To compare the diagnostic efficiency of anti-MCV, anti-CCP2 and RF detection for patients with RA.
Cross-sectional study of patients with established rheumatic disease: rheumatoid arthritis (RA; n=75), psoriatic arthritis (PsA; n=25), 27 patients with ankylosing spondylitis (AS; n=27) and connective tissue disease (CTD; n=17). Anti-CCP2, anti-MCV and RF were detected by enzyme-linked immunosorbent assays on stored serum according to the manufacturer's instructions.
IgM-RF had the highest sensitivity, but the positive likelihood ratio is just 1.43. The detection of anti-MCV has a higher sensitivity for RA (76%), a specificity similar to anti-CCP2 (96%) resulting in the lowest negative likelihood ratio (0.25). Anti-MCV levels correlate well with anti-CCP2 levels (R=0.74; p<0.01). The mean level of anti-MCV is significantly higher in RA than in other subgroups (395 U/ml versus 14.4 U/ml, χ2=61.0; p<0.001) and in each other subgroup (Mann-Whitney-Wilcoxon: U=239, p<0.001 for RA and PsA; U=215, p<0.001 for RA and AS; U=192, p<0.001 for RA and CTD). Among RA patients, anti-CCP2 levels have a dichotomous distribution whereas anti-MCV levels have a homogeneous distribution.
Anti-MCV could be a better test for diagnosing RA than anti-CCP2.