Von-Willebrand Disease Flashcards
What is von Willebrands Disease?
In VWD, there is defective platelet function as well as factor VIII:C deficiency, and both are due to a deficiency or abnormality of VWF. VWF plays a role in platelet adhesion to damaged subendothelium as well as stabilizing factor VIII in plasma
What gene is VWF located on?
Chromosome 12
What is type 1 VWD?
A partial quantitative deficiency of VWF - significant type 1 VWD is usually inherited as an autosomal dominant disorder
(reduction in production)
What is type 2 VWD?
Due to a qualitative abnormality of VWF, and it too is usually inherited as an autosomal dominant.
(produced by problem in one of the binding sites)
What is type 3 VWD?
Recessively inherited and patients have virtually complete deficiency of VWF.
Their parents are often phenotypically normal
(complete deficiency)
How do those with VWD present?
Type 1 and type 2 - relatively mild features
- Bleeding follows minor trauma or surgery
- Epistaxis
- Menorrhagia often occur
Type 3 - more severe bleeding
What are signs of VWD?
Platelet disorder
- Brusing
- Epistaxis
- Menorrhagia
What investigations would you do if you suspected VWD?
- FBC - platelets
- LFTs
- Clotting Screen - Factors, Bleeding time, PT, APTT, Thrombin time, INR
What might you find when you perform APTT in someone with VWD?
Increased APTT - due to factor VIII deficiency
What might you find when you perform PT on someone with VWD?
Normal PT
What might you find when you perform FBC on someone with VWD?
- Normal platelet count
- Normal Hb
What might you find on performing a bleeding time assay in someone with VWD?
Increased bleeding time
What might you find if you performed an assay which looked at someones clotting factors in someone with VWD?
- Decreased VWF
- Decreased VIIIc
How would you manage someone with vWD?
- DDAVP - mild bleeding
- vWF concentrate containing factor VIII
- Tranexamic Acid
- Topical applications
- OCP
What should you avoid the use of in vWD?
NSAID use
