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Coagulation

Acquired bleeding disorders

Acquired von Willebrand disease (AVWD)


Reviewers: Kendall Crookston, M.D., Ph.D., University of New Mexico; Lizabeth Rosenbaum, MD, University of New Mexico; Julie Gober-Wilcox, M.D., Resident, University of New Mexico (see Reviewers page)
Revised: 9 April 2013, last major update June 2010
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
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● A rare bleeding disorder of primary hemostasis that appears either spontaneously or associated with lymphoproliferative or myeloproliferative diseases, solid tumors, autoimmune disorders, cardiovascular disorders, drugs or other miscellaneous causes (Acta Haematol 2009;121:177)
● Mimics congenital von Willebrand disease in terms of clinical presentation and laboratory findings

Terminology
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● Also called acquired von Willebrand syndrome (AVWS)

Epidemiology
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● Usually older adults, but can occur in children

Sites
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● Typically mucocutaneous or gastrointestinal bleeding

Etiology
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● Not completely understood and most likely multifactorial; underlying mechanisms include:
● Autoantibodies to vWF or Factor VIII causing inhibition or increased clearance
● Cell-mediated or drug-induced proteolysis of vWF
● Abnormal vWF binding to tumor cells causing increased clearance of Factor VIII-vWF complex
● Decreased synthesis

Clinical features
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● Mild to moderately severe mucocutaneous or gastrointestinal bleeding in a patient with previously normal coagulation and no family history of coagulopathy (Am J Hematol 2007;82:368)
● May be underlying cause of bleeding tendency in hypothyroid patients (Haemophilia 2008;14:423)
● Many patients present with normal or increased test results, emphasizing the importance of multimer analysis in all patients with suspected disease (J Thromb Haemost 2008;6:569)
Algorithm for clinical evaluation (Mayo Medical Laboratories)

Laboratory
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Patients may have any of the following:
● Prolonged bleeding time
● Platelet assay showing prolonged closure times (PFA-100)
● Reduced vWF activity
● Reduced vWF antigen
● Reduced factor VIII activity
● Prolonged aPTT
● Most patients exhibit type II pattern on multimer electrophoresis, but can see type I as well as type III
● Use of VWF multimer assay recommended only when initial VWD testing identifies an abnormal result, or clinical information suggests a high likelihood of abnormal VWF multimer analysis (Mayo Medical Laboratories)

Prognostic factors
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● Depends on underlying disorder and other comorbidities

Case reports
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● Transient neonatal acquired von Willebrand syndrome due to transplacental transfer of maternal monoclonal antibodies (Pediatr Blood Cancer 2009;53:655)
● 55 year-old man with gastrointestinal angiodysplasia (Haemophilia 2006;12:452)

Treatment
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● Aimed at both control of the acute bleeding episode and of the underlying disorder (i.e. hypothyroidism)
● DDAVP is usually initiated first, followed by replacement therapy with plasma derived Factor VIII-vWF concentrates
● If there is no success, then IVIG (immunoglobulin) may be tried, especially if the underlying cause is thought to be autoimmune in nature
● There is little published data on the effectiveness of plasma exchange
● Immunosuppressive agents and corticosteroids have been used, but are reported to be less effective

Differential diagnosis
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● Congenital von Willebrand disease
● Bernard-Soulier Syndrome (Arch Pathol Lab Med 2007;131:1834)

Additional references
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Consultative Hemostasis and Thrombosis: Elsevier, 2007, Wikipedia, eMedicine, ARUP Consult

End of Coagulation > Acquired bleeding disorders > Acquired von Willebrand disease (AVWD)


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