What is a bleeding disorder?
A bleeding disorder is present when the blood does not clot properly. Blood clotting is a complex process that involves as many as 20 different plasma proteins. All clotting proteins and platelets need to work effectively and in the correct order to form a proper clot that is strong enough to stop bleeding. A bleeding disorder occurs when the body is unable to activate the entire clotting cascade correctly.
The clotting cascade
The body initiates the clotting cascade when an injury occurs. At a high level, coagulation works as follows:
Blood vessels constrict – When an injury occurs, the blood vessel at the site of injury contracts to limit the flow of blood to the damaged area.
Platelet plug forms – Within seconds of the injury occurring, small cells found in the blood, called platelets, spread on top of the injured vessel and release chemical signals to attract other cells circulating in the blood. Some of the cells attracted are clotting factors. The first factor to be activated during the clotting cascade is the von Willebrand factor. The vWf is a glue-like protein that forms a plug that prevents blood from flowing to the site of injury.
Fibrin clot is created – Thirteen clotting factors (I-XIII) along with calcium, vitamin K and other proteins work together in a series of complex chemical reactions to form a fibrin clot. The fibrin clot acts as a net over the wound. Depending on the size of the injury, the fibrin clot strengthens over several days or weeks, and when the wound is healed, the fibrin clot dissolves.
If any of the steps in the clotting cascade don’t work properly or are deficient, the person bleeds longer and, therefore, has a bleeding disorder. The type and severity of the disorder is determined based on the protein that is missing from the blood and how much of it is missing.
What is von Willebrand Disease?
von Willebrand Disease (vWD) is the most common type of bleeding disorder, affecting an estimated 1% of the world population. vWD affects both males and females equally. However, because symptoms can be mild, many people go undiagnosed.
von Willebrand Disease (vWD) is characterized by decreased levels or malfunctioning of von Willebrand factor. von Willebrand factor serves as the glue that allows platelets to stick together and form a proper platelet plug after a vessel is injured.
The different types of von Willebrand Disease
Type 1 vWD means levels are lower than normal. The patient may also have low levels of factor VIII as a result. Type 1 is the most common form of vWD and is also the most mild form; it usually doesn’t cause life-threatening bleeding. About 75% of people with vWD have type 1.
Type 2 vWD means that there is a defect in the structure of the protein that causes lower than normal vW factor protein activity.
Type 3 vWD is the most serious and severe form of vWD. It means that a person has very little or no von Willebrand protein production at all.
Causes of von Willebrand Disease
A person is born with von Willebrand Disease. VWD affects males and females equally. The majority of the causes are inherited, passed from parents to children through their genes. Some cases are due to spontaneous mutations caused by the change in the gene that carries the instructions to produce the vW factor. Type 1 and type 2 are usually inherited. One of the parents has the mutated gene and has a 50% chance of passing it to the child. Also, the parent may not know they carry the gene because their symptoms may be very mild or they don’t have symptoms at all. Type 3 is usually inherited and both parents pass the gene to the child.
Signs & Symptoms
Symptoms of von Willebrand Disease (vWD) vary depending on the type and severity of the disease. Symptoms can be so mild they are almost undetectable. For types 1 and 2, symptoms are typically mild to moderate and include, but are not limited to:
- Heavy bleeding after surgery or after cuts and other injuries
- Blood in stools and/or urine from bleeding in the intestines, stomach, or kidneys
- Frequent and hard-to-stop nosebleeds
- Large bruising and easy bruising from minor injuries
- Prolonged bleeding from dental procedures
- Heavy or prolonged menstrual bleeding in women
- Diagnosing von Willebrand Disease
Von Willebrand Disease (vWD) can be hard to diagnose because people with types 1 or 2 may not have major bleeding problems until they have surgery or a major trauma. People with type 3 vWD typically have serious bleeding problems during infancy, so it is usually diagnosed during the first year of life.
Diagnosing vWD generally includes a physical exam, tests, and a thorough medical history. A doctor will ask questions to help determine if you are suffering from any of the symptoms of vWD, even if you didn’t realize it at the time. Since vWD is largely an inherited disease, family history plays a large role in diagnosis.
Blood tests are used to confirm a diagnosis, however there is no one test that can conclusively diagnose VWD. Tests include blood tests to determine the amount of von Willebrand factor in the blood, the efficiency of von Willebrand factor, the structure of von Willebrand factor in the blood, a platelet function test, and factor VIII clotting ability. Determining the structure of von Willebrand Disease confirms the subtype of vWD a person has.
According to print literature, treatment for von Willebrand Disease (vWD) varies based on the type and severity. For mild cases, treatment may be necessary only on a preventative basis prior to surgery or dental work, or immediately following an accident or injury. The goals of treatment for vWD include increasing the amount of von Willebrand factor and factor VIII released into the bloodstream, preventing the breakdown of blood clots, replacing von Willebrand factor that doesn’t work well, and controlling heavy bleeding.
The most common treatments for vWD are:
Desmopressin (DDAVP) – Desmopressin can be used to treat most people with type 1 vWD and some people with type 2. It can be injected or in the form of a nasal spray. Desmopressin is a synthetic hormone that stimulates the body to release more von Willebrand factor stored in the lining of the blood vessels.
Factor Concentrates with von Willebrand Factor- Factor concentrates are used to treat people with Type 2b and Type 3. It is also used for people with Type 2a prior to surgery or if they are expecting severe bleeding.
Anti-fibrinolytic or clot-stabilizing medicines, such as Amicar and Cykloapron. These medicines can slow down the breakdown of clotting factors and therefore can help keep a clot in place once it has formed.
Contraceptives – Estrogen hormones can boost levels of vWF and factor VIII activity and therefore can help control heavy menstrual cycles.
VWD affects both males and females equally. However, because symptoms can be mild, many people go undiagnosed. Consult your physician or local treatment center before pursuing any course of treatment.