Arthritis development in patients with arthralgia is strongly associated with anti-citrullinated protein antibody status: a prospective cohort study Bos, W.H.; Wolbink, G.J.; Boers, M.; Tijhuis, G.J.; de Vries, N.; van der Horst-Bruinsma, I.E.; Tak, P.P.; van de Stadt, R.J.; van der Laken, C.J.; Dijkmans, B.A.C.; van Schaardenburg, D. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Arthritis development in patients with arthralgia is strongly associated with anti-citrullinated protein antibody status: a prospective cohort study

Background: The anti-cyclic citrullinated peptide (CCP) test has a high sensitivity and specificity for rheumatoid arthritis, although CCP is not the physiological target of the autoantibodies. Citrullinated fibrin is abundant in inflamed synovium Objective: To assess the diagnostic and prognostic value of antibodies against citrullinated fibrinogen (ACF), a soluble precursor of fibrin, in comparison with IgM-rheumatoid factor (IgM-RF) and the second generation anti-CCP test. Methods: In 379 patients with early arthritis (258 rheumatoid and 121 undifferentiated), the sensitivity, specificity, and positive predictive value of ACF, anti-CCP, and IgM-RF for diagnosing rheumatoid arthritis were calculated. Multivariate logistic regression analysis was used to assess the diagnostic and prognostic value (radiographic progression after two years) of the tests. Results: The sensitivities of the ACF, anti-CCP, and IgM-RF tests were 55.8%, 57.8%, and 44.6%, with specificities of 92.6%, 94.2%, and 96.7%, respectively. Approximately 30% of the IgM-RF negative patients were positive for ACF or anti-CCP or both. The ACF and anti-CCP test had a high agreement in early arthritis (k = 0.84). Of all baseline characteristics, the ACF test and the anti-CCP test were the best predictors for diagnosing rheumatoid arthritis at one year (odds ratio (OR) = 10.3 and 10.6, respectively) and for radiographic progression after two years (OR = 12.1 and 14.8). Conclusions: ACF is as sensitive as anti-CCP and more sensitive than IgM-RF in diagnosing rheumatoid arthritis in early arthritis. The ACF test is also a good predictor of radiographic progression, with a performance similar to the anti-CCP test. The ACF test and the anti-CCP test are especially valuable in IgM-RF negative arthritis.

Objective. To determine the association of HLA-DRB1, rheumatoid factor (RF), and anti-citrullinated protein antibody (ACPA) status with progression of joint damage in early rheumatoid arthritis (RA) treated according to different treatment strategies.Methods. The present study was conducted using data from the BeSt study ( Conclusion. In patients with early RA treated with the goal of tight control of the DAS, no significant association between HLA-DRB1 status and radiographic progression was found. RF and ACPA were predictive of progressive disease only in patients treated with sequential monotherapy. These observations suggest that effective treatment can prevent ISRCTN: 32675862.

Clinical response to treatment was similar in ACPA-positive and ACPA-negative patients. However, more ACPA-positive patients, especially those treated with initial monotherapy, had significant radiological damage progression, indicating that methotrexate monotherapy and DAS- (≤2.4) steered treatment might be insufficient to adequately suppress joint damage progression in these patients.