Diagnostic Utility of Anti-Cyclic Citrullinated Peptide and Anti-Modified Citrullinated Vimentin Antibodies in Rheumatoid Arthritis

Several autoantibodies found in RA are directed to epitopes in citrullinated proteins. One of them is anti modified citrullinated vimentin (Anti-MCV). We tested the value a newly developed ELISA for the detection of antibodies againts a genetically modified citrullinated vimentin (anti-MCV) in comparison with an anti-CCP based ELISA system for the diagnosis of RA. Thirty-five patients with RA (mean age 42.6 ± 10.87 years, mean disease duration 9.37 ± 3.98 years) were enrolled in this study. Twenty -five ankylosing spondylitis (mean age 35.88 ± 6.64 years, mean disease duration 10.25 ± 4.61 years), and 19 healthy subjects (mean age 40.26 ± 5.11 years) served as controls. Anti-CCP antibodies and Anti-MCV antibodies were measured using ELISA. In all RA patients, mean anti- CCP level was 69.07 ± 90.43 U/ml and anti-MCV level was 665.77 ± 1040.19 U/ml. In patients with AS, the mean anti-CCP level was 10.7 ± 5.22 U/ml and anti-MCV level was 40.54 ± 20.15 U/ml. In healthy controls, the mean anti-CCP level was 11.11 ± 7.65 U/ml, anti-MCV level was 23.12 ± 12.04 U/ml. In patients with active RA, the mean serum anti-CCP level was 100.54 ± 98.07 U/ml and anti-MCV level was 998.74 ± 1154.93 U/ml. In patients with inactive RA, the mean serum anti-CCP level was 8.77 ± 1.55 U/ml and anti-MCV level was 27.59 ± 23.10 U/ml. According to these results In patients with RA, the mean serum anti-MCV and anti-CCP levels were significantly high compared to patients with AS and healthy controls (p0.002, p0.001, p0.002, p0.001 respectively). The mean serum anti-MCV and anti- CCP levels were significantly higher in active patients with RA than in inactive patients with RA patients (p0.001 and p0.001 respectively). In inactive patients with RA, the mean serum anti-MCV and anti-CCP levels were similar in patients with AS and patients (p0.484, p0.308, p0.09 and p0.222 respectively). The mean serum anti-MCV levels were correlated with DAS 28 (r0.531, p0.001), VAS score (r0.332, p0.01), ESR (r0.458, p0.001), serum CRP levels (r0.568, p0.01), serum RF levels (r0.529, p0.001), swollen joints number (r0.525, p0.001) and tender joints number (r0.638, p0.001). As a result; measurement of serum anti-MCV levels is useful for diagnosis of RA and combined use of anti-MCV and RF may be more useful prognostic factor than either method alone, RF and anti-CCP.