title: Value of antibodies to citrulline-containing peptides for diagnosing early rheumatoid arthritis.
abstract: OBJECTIVE
  To compare the diagnostic values of antiperinuclear factor (APF), antikeratin antibody (AKA), and anti-cyclic citrullinated peptides (anti-CCP) to discriminate between patients with and without rheumatoid arthritis (RA) and to determine the diagnostic value of anti-CCP used alone or with other tests.
  
  
  METHODS
  Two hundred and seventy patients with early arthritis underwent standardized investigations in 1995-1997. The clinical utility of APF, AKA, and anti-CCP in first-visit sera was evaluated using receiver-operating characteristic curves. Combinations of anti-CCP with other laboratory tests were assessed by multiple logistic regression.
  
  
  RESULTS
  Anti-CCP, APF, and AKA were not perfectly correlated with one another. Anti-CCP with 53 UI as the cutoff was 47% sensitive and 93% specific, versus 52% and 79%, and 47% and 94%, for APF and AKA, respectively. Multiple logistic regression selected anti-CCP, AKA, IgM-rheumatoid factor (RF) ELISA, and the latex test.
  
  
  CONCLUSIONS
  Rheumatologists can routinely use 2 or 3 tests for diagnosing RA (latex and/or IgM RF ELISA, and either AKA or anti-CCP ELISA) and can add a third or fourth test when the diagnosis remains in doubt.
authors.affiliation: Unit of Rheumatology and the Laboratory of Immunology, Hôpital de la Cavale Blanche, CHU Brest, BP 824, F-29609 Brest-Cedex, France. Alain.Saraux@chu-brest.fr
authors.forename: Alain
authors.initials: A
authors.lastname: Saraux
authors.forename: Jean M
authors.initials: JM
authors.lastname: Berthelot
authors.forename: Valérie
authors.initials: V
authors.lastname: Devauchelle
authors.forename: Boutahar
authors.initials: B
authors.lastname: Bendaoud
authors.forename: Gérard
authors.initials: G
authors.lastname: Chalès
authors.forename: Catherine
authors.initials: C
authors.lastname: Le Henaff
authors.forename: Jean B
authors.initials: JB
authors.lastname: Thorel
authors.forename: Sylvie
authors.initials: S
authors.lastname: Hoang
authors.forename: Sandrine
authors.initials: S
authors.lastname: Jousse
authors.forename: Dominique
authors.initials: D
authors.lastname: Baron
authors.forename: Paul
authors.initials: P
authors.lastname: Le Goff
authors.forename: Pierre
authors.initials: P
authors.lastname: Youinou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000974:Antibodies, Antinuclear / Q000097:blood; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D002956:Citrulline / Q000276:immunology*; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007633:Keratins / Q000276:immunology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012219:Rheumatology / Q000379:methods*
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D010456:Peptides, Cyclic; C030902:antiperinuclear factor; D002956:Citrulline; D007633:Keratins