Hematology: Von Willebrand’s Disease

Definition

• Definition: Defect in von Willebrand Factor (vWF)
  • *See Hematology & Oncology: Coagulation Cascade
• Most Common Congenital Bleeding Disorder

Presentation

• Epistaxis – Most Common Symptom
• Bruising
• Heavy Menstrual Bleeding
• GI Bleed

Classification

• Type I (Most Common Type)
  • Reduced Quantity of vWF
  • Autosomal Dominant
  • Mildly Symptomatic
• Type II
  • Defective vWF
  • Autosomal Dominant
  • Subtypes:
    • IIA – Decreased VWF Platelet Function with Deficiency of High Molecular Weight Multimers
    • IIB – Increased Plt Affinity to GPIb
    • IIM – Decreased VWF Platelet Function without Deficiency of High Molecular Weight Multimers
    • IIN – Decreased VWF Factor VIII Affinity
• Type III
  • Complete Absence of vWF
  • Autosomal Recessive
  • Most Severe Symptoms

Diagnosis

• Labs:
  • Bleeding Time: Prolonged
  • PT: Normal
  • PTT: Variable (Based on Degree of Associated Factor VIII Deficiency)
• Confirmatory Tests:
  • vWF Antigen
  • vWF Activity (Ristocetin-Induced Platelet Agglutination Assay)
  • Factor VIII Activity
• Classification Tests: Numerous Available

Treatment

• Minor Bleeding or Surgical Prophylaxis: DDAVP
  • DDAVP Does Not Work in Type III or IIB
• Major or Life-Threatening Bleeding: vWF Concentrate
  • May Also Consider Cryoprecipitate if vWF Concentrate Unavailable