葡萄糖-6-磷酸异构酶、抗环瓜氨酸肽抗体、类风湿因子联合检测对类风湿关节炎的诊断价值

The combined determination of GPI,anti-CCP antibody and RF for the diagnosis of rheumatoid arthritis

目的探讨葡萄糖-6-磷酸异构酶（GPI）、抗环瓜氨酸肽（CCP）抗体、类风湿因子（RF）联合检测对类风湿关节炎（RA）的诊断价值。方法分别选取60例RA患者、60例非RA患者[系统性红斑狼疮（SLE）患者28例、强直性脊柱炎（AS）患者22例、骨关节炎（OA）患者10例]和30名健康体检者（正常对照组）,采用酶联免疫吸附试验检测GPI和抗CCP抗体,采用免疫透射比浊法检测RF,同时检测RA患者的红细胞沉降率（ESR）、C反应蛋白（CRP）并进行RA疾病活动性评分（DAS28）。采用受试者工作特征（ROC）曲线确定GPI诊断RA的最佳临界值,采用Pearson相关性分析评价RA患者GPI、抗CCP抗体、RF与疾病活动性指标ESR、CRP、DAS28的相关性。结果 RA组和非RA组GPI与正常对照组比较差异均有统计学意义（P〈0.05）。RA组GPI、抗CCP抗体及RF与非RA组比较差异均有统计学意义（P〈0.05）。ROC曲线分析显示GPI诊断RA的最佳临界值为0.28 mg/L,敏感性为82.2%,特异性为89.5%,ROC曲线下面积为0.87。联合检测中以各项检测均阳性定为阳性。GPI、抗CCP抗体单项检测的敏感性和特异性均高于RF单项检测。联合检测中3项联合检测的敏感性最低,但特异性最高,达99.9%。60例RA患者中有8例抗CCP抗体为阴性,其GPI浓度为0.757（0.001~3.001）μg/m L,阳性检出率为87.5%。RA患者GPI与ESR、CRP、DAS28均呈正相关（r值分别为0.117、0.041、0.104,P〈0.001）。结论 GPI可作为RA的诊断和判断疾病活动性的指标之一,尤其是在抗CCP阴性的RA患者中有较高的临床价值。GPI、抗CCP抗体、RF联合检测可显著提高RA诊断的特异性。

Objective To investigate the combined determination of glucose-6-phosphate isomerase（GPI）,anti-cyclic citrulinated peptide（CCP） antibody and rheumatoid factor（RF） for the diagnosis of rheumatoid arthritis（RA）. Methods A total of 60 RA patients were enrolled,and 60 non-RA patients were enrolled,including 28 patients with systemic lupus erythematosus（SLE）,22 patients with ankylosing spondylitis（AS）and 10 patients with osteoarthritis（OA）. A total of 30 healthy subjects were enrolled as healthy control group. GPI and anti-CCP antibody were determined by enzyme-linked immunosorbent assay,and RF was determined by turbidimetric immunoassay. Erythrocyte sedimentation rate（ESR） and C-reactive protein（CRP）were also determined. Disease activity score in 28 joints（DAS28）was used. Receiver operating characteristic（ROC）curve was used to define optimal threshold of GPI for the diagnosis of RA. Pearson correlation analysis was used to evaluate the correlations of GPI,anti-CCP antibody and RF with ESR,CRP and DAS28. Results There was statistical significance for RA and non-RA groups compared with healthy control group（P〈0.05）. There was statistical difference for GPI,anti-CCP antibody and RF in RA group compared with non-RA group（P〈0.05）. ROC curve showed that the optimal threshold of GPI was 0.28 mg/L for the diagnosis of RA,the sensitivity was 82.2%,the specificity was 89.5%,and the area under ROC curve was 0.87. The positivity of combined determination was defined as each index（GPI,anti-CCP antibody and RF） was positive,and the sensitivities and specificities of GPI and anti-CCP antibody single determinations were higher than those of RF single determination. The sensitivity of the combined determination was the lowest,but the specificity was the highest（99.9%）. There were 8 antiCCP antibody-negative patients in RA group,its concentration of GPI was 0.757（0.001-3.001）μg/m L,and its positive rate was 87.5%. GPI was positively correlated with ESR, CRP and DAS28 in RA group（r=0.117,0.041 and 0.104,P〈0.001）. Conclusions GPI can be used as an indicator for the diagnosis of RA and distinguishing RA activeness,especially for RA patients with negative anti-CCP antibody. The combined determination of GPI,antiCCP antibody and RF can improve specificity in the diagnosis of RA.