Anaemia

Question 1

What is Sickle Cell Disease?

Answer 1

A hereditary blood disorder, causing haemoglobinopathy.

Question 2

What are the major pathological manifestations of Sickle Cell Disease?

Answer 2

• Haemolytic anaemia
• Microvascular occlusions, leading to tissue ischaemia
• Splenic enlargement and dysfunction

Question 3

In general how are haemolytic anaemias classified?

Answer 3

• Inherited genetic defects (e.g. G6PD)
• Antibody-mediated (autoimmune, transfusion reaction)
• Trauma (e.g. mechanical heart valves)
• Toxins (e.g. venom)
• Infection (e.g. malaria)

Question 4

What is Thalassaemia?

Answer 4

A group of inherited disorders caused by mutations that reduce alpha- or beta-globin chain synthesis of haemoglobin.

Question 5

How are the causes of anaemia classified?

Answer 5

1. Blood loss: acute or chronic

2. Increased RBC destruction

• G6PD def, Malaria, Transfusion reaction, etc

3. Decreased RBC production

• Nutritional iron deficiency, B12 deficiency, Aplastic anaemia, EPO deficit in renal failure

Question 6

Describe the pathogenesis of iron deficiency anaemia.

Answer 6

(Causes: chronic blood loss, poor diet, impaired absorption, increased requirements)

• Iron stores are used up first: ferritin decreases
• Next, serum iron and transferrin decrease
• RBCs become hypochromic and microcytic