The relation between cartilage biomarkers (C2C, C1,2C, CS846, and CPII) and the long-term outcome of rheumatoid arthritis patients within the CAMERA trial

Arthritis Res Ther. 2011 May 8;13(3):R70. doi: 10.1186/ar3331.


Introduction: The aim of this study was to investigate whether serum biomarker levels of C2C, C1,2C, CS846, and CPII can predict the long-term course of disease activity and radiographic progression early in the disease course of rheumatoid arthritis (RA).

Methods: In patients in the CAMERA trial, levels of biomarkers were evaluated at baseline and after 1 year of treatment. Relations of (changes in) biomarker values with the mean yearly radiographic progression rate and mean disease activity over a 5-year period were evaluated by using regression analysis. The added predictive value of biomarkers over established predictors for long-term outcome was analyzed by multiple linear regression analysis.

Results: Of 133 patients, serum samples were available at baseline and after 1 year of treatment. In the regression analysis C1,2C at baseline, the change in C2C, C1,2C, and the sum of the standardized changes in C2C + C1,2C scores were statistically significantly associated with the mean yearly radiographic progression rate; the change in CPII was associated with the mean disease activity over 5 years of treatment. In the multiple linear regression analysis, only the change in C1,2C was of added predictive value (P = 0.004) for radiographic progression. Explained variances of models for radiographic progression and disease activity were low (0.28 and 0.34, respectively), and the biomarkers only marginally improved the explained variance.

Conclusions: The change in C1,2C in the first year after onset of RA has a small added predictive value for disease severity over a 5-year period, but the predictive value of this biomarker combined with current predictive factors is too small to be of use for individual patients.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Antirheumatic Agents / therapeutic use
  • Arthritis, Rheumatoid / blood*
  • Arthritis, Rheumatoid / diagnostic imaging
  • Arthritis, Rheumatoid / drug therapy*
  • Biomarkers / blood*
  • Cartilage / diagnostic imaging
  • Cartilage / metabolism*
  • Disease Progression
  • Female
  • Follow-Up Studies
  • Humans
  • Linear Models
  • Male
  • Methotrexate / therapeutic use*
  • Middle Aged
  • Predictive Value of Tests
  • Prospective Studies
  • Radiography
  • Severity of Illness Index*
  • Time
  • Treatment Outcome


  • Antirheumatic Agents
  • Biomarkers
  • Methotrexate