title: Localized monocyte chemotactic protein-1 production correlates with T cell infiltration of synovium in patients with psoriatic arthritis.
abstract: OBJECTIVE
  To examine normal and psoriatic skin and synovial tissue from patients with psoriatic arthritis (PsA) for evidence of monocyte chemotactic protein-1 (MCP-1) mediated T cell chemotaxis.
  
  
  METHODS
  Peripheral blood (PB), synovial fluid (SF), normal and psoriatic skin, and synovial biopsies were obtained from patients with PsA (n = 19) and compared to samples from normal (n = 5) and disease (n = 5) controls (NC, DC). Immune cell populations in PB and SF samples were assessed by immunofluorescent labeling and flow cytometry, levels of soluble MCP-1 were determined by quantitative ELISA, and immunohistochemistry was used to detect T cell subsets and macrophages and MCP-1 protein in frozen skin and synovial tissue sections.
  
  
  RESULTS
  CD8+ but not CD4+ T cells were elevated in SF compared to PB, and the majority of these cells expressed CD45RO. Plasma MCP-1 levels in PsA were elevated relative to NC. MCP-1 levels were significantly higher than paired plasma samples in patients with recent onset (< 6 mo) synovitis (n = 10). A positive correlation was observed between synovial T cell numbers and MCP-1 levels in SF. MCP-1 protein was present in all tissues examined, but most intense expression was observed in synovium.
  
  
  CONCLUSIONS
  Elevated concentrations of MCP-1 concomitant with memory T cell infiltration in PsA SF suggests that MCP-1 mediated chemotaxis is involved in the recruitment of T lymphocytes into the synovial compartment of patients with PsA.
authors.affiliation: Department of Immunology, Royal Hospitals NHS Trust, London, UK. e.ross@icrf.icnet.uk
authors.forename: E L
authors.initials: EL
authors.lastname: Ross
authors.forename: D
authors.initials: D
authors.lastname: D'Cruz
authors.forename: W J
authors.initials: WJ
authors.lastname: Morrow
mesh_terms: D015535:Arthritis, Psoriatic / Q000378:metabolism* / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002465:Cell Movement / Q000502:physiology; D018932:Chemokine CCL2 / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008264:Macrophages / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000378:metabolism / Q000473:pathology; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology
chemical_list: D018932:Chemokine CCL2; D017493:Leukocyte Common Antigens