Megaloblastic Anaemia - Macrocytic Anaemia

Question 1

What are Megaloblasts?

Answer 1

• Large forms of RBC with nuclei
• Megaloblasts are immature red blood cells with large nuclei
• These are seen in B12 and Folate deficiency

Question 2

What are the causes of Megaloblastic Anaemia?

Answer 2

• Vit B12 Deficiency ( Malabsorption - Pernicious anaemia, IBD), Poor dietary intake, surgical (post gastrectomy)
• Folate Deficiency ( Poor dietary intake, Increased demands ( Haemolysis, pregnancy), Malabsorption, Anti-folate drugs)

Question 3

What is Vitamin B12?

Answer 3

• Cobalamin
• Found in meats and diary products
• Essential vitamin for DNA synthesis
• Not found in plants

Question 4

How is Vitamin B12 absorbed in the body?

Answer 4

• Vit B12 absorption is aided by IF
• Parietal cells in the gastric epithelium secrete IF
• IF binds to Vitamin B12
• B12- IF complex binds to receptors within the terminal ileum where it is absorbed

Question 5

What are the causes of Vitamin B12 deficiency?

Answer 5

• Inadequate intake - strict vegetarians, vegans
• Inadequate secretion of IF (pernicious anaemia, gastrectomy)
• Malabsorption (Crohn’s)
• Inadequate release of B12 from food ( gastritis, alcohol abuse)

Question 6

What are the Neurological features of Vit B12 deficiency?

Answer 6

• Peripheral Neuropathy
• Subacute degeneration of the cord
• Focal Demyelination

Question 7

What are the Psychiatric features of Vit B12 deficiency?

Answer 7

• Depression
• Personality Change
• Memory Loss

Question 8

What investigations are done for Vit B12 deficiency?

Answer 8

• FBC
• Blood Film ( megaloblastic anaemia +/- hypersegmented neutrophils)
• Haematinics
• LDH
• LFTs
• Bone Marrow Aspirate - erythroid hyperplasia with giant metamyelocytes