Von Willebrand disease
Other Names: VWD; Von Willebrand factor, deficiency; Hereditary von Willebrand disease
Von Willebrand disease is a bleeding disorder that slows the blood clotting process. People with this disease often experience bruising, nosebleeds, and prolonged bleeding or oozing following an injury, affer surgery, or having a tooth pulled. Affected women may have heavy menstrual bleeding. In severe cases, heavy bleeding occurs after minor injury or even in the absence of injury.
Blood contains many proteins that help the body stop bleeding. One of these proteins is called von Willebrand factor (VWF). People with VWD either have a low level of VWF in their blood or the VWF protein doesn’t work the way it should.
Normally, when a person is injured and starts to bleed, the VWF in the blood attaches to small blood cells called platelets. This helps the platelets stick together, like glue, to form a clot at the site of injury and stop the bleeding. When a person has VWD, because the VWF doesn’t work the way it should, the clot might take longer to form or not form the way it should, and bleeding might take longer to stop. This can lead to heavy, hard-to-stop bleeding. Although rare, the bleeding can be severe enough to damage joints or internal organs, or even be life-threatening.
VWD is the most common bleeding disorder, found in up to 1% of the U.S. population. This means that 3.2 million (or about 1 in every 100) people in the United States have the disease. Although VWD occurs among men and women equally, women are more likely to notice the symptoms because of heavy or abnormal bleeding during their menstrual periods and after childbirth.
Types of VWD
Type 1 This is the most common and mildest form of VWD, in which a person has lower than normal levels of VWF. A person with Type 1 VWD also might have low levels of factor VIII, another type of blood-clotting protein. This should not be confused with hemophilia, in which there are low levels or a complete lack of factor VIII but normal levels of VWF. About 85% of people treated for VWD have Type 1.
Type 2 With this type of VWD, although the body makes normal amounts of the VWF, the factor does not work the way it should. Type 2 is further broken down into four subtypes―2A, 2B, 2M, and 2N―depending on the specific problem with the person’s VWF. Because the treatment is different for each type, it is important that a person know which subtype he or she has.
Type 3 This is the most severe form of VWD, in which a person has very little or no VWF and low levels of factor VIII. This is the rarest type of VWD. Only 3% of people with VWD have Type 3.
Von Willebrand disease is typically an inherited disease caused by variations (mutations) in the VWF gene. The VWF gene provides instructions for making a blood clotting protein called von Willebrand factor, which is important for forming blood clots and preventing further blood loss after an injury. If von Willebrand factor does not function normally or too little of the protein is available, blood clots cannot form properly. VWF gene mutations that reduce the amount of von Willebrand factor or cause the protein to function abnormally (or not at all) are responsible for the signs and symptoms associated with the condition.
Most, but not all, cases of von Willebrand disease (VWD) are inherited. The majority of cases of type 1 and type 2A, as well as type 2B and type 2M, are inherited in an autosomal dominant manner. VWD type 2N, type 3, and some cases of type 1 and type 2A are inherited in an autosomal recessive manner. Most individuals with an autosomal dominant type of VWD have an affected parent. However, some individuals are affected due to having a new (de novo) mutation in the VWF gene that occurred for the first time in the affected individual. If the mutation found in the affected individual cannot be detected in either parent, it is most often due to a de novo mutation but may also be due to germline mosaicism in a parent. Possible non-medical explanations which may be explored include alternate paternity or maternity (e.g., with assisted reproduction) or undisclosed adoption.
Another rare and different condition called acquired von Willebrand syndrome (AVWS). is a mild to moderate bleeding disorder that is typically seen in conjunction with other disorders, such as diseases that affect bone marrow or immune cell function. AVWS is not caused by a mutation in the VWF gene and usually begins in adulthood.
The major signs of VWD are:
Frequent or Hard-to-Stop Nosebleeds People with VWD might have nosebleeds that:
- Start without injury (spontaneous)
- Occur often, usually five times or more in a year
- Last more than 10 minutes
- Need packing or cautery to stop the bleeding
- Easy Bruising
People with VWD might experience easy bruising that:
- Occurs with very little or no trauma or injury
- Occurs often (one to four times per month)
- Is larger than the size of a quarter
- Is not flat and has a raised lump
- Heavy Menstrual Bleeding
Women with VWD might have heavy menstrual periods during which:
- Clots larger than the size of a quarter are passed
- More than one pad is soaked through every 2 hours
- A diagnosis of anemia (not having enough red blood cells) is made as a result of bleeding from heavy periods
- Longer than Normal Bleeding After Injury, Surgery, Childbirth, or Dental Work
People with VWD might have longer than normal bleeding after injury, surgery, or childbirth, for example:
- After a cut to the skin, the bleeding lasts more than 5 minutes
- Heavy or longer bleeding occurs after surgery. Bleeding sometimes stops, but starts up again hours or days later.
