The commonest mode of inheritance of Von Willebrand's disease: (AIIMS Nov 2010)
VON WILLEBRAND’S DISEASE (Ref. Hari-18th ed., Pg.- 971)
1. von Willebrand’s disease (vWD) is a common hereditary bleeding disorder.
2. It is characterized by a prolonged BT and reduced factor VIII – C levels between about 10 –40%.
3. Joint bleeding is rare.
4. The gene for von Willebrand’s factor (vWF) is located on chromosome 12 and is inherited as an autosomal disorder.
5. Type I, II and IIB are autosomal dominant type. IIC and III are autosomal recessive. (Autosomal hemophilia – New Name)
Superficial bruising, epistaxis, menorrhagia and GI bleeding are common especially after trauma or surgery.
The diagnostic pattern consist of:
a. Prolonged bleeding time and prolonged clotting time.
b. Reduced plasma vWF concentrations
c. Reduction in biological activity as measured by ristocetin cofactor assay (Platelet) aggregation in response to ristocetin is
d. Reduced factor VIII activity.
Note: Von Willebrand’s Disease PT is normal but PTT is prolonged.
Note: Von Willebrand's disease: Platelet aggregation studies with standard agonists ADP, collagen, thrombin are normal but platelet aggregation in response to ristocetin may be subnormal.
1. Reduced level of vWF 2. Secondary reduction in factor VIII c. Prolongation of the bleeding time.
2. Factor VIII – C concentrates (contain adequate vWF also)
3. Cryoprecipitate: It contains all of the vWF multimers. It is the safest and most cost – effective modality of treatment.
4. Platelet transfusions for cases with uncontrolled bleeding
5. Fresh frozen plasma (FFP) can be given for mild disease.