Von Willebrand disease: An inherited bleeding disorder in which a clotting protein called von Willebrand factor is deficient or defective. Von Willebrand factor is made by cells lining the wall of blood vessels. When vessels are damaged, platelets normally clump at the site of the injury. Von Willebrand factor acts as glue to help the platelets clump. Von Willebrand factor is also a carrier of clotting factor VIII, another protein that helps the blood to clot.
Von Willebrand disease is the most common inherited bleeding disorder. It occurs in about 1 in every 100 to 1,000 people. There are three major types of von Willebrand disease:
- Type 1 -- the mildest and most common form of the disease. There is a low level of von Willebrand factor. Levels of factor VIII may also be lower than normal.
- Type 2 -- a mild-to-moderate form of the disease. Von Willebrand factor does not work as it should. Type 2 is divided into types 2A, 2B, and 2C.
- Type 3: -- the most severe form of the disease and very rare. Von Willebrand factor is absent and factor VIII is low.
The symptoms of Types 1 and 2 are mild-to-moderate bleeding including easy bruising, nosebleeds, bleeding from the gums after a dental procedure, heavy menstrual bleeding in women, blood in the stool and urine, and excessive bleeding after a cut or other accident or after surgery. Heavy menstrual bleeding is the most common symptom in women and can lead to iron deficiency anemia. Patients with Type 3 disease bleed into soft tissues and joints and have severe bleeding episodes for no apparent reason.
Von Willebrand disease is usually mild and often does not require treatment. Treatment may only be needed after a surgery, tooth extraction, or an accident. For those who need treatment, one or more of the following may be used: medication to increase the production of the von Willebrand factor; medication to prevent breakdown of clots; medication to control heavy menstrual bleeding in women; and injection of clotting factor concentrates (containing von Willebrand factor and factor VIII). Specific treatments for von Willebrand disease include:
- Desmopressin (DDAVP) -- a synthetic hormone usually given by injection or nasal spray. It works by making the body produce more von Willebrand factor, which also increases the level of factor VIII activity. DDAVP is effective in treating most patients with Type 1 disease and some with Type 2a disease.
- Replacement therapy -- the injection of a concentrate of von Willebrand factor and factor VIII.
- Oral contraceptives -- can help women who have heavy menstrual bleeding. The hormones in the pills can increase von Willebrand factor and factor VIII activity.
- Antifibrinolytic drugs -- to prevent the breakdown of clotting factors in the blood. They are used mostly to stop bleeding following minor surgery, tooth extraction, or an injury.
- Fibrin glue -- medicine placed directly on a wound to stop the bleeding.
The disease is named for the Finnish internist Erik Adolf von Willebrand (1870-1949). In 1925 von Willebrand saw as a 5-year-old patient from the Åland Islands in the Sea of Bothnia between Finland and Sweden. Four of her siblings had died from bleeding at an early age and both her mother and father came from families with histories of bleeding. Von Willebrand went to the Åland Islands and found 23 of 66 family members had bleeding problems. In his report of the family in 1926, Willebrand concluded that this was an unknown form of hemophilia. He called it pseudohemophilia. It is also known as vascular hemophilia. Other synonyms include angiohemophilia, constitutional thrombopathy, Minot-Von Willebrand disease, and Willebrand-Juergens disease.