Differences in responses of normal and rheumatoid arthritis peripheral blood T cells to synovial fluid and peripheral blood dendritic cells in allogeneic mixed leukocyte reactions.

We examined the response of normal T cells to dendritic cells isolated from the synovial fluid (SF) of patients with either rheumatoid arthritis (RA) or seronegative spondylarthropathies (rheumatoid variants) and to dendritic cells from normal and RA peripheral blood (PB) in the allogeneic mixed leukocyte reaction. Despite the differences in the response kinetics, the stimulatory capacity of SF dendritic cells was similar to that of PB dendritic cells in a 7-day mixed leukocyte reaction. We also tested the responsiveness of normal and RA PB T cells to various allogeneic dendritic cells and found that RA PB T cells responded poorly to both rheumatoid variant SF dendritic cells and normal PB dendritic cells. However, when dendritic cells from RA SF were used as stimulators, the response of RA PB T cells was significantly greater than that of normal PB T cells (P less than 0.02). This difference in response was explained in part by a proliferation of the CD8 T cell subset. There was also a shift of low-intensity CD4+, CDw29+ cells to high-intensity CD4+, CDw29+ cells seen in RA PB T cells but not in normal PB T cells, by fluorescence-activated cell sorter analysis.