ANTIBODIES AGAINST MUTATED CITRULLINATED VIMENTIN (MCV) ARE BETTER PREDICTORS OF RADIOGRAPHIC PROGRESSION THAN ANTIBODIES AGAINST CYCLIC CITRULLINATED PEPTIDES (CCP)

Background: Predicting RA outcome is crucial for optimal clinical management. Anti-citrullinated peptide antibodies(ACPA) have proven to be useful prognostic markers. Objectives: The aim of this study was to test the prognostic capacity of the recently developed test for anti-mutated citrullinated vimentin (anti-MCV) compared to anti- CCP2 in a cohort of RA patients. Methods: The EURIDISS cohort (n=238, disease duration <4 yrs. mean 2.3 yrs, 56% RF positive) was followed longitudinally for 10 years. 125 patients with x-rays at baseline and follow-up were included in the present analyses. The radiographs were scored according to the vdH Sharp score. Both anti-CCP2 analyses (INOVA®) and anti-MCV analyses (ORGENTEC® ) were performed using ELISA assays according to the manufacturer's instructions. Positive cut-off for anti-MCV was 20U/l. Patients with an average annual progression in vdH Sharp score of hands ≥ 1.0 unit were considered progressors (dependent variable). Uni- and multivariate logistic and linear regression analyses were performed. Kruskal-Wallis test was used to compare radiographic progression between groups with different anti-MCV levels, and linearity checks were performed in the logistic regression by dividing the patients in quartiles according to anti-MCV level. Results: There was a large overlap in the anti-CCP2 positive (141/230) and anti-MCV positive patients (148/230), and the levels were highly correlated (r=0.8, p<0.01) at both baseline and follow up. The anti-MCV test had higher sensitivity (79.5 vs 75.7), specificity (65.3 vs 64.7), PPV (77.3 vs 75.7) and NPV (68.1 vs 64.7) compared to anti-CCP2 regards progression. Anti-MCV was also a stronger predictor of radiographic progression than anti-CCP2 (OR 7.3 (95% CI 3.2-16.5) vs 5.7 (2.6-12.5) in logistic regression analyses. Similar results were found in multivariate analyses when correcting for other known predictors. Anti-MCV positive patients with high levels of anti-MCV had significantly (p<0.01) higher change in the vdHSharp score than the MCV positive patients with lower levels. Patients with anti-MCV levels in the highest quartile were more likely to progress (OR 18.8 (95% CI 5.1-68.7)) compared to patients in the second (9.1 (2.9-28.4)) and third quartile (3.8 (1.3-10.8)) with the lowest quartile as a reference. Conclusion: A positive test for anti-MCV was a slightly stronger predictor of radiographic progression than a positive anti-CCP2 test, despite the overlap between the two tests. This study also indicates that the levels of anti-MCV in addition to the mere presence or absence, adds to the strength of prediction of radiographic progression. Disclosure of Interest: None declaredCitation: Annals of the Rheumatic Diseases, volume 68, supplement 3, year 2009, page 550Session: Rheumatoid arthritis Prognosis, predictorsand outcome (Poster Presentations )