الفهرس 
Von Willebrand’s Disease.Only 14 pages are availabe for public view
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Abstract
von Willebrand factor (VWF) is a high molecular weight glycoprotein
that mediates platelet adhesion at the site of vascular injury, especially under
high fluid shear conditions. The larger VWF multimers are the most
haemostatically competent and the loss of these is associated with the severe
bleeding complications as seen in patients with type 2A von Willebrand
disease.
von Willebrand disease (VWD) is the most commonly inherited
bleeding disorder, with an estimated prevalence of 1% of the population.
Unlike VWD, Acquired von Willebrand syndrome (AVWS) is a rare
bleeding disorder characterized by structural or functional defects of von
Willebrand factor. Pathogenetic mechanisms include release of
autoantibodies against VWF, selective or non-selective absorption,
mechanical destruction, increased proteolysis and decreased synthesis or
secretion of vWF.
AVWS usually occurs in association with a variety of underlying
disorders, in particular with with monoclonal gammopathy of uncertain
significance, lymphoproliferative, myeloproliferative and neoplastic
disorders, more rarely with hypothyroidism, uremia, pancreatitis, liver
cirrhosis and autoimmune disorders. Nevertheless, some cases are considered
idiopathic,when an underlying disorder cannot be identified.
Acquired von Willebrand Syndrome (AVWS) characterized by late
onset in individuals with no family or personal history of bleeding.