Von Willebrand disease

Von Willebrand's disease (vWD) is a hereditary coagulation abnormality that arises from a deficiency of von Willebrand factor (vWF), a substance that affects platelet adhesion. It is known to affect humans and, in veterinarian medicine, dogs.

Table of contents

1 Classification
2 Bleeding tendency
3 Epidemiology
4 Therapy
5 History
6 Sources
7 See also

Classification

There are three described types of vWD - type I, type II and type III, of which type I and II are inherited as autosomal dominant traits and type III is inherited as autosomal recessive.

Although very rare, acquired forms of vWD have been described. A form of vWD (type 2A) occurs in patients with aortic valve stenosis, leading to gastrointestinal bleeding (Heyde's syndrome).

Bleeding tendency

Type I vWD patients have clearly impaired clotting but usually end up leading a nearly normal life (trouble usually arises in the form of dental surgery or troublesome menorrhagia/periods).

Type III is the most severe form of vWD and may have severe mucosal bleeding, no detectable vWF antigen, and/or may have sufficiently low factor VIII that they have occasional hemarthoses like mild hemophiliacs.

Epidemiology

In humans, the incidence of vWD is roughly about 1 in 1000 individuals. Because most forms are rather mild, they are detected more often in women, whose bleeding tendency shows during menstruation.

Therapy

Patients with vWD normally require no regular treatment. However, they are always at increased risk for bleeding. Prophylactic treatment is sometimes given for patients with vWD who are scheduled for surgery. They can be treated with cyroprecipitate or with Factor VIII. Mild cases of vWD can be trialled on 1-desamino-8-D-arginine vasopressin (DDAVP, desmopressin), which works by raising the patient's own plasma levels of vWF.

History

vWD is named after Erik Adolf von Willebrand, a Finnish internist (1870-1949). He first described the disease in 1926.

Sources

Information obtained partly from Harrison's textbook of Internal Medicine, Chapter 177.