Haemolytic anaemias

Question 1

Name 2 inherited causes of haemolytic anaemia

Answer 1

• Hereditary Spherocytosis
• Hereditary Elliptocytosis
• Thalassaemia
• Sickle Cell Anaemia
• G6PD Deficiency

Question 2

Name 2 acquired causes of haemolytic anaemia

Answer 2

• Autoimmune haemolytic anaemia
• Alloimmune haemolytic anaemia (transfusions reactions and haemolytic disease of newborn)
• Paroxysmal nocturnal haemoglobinuria
• Microangiopathic haemolytic anaemia
• Prosthetic valve related haemolysis

Question 3

1) Why do haemolytic anaemias cause jaundice?
2) Why do haemolytic anaemias cause splenomegaly?

Answer 3

1) Bilirubin is released during the destruction of red blood cells
2) Spleen becomes full of destroyed RBCs

Question 4

1) In a haemolytic anaemia, what does a FBC show?
2) In a haemolytic anaemia, what does a blood film show?
3) What test is positive in autoimmune haemolytic anaemia?

Answer 4

1) Normocytic anaemia
2) Schistocytes - fragments of red blood cells
3) Direct Coombs test/direct antiglobulin test

Question 5

1) Autoimmune haemolytic anaemia causes episodes of jaundice and anemia - name 2 triggers for these episodes
2) What is the characteristic feature on a blood film?

Answer 5

1) Infection, fava beans, medication (i.e. primaquine, ciprofloxacin, sulfonylureas, sulfasalazine, methyldopa)
2) Heinz bodies

Question 6

What are the 2 scenarios where an alloimmune haemolytic anaemia occurs, and what happens in both of these conditions?

Answer 6

Haemolytic transfusion reactions - red blood cells are transfused into the patient and the immune system produces antibodies against antigens on those foreign red blood cells which destroys the RBCs

Haemolytic disease of the newborn - antibodies cross the placenta from the mother to the fetus and the maternal antibodies target antigens on the RBCs of the fetus, causing their destruction.

Question 7

1) What happens in microangiopathic haemolytic anaemia?
2) It usually occurs secondary to another condition - name 1 of these conditions

Answer 7

1) Small blood vessels have structural abnormalities that cause haemolysis of the blood cells travelling through them
2) Cancer, SLE, DIC, HUS

Question 8

1) What is thalassaemia?
2) What are the subtypes of thalassaemia?

Answer 8

1) Genetic defect in the protein chains that make up haemoglobin
2) Thalassaemia alpha and beta. Thalassaemia beta can be further subdivided into thalassaemia minor, intermedia and major

Question 9

What are 3 main aspects of managing a sickle cell crisis?

Answer 9

• IV fluids
• Oxygen
• Analgesia

Question 10

How is an acute haemolytic transfusion reaction managed (2)?

Answer 10

Stop transfusion + start IV fluids

Question 11

How is a minor allergic haemolytic transfusion reaction managed (2)?

Answer 11

Stop transfusion, give antihistamine, restart transfusion at a lower rate

Question 12

How is warm autoimmune HA managed?

Answer 12

Steroids and rituximab