von Willebrand factor


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fac·tor VIII

in the clotting of blood, also known as: antihemophilic factor A (Brinkhous), antihemophilic globulin (1) (Patek and Taylor), antihemophilic globulin A (Cramer), plasma thromboplastin factor (Ratnoff), plasma thromboplastin factor A (Aggeler), thromboplastic plasma component (Shinowara), thromboplastinogen (Quick), prothrombokinase (Feissly), platelet cofactor (Johnson), plasmokinin (Laki), thrombokatilysin (Leggenhager), and proserum prothrombin conversion accelerator. Factor VIII participates in the clotting of the blood by forming a complex with factor IXa, platelets, and calcium and by enzymatically catalyzing the activation of factor X. Deficiency of factor VIII is associated with classic hemophilia A. Factor VIIIC is the coagulant component of factor VIII which, in normal people, circulates in the plasma complexed with Factor VIIIR (von Willebrand factor), the plasma factor VIII-related protein, a large glycoprotein component that is synthesized by endothelial cells and megakaryocytes, and circulates in the plasma where it binds to arteries that have lost their endothelial cell linings, creating a surface to which platelets adhere. Disorders involving factor VIIIR comprise a heterogenous group of abnormalities called von Willebrand disease. A deficiency of factor VIII can lead to impaired blood coagulation.

von Willebrand factor

Hematology A large–> 20,000 kD multimeric molecule composed of ± 200 kD monomers, synthesized by vascular endothelium, megakaryocytes and platelets; vWF's hemostatic efficiency is related to multimer size. See Rocket electrophoresis.

von Willebrand factor

A plasma protein secreted by endothelial cells that helps platelets to adhere to the damaged lining of blood vessels.

von Willebrand factor (vWF)

A protein found in the blood that is involved in the process of blood clotting.

von Willebrand factor

the property of factor VIII necessary for normal platelet function; abbreviated VWF. Called also factor VIIIvwf.
References in periodicals archive ?
High von Willebrand factor levels increase the risk of stroke: the Rotterdam study.
Haspel RL, Jarolim P: The "cutting" edge: von Willebrand factor cleaving protease activity in thrombotic micro-angiopathies.
Inflammation-associated ADAMTS13 deficiency promotes formation of ultra-large von Willebrand factor.
For patients needing vWF screening, a vWD profile was performed which included: aPTT, factor VIII quantitative functional assay, von Willebrand factor antigen (vWF:Ag) using latex immunoassay (Liatest--Diagnostica Stago-Paris/France), vWF ristocetin cofactor (vWF: Rcof) (9,10) activity using vWFactor assay (Bio-Data-PA/USA), and ristocetin induced platelet aggregation (RIPA) using platelet aggregometry (Bio-Data-PA/USA ).
The von Willebrand factor is a protein with two functions necessary for hemostasis.
Von Willebrand factor (vWf)--induced platelet stimulation requires the coactivation of two different glycoproteins, the GpIb-V-IX complex and GpIIb-IIIa, or integrin [Alpha]IIb[Beta]3, the former being responsible for the initial contact and the latter leading to spreading and irreversible adhesion (13).
Over the next 9 years, people with the highest concentrations of von Willebrand factor were 1.
Contract award notice: Concentrate of human coagulation factor VIII containing von Willebrand factor for the treatment of von Willebrand disease in a proportion of at least 1 to 2
It builds on the company's existing Fc fusion technology by adding a region of von Willebrand factor and XTEN polypeptides to potentially extend its time in circulation.