Haemolytic anaemias: by site

Question 1

Haemolytic anaemias: by site?

Answer 1

• In intravascular haemolysis free haemoglobin is released which binds to haptoglobin.
• As haptoglobin becomes saturated haemoglobin binds to albumin forming methaemalbumin (detected by Schumm’s test).
• Free haemoglobin is excreted in the urine as haemoglobinuria, haemosiderinuria

Question 2

Intravascular haemolysis: causes?

Answer 2

• mismatched blood transfusion
• G6PD deficiency*
• red cell fragmentation: heart valves, TTP, DIC, HUS
• paroxysmal nocturnal haemoglobinuria
• cold autoimmune haemolytic anaemia

Question 3

Extravascular haemolysis: causes?

Answer 3

• haemoglobinopathies: sickle cell, thalassaemia
• hereditary spherocytosis
• haemolytic disease of newborn
• warm autoimmune haemolytic anaemia