von Willebrand Disease
Video courtesy of the National Hemophilia Foundation, Steps for Living.
Von Willebrand Disease is not as well known as hemophilia, but it is probably the most prevalent of all the disorders of bleeding. We do not know the actual occurrence rate because it is believed that many patients go undiagnosed. However, according some estimates, it may affect as many as 1% of people in the United States. It can affect both boys and girls and most patients do not experience a severe amount of bleeding unless a significant injury or surgery occurs.
The von Willebrand protein, or factor, is a partner to factor 8, another key piece of our bodies to form blood clots quickly and properly. The two proteins, when held together, help to protect each other from destruction. They are able to survive in the blood together for much longer periods of time like this. The von Willebrand factor’s function is to help bring the platelet cells to an area that has been injured and bleeding and to start the clotting process. It also helps all the platelets to stick to one another in the initial periods while a clot is forming. Lastly, it helps to deliver enough factor 8 to a clot so that a forming clot can be strengthened.
Due to its close relationship with factor 8, many patients with von Willebrand disease were mistaken as hemophilia patients. In fact, the disease was even once known as pseudo-hemophilia. However, many of these patients were girls, unlike the vast majority of hemophilia patients who are boys. A Finnish doctor, Erik von Willebrand, described the disease that would come to bear his name as a disease that was passed on from parents to their children and distinct from hemophilia, often occurring in girls, in 1926.
Today, we know it as a disease because those affected do not have enough functional von Willebrand factor. Many people can have very mild or minimal bleeding symptoms, but some can have very severe and frequent bleeding, almost like a hemophilia patient would. Some of the bleeding symptoms include abnormal bruising, unexpected and prolonged nosebleeds, frequent bleeding from the mouth and gums, excessive bleeding after an injury or surgery, and heavy and prolonged menstrual periods. Childbirth may also be a risky time for some women. Some of the differences in bleeding is explained by the fact that there is more than one type of von Willebrand disease. Specialized testing is required in order to complete the diagnosis of von Willebrand disease.
Treating patients with von Willebrand disease is tailored to the severity and type of bleeding. Many patients respond well to care and treatment of the local area of bleeding with pressure, ice, and elevation. Girls with heavy menstrual bleeding may see improvement with the use of hormonal therapy in the form of birth control pills. Still other patients may respond well to a nasal spray known as Stimate ®. Additional medicines can be given by mouth that include aminocaproic acid or tranexamic acid. When severe or life-threatening bleeding occurs, the deficient von Willebrand factor can be replaced with one of several forms of plasma-derived concentrates. In the near future, a recombinant factor that is not developed with the use of human plasma will become available in the U.S.