Factor VIII

Definition

Factor VIII, also known as antihemophilic factor, is a crucial blood plasma protein involved in the blood clotting process. It is an essential component of the intrinsic pathway of the coagulation cascade, playing a vital role in maintaining hemostasis within the body.

5 Must Know Facts For Your Next Test

1. Factor VIII acts as a cofactor for factor IXa, which in turn activates factor X, a key step in the intrinsic pathway of blood clotting.
2. The production of factor VIII is regulated by the F8 gene, and mutations in this gene can lead to the development of hemophilia A.
3. Factor VIII is produced primarily by the liver and endothelial cells, and it circulates in the bloodstream bound to von Willebrand factor, which helps stabilize and protect it.
4. Levels of factor VIII can be increased in response to various stimuli, such as stress, inflammation, or the presence of certain hormones.
5. Replacement therapy with recombinant or plasma-derived factor VIII is the primary treatment for individuals with hemophilia A, helping to restore normal clotting function.

Review Questions

• Explain the role of factor VIII in the coagulation cascade and its importance in maintaining hemostasis.
  • Factor VIII is a crucial component of the intrinsic pathway of the coagulation cascade. It acts as a cofactor for factor IXa, which activates factor X, a key step in the formation of a fibrin clot. Without adequate levels or function of factor VIII, the intrinsic pathway is disrupted, leading to prolonged bleeding and difficulty in stopping hemorrhages. This highlights the essential role of factor VIII in maintaining hemostasis and preventing excessive blood loss within the body.
• Describe the genetic and physiological factors that influence the production and regulation of factor VIII.
  • The production of factor VIII is primarily regulated by the F8 gene. Mutations in this gene can lead to the development of hemophilia A, a genetic bleeding disorder characterized by a deficiency or dysfunction of factor VIII. Additionally, factor VIII is produced by the liver and endothelial cells, and its levels can be influenced by various stimuli, such as stress, inflammation, and hormones. The binding of factor VIII to von Willebrand factor also helps stabilize and protect the protein, ensuring its proper function in the coagulation cascade.
• Explain the significance of factor VIII replacement therapy in the management of hemophilia A and its impact on the patient's quality of life.
  • For individuals with hemophilia A, a genetic disorder characterized by a deficiency or dysfunction of factor VIII, replacement therapy with recombinant or plasma-derived factor VIII is the primary treatment. This therapy aims to restore normal clotting function by replenishing the missing or defective factor VIII, allowing for the proper activation of the intrinsic pathway of the coagulation cascade. By addressing the underlying cause of the bleeding disorder, factor VIII replacement therapy can significantly improve the patient's quality of life by reducing the frequency and severity of bleeding episodes, minimizing the risk of complications, and enabling a more active and independent lifestyle.

Related terms

Coagulation Cascade:

The series of enzymatic reactions that lead to the formation of a fibrin clot, which helps stop bleeding and promote wound healing.

Intrinsic Pathway:

One of the two main pathways of the coagulation cascade, initiated by the activation of factors within the bloodstream.

Hemophilia A: A genetic bleeding disorder caused by a deficiency or dysfunction of factor VIII, leading to prolonged bleeding and difficulty in forming blood clots.