Anti-mutated citrullinatedvimentin antibody for predicting the activity of rheumatoid arthritis

Background: Anti-citrullinated protein/peptide antibodies (ACPAs) are a heterogeneous family of autoantibodies, targeting citrullinated proteins. We investigated the relationship between serum levels of anti-mutated citrullinatedvimentin antibody (anti-MCV) and rheumatoid arthritis (RA) activity. Method: A total of 271 consecutive female patients with diagnosis of RA who met the ACR/EULAR criteria were enrolled. The disease activity was measured by the Disease Activity Score in 28 joints-erythrocyte sedimentation rate (DAS28-ESR). Anti-MCV was measured by enzyme-linked immunosorbent assay using a commercial kit with a cut-off value for positivity >20 U/mL. Results: Anti-MCV was positive in 153 (56.5%) patients. Disease in anti-MCV positive patients was significantly more active. A new composite index for predicting disease activity was constructed by replacing ESR with anti-MCV in the DAS28 model. There was a correlation between the absolute scores of DAS28-anti-MCV and DAS28-ESR scores. The new composite index best cut-off values corresponding to DAS28-ESR values of 2.6, 3.2, and 5.1 were 2.94, 3.17, and 4.87, respectively. The patients were re-categorized based on the new threshold values calculated by ROC curve analysis. There was agreement between the DAS28-anti-MCV categories and DAS28-ESR disease activity categories. Conclusions: Based on the correlation between anti-MCV levels with RA disease activity index, we conclude that anti-MCV may be a useful test to determine disease activity in RA. Keywords: rheumatoid arthritis, disease activity scores in 28 joints (DAS28), anti-mutated citrullinatedvimentin (anti-MCV)