Haemolytic anaemia

Question 1

Define Haemolytic Anaemia

Answer 1

Encompasses a number of conditions that result in the premature destruction of RBCs, leading to a shortened erythrocyte life span and anaemia

Question 2

Aetiology of Inherited Haemolytic Anaemia

Answer 2

From abnormalities in the cell membrane, Hb or red cell enzymes

• Membrane: hereditary spherocytosis (autdom), elliptocytosis
• Hb: sickle cell, thalassaemia
• Enzymes: G6PD deficiency (X-linked recessive, naphthalene + broad beans), pyruvate kinase deficiency

Question 3

Aetiology of Acquired Haemolytic Anaemia

Answer 3

From extrinsic factors such as micro-organisms, chemicals or drugs

• Damage to membrane: AIHA, snake bite
• Damage/trauma to whole red cell: MAHA
• Alloimmune: transfusion, haemolytic disease of the newborn
• Infection: malaria, sepsis
• Proxysmal Nocturnal Haemoglobinuria

Question 4

Symptoms of Haemolytic Anaemia

Answer 4

Pallor 
Jaundice
Fatigue 
SOB 
Dizziness
Episodic dark urine (haemoglobin uria)
Triggered by exposure to cold

Question 5

Signs of Haemolytic Anaemia on examination

Answer 5

Pallor
Jaundice
SOB
Splenomegaly

Question 6

Investigations for Haemolytic Anaemia

Answer 6

FBC: normochromic anaemia, MCHC raised, reticulocytes raised

Peripheral smear:

• G6PD: bite cells, Heinz bodies, irregularly contracted cells
• Hereditary spherocytosis: spherocytes
• MAHA: schistocytes

Osmotic fragility test: defected cells burst

LDH and haptoglobin: high LDH, low haptoglobin

DAT or Coombs’ test: Positive (immune) or Negative (non-immune) | IgG (warm) C3d (cold)

U+Es: elevated in TTP or HUS
Flow cytometry: abnormal