Iron deficiency and ACD

Question 1

What role does iron play in erythropoiesis?

Answer 1

Ferrous iron (2+) sits in centre of haem ring, which, together with the globin chains, forms haemoglobin

Question 2

What are the dietary sources of iron?

Answer 2

Meat and fish (haem iron)
Vegetables
Whole grain cereal
Chocolate

Question 3

How is iron absorbed?

Answer 3

• Can only absorb ferrous iron (2+)
• Iron passes into epithelial cell
• At BM, ferroportin transports iron into blood
• High hepcidin (when iron levels are high) blocks ferroportin - stops iron absorption
• Low hepcidin and iron –> ferroportin is less inhibited –> increased iron absorption

Question 4

What are the causes of iron deficiency?

Answer 4

1. Bleeding - e.g. menstrual, GIT
2. Increased use - e.g. growth/pregnancy
3. Dietary deficiency - e.g. vegetarian
4. Malabsorption - e.g. coeliac disease

Question 5

What are the haematological features of iron deficiency?

Answer 5

Low Hb
Low MCV
Low serum iron
Low ferritin
High transferrin
Low transferrin saturation

Question 6

What factors increase iron absorption?

Answer 6

Iron deficiency
Anaemia/hypoxia
Pregnancy

Question 7

How is iron deficiency diagnosed?

Answer 7

Laboratory diagnosis:
Low Hb
Low MCV
Low serum iron
Low ferritin
High transferrin (or TIBC)
Low transferrin saturation

Question 8

How is iron deficiency managed?

Answer 8

Iron supplements

Treat underlying cause, e.g. bleeding, coeliac disease

Question 9

What is transferrin?

Answer 9

Molecule that transports iron around body in plasma

Usually around 20-40% saturated with iron

Question 10

When should full GI investigations be performed if found to be iron deficient?

Answer 10

Male
Women over 40
Post-menopausal women
Women with scanty menstrual loss

Question 11

What are the clinical features of iron deficiency?

Answer 11

• Extreme fatigue
• Weakness
• Pale skin
• Chest pain, tachycardia or shortness of breath
• Headache, dizziness or lightheadedness
• Cold hands and feet
• Pagophagia - crave non-nutritive substances (ice)
• Poor appetite, especially in infants and children
• Menorrhagia
• Melaena
• Oesophageal webbing, koilonychia, glossitis, angular stomatitis, gastric atrophy

Question 12

How can iron deficiency be differentiated from anaemia of chronic disease?

Answer 12

Iron deficiency = low MCV, low ferritin, high transferrin, low transferrin saturation

ACD = low or normal MCV, high or normal ferritin, normal or low transferrin, normal transferrin saturation