00:00 / 00:00
Autoimmune hemolytic anemia
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Hemolytic disease of the newborn
Paroxysmal nocturnal hemoglobinuria
Pyruvate kinase deficiency
Sickle cell disease (NORD)
Folate (Vitamin B9) deficiency
Vitamin B12 deficiency
Anemia of chronic disease
Iron deficiency anemia
Anemia of chronic disease
Coagulation disorders: Pathology review
Extrinsic hemolytic normocytic anemia: Pathology review
Heme synthesis disorders: Pathology review
Intrinsic hemolytic normocytic anemia: Pathology review
Leukemias: Pathology review
Lymphomas: Pathology review
Macrocytic anemia: Pathology review
Microcytic anemia: Pathology review
Mixed platelet and coagulation disorders: Pathology review
Myeloproliferative disorders: Pathology review
Non-hemolytic normocytic anemia: Pathology review
Plasma cell disorders: Pathology review
Platelet disorders: Pathology review
Thrombosis syndromes (hypercoagulability): Pathology review
Von Willebrand disease
0 / 1 complete
Von Willebrand disease is a bleeding disorder caused by a deficiency in the quantity, or the quality of von Willebrand factor, a plasma glycoprotein that plays a key role in forming blood clots needed to stop bleeding. The disease was named after Erik Adolf Von Willebrand, a Finnish physician who first described it in 1924.
Von Willebrand factor is synthesized and stored in the endothelial cells and megakaryocytes. Its synthesis is regulated by the von Willebrand factor gene located on the short arm of chromosome 12.
Alright, when there is a bleeding injury to a blood vessel, histamine and thrombin stimulate the local endothelial cells and megakaryocytes to release the von Willebrand factor into the bloodstream.
After its release, it attaches to the exposed collagen fibers located in the wall of an injured blood vessel, where it serves as a glue-like substance that sticks to platelet receptors known as glycoprotein 1b or simply Gp1b.
Within the bloodstream, more of von Willebrand factor start to bind more platelets together into kind of a mass, over which fibrin fibers deposit forming a clot needed to plug the injured vessel, and thus stop bleeding.
In addition to binding platelets together, von Willebrand factor also binds and carries factor VIII. Factor VIII plays a major role in the blood clot formation process, and to work well, it is supposed to be bound to the von Willebrand factor, because in this case it is protected from early degradation by protein C, and S, which would remove it from the circulation before it does its job.
The majority of von Willebrand disease cases are inherited, but it can also be acquired. In the inherited form, there is a mutation in the Von Willebrand gene, and the gene gets passed from parents to children. Inherited von Willebrand disease is classified into three main types - type I, II, and III.
Von Willebrand disease type I is the most common, making up 75 percent of all cases. It is autosomal dominant, meaning that a mutation in only one allele results in insufficient, or even defective production of von Willebrand factor.
Von Willebrand disease is a bleeding disorder caused by a deficiency in the quantity or quality of von Willebrand factor, a plasma glycoprotein that plays a key role in forming blood clots. Symptoms depend on the type of the disease and range from mild to severe. People with acquired von Willebrand disease present with new onset of bleeding in the context of other pathologic conditions or medication use. For treatment, people who present with minor bleeding are treated with desmopressin analogs, while those with severe bleeding receive exogenous von Willebrand factor and factor VIII concentrates.
Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.