was found in 16 of 22 rheumatoid fluids (73%), in 3 of 15 osteoarthritis fluids (20%), and in 3 of 11 fluids from patients with various inflammatory arthritides (27%). Blastogenic activity was present in 14 of 15 rheumatoid fluids and in 1 of 7 nonrheumatoid effusions. The active materials eluted with the third peak from Sephadex G-200 and were therefore smaller than immunoglobulin or immune complexes. These findings suggest that lymphokine-like substances were present in effusions and synovial tissue of most patients with rheumatoid arthritis and some patients with other forms of chronic synovitis.