title: Differential expression of the urokinase receptor (CD87) in arthritic and normal synovial tissues.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Medicine, Northwestern University Medical School, Chicago, Illinois, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Szekanecz
authors.forename: G K
authors.initials: GK
authors.lastname: Haines
authors.forename: A E
authors.initials: AE
authors.lastname: Koch
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008264:Macrophages / Q000378:metabolism; D010003:Osteoarthritis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D055293:Receptors, Urokinase Plasminogen Activator; D013583:Synovial Membrane / Q000098:blood supply / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
chemical_list: C524898:PLAUR protein, human; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator