Von Willebrand Disease (vWD) is a common and usually mild inherited bleeding disorder. It is characterized by a lifelong tendency toward easy bruising, frequent epistaxis and menorrhagia. It was first described by Erik Adolf von Willebrand in 1926. This Finnish doctor was coincidentally named von Willebrand.

Von Willebrand factor (vWF) is a glycoprotein produced by platelets and by cells lining blood vessels. Platelets are blood cells involved in clotting. It is made up of several smaller proteins bound together. Von Willebrand disease results when there is a defect in any of these proteins. When a blood vessel tears and bleeding occurs, platelets are called to the area to plug the hole and stop the bleeding. The cascade of blood clotting factors lead to the production of fibrin. Fibrin is the material that scars are made of. This more permanently seals the vessel. The Von Willebrand Factor acts as glue and holds the platelets together. It holds them to the surface of the torn blood vessel. The Von Willebrand Factor carries one of these clotting factors in the blood. It is called Factor
VIII.

WHO GETS VON WILLEBRAND DISEASE?

Von Willebrand Disease is a hereditary disorder that is caused by an abnormal gene. Each cell of the body contains structures that are called chromosomes. A chromosome is a long chain of chemicals known as DNA. DNA is arranged into hundreds of units called genes. Genes determine things such as the color of a person’s eyes. Each cell contains 46 of these chromosomes. They are arranged into 23 pairs. Von Willebrand Disease is caused by a defect on chromosome 12. This defect could be on the chromosome 12 from the mother or from the father.

There are two ways to get Von Willebrand Disease. It can be passed from a parent who is the carrier, to the child at birth. The second way is due to a genetic mutation. One of the baby’s genes undergoes a change. In this case the parents are normal.

TYPES OF VON WILLEBRAND DISEASE

Type 1 There is less Von Willebrand Factor in the blood than normal. The symptoms may be so mild that they are never diagnosed, but the condition can be made worse by taking aspirin and other nonsteroidal anti-inflammatory drugs because they block blood from clotting. Those with Type 1 Von Willebrand Factor usually don’t bleed spontaneously. However there is significant bleeding with injuries, surgery or when they have a tooth pulled. Type 1 is the most common and the mildest form of Von Willebrand Disease.

Type 2 The body makes a Von Willebrand Factor that is abnormal. This leads to bleeding problems. Fifteen to twenty percent of those with Von Willebrand Disease have Type 2. Within this type there are two kinds of Von Willebrand Disease.

Type 2A The building blocks that makeup the factor are smaller than usual or they breakdown too easily.
Type 2B The factor sticks to the platelets too well. This leads to clumping of the platelets. This causes a low platelet count.

Type 3 Patients have severe bleeding problems. The patient has no measurable Von Willebrand Factor and they have very low Factor VIII levels.

Pseudo, or platelet type This is similar to Type 2B, but the defect is in the platelets instead of the factor.

SYMPTOMS OF VON WILLEBRAND DISEASE

Milder symptoms of Von Willebrand Disease are frequent nose bleeds, occasional bleeding from the gums and heavy menstrual periods in women (menorrhagia). Over half of all women with Von Willebrand Disease have excessive menstrual bleeding.

More severe symptoms include blood in urine; bruising easily; black, tarry or bloody stools and bleeding into joints, resulting in stiffness, pain and swelling. Bleeding into the joints is a rare symptom.

The severity of the symptoms varies greatly, even within the same family.

DIAGNOSIS OF VON WILLEBRAND DISEASE

Diagnosis is made by a combination of blood tests.

The Von Willebrand Factor antigen is a test that measures the amount of the Von Willebrand Factor in the blood.

Ristocetin Cofactor activity shows how well the Von Willebrand Factor works.

Von Willebrand Factor Multimers shows the makeup or structure of the Von Willebrand Factor. This test helps in diagnosing the type of disease that is present.

Platelet Function test measures how well platelets are working.

TREATMENT OF VON WILLEBRAND DISEASE

The most common treatment is desmopressin. Desmopressin causes a temporary increase in the Von Willebrand levels. It can be given intravenously or intranasally. This treatment may be ineffective in treating Type 2A or Type 2B.

Type 3 and in some cases Types 2A and 2B are treated with humate P. This medication is derived from human plasma. It contains both Factor VIII and Von Willebrand Factor. It is given intravenously.

Von Willebrand Disease is estimated to affect fewer than three percent of the population in the United States. The prevalence world wide is estimated at 0.9-1.3%.