Von Willebrand Disease

• Von Willebrand disease is the most common inherited cause of abnormal and prolonged bleeding
• There are many underlying genetic causes of VWD - most commonly autosomal dominant
• VWD results in a deficiency, absence of or malfunctioning of von Willebrand factor:

  • Type 1 (most common and mild) - partial deficiency of vWF
  • Type 2 - reduced function of vWF
  • Type 3 (rarest and most severe) - complete deficiency of vWF
• Function of vWF:

  • Important role in platelet adhesion and aggregation in damaged vessels
  • Stabilises factor VIII in the intrinsic pathway - secondary homeostasis
• VWD presentation:

  • bleeding gums with brushing
  • Epistaxis
  • Easy bruising
  • Menorrhagia
  • Heavy bleeding during and after surgical operation
• VWD investigations:

  • FBC - Mostly normal - type 2 VWD may have low platelets
  • Prolonged APTT - measures intrinsic pathway (affects factor VIII)
  • PT usually normal - measures extrinsic pathway
  • Factor VIII - usually low as vWF prolongs the life of factor VIII
  • Prolonged bleeding time
  • Quantitative/functional immunoassay
• Management of VWD:

  • Avoid NSAIDs and anti-platelet drugs
  • Minor bleeds don't require any specific treatment - treatment needed in response to significant bleeding or in preparation for operations
  • Desmopressin - stimulates the release of vWF
  • Tranexamic acid
  • Factor VIII and/or vWF infusions can be given