Disorders of Haemostasis

Question 1

What is haemophilia A?

Answer 1

X linked genetic disorder
1 in 5000 males
Females can exhibit symptoms in lyonisation

Mutations in factor VIII –> dysfunction –> bleeding
Most common = intron 22

Worse bleeds and worse outcomes than haemophilia B

Question 2

What is haemophilia B?

Answer 2

X linked genetic disease
1 in 30 000 males

Mutations in Factor IX –> dysfunction

Question 3

Treatment of Haemophilia A

Answer 3

Prophylactic recombinant factor VIII
–> Can result in formation of factor VIII antibodies

ACE910 - antibody which activates factors XI and X without factor VIII

Question 4

Treatment of Haemophilia B

Answer 4

Prophylactic recombinant factor IX

Rare to have antibody formation

? gene therapy

Question 5

Types of von Willebrand disease?

Answer 5

Type 1 = AD = decreased vWF

Type 2 = AD = Qualitative defect in vWF - will have normal levels but dysfunctional

Type 3 = AR = Severe vWF deficiency –> loss of factor VIII and vWF

Question 6

Presentation of von Willebrand disease?

Answer 6

Easy bruising
Skin bleeding
Prolonged mucosal bleeding
Heavy menstrual bleeding and post partum bleeding

Type 3 presents like haemophillia

Question 7

Testing for vWD?

Answer 7

vWF antigen
vWF activity
Factor VIII activity

Question 8

Acquired vWD?

Answer 8

• Lymphoma, leukaemia and myeloproliferative disease
• Wilm’s tumour
• SLE
• States of high vascular flow - VSD, AS, mitral valve prolapse, LVAD
• Hypothyroidism
• Uraemia
• Valproate
• Ciprofloxicin

Question 9

Treatment of vWD?

Answer 9

Desmopressin - DDAVP
–> release of endothelial vWF

Recombinant human vWF