title: T cells: pathogenic cells and therapeutic targets in rheumatoid arthritis.
abstract: OBJECTIVE
  To provide: 1) a brief review of current thought on the role of T cells in the pathogenesis of rheumatoid arthritis (RA); and 2) To provide an overview of RA therapies directed against T cells.
  
  
  METHODS
  The following papers in relevant American and European medical journals were reviewed. Those related to: the role of T cells in the pathogenesis of RA; to biological therapy directed against cell surface markers specific to T cell populations implicated in RA; and to treatment of RA with cyclosporin A and leflunomide, pharmacological agents known to interfere with the T cell response to antigens.
  
  
  RESULTS
  Although a variety of cell types are now recognized as contributors to the progressive joint destruction that is a hallmark of RA, T cell activation is still thought to be a central event in the initiation and progression of this disease. As a result, various therapeutic options directed against T cells have been developed. These include biological agents directed against specific populations of activated T cells and pharmacological agents that have specific T cell-modulatory actions.
  
  
  CONCLUSIONS
  Use of T cell-directed biological therapies for RA has been disappointing, as a result of both lack of efficacy and serious toxicity. Treatment of RA with pharmacological agents that interfere with antigen-driven T cell proliferation has been more successful.
authors.affiliation: Department of Rheumatology and Immunology, University of Arizona Health Sciences Center, Tucson 85724, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Yocum
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D015703:Antigens, CD / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000628:therapy*; D002999:Clone Cells / Q000276:immunology; D020022:Genetic Predisposition to Disease; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007167:Immunotherapy; D007555:Isoxazoles / Q000627:therapeutic use; D000077339:Leflunomide; D008213:Lymphocyte Activation / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D015703:Antigens, CD; D007166:Immunosuppressive Agents; D007555:Isoxazoles; D000077339:Leflunomide