Changes in CD4+ T lymphocyte subsets in circulating blood and synovial fluid following filtration leukocytapheresis therapy in patients with rheumatoid arthritis

Abstract

The purpose of this study is to determine the changes in CD4+ T lymphocyte subsets in the circulating blood and synovial fluid following filtration leukocytapheresis (LCP) therapy for patients with rheumatoid arthritis (RA). A Cellsorba column packed with polyester fibers was used for the removal of circulating leukocytes. For patients with RA, filtration LCP or sham procedures were performed 3 times with 1 week intervals between procedures. T lymphocyte surface markers in the peripheral blood and synovial fluid were measured by flow cytometry. The proportions of activated CD4+ T cells (CD4+DR+, CD4+CD25+, and CD4+CD71+) and CD4+CD29+ T cells increased significantly in the peripheral blood, but the counts of these cells were significantly reduced in the synovial fluid after 2 treatment sessions in the LCP group. No significant changes were observed in the proportion of these cells in the control group. Our findings suggest that filtration LCP may cause a redistribution of activated T cells from affected joints into the circulating blood.