VON WILLEBRAND'S DISEASE (TYPE IIB)

• Biochemical aspects:
  • In type IIB of von Willebrand's disease, the large multimers are absent from plasma, as determined by sodium dodecyl sulfate-agarose gel electrophoresis
• Pathological Basis:
  Mode of inheritance: autosomal dominant.
• Treatment:
  • Humate-P (F VIII/vWF preparation): loading 40-75 IU/kg with tapering doses
  • Cryoprecipitate: 1 bag per 10 kg of body weight, twice a day. Now less commonly used due to potential infection.
  • Epsilon-aminocaproic acid (EACA): is a useful adjuvant in dental surgery. The usual loading dose is 5 gm, followed by 1 gm per hour for 5 - 7 days.
  • Avoidance of aspirin-containing compounds.
  • DDAVP is contraindicated since it has been shown to induce platelet aggregation in vivo and shorten platelets' life span without correcting the bleeding time.