vWFtekijä

vWFtekijä, also known as von Willebrand factor (vWF), is a large, multifunctional plasma protein that plays a crucial role in hemostasis, the process by which blood clots to stop bleeding. It was first identified by Erik von Willebrand in 1926, and its genetic mutations are associated with von Willebrand disease (vWD), a common inherited bleeding disorder.

vWF is synthesized by endothelial cells and megakaryocytes, and it is stored in Weibel-Palade bodies within these cells. It is released into the bloodstream in response to vascular injury or other stimuli. vWF has several functions in hemostasis:

1. It acts as a carrier protein for factor VIII, a key clotting factor, facilitating its release from endothelial cells and its binding to platelets.

2. It promotes platelet aggregation and adhesion to the site of injury.

3. It stabilizes the platelet plug formed at the site of injury.

vWF is a large protein with a molecular weight of approximately 2 million Daltons. It is composed of multiple domains, including D' (disulfide-rich), A1, A2, A3, C1, C2, and D3. The D' domain is responsible for binding factor VIII, while the A domains are involved in platelet adhesion and aggregation.

vWF levels in the blood can be measured to diagnose and monitor vWD. The most common types of vWD are type 1 (quantitative deficiency), type 2 (qualitative deficiency), and type 3 (deficiency of both vWF and factor VIII). Treatment for vWD typically involves replacing the missing or defective vWF and factor VIII, either through plasma transfusions or with recombinant factor VIII.