Willebrand factor Antigen

General Information

Willebrand factor (protein) is one of the factors of the human coagulation system. The test determines the amount of Willebrand protein in the blood plasma, because its amount determines the functional activity of the factor.

Under physiological conditions, when the integrity of the blood vessel wall is broken and bleeding begins, the Willebrand protein forms an adhesive (binding) bridge between platelets in the area of ​​injury. This ensures aggregation and adhesion of platelets to the wall of the damaged blood vessel. As a result, the coagulation cascade (sequence of reactions) is activated, followed by the formation of a stable thrombus in the area of ​​damage to the blood vessel.

Willebrand factor binds to factor 8 of coagulation, increases its half-life to 8-12 hours and ensures its inclusion in the coagulation cascade.

When Willebrand factor is deficient or functionally inactive, it impairs the platelet aggregation-adhesion process, as well as reduces the activity of coagulation factor 8, resulting in prolongation of thrombus formation time and bleeding.

When should we do the research?

• Diagnosis of excessive or repeated, unexplained bleeding
• Diagnosis of von Willebrand disease
• Differentiation of types of von Willebrand disease
• Family history of von Willebrand disease or other congenital coagulopathy