1. Background

• Factor VIII is a complex of two components each with a different genetic control and biochemical function:
  1. Factor VIIIc - coagulation protein
  2. Factor VIIIvW - platelet adhesion protein
• Factor VIIIvW is a large polymeric protein necessary for normal platelet adhesion and acts as a bridge between a receptor on the platelet surface and the exposed basement membrane or subendothelial collagen
• Factor VIIIc is complexed with Factor VIIIvW in the plasma, the latter acting as a carrier protein
• there are at least 5 variants of von Willebrand Disease

2. Genetic Defect

• genetic defect -> reduced Factor VIIIvW protein and function but normal multimeric structure -> clinical features

1. Hematological Manifestations

• spontaneous bleeding is rare
• bleeding from mucous membranes (epistaxis, gums)
• menorrhagia
• prolonged oozing from cuts
• increased bleeding after surgery or trauma

1. Serum

• prolonged bleeding time
• decreased Factor activity
  • Factor VIIIvW
  • Factor VIIIc
• also have reduced ristocetin cofactor and reduced ristocetin-induced platelet aggregation (agglutination)
• normal or prolonged PTT
• normal PT, thrombin time, platelet count

1. Supportive

• avoid trauma and anticoagulants (i.e., ASA)
• pressure and cold compresses to bleeding sites

2. Replacement Therapy