Wang G, Csernok E, de Groot K, Gross W L
Department of Rheumatology, University of Lübeck, Lübeck/Rheumaklinik Bad Bramstedt GmbH, Germany.
J Immunol Methods. 1997 Oct 27;208(2):203-11. doi: 10.1016/s0022-1759(97)00154-3.
Antineutrophil cytoplasmic antibodies (ANCA) are used as diagnostic markers for systemic vasculitis. However, the specificity and sensitivity of ANCA detection differs from centre to centre due in large part to variations in methodology. We compared 8 commercial ELISA kits and an in-house method (HM) for their specificity and sensitivity in detecting ANCA against proteinase 3 (PR3-ANCA, 7 kits) and meyloperoxidse (MPO-ANCA, 8 kits). Sera from 5 patients with systemic lupus erythematosus (SLE), 28 with Wegener's granulomatosis (WG), 22 with microscopic polyangiitis (MPA), 5 with idiopathic rapidly progressive glomerulonephritis (RPGN), and 5 healthy controls were examined by both the indirect immunofluorescence technique (IFT) and the ELISA kits. Sera from healthy controls and patients with SLE or cANCA-negative WG were shown to be PR3-ANCA negative by all 7 PR3-ANCA kits. In 25 cANCA-positive sera from WG patients, PR3-ANCA positivity ranged from 44% to 84%. An absolute concordance among the 7 kits was noted in 56% of the cANCA-positive samples. The PR3-ANCA levels in 5 of the 7 kits correlated with the cANCA titers in IFT. Sera from the healthy controls and 4 out of the 5 SLE and pANCA-negative patients were found to be MPO-ANCA negative in all 8 MPO-ANCA kits. In 20 pANCA-positive sera, MPO-ANCA positivity ranged from 25% to 75%. Thirty-five percent of MPO-ANCA-positive sera were confirmed by capture ELISA, immunoblot and inhibition assay. The concordance rate was only 30% among pANCA-positive sera in the 8 MPO-ANCA kits. No significant correlation was observed between pANCA titers and MPO-ANCA levels. The HM showed that 65% of cANCA-positive sera were PR3-ANCA positive, and 45% of pANCA-positive sera were MPO-ANCA positive. Our results indicate that the sensitivities and specificities for ANCA detection differ significantly among the commercial kits tested and underline the necessity of establishing uniform international standards for ANCA ELISA procedures in order to permit more reliable interpretation and comparison of data.
抗中性粒细胞胞浆抗体（ANCA）被用作系统性血管炎的诊断标志物。然而，ANCA检测的特异性和敏感性在不同中心之间存在差异，这在很大程度上归因于方法学的不同。我们比较了8种商用ELISA试剂盒和一种内部方法（HM）在检测抗蛋白酶3（PR3-ANCA，7种试剂盒）和髓过氧化物酶（MPO-ANCA，8种试剂盒）的ANCA时的特异性和敏感性。通过间接免疫荧光技术（IFT）和ELISA试剂盒检测了5例系统性红斑狼疮（SLE）患者、28例韦格纳肉芽肿（WG）患者、22例显微镜下多血管炎（MPA）患者、5例特发性快速进展性肾小球肾炎（RPGN）患者以及5名健康对照者的血清。所有7种PR3-ANCA试剂盒均显示健康对照者以及SLE或cANCA阴性的WG患者的血清PR3-ANCA呈阴性。在25份来自WG患者的cANCA阳性血清中，PR3-ANCA阳性率在44%至84%之间。在56%的cANCA阳性样本中，7种试剂盒之间完全一致。7种试剂盒中的5种PR3-ANCA水平与IFT中的cANCA滴度相关。所有8种MPO-ANCA试剂盒均显示健康对照者以及5例SLE患者中的4例和pANCA阴性患者的血清MPO-ANCA呈阴性。在20份pANCA阳性血清中，MPO-ANCA阳性率在25%至75%之间。35%的MPO-ANCA阳性血清通过捕获ELISA、免疫印迹和抑制试验得到证实。8种MPO-ANCA试剂盒中pANCA阳性血清之间的一致率仅为30%。未观察到pANCA滴度与MPO-ANCA水平之间存在显著相关性。内部方法显示，65%的cANCA阳性血清PR3-ANCA呈阳性，45%的pANCA阳性血清MPO-ANCA呈阳性。我们的结果表明，在所测试的商用试剂盒中，ANCA检测的敏感性和特异性存在显著差异，并强调有必要建立统一的国际ANCA ELISA程序标准，以便能够更可靠地解释和比较数据。
