Lymphocytes of synovial fluid and peripheral blood in reactive arthritis. A case report

Lymphocytes were isolated from eight samples of synovial fluid obtained over a period of six weeks from a patient with reactive arthritis after venereal infection of unknown microbial etiology. The percentages of T lymphocytes were consistently higher in synovial fluid than in paired blood samples, whereas those of B lymphocytes were consistently lower in synovial fluid than in blood. When incubated in vitro the spontaneous DNA synthesis of the synovial fluid and blood lymphocytes was low. When phytohaemagglutinin or tuberculin was present in the cultures the lymphocytes from blood as well as those from synovial fluid responded with synthesis of deoxyribonucleic acid and phytohaemagglutinin dose response curves of lymphocytes from the two sources were similar. Thus T lymphocytes of synovial fluid showed a similar in vitro reactivity as those from blood.