title: CRP and a biomarker of type I collagen degradation, C1M, can differentiate anti-inflammatory treatment response in ankylosing spondylitis.
abstract: OBJECTIVE
  To investigate if tissue turnover biomarkers were efficacy biomarkers in ankylosing spondylitis and if the biomarkers at baseline predicted a good outcome (BASDAI50).
  
  
  METHODS
  Twenty-two etanercept treated ankylosing spondylitis patients were investigated for inflammation (CRP, ESR, CRPM) and tissue turnover (C1M, C2M, C3M) during the first year of treatment. Biomarkers profiles and treatment response were investigated.
  
  
  RESULTS
  ESR, CRP, BASDAI and C1M were decreased with treatment (p ≤ 0.04). C1M and CRP segregated patients into two populations predicting treatment efficacy.
  
  
  CONCLUSIONS
  C1M and CRP were efficacy biomarkers and baseline biomarkers could select who benefited (by biomarkers) from treatment. C1M was not superior to CRP, but the biomarkers evaluate different pathologic events, indicating that C1M and CRP identify different events.
authors.affiliation: Nordic Bioscience, Biomarkers & Research, Herlev Hovedgade 207, Herlev DK-2730, Denmark.
authors.forename: Anne Sofie
authors.initials: AS
authors.lastname: Siebuhr
authors.affiliation: Nordic Bioscience, Biomarkers & Research, Herlev Hovedgade 207, Herlev DK-2730, Denmark.
authors.forename: Anne C
authors.initials: AC
authors.lastname: Bay-Jensen
authors.affiliation: Nordic Bioscience, Biomarkers & Research, Herlev Hovedgade 207, Herlev DK-2730, Denmark.
authors.forename: Morten Asser
authors.initials: MA
authors.lastname: Karsdal
authors.affiliation: Skeletal Biology & Engineering Research Center, KU Leuven & Division of Rheumatology, UZ Leuven, Herestraat 49, B-3000 Leuven, Belgium.
authors.forename: Rik J
authors.initials: RJ
authors.lastname: Lories
authors.affiliation: Skeletal Biology & Engineering Research Center, KU Leuven & Division of Rheumatology, UZ Leuven, Herestraat 49, B-3000 Leuven, Belgium.
authors.forename: Kurt
authors.initials: K
authors.lastname: de Vlam
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D054316:Biomarkers, Pharmacological / Q000097:blood*; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis*; D024042:Collagen Type I / Q000097:blood / Q000378:metabolism*; D024043:Collagen Type II / Q000097:blood / Q000378:metabolism; D024061:Collagen Type III / Q000097:blood / Q000378:metabolism; D017364:Collagenases / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D000068800:Etanercept / Q000627:therapeutic use*; D006801:Humans; D008875:Middle Aged; D013167:Spondylitis, Ankylosing / Q000175:diagnosis / Q000188:drug therapy*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D054316:Biomarkers, Pharmacological; D024042:Collagen Type I; D024043:Collagen Type II; D024061:Collagen Type III; D002097:C-Reactive Protein; D017364:Collagenases; D000068800:Etanercept
keywords: ankylosing spondylitis; extracellular matrix turnover; protein fingerprint biomarkers; segregation of patients at baseline; structural benefit assessed by serological biomarkers; treatment efficacy of etanercept