The performance of anti-cyclic citrullinated peptide antibodies in predicting the severity of radiologic damage in inflammatory polyarthritis: results from the Norfolk Arthritis Register

Arthritis Rheum. 2007 Sep;56(9):2929-35. doi: 10.1002/art.22868.

Abstract

Objective: Anti-cyclic citrullinated peptide (anti-CCP) antibodies are a stronger predictor of the severity of rheumatoid arthritis than is rheumatoid factor (RF). Their role in predicting outcome in unselected patients with new-onset inflammatory polyarthritis (IP) has not been examined. The aims of this study were to examine the role of baseline RF and anti-CCP antibodies in determining the likelihood of patients having erosions at presentation or in predicting future radiologic damage, and to determine whether anti-CCP antibodies or RF is sufficiently robust to be clinically useful in guiding treatment decisions in early IP.

Methods: Patients were recruited from the Norfolk Arthritis Register. Logistic regression models were fitted to test the ability of anti-CCP antibodies and RF to predict erosions. Further models were investigated to examine the role of anti-CCP antibodies in patients stratified by RF status.

Results: The presence of anti-CCP antibodies at baseline was strongly associated with both prevalent erosions (odds ratio [OR] 2.53 [95% confidence interval (95% CI) 1.48-4.30]) and developing erosions at 5 years (OR 10.2 [95% CI 6.2-16.9]). These ORs were higher than those for RF (OR 1.63 [95% CI 0.94-2.82] and OR 3.4 [95% CI 2.2-5.2], respectively). The likelihood ratio (LR) for the prediction of prevalent erosions and erosions at 5 years was highest in the RF-subgroup (LR 2.2 and 5.8, respectively). However, 27% of anti-CCP-patients had developed erosions by 5 years.

Conclusion: Despite their strong association with the presence, development, and extent of erosions, anti-CCP antibodies alone are not a sufficiently accurate measure upon which to base clinical treatment decisions. Knowledge of anti-CCP antibody status is most informative in RF-negative patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Arthritis / blood*
  • Arthritis / immunology*
  • Arthritis / pathology
  • Autoantibodies / blood*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Peptides, Cyclic / immunology*
  • Predictive Value of Tests
  • Rheumatoid Factor / blood
  • Severity of Illness Index

Substances

  • Autoantibodies
  • Peptides, Cyclic
  • cyclic citrullinated peptide
  • Rheumatoid Factor