Sunday 31 October 2010

MRCP revision battle 38.1: Von Willebrands Disease

We're about to enter a 2 day fest of haematology.  Try to get through the dull battles of B and T cell disorders as the topics on the other side of them are slightly more stimulating.  Good luck!


MRCP revision battle 38.1: Von Willebrands Disease
MRCP revision battle 38.2: B cell disorders
MRCP revision battle 38.3: T cell disorders
MRCP revision battle 38.4: Combined B and T cell disorders
MRCP revision battle 38.5: Thrombotic thrombocytopenic purpura
MRCP revision battle 38.6: Microangiopathic haemolytic anaemia
MRCP revision battle 38.7: Sideroblastic anaemia




MRCP revision battle 38.1: Von Willebrands Disease


Von Willebrand's disease is the commonest inherited coagulopathy in the UK.


Von Willebrand's factor is a substance made in epithelial cells which:
  • helps platelets bind to the exposed subendothelium
  • helps platelets bind to each other
  • binds to factor VIII,  helping prevent its destruction in the circulation

There are many types of Von Willebrand's disease.  The commonest 3 are:
  • Type 1: decrease in Von Willebrand's factor 
    • accounts for 80% of Von Willebrand Disease
    • autosomal dominant
  • Type 2: abnormal form of Von Willebrand's factor
    • autosomal dominant
  • Type 3: total lack of Von Willebrand's factor
    • autosomal recessive

Symptoms/signs of Von Willebrand's disease include bruising, menorrhagia, epistaxis and increased bleeding after tooth extraction (a favourite in MRCP exams)


Diagnosis is by:
  • low levels factor VIII
  • low levels VWF antigen
  • deficient ristocetin-induced platelet aggregation

Treatment is:
  • DDVAP (=desmopressin) in mild disease
  • factor VIII concentrate/cryoprecipitate in severe disease
  • avoid NSAIDs.


Next up.... B cell disorders