Vexing Von Willebrand’s Disease

You get nosebleeds which don’t clot. You drift off to sleep in your office cubicle because you are anemic. You menstruate for two weeks at a time. You could have von Willebrand’s disease.

Von Willebrand’s disease is a deficiency of a protein in the blood called the von Willebrand factor that allows clotting. The deficiency results in excessive and prolonged bleeding. According to the Centers for Disease Control and Prevention, von Willebrand’s disease affects 1 percent of the general population.

Von Willebrand’s disease is the No. 1 inherited bleeding disorder. It is much more common than hemophilia and it is much less severe than that better known bleeding disease. Many people walk around without the slightest idea that they have the disorder.

Von Willebrand factor is a blood protein that acts in concert with other blood proteins to seal leaks in blood vessels. It transports another clotting factor, factor VIII, that plays a pivotal role in clot formation. It also encourages blood platelets to clump, adding to the strength of the clot that seals broken blood vessels.

The seriousness of von Willebrand’s disease hinges on the deficiency of that clotting factor. For mild cases, bleeding problems become a serious matter only when a person has sustained major trauma or when major surgery must be performed. In the latter case, preparations for bleeding are made.

If the deficiency of von Willebrand’s factor is great, then life can be miserable. Alarming amounts of blood can be lost during menstrual periods.

Like hemophilia, von Willebrand’s disease is hereditary. Hemophilia is caused by a recessive gene passed on to sons by a mother who carries the gene on one of her X chromosomes. Boys inherit only one X chromosome and only from their mothers. Although two recessive genes are usually needed for a characteristic to be expressed, in hemophilia the recessive gene is expressed in male children because there is no typical dominant gene to oppose it.

The gene for von Willebrand’s disease is a dominant gene, so only one is needed to cause it. In addition, it is carried on an autosome (a nonsex chromosome) and can therefore be passed on to sons or daughters by either parent.

The gene involved in von Willebrand’s disease specifies the production of a protein, von Willebrand factor, that circulates in the blood and is important to the initial stages of clotting. Produced by cells that line blood vessel walls, the protein acts like glue, forming a plug of blood platelets to seal off blood flow. It also helps to stabilize factor VIII, the clotting protein often missing in hemophilia.

The symptoms of von Willebrand’s disease include frequent nosebleeds, easy bruising, heavy menstrual periods and prolonged bleeding after certain surgical procedures. During pregnancy, the von Willebrand factor usually increases, which offers extra protection for women in childbirth. Bleeding at delivery or after childbirth is only likely if the von Willebrand factor is completely off.

There are three types of von Willebrand’s disease. In Type I, the patient has reduced levels of von Willebrand factor in the blood, but what is there is typical. In Type II, the von Willebrand factor produced is abnormal and does not work properly even when plenty of the factor is produced. In Type III, the factor is absent or nearly absent. These patients are most likely to have severe von Willebrand’s disease.

Diagnosis of von Willebrand’s disease is done through various tests, including measuring bleeding time and studying levels of von Willebrand factor in the blood.

The treatments for von Willebrand’s disease depend on the type and the seriousness of symptoms. With the risk of HIV and hepatitis infection, von Willebrand patients and their families are obviously afraid of receiving blood products.

Fortunately, one of the preferred treatments is a synthetic hormone known as DDAVP, which is not a blood product. It is used mainly for those with Type I or II von Willebrand’s disease and does not work for everyone. When it does, it can be injected or even used as a nasal spray.

Other treatments include Humate P, a factor VIII clotting factor made from human blood and cryoprecipitate, another blood product. When obtained from well-screened unaffected family members, cryoprecipitate can be a safe and viable treatment. New methods of viral-inactivate cryoprecipitate may make this a safer treatment for von Willebrand patients who need it.