Pediatric Clinics of North America - CIPERJ

VON WILLEBRAND DISEASE
379
Fig. 1. Role of VWF in mediating the initial events in the hemostatic process. Platelets, rolling
along the endothelial cell surface, are tethered to the site of endothelial cell injury through the
binding of subendothelial VWF to the GpIb protein of the Ib/IX receptor. The platelets subsequently
are activated and the GpIIb/IIIa complex is exposed on the platelet surface. Interaction
of fibrinogen and VWF with GpIIb/IIIa then consolidates the platelet adhesive event and
initiates platelet aggregation.
Clinical features of von Willebrand disease
VWD is stated as the most common inherited bleeding disorder known in
humans. This is based on two large epidemiologic studies that reported the
prevalence of VWD in healthy school-aged children to be approximately 1%
[17,18]. More recent studies, however, suggest that the prevalence of individuals
who have VWD who present to primary care physicians with symptomatic
bleeding or bruising is closer to 1 in 1000 [19]. The number of
individuals referred to a tertiary care center for management of VWD is
much lower, at approximately 1 in 10,000 [20].
VWD is characterized by three key features: a personal history of excessive
mucocutaneous bleeding, abnormal VWF laboratory studies, and
evidence of a family history of the condition. A diagnostic algorithm for
possible VWD cases is presented in Fig. 2.
Bleeding histories
The clinical hallmark of VWD is the presence of excessive and prolonged
mucocutaneous bleeding. Most often, this involves bruising, epistaxis,
bleeding from the gums and trivial wounds, and menorrhagia and postpartum
hemorrhage in women. Prolonged and excessive bleeding also occurs