VON WILLEBRAND'S DISEASE (TYPE III)

• Biochemical aspects:
  • Factor VIII R:RCo and factor VIII R:Ag are typically undetectable in patients with this type of von Willebrand's disease. In most instances, the bleeding time is greater than 15 minutes. Factor VIII:C ranges from 1% to 5%.
  • It appears that the basic biochemical abnormality in such patients is an inability to synthesize von Willebrand factor. Consequently, such patients do not respond to DDAVP.
• Pathological Basis:
  • Mode of inheritance: autosomal recessive or double- heterozygous.
  • Patients have a clinical picture that closely resembles that of severe hemophelia A.
• 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.
  • DDAVP (1-desamino-8-D-arginine vasopressin) is not useful
  • Avoidance of aspirin-containing compounds.