Expression of activation markers on lymphocytes in synovial fluid from patients with rheumatoid arthritis

Objective: To study the expression of activation markers CD69, CD25, CD71, HLA-DR on synovial fluid lymphocytes in patients with rheumatoid arthritis (RA) and to identify their role in the pathogenesis of RA. Methods: Cell surface expression of activation markers CD69, CD25, CD71 and HLA-DR on lymphocytes of synovial fluid in 20 patients with RA were studied with flow cytometry and 10 controls. Results: The expressions of CD25 and CD71 on lymphocytes in patients's synovial fluid were significantly higher than those in controls (P<0.01). But the expressions of CD69 and HLA-DR were not significantly different (P>0.05). Conclusion: The over-expression of CD25, CD71 on lymphocytes in synovial fluid of patients with RA may play an important role in the pathogenesis of RA. (authors)