Liu Xia, Jia Rulin, Zhao Jinxia, Li Zhanguo
Department of Rheumatology and Immunology, Peking University People's Hospital, 11 South Xizhimen Street, Beijing 100044, China.
J Rheumatol. 2009 Jun;36(6):1136-42. doi: 10.3899/jrheum.080796. Epub 2009 May 15.
Anti-mutated citrullinated vimentin (MCV) antibodies have been reported as a fairly sensitive serological marker of rheumatoid arthritis (RA). We evaluated the diagnostic value of anti-MCV in a large cohort of Chinese patients with early RA.
One hundred seventy patients with early RA (<1 yr duration), 66 with other rheumatic diseases, 10 with infectious diseases, and 60 healthy individuals were included in our study. Serum anti-MCV and second-generation anti-cyclic citrullinated peptide antibodies (anti-CCP2) were measured by ELISA, and rheumatoid factor (RF) was measured by rate nephelometry. The associated clinical data of patients with early RA were also evaluated. Then disease activity was scored by the formula for Disease Activity Score (DAS)28, and the degree of radiological changes was assessed by Sharp score.
The prevalence of serum anti-MCV in patients with early RA (78.2%, 133/170) was significantly higher than that of other rheumatologic patients and patients with infectious diseases. It was 12% (3/25) in systemic lupus erythematosus, 9.5% (2/21) in primary Sjögren's syndrome, 10% (1/10) in systemic sclerosis, 20% (2/10) in ankylosing spondylitis, 12.5% (1/8) in viral hepatitis type B, and 0% (0/2) in tuberculosis. Anti-MCV was not found in the serum of healthy subjects. The sensitivities of anti-MCV, anti-CCP2, and RF tests for early RA were 78.2%, 61.8%, and 72.4%, respectively, and the specificities were 93.4%, 96.3%, and 80.1%. The combination of anti-MCV and anti-CCP2 positivity showed a very high specificity (97.8%) and positive predictive value (97.1%), but a low sensitivity (58.8%). The sensitivity reached 81.2% when the union of anti-MCV and anti-CCP2 positivities was used as one combined criterion. Statistically, anti-MCV had significant correlation with anti-CCP2 (r=0.587, p=0.01, 2-tailed) and RF (r=0.389, p=0.01, 2-tailed). In addition, it had an interesting correlation with radiological assessment (r=0.349, p=0.05, 2-tailed). The anti-MCV had no significant correlation with other factors, such as erythrocyte sedimentation rate, C-reactive protein, antikeratin antibody, antiperinuclear factor, global visual analog scale score for joint pain, IgA, IgG, IgM, C3, C4, hidden rheumatoid factor for IgA (HRFIgA), HRFIgG, and DAS28.
Anti-MCV is a novel diagnostic marker for early RA. It may be more useful if the anti-CCP2 assay is performed concomitantly to diagnose patients with early RA.
抗突变型瓜氨酸波形蛋白（MCV）抗体已被报道为类风湿关节炎（RA）相当敏感的血清学标志物。我们评估了抗MCV在一大群中国早期RA患者中的诊断价值。
本研究纳入了170例早期RA（病程<1年）患者、66例其他风湿性疾病患者、10例感染性疾病患者和60例健康个体。采用酶联免疫吸附测定法（ELISA）检测血清抗MCV和第二代抗环瓜氨酸肽抗体（抗CCP2），采用速率散射比浊法检测类风湿因子（RF）。还评估了早期RA患者的相关临床资料。然后用疾病活动评分（DAS）28公式对疾病活动度进行评分，并用Sharp评分评估放射学改变程度。
早期RA患者血清抗MCV的患病率（78.2%，133/170）显著高于其他风湿性疾病患者和感染性疾病患者。在系统性红斑狼疮中为12%（3/25），在原发性干燥综合征中为9.5%（2/21），在系统性硬化症中为10%（1/10），在强直性脊柱炎中为20%（2/10），在乙型病毒性肝炎中为12.5%（1/8），在结核病中为0%（0/2）。健康受试者血清中未发现抗MCV。抗MCV、抗CCP2和RF检测对早期RA的敏感性分别为78.2%、61.8%和72.4%，特异性分别为93.4%、96.3%和80.1%。抗MCV和抗CCP2阳性联合显示出非常高的特异性（97.8%）和阳性预测值（97.1%），但敏感性较低（58.8%）。当抗MCV和抗CCP2阳性联合作为一个联合标准时，敏感性达到81.2%。统计学上，抗MCV与抗CCP2（r=0.587，p=0.01，双侧）和RF（r=0.389，p=0.01，双侧）有显著相关性。此外，它与放射学评估有有趣的相关性（r=0.349，p=0.05，双侧）。抗MCV与其他因素，如红细胞沉降率、C反应蛋白、抗角蛋白抗体、抗核周因子、关节疼痛的整体视觉模拟量表评分、IgA、IgG、IgM、C3、C4、IgA隐匿性类风湿因子（HRFIgA）、HRFIgG和DAS28无显著相关性。
抗MCV是早期RA的一种新型诊断标志物。如果同时进行抗CCP2检测来诊断早期RA患者，可能会更有用。
