title: [Predictive values of anti-cyclic citrullinated peptide antibody, antikeratin antibody and rheumatoid factor in diagnosing articular erosions in patients with rheumatoid arthritis].
abstract: OBJECTIVE
  To explore the diagnostic significance of anti-cyclic citrullinated peptide (CCP) antibody (anti-CCP), antikeratin antibody (AKA) and rheumatoid factor (RF) for predicting articular erosions in patients with rheumatoid arthritis (RA).
  
  
  METHODS
  One hundered and fifty eight RA patients were devided into 2 groups [limited radiographic damage group (Group 1) and severe radiographic damage group (Group 2)] based on the Larsen's score system. Enzyme linked immunosorbent assay, indirect immunofluorescence and rate naphelometry were used to measure anti-CCP, AKA and RF, respectively.
  
  
  RESULTS
  The sensitivity and specificity of Anti-CCP, AKA and RF for detecting RA were 49% and 94%, 50% and 93%, and 79% and 67%, respectively. The specificity increased when any two markers were combined. The patients with severe radiographic damage had higher positive rates of these three antibodies than the patients with limited radiographic damage. Anti-CCP had the highest OR (6.71) for predicting articular erosions in RA patients. The logistic regression analysis showed a strong correlation between anti-CCP, AKA, CRP or cutaneous nodules and the severity of articular erosions. Anti-CCP had the strongest correlation with the severe radiographic damages.
  
  
  CONCLUSIONS
  Anti-CCP has advantages over the other two antibodies in diagnosing RA. However, the diagnostic accuracy can be improved when anti-CCP is combined with AKA or RF. Anti-CCP and AKA have strong correlations with severe articular erosions, which will be helpful for predicting the outcomes of RA.
authors.affiliation: Department of Rheumatology, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Qi-bing
authors.initials: QB
authors.lastname: Xie
authors.forename: Geng
authors.initials: G
authors.lastname: Yin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007633:Keratins / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D011237:Predictive Value of Tests; D012217:Rheumatoid Factor / Q000097:blood*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D007633:Keratins; D012217:Rheumatoid Factor