Introduction to Anaemia

Question 1

Categorise by size of red cell

Answer 1

Mean corpuscular volume: 80-100fL
Microcytic: iron deficiency, inherited disorders of Hb
Macrocytic: B12/folate deficiency, myelodysplasia
Normocytic: anaemia of chronic disease, acute haemorrhage, renal failure

Question 2

Reticulocyte count

Answer 2

causes polychromasia on a blood film
Indicates rate of production of RBCs
low during precursor deficiencies/bone marrow infiltration
high in chronic bleeding, haemolysis

Question 3

B12 Deficiency

Answer 3

• Pernicious anaemia: autouimmune, deficiency of intrinsic factor, can’t absorb B12, check for autoantibodies and treat with B12 injections
• Dietary
• Malabsorption: Coeliac’s/Crohn’s disease, or post gastric/ileal surgery

Question 4

Folate Deficiency

Answer 4

Dietary
Malabsorption
Excess utilisation (pregnancy)
Alcohol and drugs (phenytoin, methotrexate)

Question 5

Anaemia of chronic disease

Answer 5

Causes: chronic inflammation, infection, autoimmune, cancer, renal failure
Poor utilisation of iron
Dysregulation of iron haemostasis (decreased transferrin)
Impaired proliferation of erythroid progenitors (blunted response to EPO)

Question 6

Sickle Cell Anaemia

Answer 6

Increased turnover of RBCs - survival only 20 days
Sickle cell crisis - triggered by low O2 blood level
Management: analgesics, hydration, transfusion
Mechanism: HbS forms long filamentous strands, and RBCs become inflexible/spiky

Question 7

Thalassemia

Answer 7

Insufficient production of Hb
Imbalance of alpha and beta chains
Autosomal recessive
Enlarged spleen, liver and heart

Question 8

Bone Marrow Infiltration

Answer 8

Leukaemia: non specific symptoms, bone marrow failure
Lymphoma: lymphadenopathy, weight loss
Myeloma: anaemia, hypercalcaemia, renal failure, bone lesions
Bone marrow sample obtained from iliac crest

Question 9

Worldwide Impact

Answer 9

increased risk of morbidity in children
impaired physical and cognitive development
poor pregnancy outcome
contributes to 20% of maternal deaths
reduced work productivity

Question 10

Iron Deficient Anaemia

Answer 10

Causes: bleeding, nutritional deficiency, increased requirements
Confirm with iron studies - ferritin, serum Fe, transferrin
Iron deficiency is not a diagnosis - other investigations needed to find underlying cause

Question 11

Diagnostic tests for iron

Answer 11

Serrum Ferritin: storage form of iron, low = iron deficient
Serum Fe: labile in blood, for reflects recent intake
Serum transferrin: carrier molecule for iron gut to stores, homeostatic ally goes up if iron is deficient, reflects total iron binding capacity of blood
% transferrin saturation: sensitive measure of iron status, reflects proportion bound, low TF sats = iron deficiency

Question 12

Signs and Symptoms

Answer 12

Symptoms: tiredness, breathlessness, palpitations, headache
Signs: skin pallor, pale conjunctivae, tachypnoea, tachycardia
Main causes: inadequate synthesis (deficiency/bone marrow dysfunction); blood loss or consumption (haemolytic anaemia - increased roc destruction)