HLA-DR, DQ and DP antigen expression in synovial fluid T lymphocytes in rheumatoid arthritis: cell cycle analysis of HLA-DP positive T cells.

Abstract

Cell surface expression of HLA-DR, DQ and DP antigens on synovial fluid (SF) T cells was analyzed in 43 patients with rheumatoid arthritis. Marked increase in the positive expression of all 3 Ia antigens was observed in the SF T cells compared to the counterpart, peripheral blood T cells. Both the DNA and RNA content of HLA-DP+ T cells were analyzed using acridine orange stain. RNA content in the HLA-DP+ SF T cells increased in comparison to that in the HLA-DP- SF T cells or normal peripheral blood T cells. Our findings suggest that majority of the SF T cells are activated and express HLA-DP antigen, while not proliferating.