title: Usefulness of anti-cyclic citrullinated peptide antibody and rheumatoid factor to detect rheumatoid arthritis in patients with systemic sclerosis.
abstract: OBJECTIVE
  The purpose of this study was to determine the prevalence of anti-CCP antibodies (anti-CCP Abs) and to assess associations between the presence of anti-CCP Ab and arthritis or arthralgia in SSc patients.
  
  
  METHODS
  Serum samples were obtained from 146 SSc patients. Anti-CCP Ab, anti-agalactosyl (AG) IgG Ab, IgM-RF, IgG-RF and MMP-3 were determined, respectively.
  
  
  RESULTS
  The presence of anti-CCP Ab was found in 18/146 (12%) patients with SSc. Elevated levels of anti-AG IgG Abs, IgM- and IgG-RFs were observed in 50/146 (34%), 17/146 (12%) and 4/146 (3%), respectively. Serum anti-CCP Ab levels were significantly elevated in SSc-RA overlap patients compared with SSc patients with or without arthralgia (P < 0.05 or P < 0.001, respectively). Serum MMP-3 levels did not correlate with the presence of arthritis or arthralgia but were significantly associated with modified Rodnan total skin thickness score. In SSc-RA overlap patients, 10/11 (91%) patients were positive for two or more RA-related Abs.
  
  
  CONCLUSIONS
  The serum titre of anti-CCP Ab is higher in SSc-RA overlap patients than in SSc patients with or without arthralgia. The finding of high titres of anti-CCP Abs and the elevated levels combinatory with other RA-related Abs may help to define the diagnosis of SSc-RA overlap. MMP-3 might be a better marker to assess skin involvement rather than joint involvement in SSc patients.
authors.affiliation: Department of Dermatology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan. uedaik@hirakata.kmu.ac.jp
authors.forename: Ikuko
authors.initials: I
authors.lastname: Ueda-Hayakawa
authors.forename: Minoru
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Sayako
authors.initials: S
authors.lastname: Kumada
authors.forename: Chihiro
authors.initials: C
authors.lastname: Tanaka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Komura
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Hamaguchi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Takehara
authors.forename: Manabu
authors.initials: M
authors.lastname: Fujimoto
mesh_terms: D000368:Aged; D000888:Antibodies, Anti-Idiotypic; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000276:immunology; D044466:Asian People; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic; D012217:Rheumatoid Factor; D012595:Scleroderma, Systemic / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D000888:Antibodies, Anti-Idiotypic; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor