Abstract: 【Abstract】Objective To evaluate the clinical values of two kinds of antibodies against citrullinated proteins/peptides, third-generation anti-cyclic citrullinated peptides (anti-CCP-3) and anti-mutated citrullinated vimentin (anti-MCV), and rheumatoid factor (RF) to early diagnosis of rheumatoid arthritis (RA). Methods Thirty Patients with early RA served as early RA group, 32 patients with osteoarthritis (OA) and ankylosing sporidylitis (AS) served as OA/AS group, and 30 healthy persons served as control group. The levels of anti-MCV, anti-CCP-3 and RF were determined. Results While RF≥30 IU/mL, anti-CCP-3＞12 RU/mL, anti-MCV≥20 U/mL served as the cut-off value for RA, anti-MCV tended to have the highest predictive value for RA, and the sensitivity of anti-MCV was 76.67%, the specificity of anti-MCV was 96.77%, and the accuracy of anti-MCV was 90.22%. The sensitivity of performing combinations of RF and anti-MCV tests was 83.33%, while the sensitivity of performing combinations of anti-MCV and anti-CCP-3 tests was 80.00%. The presences of anti-MCV, anti-CCP-3 and RF in early RA group were significantly higher than control group and OA/AS group respectively (P＜0.01), while the presences of anti-MCV, anti-CCP-3 and RF had no significant differences between control group and OA/AS group (P> 0.05). The levels of DAS28, ESR and CRP were lower after treatment in patients with RA (P＜0.01), while the levels of anti-MCV and RF were lower after treatment in patients with RA (P＜0.05). Conclusions Anti-MCV antibodies are valuable to early diagnosis of RA. Performing combinations of RF and anti-MCV tests and performing combinations of anti-MCV and anti-CCP-3 tests can increase the sensitivity of early diagnosis. Anti-MCV, anti-CCP-3 and RF can differentiate RA, OA and AS. Anti-MCV and RF are valuable for effect evaluation and activity evaluating in patients with RA.

Key words: rheumatoid arthritis, ACPA, rheumatoid factor, diagnosis, activity