Diagnosing von Willebrand Disease

Medical History
Physicial Exam and Testing

A Genetic Disease

Von Willebrand disease (vWD) is passed on genetically from parent to child in an autosomal dominate fashion, which means that if one parent has the disease, then approximately 50% of the children may also be affected. A new mutation means the abnormal gene just appears in a person where there is no family history.

Diagnosing vWD can sometimes be difficult, but an early diagnosis is important to make sure that you’re treated and can live a normal, active life. People with type II or type II vWD may not have major bleeding problems. As a result, they may not be diagnosed until they have heavy bleeding after surgery or some other trauma. On the other hand, type III vWD can cause major bleeding problems during infancy and childhood. As a result, children with type III vWD are usually diagnosed during their first year of life.

To find out if you or your child has vWD, your physician will review your medical history and the results from a physical exam and tests.

Medical History

An in-depth family history and personal bleeding history are important in diagnosing vWD. If the results of vWD screening tests are positive, it is necessary to diagnose the type of vWD. The tests performed to diagnose vWD can show higher values than the person really has if the blood is drawn under stressful conditions, such as the stress and anxiety caused by a crying child. Pregnancy, estrogen, surgery, certain blood types and a recent blood transfusion can also contribute to higher values. The variables in testing reinforce the need for a good patient history.

Your physician will likely ask questions about your medical history and your family’s medical history. He or she may ask about:

Any bleeding from a small wound that lasted more than 15 minutes or started up again within the first 7 days following the injury.
Any extended, heavy or repeated bleeding that required medical attention after surgery or dental extractions.
Any bruising with little or no apparent trauma, especially if you could feel a lump under the bruise.
Any nose bleeds that occurred for no apparent reason and lasted more than 10 minutes despite pressure on the nose, or any nose bleeds that needed medical attention.
Any blood in your stools for no apparent reason.
For women, any heavy menstrual bleeding. This bleeding usually involves clots or lasts longer than 7 to 10 days.
Any history of muscle or joint bleeding.
Any medicines you've taken that might cause bleeding or increase the risk of bleeding. For example, aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), clopidogrel (Plavix®), warfarin or heparin.
Any history of liver or kidney disease, blood or bone marrow disease, or high or low blood platelet counts.

Physical Exam

Your physician will do a physical exam to look for unusual bruising or other signs of recent bleeding. He or she also will look for evidence of liver disease or anemia.

Diagnostic Tests

The blood tests required to diagnosis vWD are specialized and need to be done at a coagulation lab which is usually associated with a hemophilia treatment center (HTC). Sometimes the tests need to be repeated before an accurate diagnosis can be made. As vWD is an inherited disorder, there can be many genetic variants which make diagnosis more difficult. No single test can diagnose vWD. Your physician will order a combination of blood tests to diagnose the disease. These tests may include:

Von Willebrand factor antigen: this test measures the amount of von Willebrand factor in your blood.
Von Willebrand factor ristocetin cofactor activity: this test shows how well the von Willebrand factor works.
Factor VIII clotting activity: some people with vWD have low levels of factor VIII activity, while others have normal levels.
Von Willebrand factor multimers: this test is done if one or more of the first three tests are abnormal. It shows the makeup or structure of the von Willebrand factor. It helps your physician diagnose what type of vWD you have.
Platelet function test: his test measures how well your platelets are working.

Your physician may order these tests more than once to confirm the diagnosis. He or she may also refer you to a hematologist (a physician who specializes in treating blood diseases) to confirm the diagnosis and for follow-up care.

Awareness in Women

There is an increasing awareness today of women with bleeding disorders, alerting more and more physicians to get a detailed history of the number of days of menses duration. Women also are becoming aware that more than seven days is too long for a normal menstrual period. Von Willebrand disease and other bleeding disorders should be considered in the differential diagnosis of all females presenting with hemorrhage to any physician.