抗氨甲酰化蛋白抗体对类风湿关节炎的诊断价值

Clinical value of anti-carbamylated protein antibody in the diagnosis of rheumatoid arthritis

目的检测抗氨甲酰化蛋白抗体(抗CarP抗体)在类风湿关节炎(RA)患者血清及关节液中的表达水平,探讨其在RA诊断中的应用价值及其与疾病活动的关系。方法收集山西医科大学第一临床医学院风湿科2015年3月至2016年3月门诊及住院的108例RA患者、28例其他结缔组织病(CTD)患者及30名健康体检者外周血标本,收集同时期31例RA患者及8例骨关节炎(OA)患者关节液。用酶联免疫吸附试验(ELISA)法检测血清及关节液中抗CarP抗体水平。采用SPSS 22.0软件进行统计学处理。结果 (1)RA组、CTD组及健康对照组血清中抗CarP抗体滴度分别为(3.724±2.104)U/ml、(1.823±1.029)U/ml、(1.165±0.851)U/ml,差异有统计学意义(P<0.01),且在RA患者中抗CarP抗体水平明显高于其他两组。(2)抗CCP抗体阴性的RA患者中抗CarP抗体可为阳性,阳性率为2/13(15.4%),两者没有相关性。(3)抗CarP抗体对于诊断RA的敏感度、特异度、阳性预测值、阴性预测值及ROC曲线下面积分别为46.3%、93.1%、92.6%、48.2%、0.891。联合抗CCP抗体敏感度和特异度分别为90.7%、84.5%。(4)抗CarP抗体与DAS28、ESR、CRP、关节肿胀数(SJC)及关节疼痛数(JTC)无相关性(rDAS28=0.133、rESR=0.067、rCRP=0.375、rSJC=0.088、rJTC=0.146,P均>0.05),抗CCP抗体/抗体CarP抗体与DAS28呈正相关(r=0.959,P<0.05)。(5)RA及OA患者关节液内均有抗CarP抗体表达,差异有统计学意义(P<0.05),且RA组抗CarP抗体滴度大于OA组。结论抗CarP抗体存在于RA患者中,对于诊断RA具有较高的特异性,对于抗CCP抗体阴性的RA患者可作为补充诊断指标,与病情活动性有一定相关性。

Objective To detect the levels of anti-carbamylated protein antibody(anti-Car P antibody) in serum and synovial fluid in patients with rheumatoid arthritis(RA) and osteoarthritis(OA),and to analyze their value in the differential diagnosis of RA and whether it is associated with disease activity.Methods The peripheral blood samples of 108 patients with RA,28 patients with other connective tissue diseases(CTD) and 30 healthy controls,synovial fluid samples from 31 patients with RA and 8 patients with OA were all collected,all the samples came from Department of Rheumatoid and Immunology,the First Hospital of Shanxi Medical University,from March 2015 to March 2016.Anti-Car P antibody levels in serum were detected by enzyme-linked immunosorbent assay(ELISA).SPSS 22.0 software were used for statistical processing.Results(1) The serum anti-Car P antibody titers in RA group,CTD group and healthy control group were(3.724±2.104) U/ml,(1.823±1.029) U/ml,(1.165±0.851) U/ml,respectively,the difference was statistically significant(P<0.01),and anti-Car P antibody in RA group was significantly higher than the other groups.(2) Anti-Car P antibody was positive in anti-CCP antibody negative in RA patients,the positive rate was 2/13(15.4%),there was no correlation between them.(3)The sensitivity,specificity,positive predictive value,negative predictive value and the area of ROC curve for the diagnosis of RA were 46.3%,93.1%,92.6%,48.2%,0.891,the sensitivity and specificity of combined anti-CCP antibody were 90.7%and 84.5%.(4)There was no correlation between anti-Car P antibody and DAS28 score,erythmcyte sedimentation rate,C reactive protein,swollen joint count and tender joint count(r_(DAS28)=0.133,r_(ESR)=0.067,r_(CRP)=0.375,r_(SJC)=0.088,r_(JTC)=0.146,all P>0.05).When one anti-CCP antibody was combined with anti-Car P antibody in a score(anti-CCP antibody divided by anti-Car P antibody),a statistically relevant correlation was found(r=0.959,P<0.05).(5)All synovial fluid from patients with RA and OA had anti-Car P antibody expression,the difference was statistically significant(P<0.05),and the titer of anti-Car P antibody in RA group was higher than OA group.Conclusion Anti-CarP antibody exists in patients with RA,which has a high specificity for the diagnosis of RA,and can be used as a supplementary diagnostic index for RA negative patients with anti-CCP antibody.