Anaemias

Question 1

Name 2 drugs that can cause an acquired haemolytic anaemia?

Answer 1

Penicillin (by binding to RBC membrane).

Quinine (by production of immune complexes)

Question 2

What is the main treatment for TTP?

Answer 2

Plasma exchange

Question 3

What are the causes of microangiopathic haemolytic anaemia?

Answer 3

TTP, HUS, DIC, pre-eclampsia, eclampsia.

Question 4

What enzyme defects cause haemolytic anaemia?

Answer 4

G6PD deficiency, pyruvate kinase deficiency

Question 5

What virus may exacerbate haemolytic anaemia?

Answer 5

Parvovirus (it produces a cessation of marrow erythropoiesis (aplastic crisis).

Question 6

Which enzyme is inhibited in most cases of TTP, and what is its role?

Answer 6

ADAMS13. It is a metalloprotease responsible for cleaving large multimers of vWF into smaller fragments. The increase in multimers increases platelet adhesion to areas of endothelial injury, particularly at arteriole-capillary junctions.

When large multimers persist this gives a tendency for coagulation.

Question 7

In sickle cell, what can precipitate crises?

Answer 7

Cold, infection, dehydration, hypoxia.

Question 8

How is a sequestration crises in sickle cell treated?

Answer 8

Urgent blood transfusion.