• Most common inherited bleeding disorder (asymptomatic deficiencies 1%, symptomatic disease 100 per million)
  • von Willeband factor (vWF) important in platelet adhesion and factor VIII transport

Types of vWD
Type 1: decreased concentration of vWF, 80%, often autosomal dominant
Type 2: qualitative deficiency – AD or AR inheritance

  • 2a – lack of high molecular weight vWF
  • 2b – defective adhesion due to increased binding
  • 2m – decreased platelet dependent vWF function
  • 2n – failure to bind factor VIII

Type 3: near complete deficiency of vWF, AR inheritance, mimics haemophilia

  • ·Severe vWD: spontaneous mucosal bleeding, death secondary to massive GI haemorrhage
  • Blood count normal except for a moderate reduction in platelets in some with type 2
  • APTT prolonged (factor VIII), PT usually normal
  • Diagnosis: quantitative immunoassay/functional assay of vWF, electrophoresis
  • Interpret vWF levels with blood group (usually lower in blood group O)
  • Mild cases: local measures, tranexamic acid, DDAVP infusion/nasal spray (release stored vWF, type 1)
  • Factor VIII concentrates with vWF may be given

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