Von Willebrand's disease

Question 1

What is the role of Von Willebrand factor in clotting?

Answer 1

Bring platelets into contact with exposed subendothelium
Make platelets bind to each other
Bind to factor 8, protecting it from destruction in circulation

Question 2

What is Von Willebrand’s disease?

Answer 2

bleeding disorder which may present with mucocutaneous bleeding (mouth, epistaxis, menorrhagia), increased bleeding after trauma + easy bruising

Question 3

What is type 1 Von Willebrand’s disease?

Answer 3

vWF works well but there isn’t enough of it
60-80%
Mild Sx
Autosomal dominant

Question 4

What is type 2 Von Willebrand’s disease?

Answer 4

Normal levels of vWF but it’s abnormal + doesn’t function correctly
20-30%
Bleeding tendency varies amongst the 4 subtypes
Usually autosomal dominant

Question 5

What is type 3 Von Willebrand’s disease?

Answer 5

NO vWF
1-5%
Severe symptoms
Autosomal recessive

Question 6

Describe the aetiology of Von Willebrand’s disease

Answer 6

Caused by abnormality in the expression/ function of vWF

Usually autosomal dominant

Question 7

List 8 signs and symptoms of Von Willebrand’s disease

Answer 7

Easy bruising  
Epistaxis: hard to stop  
Prolonged bleeding from gums after dental procedures  
Menorrhagia  
Blood in stools: haematochezia  
Haematuria  
Heavy bleeding from a cut or other accident
Anaemia + Liver disease

Question 8

What investigations are used in Von Willebrand’s disease?

Answer 8

Bleeding time: HIGH
APTT: HIGH (PT norm range)
Factor VIII: LOW
INR + platelets: normal

Question 9

What is seen on testing with Ristocetin cofactor in Von Willebrand’s disease? What is this?

Answer 9

Type 1+3: ABNORMAL
Type 2: NORMAL
Abx that causes vWF + platelets to stick together

Question 10

Describe the presence of vWF antigen in Von Willebrands disease

Answer 10

Type 1+3: LOW

Type 2: NORMAL