[beta2-Microglobulin in synovial fluid (author's transl)].

In a series of patients with rheumatoid arthritis we found higher levels of synovial beta2-microglobulin (5,2 +/- 3 mg/l) than in gouty arthritis (2,4 +/- 0,6) or osteoarthritis (1,2 +/- 0,3 mg/l). The ratio of synovial/plasma beta2-microglobulin was always superior to unity (2,3 +/- 0,7) in the R.A. patients whereas it is always inferior to unity in the other groups. The correlation between plasma or synovial beta2-microglobulin and synovial lymphocyte count was highly significant in all cases in RA patients plasma and synovial beta2-microglobulin are significantly related to the degree of joint involvement as expressed by the joint count.