Von Willebrand disease

Definition

Von Willebrand disease is the most common hereditary bleeding disorder.

Causes, incidence, and risk factors

Von Willebrand disease is caused by a deficiency of von Willebrand factor. Von Willebrand factor helps blood platelets clump together and stick to the blood vessel wall, which is necessary for normal blood clotting.

Von Willebrand disease affects both men and women. Most cases are mild. Bleeding may occur after surgery or when you have a tooth pulled. Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) can make this condition worse. Bleeding may decrease during pregnancy.

A family history of a bleeding disorder is the primary risk factor. In women with heavy or prolonged menstrual bleeding, von Willebrand is more common in Caucasian women than in African American women. The majority of women with heavy or prolonged menstrual bleeding do NOT have Von Willebrand disease.

Symptoms

• Abnormal menstrual bleeding
• Bleeding of the gums
• Bruising
• Nose bleeds
• Skin rash

Signs and tests

Tests that may be done to diagnose this disease include:

• Bleeding time (is prolonged)
• Platelet aggregation test
• Platelet count (may be normal)
• Ristocetin cofactor test (the primary assay test used to diagnose von Willebrand disease)
• Von Willebrand factor level (level is reduced)

This disease may also alter the results of the following tests:

• Factor VIII level
• Von Willebrand factor multimers (parts of the von Willebrand factor protein molecule)

Von Willebrand disease may be hard to diagnose. Low von Willebrand factor levels and bleeding do not always mean you have von Willebrand disease.

Treatment

Medications such as desamino-8-arginine vasopressin (DDAVP) can be given to raise the levels of von Willebrand factor, which will reduce the tendency toward bleeding.

Some types of von Willebrand disease do not respond to DDAVP. Tests should be done to determine a patient's specific type of von Willebrand disease before trauma or surgery occurs. A trial of DDAVP can be done before surgery to test whether von Willebrand factor levels increase.

The drug Alphanate (antihemophilic factor) is approved to decrease bleeding in patients with the disease who must have surgery or any other invasive procedure.

Blood plasma or certain factor VIII preparations may also be used to decrease bleeding.

Expectations (prognosis)

Women who have this condition generally do NOT have excessive bleeding during childbirth.

Although this disease is passed down through families, genetic counseling is only rarely recommended for those considering pregnancy.

Complications

Bleeding (hemorrhaging) may occur after surgeries or other invasive procedures.

If you have von Willebrand disease, do not take nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin or ibuprofen, without talking to your health care provider.

Calling your health care provider

Call your health care provider if bleeding occurs without reason.

If you have von Willebrand disease and are scheduled for surgery or are in an accident, be sure you or your family notify the health care providers about your condition.

References

Kumar V, Abbas AK, Fausto N. Robbins and Cotran Pathologic Basis of Disease. 7th ed. St. Louis, Mo: WB Saunders; 2005:654-655.

Noble J. Textbook of Primary Care Medicine. 3rd ed. St. Louis, Mo: Mosby; 2001:1047.

Marx J. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 5th ed. St. Louis, Mo: Mosby; 2002:1693.

Sadler JE. New concepts in von Willebrand disease. Annu Rev Med. 2005;56:173-191.