VON WILLEBRAND'S DISEASE (TYPE I)

• Biochemical aspects:
  von Willebrand factor consists of a series of multimers that range in molecular weight from 800,000 to more than 12,000,000.
• Pathological Basis:
  • Mode of inheritance: autosomal dominant.
  • The biochemical abnormality in type I of von Willebrand's disease is strictly quantitative. In such patients, analysis of the multimeric structure of von Willebrand factor with sodium dodecyl sulfate-agarose gel electrophoresis shows proportional decrease in all multimers. There are concordant decreases in the levels of factors VIII R:RCo, VIII R:Ag, and VIII:C.
• Treatment:
  • Humate-P (F VIII/vWF preparation): loading 40-75 IU/kg with tapering doses
  • DDAVP (1-desamino-8-D-arginine vasopressin): 0.3 ug/kg (IV or sq)
  • 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.