Damoiseaux J, Dähnrich C, Rosemann A, Probst C, Komorowski L, Stegeman C A, Egerer K, Hiepe F, van Paassen P, Stöcker W, Schlumberger W, Tervaert J W Cohen
Department of Clinical and Experimental Immunology, University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands.
Ann Rheum Dis. 2009 Feb;68(2):228-33. doi: 10.1136/ard.2007.086579. Epub 2008 Mar 28.
Antineutrophil cytoplasmic antibodies (ANCA) with a C-ANCA or P-ANCA pattern are detected in ANCA-associated vasculitis (AAV). While in most patients with AAV a C-ANCA pattern is due to reactivity with proteinase-3 (PR3)-ANCA, some C-ANCA-positive sera do not react with PR3.
The development and evaluation of a direct enzyme-linked immunosorbent assay (ELISA) for PR3-ANCA with increased sensitivity.
A mixture of human native (hn) and human recombinant (hr) PR3 was used as antigen coating. The resulting ELISA (anti-PR3-hn-hr) was compared with ELISAs using directly coated hn-PR3 or hr-PR3, as well as with a hn-PR3 capture ELISA. Assay characteristics were determined in patients with AAV (n = 248), with special attention for those patients with C-ANCA (n = 132), as well as disease controls (n = 585) and healthy controls (n = 429). Additionally, for prediction of relapses serial samples of 46 patients with PR3-AAV were analysed.
At a predefined specificity of 99% both ELISAs containing hr-PR3 revealed a substantial increase in sensitivity. For the prediction of relapses by rises in PR3-ANCA titres the capture ELISA was most optimal (odds ratio 12.5). With an odds ratio of 8.9 the novel anti-PR3-hn-hr ELISA was second best.
Owing to the very high sensitivity of the novel anti-PR3-hn-hr ELISA for the detection of PR3-ANCA in C-ANCA-positive samples of patients with AAV this assay has an excellent diagnostic performance. This feature is combined with a good predictability of clinical relapses in patients with PR3-AAV. These characteristics challenge the dogma that, for detection of PR3-ANCA, capture ELISAs are superior for diagnosis and follow-up.
在抗中性粒细胞胞浆抗体（ANCA）相关血管炎（AAV）中可检测到具有C-ANCA或P-ANCA模式的ANCA。虽然在大多数AAV患者中，C-ANCA模式是由于与蛋白酶3（PR3）-ANCA反应所致，但一些C-ANCA阳性血清与PR3不发生反应。
开发并评估一种用于PR3-ANCA的直接酶联免疫吸附测定（ELISA），提高其灵敏度。
使用人天然（hn）和人重组（hr）PR3的混合物作为抗原包被。将所得的ELISA（抗PR3-hn-hr）与使用直接包被的hn-PR3或hr-PR3的ELISA以及hn-PR3捕获ELISA进行比较。在AAV患者（n = 248）中确定检测特征，特别关注那些C-ANCA患者（n = 132），以及疾病对照（n = 585）和健康对照（n = 429）。此外，对46例PR3-AAV患者的系列样本进行分析以预测复发情况。
在预定义的99%特异性下，两种含有hr-PR3的ELISA显示灵敏度大幅提高。对于通过PR3-ANCA滴度升高预测复发，捕获ELISA最为理想（优势比12.5）。新型抗PR3-hn-hr ELISA的优势比为8.9，排名第二。
由于新型抗PR3-hn-hr ELISA在检测AAV患者C-ANCA阳性样本中的PR3-ANCA时具有非常高的灵敏度，该测定具有出色的诊断性能。此特征与PR3-AAV患者临床复发的良好预测性相结合。这些特性挑战了对于检测PR3-ANCA，捕获ELISA在诊断和随访方面更具优势的教条。
