title: Meta-analysis: diagnostic accuracy of anti-cyclic citrullinated peptide antibody and rheumatoid factor for rheumatoid arthritis.
abstract: BACKGROUND
  Rheumatoid factor (RF) and autoantibodies against cyclic citrullinated peptide (CCP) are markers that might help physicians diagnose rheumatoid arthritis.
  
  
  OBJECTIVE
  To determine whether anti-CCP antibody more accurately identifies patients with rheumatoid arthritis and better predicts radiographic progression than does RF.
  
  
  METHODS
  MEDLINE through September 2006 and reference lists of retrieved studies and review articles.
  
  
  METHODS
  Studies in any language that enrolled at least 10 participants and that examined the role of anti-CCP antibody and RF in the diagnosis or prognosis of known or suspected rheumatoid arthritis.
  
  
  METHODS
  Two authors independently evaluated studies for inclusion, rated methodological quality, and abstracted relevant data.
  
  
  RESULTS
  The DerSimonian-Laird random-effects method was used to summarize sensitivities, specificities, and positive and negative likelihood ratios from 37 studies of anti-CCP antibody and 50 studies of RF. The pooled sensitivity, specificity, and positive and negative likelihood ratios for anti-CCP antibody were 67% (95% CI, 62% to 72%), 95% (CI, 94% to 97%), 12.46 (CI, 9.72 to 15.98), and 0.36 (CI, 0.31 to 0.42), respectively. For IgM RF, the values were 69% (CI, 65% to 73%), 85% (CI, 82% to 88%), 4.86 (CI, 3.95 to 5.97), and 0.38 (CI, 0.33 to 0.44). Likelihood ratios among IgM RF, IgG RF, and IgA RF seemed to be similar. Results from studies of patients with early rheumatoid arthritis were similar to those from all studies. Three of 4 studies found that risk for radiographic progression was greater with anti-CCP antibody positivity than with IgM RF positivity.
  
  
  CONCLUSIONS
  Many studies had methodological limitations. Studies of RF were heterogeneous and had wide ranges of sensitivity and specificity.
  
  
  CONCLUSIONS
  Anti-CCP antibodies are more specific than RF for diagnosing rheumatoid arthritis and may better predict erosivedisease.
authors.affiliation: Department of Health Policy Management, Harvard School of Public Health, Boston, Massachusetts 02215, USA. knishimu@hsph.harvard.edu
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Nishimura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sugiyama
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kogata
authors.forename: Goh
authors.initials: G
authors.lastname: Tsuji
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakazawa
authors.forename: Seiji
authors.initials: S
authors.lastname: Kawano
authors.forename: Katsuyasu
authors.initials: K
authors.lastname: Saigo
authors.forename: Akio
authors.initials: A
authors.lastname: Morinobu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Koshiba
authors.forename: Karen M
authors.initials: KM
authors.lastname: Kuntz
authors.forename: Isao
authors.initials: I
authors.lastname: Kamae
authors.forename: Shunichi
authors.initials: S
authors.lastname: Kumagai
mesh_terms: D001172:Arthritis, Rheumatoid / Q000175:diagnosis*; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D016013:Likelihood Functions; D010456:Peptides, Cyclic / Q000276:immunology*; D011379:Prognosis; D012217:Rheumatoid Factor / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor