The clinical and genetic associations of anti-cyclic citrullinated peptide antibodies in psoriatic arthritis

Rheumatology (Oxford). 2005 Aug;44(8):1056-60. doi: 10.1093/rheumatology/keh686. Epub 2005 May 18.


Objectives: Antibodies recognizing a cyclic citrullinated peptide (anti-CCP) are highly specific for rheumatoid arthritis (RA) but their role in psoriatic arthritis (PsA) remains unclear. The aim of this study was therefore to investigate the prevalence of anti-CCP antibodies in PsA and assess their clinical and genetic associations.

Methods: One hundred and twenty-six patients with PsA, 40 patients with seropositive RA and 40 controls were tested for the presence of anti-CCP antibodies, rheumatoid factor (RF) and the HLA-DRB1 shared epitope. Clinical and radiological data were collected prospectively on all patients and compared between anti-CCP-positive and -negative patients.

Results: Seven (5.6%) patients with PsA were positive for anti-CCP antibodies compared with 0% of controls and 97% of patients with seropositive RA. The presence of anti-CCP antibodies in PsA was significantly associated with the HLA-DRB1 shared epitope (P<0.005), erosive disease (P<0.05), number of swollen joints (P<0.02) and DMARD use (P<0.05).

Conclusions: Overall, the increased prevalence of anti-CCP antibodies in this PsA population failed to reach statistical significance. However, when present, they were a marker of disease severity and had RA-linked MHC class II associations. Further studies are needed in a larger population of patients with PsA and appropriate controls to confirm any true association that may be present.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Arthritis, Psoriatic / genetics
  • Arthritis, Psoriatic / immunology*
  • Arthritis, Rheumatoid / immunology
  • Autoantibodies / blood*
  • Biomarkers / blood
  • Female
  • HLA-DR Antigens / blood
  • HLA-DRB1 Chains
  • Humans
  • Male
  • Middle Aged
  • Peptides, Cyclic / immunology*
  • Prospective Studies
  • Rheumatoid Factor / blood
  • Severity of Illness Index


  • Autoantibodies
  • Biomarkers
  • HLA-DR Antigens
  • HLA-DRB1 Chains
  • Peptides, Cyclic
  • cyclic citrullinated peptide
  • Rheumatoid Factor