Von Willebrand

Question 1

what is the typical presentation of von willbrand disease?

Answer 1

Superficial bleedinge.g. Nosebleeds + gums bleeding + increased APTT + decreased FVIII and vWF + norm plt and PT

Question 2

what are the 3 role of vWF in clotting?

Answer 2

To bring platelets into contact with exposed subendothelium

To make platelets bind to each other

To bind to factor 8, protecting it from destruction in the circulation

Question 3

define von willebrand disease?

Answer 3

Von Willebrand’s disease is a bleeding disorder which may present with mucocutaneous bleeding (mouth, epistaxis, menorrhagia), increased bleeding after trauma and easy bruising

Question 4

what are the 3 common types of von willebrand disease?

Answer 4

Type 1- the von Willebrand factor works well but there isn’t enoughof it

• 60-80%, mild symptoms, autosomal dominant

Type 2- there are normal levels of von Willebrand factor but it is abnormal and doesn’t function correctly

• 20-30%, bleeding tendency varies amongst the 4 subtypes, usually autosomal dominant

Type 3- there is NO von Willebrand factor

• 1-5%, severe symptoms, autosomal recessive

Question 5

describe the aetiology of von willebrand disease?

Answer 5

Caused by abnormality in the expression/function of vWF

Usually autosomal dominant

Question 6

what are the investigations for von willebrand disease and interpret the results?

Answer 6

Bleeding time - HIGH

APTT - HIGH (PT – norm range)

Factor VIII - LOW

vWF Ag - LOW in type 1 and 3, normal in type 2

INR and platelets – normal

Ristocetin cofactor – normal in type 2, abnormal in type 1 and 3