Von Willebrand disease
Von Willebrand disease is a common genetic disorder that involves the clotting of the blood. The disease causes a deficiency in a protein called von Willebrand factor. With impairment of the protein, excessive bleeding may occur. In rare cases the disorder may occur later in life without genetic markers. Unlike hemophilia, the disease affects males and females equally.
Definition & Facts
Von Willibrand disease may affect one in 100 to 10,000 individuals. People with mild symptoms of the disease may not report the condition, so it is thought to be under-diagnosed. Reduced levels of the factor affect about one percent of the population. Sometimes the disease may be acquired through certain diseases. The condition seldom requires support via infusions of clotting factor to control bleeding, unless certain surgical procedures are planned. The three major types of VWD are:
- Type 1. Levels of factor VIII are low, but not absent. Symptoms are mild to non-existent.
- Type 2. Levels of factor VIII may be present, but do not function properly, causing symptoms of excessive bleeding.
- Type 3. This type is rare, but significantly damaging. Factor VIII is very low. Symptoms are severe and include bleeding into joints and tissue.
Symptoms & Complaints
Sometimes bleeding from the lining of the stomach will reveal itself with blood in the stool. Heavy menstrual bleeding with clots may be a marker of VWD, especially if the menstrual period lasts longer than seven to ten days. Women are more likely to note the disease with heavy bleeding after childbirth as well. Muscle or joint bleeding can occur upon heavy exertion.
Type 3 VWD, the most severe condition, may include all or any of the above symptoms as well as sudden bleeding for no cause and painful swelling of soft tissue and joints, indicative of bleeding into these areas. Symptoms of this common disorder can become evident at any time after birth, and most people with moderate to severe von Willebrand disease are diagnosed early in life.
Von Willebrand disease is usually inherited. Symptoms vary with parents and children. A person diagnosed with type 1 von Willebrand disease, the mildest form, or type 2 VWD, the moderate form, inherited the disease even if just one parent passed the gene along. Some people have the gene for von Willebrand disease, but show no symptoms. Sometimes a person can get VWD later in life, but this is the result of other medical conditions. This kind of VWD is called acquired von Willebrand syndrome.
Diagnosis & Tests
Von Willebrand disease can be difficult to diagnose, because many people have very mild symptoms. If an individual has any symptoms of a bleeding disorder, the physician may recommend consultation with a blood disorder specialist, or hematologist. A hematologist will perform blood tests to confirm or rule out suspicions of VWD.
A medical history and physical examination will be taken/performed, and questions will be asked about any history of bleeding or if anyone in the immediate family suffers from excessive bleeding. The physical examination will check for signs of recent bleeding such as bruising or lumps under the skin characteristic of VWD.
If the physical examination is indicative of more bleeding than is considered within the norm, specific blood tests will be ordered. These could include:
- A von Willebrand factor (vWF) antigen test will determine the level of von Willebrand factor present.
- A factor VIII clotting activity test will check the level and activity of factor VIII present.
- A ristocetin cofactor activity evaluation determines how well von Willebrand factor works in a person's clotting process.
- A platelet function test may be ordered to discover how well platelets function in the clotting process.
- A von Willebrand factor multimers test will evaluate what type of von Willebrand disease a person may have.
Treatment & Therapy
Von Willebrand disease is a chronic condition and has no cure. Even so, treatment is quite effective. The medications that will be prescribed for VWD depend upon the type and severity of the disease, as well as other medications a person might be taking. Commonly prescribed medicines for von Willebrand disease are:
- Desmopressin. Most doctors consider this drug the first line of defense for VWD. It can be administered via injection, but is often administered through a nasal spray. The drug is a synthetic hormone that regulates bleeding and encourages the body to release more von Willebrand factor that may be stored in vessel linings. It is most effective for those with type 1 or type 2 of the disease.
- Infusion of blood clotting factors.
- Estrogen hormones via oral contraceptive pills. Th estrogen raises the levels of VWF in the blood.
- Blood clotting medications which slow clot breakdown.
- Fibrin sealants, which is a synthetic that acts very similarly to a scab on a sore that ends bleeding.
If von Willebrand disease is considered mild, clotting medications may only be prescribed for surgery, dental extractions, or accidental injuries.
Prevention & Prophylaxis
Prevention is important because there is a risk to patients of acquired infections from frequent blood transfusions. Focus upon preventing bleeding episodes for those with severe von Willebrand disease is considered optimal.