Sinico Renato Alberto, Radice Antonella, Corace Caterina, DI Toma Lucafrancesco, Sabadini Ettore
Dipartimento di Nefrologia e Immunologia, Azienda Ospedaliera, Ospedale San Carlo Borromeo, Via Pio Secondo 3, 20153 Milano, Italy.
Ann N Y Acad Sci. 2005 Jun;1050:185-92. doi: 10.1196/annals.1313.019.
The value of anti-neutrophil cytoplasmic antibody (ANCA) detection for monitoring disease activity in ANCA-associated systemic vasculitis (AASV) remains controversial. The aim of our work was to rate the performance of a new automated fluorescence PR3 and MPO-ANCA immunoassay (EliA) for monitoring disease activity in AASV. We evaluated 100 serum samples from 71 AASV patients (with Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome) as well as sera from 58 pathological and 35 normal controls. In addition to PR3 and MPO-ANCA EliA, we performed indirect immunofluorescence and "homemade" PR3 and MPO-ANCA ELISA tests. In AASV patients, ANCA levels were correlated with disease activity, according to the Birmingham Vasculitis Activity Score (BVAS). We derived cutoff limits from receiver operating characteristic (ROC) curve analysis comparing AASV with pathological controls. Our results showed that EliA and ELISA had comparable sensitivity (76%) and specificity (95%). The analysis of active versus inactive status and correlation with ANCA levels showed a clear difference between BVAS Group I (score < or = 4) and BVAS Group II (scores > 4) (AUC = 0.86 vs. 0.72; relative risk [RR] = 2.4; P < 0.0001) for PR3-ANCA, but not for MPO-ANCA (AUC = 0.94 vs. 0.87; RR = 1.48; P = 0.46). Serial serum samples from 16 patients were examined in detail. For the majority of patients, for both PR3 and MPO-ANCA, change in titer was strongly associated with change in BVAS score. Our data showed a good correlation between ANCA titer (especially for PR3) and AASV disease activity. We recommend that ANCA titer be used to monitor AASV disease activity with the caveat that a few exceptions, in particular with MPO-ANCA, are possible.
抗中性粒细胞胞浆抗体（ANCA）检测在监测ANCA相关性系统性血管炎（AASV）疾病活动度方面的价值仍存在争议。我们研究的目的是评估一种新型的自动化荧光PR3和MPO-ANCA免疫测定法（EliA）在监测AASV疾病活动度方面的性能。我们评估了来自71例AASV患者（包括韦格纳肉芽肿、显微镜下多血管炎和变应性肉芽肿性血管炎）的100份血清样本，以及58份病理对照血清和35份正常对照血清。除了PR3和MPO-ANCA EliA检测外，我们还进行了间接免疫荧光以及“自制”的PR3和MPO-ANCA ELISA检测。根据伯明翰血管炎活动评分（BVAS），在AASV患者中，ANCA水平与疾病活动度相关。我们通过比较AASV患者与病理对照的受试者工作特征（ROC）曲线分析得出临界值。我们的结果显示，EliA和ELISA具有相当的敏感性（76%）和特异性（95%）。对活动状态与非活动状态的分析以及与ANCA水平的相关性显示，PR3-ANCA在BVAS I组（评分≤4）和BVAS II组（评分>4）之间存在明显差异（AUC = 0.86对0.72；相对危险度[RR]=2.4；P<0.0001），但MPO-ANCA不存在明显差异（AUC = 0.94对0.87；RR = 1.48；P = 0.46）。我们详细检测了16例患者的系列血清样本。对于大多数患者，PR3和MPO-ANCA的滴度变化都与BVAS评分变化密切相关。我们的数据显示ANCA滴度（尤其是PR3）与AASV疾病活动度之间具有良好的相关性。我们建议使用ANCA滴度来监测AASV疾病活动度，但需要注意的是，可能存在一些例外情况，特别是MPO-ANCA。
