Objective: To investigate the role of thrombospondin 1 (TSP-1) in RA. Methods: Expression of TSP-1 in synovial tissues was determined by immunohistochemistry. Expression of TSP-1 in rheumatoid fibroblast-like synovial cells (FLS) was investigated by quantitative real-time PCR and ELISA. Correlations among the plasma TSP-1 and other variables in patients with RA were examined. Results: Expression of TSP-1 was increased in rheumatoid synovial tissues. Transforming growth factor-β1 (TGF-β1) clearly increased TSP-1 expression in FLS on both mRNA and protein levels. Changes in plasma TSP-1 were associated with those in 28-joint Disease Activity Score-erythrocyte sedimentation rate and plasma TGF-β1. Conclusion: TSP-1 might be critically involved in the disease process of RA through the TGF-β1/TSP-1 axis.;開始ページ : 943;終了ページ : 947;元資料の権利情報 : (C) 2015 The Journal of Rheumatology Publishing Company Limited.;元資料の権利情報 : This is a pre-copy-editing, author-produced PDF of an article accepted for publication in The Journal of Rheumatology following peer review. The definitive publisher-authenticated version: The Journal of Rheumatology, 42(6), pp.943-947; 2015 is available online at: http://dx.doi.org/10.3899/jrheum.141292.