Von Willebrand Disease

The von Willebrand disease (vWD) is the most common inherited bleeding disorder that comprises seven types of qualitative and/or quantitative inherited abnormalities of vWD. vWD has a prevalence of approximately 1:100. Normally, von Willebrand factor (vWF) plays a role in primary hemostasis by mediating platelet adhesion (via the GP1b receptor) to exposed collagen at the site of vascular injury and secondarily serves as a protective transporter of factor VIII (the von Willebrand multimer carries receptors for platelet glycoprotein and factor VIII antigen). Without vWF, factor VIII is rapidly cleared. vWF is stored in the Weibel-Palade bodies and produced by megakaryocytes. Quantitative abnormalities of vWD occur in types 1, 1C, and 3, whereas qualitative abnormalities occur in types 2A, 2B, 2M, and 2N. vWD can also be acquired and is seen as recent onset with no personal or family history of bleeding propensity. Some patients have an autosomal-dominant defect in platelet GP1b receptors that results in enhanced binding of vWF that can mimic vWD type 2B, termed platelet type vWD (Table 30.1). Type 1 vWD represents approximately 75% of all cases. Common symptoms of vWD include mucocutaneous bleeding, bruising without recognizable trauma, prolonged and/recurrent nosebleeds, bleeding gums, or menorrhagia.