What are the other Names for this Condition? (Also known as/Synonyms)

• Acquired Von Willebrand Disease
• Acquired VWS
• aVWS (Acquired Von Willebrand Syndrome)

What is Acquired Von Willebrand Syndrome? (Definition/Background Information)

• Acquired Von Willebrand Syndrome (aVWS) is a bleeding disorder that can occur due to a variety of conditions, but is not caused by a VWF gene mutation. It is most often seen in persons over age 40 years with no prior bleeding history
• This condition may result from lymphoproliferative disorders, autoimmune disorders (including systemic lupus erythematosus, scleroderma, and antiphospholipid antibody syndrome), heart conditions such as aortic valvular stenosis, increased blood platelet count such as essential thrombocythemia, and certain drugs
• About 300 cases of this condition have been reported in the medical literature thus far. Treatment depends on the underlying cause of the condition

(Source: Acquired Von Willebrand Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Acquired Von Willebrand Syndrome? (Age and Sex Distribution)

• Acquired Von Willebrand Syndrome is a rare bleeding disorder that is not inherited. Thus far, about 300 cases have been reported in the medical literature
• The disorder is often seen in persons over age 40 with no prior bleeding history

(Source: Acquired Von Willebrand Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Acquired Von Willebrand Syndrome? (Predisposing Factors)

The risk factors for Acquired Von Willebrand Syndrome may include:

• Individuals with lymphoproliferative disorders 
• Certain autoimmune disorders 
• Certain heart conditions (such as aortic valvular stenosis) 
• Conditions that lead to increased blood platelet counts, such as essential thrombocythemia

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Acquired Von Willebrand Syndrome? (Etiology)

Acquired Von Willebrand Syndrome is caused by conditions that reduce the level of the Von Willebrand factor (VWF). The conditions under which the clotting factor VWF can get depleted from circulation may include:

• Presence of autoantibodies to VWF, which can result from autoimmune disorders and monoclonal gammopathies
• Absorption of VWF onto malignant cell clones (the mechanism implicated in AVWS associated with neoplasia)  
• Increased proteolysis of high molecular weight VWF multimers under abnormal hemorheologic conditions caused by cardiovascular malformations (such as aortic valve stenosis)

(Source: Acquired Von Willebrand Syndrome; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

What are the Signs and Symptoms of Acquired Von Willebrand Syndrome?

The signs and symptoms of Acquired Von Willebrand Syndrome may vary among affected individuals in type and severity, and may include:

• Prolonged bleeding after trauma
• Epistaxis (nosebleeds)
• Bruising (ecchymosis)
• Gastrointestinal bleeding, associated with vascular malformation(s) of the gut

(Source: Acquired Von Willebrand Syndrome; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

How is Acquired Von Willebrand Syndrome Diagnosed?

The diagnosis of Acquired Von Willebrand Syndrome may involve the following:

• The most accurate diagnostic tests rely on detection of abnormally low levels of VWF activity (ristocetin cofactor or collagen binding assays) in comparison to VWF antigen levels, and on demonstration of a selective deficiency of high molecular weight VWF multimers
• Measurement of VWF propeptide levels may also be useful as they reflect the abnormally rapid clearance of VWF from the circulation
• However, none of these tests allow AVWS to be distinguished from hereditary VWD. Detection of anti-VWF antibodies is pathognomonic of the acquired mechanism of VWF deficiency; however, these antibodies are only detected in 14% of suspected cases of AVWS
• The finding of a monoclonal protein detected by serum protein electrophoresis is an argument for aVWS
• Thus, it is the presentation of an acute bleeding disorder, in association with an underlying pathology (such as lympho- or myeloproliferative disorders, solid tumors, immunological or cardiovascular disorders) which generally leads to the diagnosis of acquired VWF deficiency

(Source: Acquired Von Willebrand Syndrome; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Acquired Von Willebrand Syndrome?

The complications of Acquired Von Willebrand Syndrome may include:

• Intra-cerebral hemorrhage - bleeding in the brain
• Allergic reaction to infusion of blood products
• Internal bleeding in various organs
• Relapse of bleeding episodes following treatment

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Acquired Von Willebrand Syndrome Treated?

The treatment for Acquired Von Willebrand Syndrome typically depends on the factors leading to the syndrome and the severity of symptoms, and may include the following:

• Corticosteroids or immunosuppressors
• Chemotherapy
• Plasmapheresis 
• Valve replacement
• Desmopressin or VWF concentrates (although pharmacokinetic studies may be required before any major surgical intervention as the half-life of endogenous or exogenous VWF may be significantly reduced)
• Recombinant factor VIII concentrates (completely depleted of VWF) 
• Recombinant activated factor VII (as a last-resort treatment option)

(Source: Acquired Von Willebrand Syndrome; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

How can Acquired Von Willebrand Syndrome be Prevented?

• Acquired Von Willebrand Syndrome may not be preventable in situations where a serious underlying disorder causes Von Willebrand Syndrome
• Seeking medical attention for the underlying disorder may help minimize bleeding episodes
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Acquired Von Willebrand Syndrome? (Outcomes/Resolutions)

• The prognosis of Acquired Von Willebrand Syndrome depends on the underlying pathology associated with the disease

(Source: Acquired Von Willebrand Syndrome; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Acquired Von Willebrand Syndrome:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/