Antibodies against a mutated citrullinated vimentin in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by autoantibodies against citrullinated antigens. The anti-cyclic citrullinated peptide (Anti-CCP) test is commonly used to diagnose rheumatoid arthritis, whereas the anti-mutated citrullinated vimentin (Anti-MCV) is another anti-citrullinated antibody that reacts with mutated citrullinated vimentin. Therefore, we aimed to assess the diagnostic value of anti-MCV antibodies in RA patients and their relation to disease activity. This study included 60 RA patients and 25 normal controls. The disease activity of RA patients was assessed by disease activity score (DAS-28). ELISA was used to test patients and controls for anti-MCV and anti-CCP. The level of anti-MCV was significantly higher among patients with RA compared to the control group (1.56 ± 0.56 vs. 1.20 ± 0.19 mol/l; P< 0.001). Anti-MCV at cut-off point of > 1.2 mol/l had 76% sensitivity and 100% specificity, with an overall diagnostic accuracy of 83.2% for diagnosing RA. Regarding early RA diagnosis, anti-MCV at the cut-off point was > 1.2 mol/l with 70% sensitivity and 100% specificity. For diagnosis of late RA, the cut-off point was > 1.2 mol/l, with 93.3% sensitivity and 100% specificity, whereas the overall diagnostic accuracy was 96.3%. In this study, patients with positive anti-CCP had a marginally higher level of anti-MCV compared to those with negative anti-CCP (1.64 ± 0.28 vs. 1.48 ± 0.73 mol/l; P= 0.29). We concluded that serum levels of Anti-MCV can be used as a diagnostic test in RA. The increased serum levels of Anti-MCV, demonstrated the importance of Anti-MCV as an independent serum marker in predicting the outcome of RA.