Understand Childhood Cancers and Blood Disorders
von Willebrand Disease
Von Willebrand Disease (VWD) is the most common inherited bleeding disorder, affecting about one percent of the general population. It is named after Erik von Willebrand who first described it in 1925. Individuals with this disorder commonly present with post-traumatic, post-surgical, or mucocutaneous bleeding (e.g. nosebleeds, gumbleeds, heavy periods, or blood in the urine or stool). Often, affected individuals are asymptomatic and are diagnosed only after they have presurgical testing that reveals prolonged time to form a blood clot.
Once VWD is suspected, a hematologist should be consulted so that the appropriate blood tests can be performed to confirm the diagnosis, and the appropriate treatment can be given to prevent major bleeding. There are three types of VWD: Type I VWD has decreased amounts of von Willebrand factor (VWF), a protein in the blood that helps the blood to clot; Type II VWD comprises different problems in VWF that affect VWF's function; and Type III VWD has no VWF present.
The treatment for VWD depends on the type of VWD. The most common type of VWD is Type I. Since individuals with this type of VWD make some VWF, they can be given a medicine called Desmopressin or DDAVP that helps to release VWF that is stored in the body so that the blood level of VWF can increase to normal. To make sure that a person is Type I, a hematologist will often perform a test called a "DDAVP challenge." For this test, blood is drawn and then DDAVP is given to the individual through an IV over 30 minutes. Blood is then drawn again one hour and two hours after the DDAVP is given. If the amount of VWF increases to normal after the DDAVP is given, then the person is likely to be Type I and DDAVP can be given before any surgical procedures to help prevent bleeding.
In Type III VWD, since there is no VWF present, the only treatment is administration of VWF that is separated from donated blood of individuals with normal amounts of VWF. These VWF concentrates are small volumes of fluid that can be given by IV over five minutes.
There are different types of problems with VWF that comprise Type II VWD, and therefore different treatments are indicated for different individuals. Individuals who make a VWF that functions a little less than normal can be given DDAVP. Individuals who make a VWF that does not function well (e.g. it doesn't bind to platelets or it binds too much to platelets), need to receive VWF concentrates.
Treatment is generally only indicated if there is significant bleeding or before surgery. Since VWD is inherited, family members should be tested so that they can receive treatment if they need it. Aspirin, Motrin, Ibuprofen, Advil and other similar anti-inflammatory medicines should be avoided because they can increase the risk of bleeding.