What factor is deficient in von Willebrand disease?
VWD is caused by a defect or deficiency in von Willebrand Factor (VWF), a large protein made up of multiple subunits. VWF binds to clotting factor VIII in the circulation and protects it from being broken down. VWF also helps platelets bind to the inside of injured blood vessels.
What does a low von Willebrand antigen mean?
A sufficiently low level of von Willebrand factor (VWF) predisposes to bleeding that can be quite serious, and low VWF is a diagnostic feature of von Willebrand disease (VWD) type 1, which is characterized by partial quantitative deficiency of VWF.
What does a high von Willebrand antigen mean?
Increased concentrations of VWF antigen and VWF activity are not considered diagnostic. VWF is one of many acute phase reactants. This means that levels will be temporarily increased with infections, inflammation, trauma, and with physical and emotional stressors.
How common is VWF?
This means that 3.2 million (or about 1 in every 100) people in the United States have the disease. Although VWD occurs among men and women equally, women are more likely to notice the symptoms because of heavy or abnormal bleeding during their menstrual periods and after childbirth.
What blood test is used for von Willebrand disease?
The blood tests that a doctor can order to diagnose VWD (or another platelet disorder) include: Factor VIII clotting activity―To measure the amount of factor VIII in the blood. Von Willebrand factor antigen―To measure the amount of VWF in the blood.
How do you treat low von Willebrand factor?
Treatment options for patients with low VWF and significant bleeding phenotypes include antifibrinolytic agents, such as tranexamic acid or aminocaproic acid, DDAVP, and VWF-containing concentrates. Tranexamic acid has been widely used in the management and prevention of bleeding in VWD.
What causes elevated von Willebrand factor?
VWF is an acute-phase reactant and may be elevated above baseline in association with a variety of conditions including inflammation, stress, exercise, liver disease, pregnancy or estrogen therapy. Baseline VWF levels also increase with aging.
What is elevated von Willebrand factor?
Von Willebrand factor (VWF) is a plasma glycoprotein that acts as carrier for factor VIII. Elevated levels of VWF are associated with elevated coagulation factor VIII levels. An increased VWF level in plasma is found to be associated with VTE [4, 5, 11, 13].
What is the malattia di von Willebrand?
La malattia di von Willebrand è un deficit ereditario del fattore di von Willebrand, ed è causa di disfunzione piastrinica. La tendenza emorragica è di solito lieve.
What is von Willebrand factor?
von Willebrand factor (factor VIII-related antigen) is a large glycoprotein that is present in the plasma and endothelium and binds to other proteins, particularly factor VIII, preventing its rapid degradation. It is absent in von Willebrand’s disease.
What is the difference between l’antigene del Fattore di von Willebrand and difetto?
L’antigene del fattore di von Willebrand è superiore al previsto, perché il difetto del fattore di von Willebrand di tipo 2 è di tipo qualitativo (perdita di multimeri di fattore di von Willebrand ad alto peso molecolare) non quantitativo.
What are normal von Willebrand factor (VWF) levels by blood type?
50% to 150%. Average vWF levels (both antigen and activity) tend to vary by blood type. 6 One study found the mean vWF levels by blood type to be as follows: 7 See von Willebrand Factor (vWF) Profile  for more clinical information.