title: Fetuin-A is related to syndesmophytes in patients with ankylosing spondylitis: a case control study.
abstract: OBJECTIVE
  New bone formation is one of the hallmark characteristics of ankylosing spondylitis, which is thereby associated with syndesmophytes. Fetuin-A is a molecule that is abundantly found in calcified tissues and it shows high affinity for calcium phosphate minerals and related compounds. Considering the role of fetuin-A in the regulation of calcified matrix metabolism, we compared the fetuin-A levels in ankylosing spondylitis patients with syndesmophytes with those in patients without syndesmophytes and in healthy controls. We also studied other biomarkers that are thought to be related to syndesmophytes.
  
  
  METHODS
  Ninety-four patients (49 patients without syndesmophytes, 67.3% male, 40.7±8.7 years; 45 patients with syndesmophytes, 71.1% M, 43.9±9.9 years) and 68 healthy controls (44.2±10.6 years and 70.6% male) were included in this study. Syndesmophytes were assessed on the lateral radiographs of the cervical and lumbar spine. The serum levels of fetuin-A, dickkopf-1, sclerostin, IL-6, high-sensitivity C-reactive protein and bone morphogenetic protein-7 were measured with an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Patients with syndesmophytes had significantly higher levels of fetuin-A compared with patients without syndesmophytes and controls (1.16±0.13, 1.05±0.09 and 1.08±0.13 mg/ml, respectively). However, fetuin-A was not different between the patients without syndesmophytes and controls. Bone morphogenetic protein-7 was significantly lower; dickkopf-1 was significantly higher in patients with ankylosing spondylitis compared with controls. The sclerostin concentrations were not different between the groups. In regression analysis, fetuin-A was an independent, significant predictor of syndesmophytes.
  
  
  CONCLUSIONS
  Our results suggest that fetuin-A may a role in the pathogenesis of bony proliferation in ankylosing spondylitis.
authors.affiliation: Department of Internal Medicine, Dokuz Eylul University School of Medicine, Izmir, Turkey.
authors.forename: Tugba
authors.initials: T
authors.lastname: Tuylu
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Dokuz Eylul University School of Medicine, Izmir, Turkey.
authors.forename: Ismail
authors.initials: I
authors.lastname: Sari
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Dokuz Eylul University School of Medicine, Izmir, Turkey.
authors.forename: Dilek
authors.initials: D
authors.lastname: Solmaz
authors.affiliation: Department of Biochemistry, Adnan Menderes University School of Medicine, Aydin, Turkey.
authors.forename: Didem Leyla
authors.initials: DL
authors.lastname: Kozaci
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Dokuz Eylul University School of Medicine, Izmir, Turkey.
authors.forename: Servet
authors.initials: S
authors.lastname: Akar
authors.affiliation: Bilim ve Teknoloji Araştırma ve Uygulama Merkezi (ADU-BILTEM), Adnan Menderes University, Aydin, Turkey.
authors.forename: Necati
authors.initials: N
authors.lastname: Gunay
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Dokuz Eylul University School of Medicine, Izmir, Turkey.
authors.forename: Fatos
authors.initials: F
authors.lastname: Onen
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Dokuz Eylul University School of Medicine, Izmir, Turkey.
authors.forename: Nurullah
authors.initials: N
authors.lastname: Akkoc
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D055419:Bone Morphogenetic Protein 7 / Q000097:blood; D019485:Bone Morphogenetic Proteins / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005819:Genetic Markers; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000378:metabolism* / Q000473:pathology; D011859:Radiography; D012016:Reference Values; D013167:Spondylitis, Ankylosing / Q000378:metabolism* / Q000473:pathology; D018709:Statistics, Nonparametric; D060749:alpha-2-HS-Glycoprotein / Q000032:analysis* / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015415:Biomarkers; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; C501126:DKK1 protein, human; D005819:Genetic Markers; D036341:Intercellular Signaling Peptides and Proteins; D015850:Interleukin-6; C422903:SOST protein, human; D060749:alpha-2-HS-Glycoprotein; D002097:C-Reactive Protein