Anaemia

Question 1

Explain how anaemia is classified on the basis of either mechanism or red cell size and how this contributes to the differential diagnosis

Answer 1

Problems making Hb:
Gene mutations - thalassaemia, sickle cell
Low iron - iron deficiency, anaemia of chronic disease
Low building blocks - vitamin B12/folate deficiency
Problems with RBC membrane/metabolism - hereditary spherocytosis/elliptocytosis, G6PD deficiency, pyruvate kinase deficiency
Enlargement of spleen - liver disease, malaria, malignancy
Lack of erythropoiesis - bone marrow failure, erythropoietin deficiency

Question 2

List the common causes of microcytic, normocytic and macrocytic anaemia

Answer 2

Microcytic - thalassaemia, anaemia of chronic disease, iron deficiency, lead poisoning
Normocytic - anaemia of chronic disease, iron/B12/folate deficiency, bone marrow failure
Macrocytic - B12/folate deficiency

Question 3

Define the term ‘reticulocyte’ and explain the significance of the reticulocyte count

Answer 3

Reticulocyte - immature RBC, made in bone marrow, circulates and matures
Reticulocyte count may indicate bone marrow failure

Question 4

Describe the role of iron in erythropoiesis

Answer 4

Iron is essential for formation of Hb

Question 5

List the dietary sources of iron, factors influencing the absorption of iron and the causes of iron deficiency

Answer 5

Dietary sources - red meat, leafy green vegetables
Absorption - at duodenum/jejunum, inhibited by antacids, PPIs, calcium, enhanced by vitamin C
Causes of deficiency - lack of dietary iron, unable to absorb iron, loss of blood

Question 6

Describe some symptoms and signs of anaemia

Answer 6

SOB, weakness, lethargy, palpitations, headache, angina
Pallor, tachycardia, heart failure, murmur
Koilonychia, glossitis, leg ulceration, angular stromatitis

Question 7

Describe the clinical and haematological features of anaemia of chronic disease

Answer 7

Associated with chronic inflammation/infection
Cytokine driven reduction in serum iron –> increased hepcidin –> reduced gut iron absorption, iron pushed into stores
Reduction in erythropoietin production
Reduction in RBC lifespan
Normocytic/microcytic, ferritin normal/raised, serum iron low, transferrin saturation normal

Question 8

Explain that synthesis of DNA requires both vitamin B12 and folate

Answer 8

Building blocks

Formation of Hb, myoglobin, cytochromes

Question 9

Describe the major neurological complications of vitamin B12 deficiency

Answer 9

Myelin decays, fibric sclerosis of nervous tissue in dorsal parts of spinal cord and pyramidal tracts
Impaired perception of deep touch, pressure, vibration
Loss of sense of touch
Paraesthesia
Ataxia
Decrease/loss of deep muscle tendon reflexes
Positive babinski reflex
Psychological - mania, psychosis, fatigue, memory impairment, irritability, depression, personality changes

Question 10

Explain the term ‘anaemia’

Answer 10

Haemoglobin