title: The relationship between anti-cyclic citrullinated peptide and bone mineral density and radiographic damage in patients with rheumatoid arthritis.
abstract: OBJECTIVE
  We aimed to investigate the relationship between anti-cyclic citrullinated peptide (anti-CCP) levels and bone mineral density (BMD), bone turnover, and radiographic damage in patients with rheumatoid arthritis (RA).
  
  
  METHODS
  Eighty patients (68 females, 12 males, mean age 46.50+/-14.59 years) with RA were included in the study. Anti-CCP antibodies were measured by enzyme-linked immunosorbent assay (ELISA). Bone turnover was studied by analysing serum levels of C-terminal telopeptide of type I collagen (sCTX, ng/mL), using an enzyme immunoassay. BMD was measured by dual-energy X-ray absorptiometry (DXA). Disease activity was assessed according to the Disease Activity Score that includes 28 joint counts (DAS28). Functional capacity was assessed by the Health Assessment Questionnaire (HAQ).
  
  
  RESULTS
  Anti-CCP-positive patients were defined as group 1 and anti-CCP-negative patients as group 2. The mean disease duration was 7.53+/-6.27 years in group 1 and 6.25+/-6.51 years in group 2. Anti-CCP had a limited negative correlation with lumbar BMD (r = -0.220, p = 0.050) and a negative correlation with femoral BMD (r = -0.242, p = 0.031). There was no statistically significant correlation between anti-CCP and sCTX values (r = 0.117, p = 0.301). Sharp scores were significantly higher in anti-CCP-positive than anti-CCP-negative patients (p = 0.012), and anti-CCP levels were significantly correlated with Sharp scores (r = 0.240, p = 0.032).
  
  
  CONCLUSIONS
  We found that RA patients with higher levels of anti-CCP antibody had lower lumbar and femoral BMD. Anti-CCP levels were also associated with radiographic damage. Therefore, we suggest that anti-CCP may be a determinant of bone loss in patients with RA.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Mustafa Kemal University, Hatay, Turkey. hayalguler@superonline.com
authors.forename: H
authors.initials: H
authors.lastname: Guler
authors.forename: A D
authors.initials: AD
authors.lastname: Turhanoglu
authors.forename: B
authors.initials: B
authors.lastname: Ozer
authors.forename: C
authors.initials: C
authors.lastname: Ozer
authors.forename: A
authors.initials: A
authors.lastname: Balci
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000097:blood* / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015519:Bone Density / Q000502:physiology*; D024042:Collagen Type I / Q000097:blood; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology / Q000503:physiopathology; D010455:Peptides / Q000097:blood; D010456:Peptides, Cyclic / Q000097:blood* / Q000276:immunology; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D000888:Antibodies, Anti-Idiotypic; D024042:Collagen Type I; D010455:Peptides; D010456:Peptides, Cyclic; C052929:collagen type I trimeric cross-linked peptide; C487763:cyclic citrullinated peptide