Clinic Evaluation Of Anti-Mutated Citrullinated Vimentin In Early Rheumatoid Arthritis

Objective:Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic synovial inflammation that may eventually lead to joint destruction . The deposition of citrulline autoantibody in RA articular cavity is primary cause of synovitis.moreover,Genetic factors and environmental factors are all involved in the pathogenesis of the disease . However, until recently, rheumatoid factor (RF) of the IgM isotype has been the frequent laboratory marker routinely used in RA. The assessment of IgM RF has rather low specificity for RA as it can also be detected in sera of patients with other autoimmune diseases, infectious disorders, as well as in the healthy elderly population.recently Anti- citrullinated protein antibodies (ACPAs) have emerged as sensitive and specific serological markers of rheumatoid arthritis (RA), providing superior alternative of the rheumatoid factor (RF),test in the laboratory diagnostics of RA.(ACPAs) include anti-perinuclear factor (APF) , anti- antikeratin(AKA), anti-cyclic citrullinated peptide (Anti- CCP) and anti- mutated citrullinated vimentin (anti-MCV). The presence of several citr- ullinated proteins has been demonstrated in the RA synovium.some of them have been widely used in clinical diagnosis.Anti-cycle citrullinated peptide(CCP) antibodies have emerged as sensitive and specific markers of rheumatoid arthritis ( RA )moreover,anti-CCP antibody has significant predictive value ,as they can be found very early ,sometimes even during the preclinical phase of RA,however,detected in patients with RA, suggesting that citrulline is an essential constituent of autoantigens for RA-specific autoantibodies . The newly developed anti-mutated citrullinated vimentin (anti- MCV) assay has similar diagnostic performance than the anti-CCP ELISA; however, the diagnostic spectrum of the anti-MCV test is somewhat different from that of anti- CCP2. It's especially useful in the diagnosis of RA in RF and anti-CCP2 seronegative patients. The combined application of anti-CCP2 and anti-MCV assays can improve the laboratory diagnostics of RA.we mainliy study the diagnosis manifestations of RA.Methods:(1)Anti-MCV,Anti-CCP were detected in 88 serum samples including 30 from advanced stage RA(accord with the diagnostic criteria of ARA in 1987),30 from early RA(Their disease durations were no more than one year tand they had no bone erosion in X-ray).and 28 from non-RA rheumatic diseases.(2)Anti-MCV,Anti-CCP activity was determined by an enzyme linked immunosorbent assay (ELISA) using a commercial assay provided by Germen.Other antoantibodies were detected by different techniques.At the same time, Record the patient's age, duration, morning stiffness of time, joint tenderness index, joint swelling index, joint activity pain index, joint resting pain index, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), rheumatoid factor (RF) and hands in each stage of X line(.3)Utilize SPSS 17.0 statistic software to statistical analysis. Utilize area under the curve of ROC to analysis diagnostic value of anti-MCV and anti-CCP. A X2 test was used to compare percentages, Correlation between Anti-MCV and other index was assessed by spearman's correlation analysis.Result:(1) Anti-MCV's positive rate is 83.3% in early RA, 90.0% in advanced stage RA,14.0% in non-RA rheumatic diseases. The serum level of Anti-MCV in three group: early RA was 599.77±650.44U/ml, advanced stage RA was 632.86±544.61U/ml, non-RA rheumatic diseases was 22.36±20.83U/ml. According to statistics analysis the early RA, advanced stage RA have significant difference with non-RA rheumatic diseases(P<0.05) (2) the sensitivity and specificity of Anti-MCV in RA were85%,92.9% ,the positive and negative predictive value was96.2%,74.3% , the sensitivity and specificity of Anti-CCP in RA were78.3%,96.4% ,the positive and negative predictive value was97.9%,67.5% , the sensitivity and specificity of RF in RA were 69.2%,34.8% ,the positive and negative predictive value was75%,28.6%;the sensitive and specific of anti-MCV and anti-CCP all super to that of RF.Moreover , anti-MCV show higher sensitivity than anti-CCP .(3)According to receiver operating characteristic curve analysis, area under the curve of anti-MCV was 0.909 , standard error was 0.030, 95% CI(0.849-o.908); area under the curve of anti-CCP was 0.923 , standard error was 0.030, 95% CI (0.863 -o.982);the diagnostic value of them are similar. (4)The combination detection of anti-MCV and other antibody Indicate The sensitivity and specificity of MCV/CCP were76.7%,100%,the positive and negative predictive value were100%,66.7%;The sensitivity and specificity of MCV/RF were68.3%,95.3%,the positive and negative predictive value were93.2%,56.8%; The result display The combination detection have an advantage to the single test in specificity,but lower in sensitivity. MCV/CCP were detected together surpass MCV/RF together in the sensitivity and specificity.(5)Anti-MCV between early RA and advance stage RA has no significant difference .In early RA the sensitivity of Anti-MCV super to that of Anti-CCP.but show lower specific than Anti-CCP. (6)Anti-MCV has correlated to Anti- CCP (r= 0.479, p=0.000),and RF(r=0.308 p=0.017).No differences was found be- tween Anti-MCV and other clinical parameters(ESR,CRP,morningstiffness,restpain,actionpain,tenderness,swelling).But has correlation with radiology destruction. (7) Anti-MCV between early ,advance stage RA and other connective tissue disease has no significant difference .(8) The concentration of anti-MCV in release of RA and the activity of RA have no significant deviation.Conclusion: (1)Anti-MCV antibody is a sensitive marker for RA,which show high diagnostic sensitivity and specificity,we utilized anti-MCV and anti-CCP ELISA to assess the performance of this test,indicated they are similar in the diagnostic value. The combination detection can improve the specificity of RA.(2) Anti-MCV has correlated to Anti-CCP (r= 0.479, p=0.000),and RF(r=0.308 p=0.017).No differences was found between Anti-MCV and other clinical parameters.(3) The high concentration of anti- MCV antibody indicate possiblity of osteoclasia. (4) The titer of Anti-MCVantibody have No differences with activity of disease.