title: Plasma level of CXC-chemokine CXCL12 is increased in rheumatoid arthritis and is independent of disease activity and methotrexate treatment.
abstract: OBJECTIVE
  Several actions of the chemokine CXCL12 have potential relevance for rheumatoid arthritis (RA). Interaction with CXCR4, the unique receptor for CXCL12, stimulates angiogenesis, mononuclear cell trafficking into the joints, lymphoid-tissue-like rearrangement of T cells within the synovium, and chondrocyte release of cartilage-degrading metalloproteinases. We investigated the level of CXCL12 in plasma (p-CXCL12) as a marker of RA diagnosis, RA disease activity, and response to methotrexate (MTX) treatment.
  
  
  METHODS
  A prospective study including 36 patients with RA (ACR criteria) of at least 6 months' duration, and 50 sex and age matched healthy controls. ELISA for CXCL12 was performed on plasma prior to and after 16 and 28 weeks of MTX treatment in the patients with RA and once in controls.
  
  
  RESULTS
  The p-CXCL12 was 1855 +/- 145 pg/ml in RA patients and 1273 +/- 79 pg/ml in controls (p < 0.001). During the 28 weeks of MTX treatment, the ACR disease activity variables decreased, whereas the p-CXCL12 level remained constant and increased. P-CXCL12 was not correlated to any ACR disease activity variable at any time (p > 0.05).
  
  
  CONCLUSIONS
  Patients with RA had a significantly and constantly increased p-CXCL12 level compared to controls. The p-CXCL12 level was independent of any ACR disease activity variables, as well as response to MTX treatment.
authors.affiliation: Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark. pip@dadlnet.dk
authors.forename: I B
authors.initials: IB
authors.lastname: Hansen
authors.forename: Torkell
authors.initials: T
authors.lastname: Ellingsen
authors.forename: Nete
authors.initials: N
authors.lastname: Hornung
authors.forename: Jørgen H
authors.initials: JH
authors.lastname: Poulsen
authors.forename: Tine
authors.initials: T
authors.lastname: Lottenburger
authors.forename: Kristian
authors.initials: K
authors.lastname: Stengaard-Pedersen
mesh_terms: D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy*; D015415:Biomarkers / Q000097:blood; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000097:blood*; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic
chemical_list: D018501:Antirheumatic Agents; D015415:Biomarkers; C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D007166:Immunosuppressive Agents; D008727:Methotrexate