title: [Detecting anti-cyclic citrullinated peptide antibody in patients with connective tissue diseases].
abstract: OBJECTIVE
  To determine the clinical significance of anti-cyclic citrullinated peptide antibody (anti CCP) in mixed connective tissue diseases (MCTD).
  
  
  METHODS
  Enzyme linked immunosorbent assay was performed to detect anti-CCP in 57 patients with MCTD, 78 with rheumatoid arthritis (RA), 64 with systemic lupus erythematosus (SLE), 56 with polymyositis/dermatomyositis (PM/DM), 53 with Sjögren syndrome (SS) and with 33 systemic sclerosis (SSc). The association between anti-CCP and clinical features of MCTD was analysed.
  
  
  RESULTS
  Anti-CCP was detected in 87.5% RA cases, 15.8% MCTD cases, 57.1% MCTD with RA cases, 14.1% SLE cases, 15.2% PM/DM cases, 18.9% SS cases and 9.1% SSc cases. Patients with RA (or MCTD with RA) were more likely to be anti-CCP positive than those without RA (P < 0.05). The MCTD patients with positive anti-CCP had higher prevalence of RA and SS related manifestations than those MCTD patients with negative anti-CCP (P < 0.05). The MCTD patients with RA had higher prevalence of RA-related symptoms, diffuse sclerosis and positive anti-CCP than those MCTD patients without RA (P < 0.01). Significant deviation of disease spectrum was found in the MCTD patients with RA compared with the anti-CCP positive MCTD patients without RA.
  
  
  CONCLUSIONS
  High titer of anti-CCP in combination with RA, SLE and SSc manifestations in MCTD patients can be an indicator of erosive arthritis.
authors.affiliation: Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Geng
authors.initials: G
authors.lastname: Yin
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Cen
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Qi-Bing
authors.initials: QB
authors.lastname: Xie
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000097:blood / Q000276:immunology*; D010456:Peptides, Cyclic / Q000276:immunology*; D055815:Young Adult
chemical_list: D000906:Antibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide