Von Willebrand Disease

Von Willebrand disease (VWD) is an inherited bleeding disorder caused by an abnormal blood-clotting protein called von Willebrand factor (VWF). The VWF is important for the body to create the first steps of a blood clot to stop bleeding with injury and surgery. It’s particularly important for helping to making needed blood clots when one has a bloody nose, mouth bleeding or a monthly period. VWF acts like glue to help the platelets stick together and form a blood clot. VWF is one of several clotting proteins in the body that must work together to prevent abnormal bleeding.

VWD is one of several bleeding disorders. Others include hemophilia, platelet disorders, and other factor deficiencies. It is important to know that different bleeding disorders have different risks of bleeding and different patterns or common locations of bleeding. VWD is the most common inherited bleeding disorder and affects about 1 in every 1000 individuals. Males and females have an equal chance of inheriting VWD; however, due to the bleeding challenge of monthly menses (periods), VWD is more frequently diagnosed in females. Some individuals can have very mild decreases in the VWF without any (or very minimal) bleeding symptoms; these individuals are not considered to have VWD.

Parents with VWD has a 50% chance of passing the abnormal VWF gene to their child. VWD is a lifelong condition that currently does not have a cure but can be successfully managed with several types of treatments available to manage and prevent bleeding.

Yes, broadly there are three types of von Willebrand disease: Types 1, 2, and 3. There are also subtypes of type 1 and type 2. Type 1 VWD is most common.

• Type 1 VWD: VWF are lower than normal (<30%). This is measured my both amount (antigen level) of VWF as well as by function (activity level) of VWF.
• Type 2 VWD: VWF is often in the low or low-normal range but VWF does not function normally. There are several subtypes noted by different letters (2A, 2B, 2M, and 2N). Each of these subtypes are defined by the specific function of VWF that is not working properly, for example VWF’s ability to interact with platelets or with factor VIII (8). Specialty testing is needed to identify the subtype.
• Type 3 VWD: VWF is absent. This is the rarest and most severe type of VWD. In these patients, bleeding symptoms are similar to those of moderate hemophilia.

Von Willebrand Disease (VWD) symptoms vary depending on the type and severity of the disease and are different for each individual. Many children with VWD have no or minimal symptoms. Others can experience symptoms such as:

• Frequent large bruises from minor bumps or injuries
• Frequent or prolonged nosebleeds
• Heavy or prolonged menstrual bleeding in girls
• Heavy or prolonged bleeding from the gums during teeth cleaning or other dental procedures
• Heavy or prolonged bleeding during or shortly after surgery
• Excessive bleeding from minor cuts

It is important to understand that some symptoms of VWD may resemble those of other more common medical problems. Because some of these symptoms can also point to other conditions, it’s important to have your child evaluated by a qualified medical professional for an accurate diagnosis and prompt development of a treatment plan.

VWD is an inherited bleeding disorder. If there in an abnormality in the gene responsible for allowing the body to make VWF, the amount or function of VWF can be abnormal and led to bleeding symptoms. Each individual should have two copies of the VWF gene; one is inherited from each parent. Parents with an abnormality in one of their VWF genes have a 50% chance of passing the abnormal VWF gene to their children.

If your child is suspected of having von Willebrand Disease (VWD), they should be referred to a hematologist, a doctor with specialized training in treating blood disorders. Blood tests are needed to measure the levels and function of VWF. This include:

• Von Willebrand Factor antigen
• Von Willebrand Factor activity (commonly by Ristocetin cofactor activity)
• Factor VIII activity

Additional diagnostic tests may be necessary depending on your child's individual situation. Once all necessary tests have resulted, our experts meet with you to review what they have learned about your child's results and to outline the best possible treatment options if needed.

The approach to VWD treatment depends on the VWD type and the individual’s severity and frequency of bleeding symptoms. Most often treatment is only needed prior to a procedure (such as surgery or tooth extraction) or for infrequent bleeding symptoms. In some cases, bleeding symptoms are more severe and more frequent treatment is necessary. The most commonly used treatments include:

• Desmopressin (DDAVP): A synthetic hormone given by an injection into a vein or through a nasal spray called Stimate®. DDAVP causes an increased release of VWF from blood vessel cells. It is usually effective for most patients with type 1 and some with type 2 VWD. Your physician will usually perform a DDAVP challenge on your child to evaluate the response to DDAVP prior to using it for treatment.
• Von Willebrand Factor replacement therapies: Special concentrate of VWF (as well as factor VIII) are available for treatment of VWD. The VWF concentrates are administered by infusion (injections into a vein) and allow for replacement of VWF. This treatment is used if your child does not respond to DDAVP, needs therapy for an extended time, or has a severe injury.
• Antifibrinolytic agents: Oral or IV medicines such as aminocaproic acid and tranexamic acid can be used to help make clots more stable. These medications may be particularly helpful for managing bloody noses (epistaxis), heavy menstrual bleeding, and after dental procedures for patients with bleeding disorders. An antifibrinolytic agent may be used alone or combined with DDAVP or VWF replacement therapy.

Your VWD treatment team will take many considerations into account to ensure the best treatment and follow-up plan for your child including:

• Your child's age, overall health and medical history
• The severity of the disease
• Your child's tolerance for certain medications, procedures or therapies
• How your child's doctors expect the disease to progress
• Your opinion and preferences

Von Willebrand Disease is a lifelong condition with no cure. The long-term outlook for children with VWD is generally good and most have a normal lifespan. Throughout their lifetime, many patients require periodic treatment for bleeding symptoms or treatment before surgery or dental procedures. We generally recommend avoiding aspirin and ibuprofen (NSAIDS), as well as products containing them, since they may increase bleeding symptoms in children with bleeding disorders.

We treat our patients who have von Willebrand Disease within the Boston Bleeding Disorders Center, a federally supported joint program between Boston Children’s Hospital and Brigham and Women's Physicians Organization. The Boston Bleeding Disorders Center is the largest hemophilia treatment program in New England, and it provides treatment for a variety of bleeding disorders, including VWD.

Our team helps children and adults with bleeding disorders to manage their disease as independently as possible and supports the wellness of each individual. Living a healthy life and achieving your goals is possible. Our patients receive the benefit of access to cutting edge treatments pioneered by our researchers and the national network of hemophilia treatment centers (HTCs).

For many children with rare or hard-to-treat conditions, clinical trials provide new treatment options. Participation in clinical trials has risks and benefits, but it is through clinical trials and clinical research studies that we are able to forward the field of VWD and other bleeding disorders.

Participation in a clinical trial is always voluntary. The doctor leading the clinical trial (study) at the site will review with you in detail the purpose of the study and what is required of you/your child during the course of the study before you agree to participate. Search our clinical trials or contact us if you’re not sure which clinical trials might be right for your child. We can help you navigate your options.