Patzke Jürgen, Favaloro Emmanuel J
Siemens Healthcare Diagnostics Products GmbH, Assay Development, Emil-von-Behring-Str. 76, 35041, Marburg, Germany.
Haematology Department, Sydney Centres for Thrombosis and Haemostasis, Institute of Clinical Pathology and Medical Research (ICPMR), Westmead Hospital, NSW Health Pathology, Westmead, NSW, 2145, Australia.
Methods Mol Biol. 2017;1646:453-460. doi: 10.1007/978-1-4939-7196-1_33.
In addition to assessment of von Willebrand factor (VWF) antigen (VWF:Ag), the first-line laboratory investigation of possible von Willebrand disease (VWD) often includes an assay to measure GPIb (glycoprotein Ib) binding activity of VWF. A decreased GPIb binding activity is characteristic for most of the VWD types. For many years, the most frequently used assay for measuring GPIb binding activity was the ristocetin cofactor assay (VWF:RCo), which measures the agglutination of fixed human platelets by VWF in the presence of ristocetin. Because of performance issues, including high assay variability and a lack of VWF sensitivity, this assay is currently being replaced or supplemented by assays based on the binding of VWF to recombinant GPIb. One published method (now abbreviated VWF:GPIbR) uses wild-type GPIb for triggering the binding reaction in the presence of ristocetin. Another more widely used method (now abbreviated VWF:GPIbM) uses gain-of-function GPIb without ristocetin; this permits spontaneous binding of VWF to GPIb and avoids problems associated with the nonphysiological substance ristocetin. The binding of VWF to GPIb can be quantified by using different principles, e.g., ELISA, particle agglutination, or chemiluminescence. The following chapter describes a ristocetin-free method based on particle agglutination in more detail.
除了评估血管性血友病因子（VWF）抗原（VWF:Ag）外，对疑似血管性血友病（VWD）进行的一线实验室检查通常还包括一项检测VWF糖蛋白Ib（GPIb）结合活性的分析。GPIb结合活性降低是大多数VWD类型的特征。多年来，测量GPIb结合活性最常用的分析方法是瑞斯托霉素辅因子分析（VWF:RCo），该方法通过在瑞斯托霉素存在的情况下测量VWF对固定人血小板的凝集来进行。由于存在性能问题，包括分析变异性高和VWF敏感性不足，目前该分析方法正被基于VWF与重组GPIb结合的分析方法所取代或补充。一种已发表的方法（现缩写为VWF:GPIbR）使用野生型GPIb在瑞斯托霉素存在的情况下引发结合反应。另一种更广泛使用的方法（现缩写为VWF:GPIbM）使用功能获得性GPIb且不使用瑞斯托霉素；这使得VWF能够自发地与GPIb结合，并避免了与非生理性物质瑞斯托霉素相关的问题。VWF与GPIb的结合可以通过不同原理进行定量，例如酶联免疫吸附测定（ELISA）、颗粒凝集或化学发光。以下章节将更详细地描述一种基于颗粒凝集的无瑞斯托霉素方法。