- Heavy bleeding occurs during or after childbirth
People with VWD might have longer than normal bleeding during or after dental work, for example:
- Heavy bleeding occurs during or after dental surgery
- The surgery site oozes blood longer than 3 hours after the surgery
- The surgery site needs packing or cautery to stop the bleeding
The amount of bleeding depends on the type and severity of VWD. Other common bleeding events include:
- Blood in the stool (feces) from bleeding into the stomach or intestines
- Blood in the urine from bleeding into the kidneys or bladder
- Bleeding into joints or internal organs in severe cases (Type 3)
Screening Tests A combination of blood tests is needed to diagnose the disease. The following screening tests are done first to show if the blood is clotting properly. These tests may show if there is a bleeding disorder, but more tests are needed to tell the type of bleeding disorder present. Screening tests are often normal in VWD, and more specific tests are required.
Complete Blood Count (CBC) This common test measures the amount of hemoglobin (the red pigment inside red blood cells that carries oxygen), the size and number of red blood cells, and the numbers of different types of white blood cells and platelets found in blood. The CBC is normal among people with VWD. However, if a person with VWD has unusually heavy bleeding or bleeds for a long time, the hemoglobin and the red blood cell count can be low.
Activated Partial Thromboplastin Time (APTT) Test This test measures how long it takes for blood to clot. It measures the clotting ability of factors VIII (8), IX (9), XI (11), and XII (12). If any of these clotting factors is too low, it will take longer than normal for the blood to clot. The results of this test will show a longer clotting time among some people with VWD. However, the results of this test will be normal among people with mild VWD.
Prothrombin Time (PT) Test This test also measures the time it takes for blood to clot. It measures primarily the clotting ability of factors I (1), II (2), V (5), VII (7), and X (10). If the level of any one of these factors is too low, it will take longer than normal for the blood to clot. The results of this test will be normal among most people with VWD.
Fibrinogen Test This test also helps doctors assess a patient’s ability to form a blood clot. This test is ordered either along with other blood clotting tests or when a patient has an abnormal PTexternal icon or APTT testexternal icon result, or both. The results of this test will be normal among people with VWD. Fibrinogen is another name for clotting factor I (1).
Diagnostic Tests Specific tests are required to diagnose which bleeding disorder is there. Often these tests need to be repeated several times before an accurate diagnosis can be made. This is because the levels of clotting factors in the blood vary over time as a result of changes the body might be reacting to―such as stress, pregnancy, and infections―that can affect the test results.
The blood tests that a doctor can order to diagnose VWD (or another platelet disorder) include:
- Factor VIII clotting activity―To measure the amount of factor VIII in the blood
- Von Willebrand factor antigen―To measure the amount of VWF in the blood
- Ristocetin cofactor or other VWF activity―To measure how well the VWF works
- Von Willebrand factor multimers―To measure the makeup or structure of the VWF
- Platelet aggregation tests―To measure how well the platelets are working.
The type of treatment prescribed for VWD depends on the type and severity of the disease. For minor bleeds, treatment might not be needed.
The most commonly used types of treatment are:
Desmopressin Acetate Injection This medicine (DDAVP®) is injected into a vein to treat people with milder forms of VWD (mainly type 1). It works by making the body release more VWF into the blood. It helps increase the level of factor VIII in the blood as well.
Desmopressin Acetate Nasal Spray This high-strength nasal spray (Stimate®) is used to treat people with milder forms of VWD. It works by making the body release more VWF into the blood.
Factor Replacement Therapy Recombinant VWF (such as Vonvendi®) and medicines rich in VWF and factor VIII (for example, Humate P®, Wilate®, Alphanate®, or Koate DVI®) are used to treat people with more severe forms of VWD or people with milder forms of VWD who do not respond well to the nasal spray. These medicines are injected into a vein in the arm to replace the missing factor in the blood.
Birth Control Pills Birth control pills can increase the levels of VWF and factor VIII in the blood and reduce menstrual blood loss. A doctor can prescribe these pills for women who have heavy menstrual bleeding.
The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition.
- Antihemophilic factor (human) (Brand name: Alphanate®) For surgical and/or invasive procedures in patients with von Willebrand Disease (VWD) in whom desmopressin is either ineffective or contraindicated. It is not indicated for patients with severe VWD (Type 3) undergoing major surgery
- Antihemophilic factor/von Willebrand factor complex (human), dried, pasteurized (Brand name: Humate-P) 1) In adult patients for treatment and prevention of bleeding in hemophilia A (classic hemophilia) and (2) in adult and pediatric patients for treatment of spontaneous and trauma-induced bleeding episodes in severe von Willebrand disease, and in mild .
- Desmopressin acetate (Brand name: Stimate) desmopressin acetate (Stimate) was approved for the treatment of patients with hemophilia A or von Willebrand's disease (type I) whose factor VIII coagulant activity level is greater than 5%.
- Recombinant von Willebrand factor (rhVWF) (Brand name: Vonvendi) approved for use in adults (age 18 and older) diagnosed with von Willebrand disease (VWD) for perioperative management of bleeding. December 2015 approved for use for on-demand treatment and control of bleeding episodes in adults diagnosed with von Willebrand disease (VWD).
- Human Plasma Coagulation Factor VIII And Human Plasma Von Willebrand Factor (Brand name: Wilate(R))Treatment of spontaneous or trauma-induced bleeding episodes in patients with severe von Willebrand disease (VWD) as well as patients with mild or moderate VWD in whom the use of desmopressin is known or suspected to be ineffective or contraindicated.
NIH genetic and rare disease info
Von Willebrand disease is a rare disease.