TY - JOUR T1 - Differential expression of the urokinase receptor (CD87) in arthritic and normal synovial tissues. JF - Journal of Clinical Pathology JO - J Clin Pathol SP - 314 LP - 319 DO - 10.1136/jcp.50.4.314 VL - 50 IS - 4 AU - Z Szekanecz AU - G K Haines AU - A E Koch Y1 - 1997/04/01 UR - http://jcp.bmj.com/content/50/4/314.abstract N2 - AIM: To determine whether the urokinase plasminogen activator receptor (u-PAR; CD87) exhibits a possible pathogenic role in rheumatoid and osteoarthritis. METHODS: A semiquantitative, indirect immunoperoxidase histochemical analysis was performed on frozen synovial tissue sections. The recently characterised monoclonal antibody 10G7 recognising transfectants bearing u-PAR was used. Synovial tissue was obtained from 10 patients with rheumatoid arthritis, 10 patients with osteoarthritis, and four normal subjects. RESULTS: u-PAR was expressed on 70-90% of synovial tissue lining cells and subsynovial, interstitial macrophages from the arthritis patients, but only on a few myeloid cells from the normal subjects. It was also present on more endothelial cells from the rheumatoid and osteoarthritis patients, than from normal synovial tissue. CONCLUSIONS: Plasminogen activators are important in joint destruction underlying arthritis. The up-regulated expression of u-PAR in diseased versus normal synovial tissue suggests a role for this antigen in the inflammatory and angiogenic mechanisms underlying rheumatoid and osteoarthritis. ER -