title: Anti-cyclic citrullinated peptide antibody titer predicts time to rheumatoid arthritis onset in patients with undifferentiated arthritis: results from a 2-year prospective study.
abstract: BACKGROUND
  The diagnostic, predictive and prognostic role of anti-cyclic citrullinated peptide (CCP) antibodies in rheumatoid arthritis (RA) patients is widely accepted. Moreover, detection of these antibodies in subjects presenting with undifferentiated arthritis (UA) is associated with a significant risk to develop the disease. On the other hand, clinical and prognostic significance of evaluating anti-CCP levels in subjects with inflammatory arthritis at disease onset has not been fully clarified. The goal of this prospective study is to analyze the value and prognostic significance of anti-CCP titer quantification in UA subjects.
  
  
  METHODS
  Serial anti-CCP assays were measured in 192 consecutive patients presenting with UA lasting less than 12 weeks. Clinical and serological data and arthritis outcome were evaluated every 6 months until two years of follow-up.
  
  
  RESULTS
  Anti-CCP positivity, at both low and high titer, and arthritis of hand joints significantly predicted RA at two years, risk increasing in subjects with high anti-CCP titers at baseline. Moreover, time to RA diagnosis was shorter in patients with high anti-CCP2 titers at enrollment with respect to those with low antibody concentration.
  
  
  CONCLUSIONS
  Presence of anti-CCP antibodies, at both low and high concentration, is significantly associated with RA development in subjects with recent onset UA. However, time interval from the onset of the first symptoms to the fulfilment of the classification criteria appears to be directly related to the initial anti-CCP level.
authors: Nicola
authors: N
authors: Bizzaro
authors: Elena
authors: E
authors: Bartoloni
authors: Gabriella
authors: G
authors: Morozzi
authors: Stefania
authors: S
authors: Manganelli
authors: Valeria
authors: V
authors: Riccieri
authors: Paola
authors: P
authors: Sabatini
authors: Matteo
authors: M
authors: Filippini
authors: Marilina
authors: M
authors: Tampoia
authors: Antonella
authors: A
authors: Afeltra
authors: Giandomenico
authors: G
authors: Sebastiani
authors: Claudia
authors: C
authors: Alpini
authors: Vittorio
authors: V
authors: Bini
authors: Onelia
authors: O
authors: Bistoni
authors: Alessia
authors: A
authors: Alunno
authors: Roberto
authors: R
authors: Gerli
mesh_terms: D000328:Adult; D001168:Arthritis / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D011379:Prognosis; D011446:Prospective Studies
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide