de Romeuf C, Mazurier C
Laboratoire de Recherche sur l'Hémostase, Laboratoire Français du Fractionnement et des Biotechnologies, Lille, France.
Thromb Haemost. 1998 Jul;80(1):37-41.
Von Willebrand disease is characterised by a quantitative (type 1) or qualitative (type 2) decrease in von Willebrand factor (vWF) a multimeric glycoprotein involved in primary haemostasis. The propeptide of von Willebrand, also named vWF antigen II (vWF:AgII), is released from platelets and endothelial cells and circulates in plasma as a glycoprotein of 100 kD. In the present study, we attempted to determine whether vWF:AgII level may provide information on the synthesis of vWF, specially in patients with von Willebrand disease (vWD). To elucidate that point, we developed an ELISA and quantify the vWF:AgII in normal individuals and in various vWD patients. The propeptide molar concentration was found to be 5 nM as compared to 31 nM for mature vWF. In normal individuals, the level of vWF:AgII was significantly decreased in females from O and A blood groups. In type 2 vWD patients the level of plasma vWF:AgII appears normal in the patients with normal level of platelet vWF. In type 2 B vWD characterised by increased affinity of mature vWF for platelet glycoprotein Ib, the vWF:AgII in contrast to the vWF antigen (vWF:Ag) was not decreased. In type 2A vWD patients the level of vWF:AgII was decreased in patients with absence of high molecular weight vWF in platelets and plasma but normal in patients with increased sensitivity to proteolysis. Finally, in type 1 vWD, some studied patients have a parallel decrease in vWF:AgII and vWF:Ag whereas in others, the vWF:Ag levels were much more affected than corresponding vWF:AgII levels, as observed in some type 2 vWD patients. Thus, in contrast to that already described, the plasma vWF:AgII level cannot discriminate type 1 from type 2 vWD patients. We conclude that the vWF:AgII measurement provides additional information on the mechanisms responsible for vWD and might also contribute to the classification of vWD patients.
血管性血友病以血管性血友病因子（vWF）定量（1型）或定性（2型）减少为特征，vWF是一种参与初级止血的多聚体糖蛋白。血管性血友病前肽，也称为vWF抗原II（vWF:AgII），从血小板和内皮细胞中释放出来，并作为一种100kD的糖蛋白在血浆中循环。在本研究中，我们试图确定vWF:AgII水平是否可以提供有关vWF合成的信息，特别是在血管性血友病（vWD）患者中。为了阐明这一点，我们开发了一种酶联免疫吸附测定法（ELISA）并对正常个体和各种vWD患者的vWF:AgII进行定量。发现前肽摩尔浓度为5 nM，而成熟vWF为31 nM。在正常个体中，O型和A型血的女性vWF:AgII水平显著降低。在2型vWD患者中，血小板vWF水平正常的患者血浆vWF:AgII水平似乎正常。在以成熟vWF对血小板糖蛋白Ib亲和力增加为特征的2B型vWD中，与vWF抗原（vWF:Ag）相反，vWF:AgII没有降低。在2A型vWD患者中，血小板和血浆中缺乏高分子量vWF的患者vWF:AgII水平降低，但对蛋白水解敏感性增加的患者vWF:AgII水平正常。最后，在1型vWD中，一些研究患者的vWF:AgII和vWF:Ag平行降低，而在其他患者中，vWF:Ag水平比相应的vWF:AgII水平受影响更大，正如在一些2型vWD患者中观察到的那样。因此，与已描述的情况相反，血浆vWF:AgII水平不能区分1型和2型vWD患者。我们得出结论认为，vWF:AgII测量为vWD的发病机制提供了额外信息，也可能有助于vWD患者的分类。
