Haem - Pernicious Anaemia

Question 1

What is pernicious anaemia?

Answer 1

Autoimmune condition which leads to antibodies attacking Parietal cells or Intrinsic factor

Question 2

What is the pathophysiology of pernicious anaemia?

Answer 2

Parietal cells produce intrinsic factor

IF is essential for B12 absorption in the distal ileum

Parietal cells are attacked causing reduced IF and reduced B12 absorption

Question 3

What does B12 deficiency cause?

Answer 3

Macrocytic anaemia

Neurological symptoms
- Peripheral neuropathy with numbness or paraesthesia
- Loss of vibration sense
- Loss of proprioception
- Visual changes
- Mood and cognitive changes

Question 4

What should patients with peripheral neuropathy always be tested for?

Answer 4

Vitamin B12 deficiency
Pernicious anaemia

Due to the neurological symptoms

Question 5

What autoantibodies are used to diagnose pernicious anaemia?

Answer 5

First line
Intrinsic factor antibodies

Gastric parietal cell antibodies (less useful)

Question 6

How is pernicious anaemia managed?

Answer 6

IM hydroxocobalamin
Given to all patients with B12 deficiency initially

No neurological symptoms
3 times weekly for 2 weeks

Neurological symptoms
Alternate days until no further improvement in symptoms

Question 7

What does IM hydroxocobalamin maintenance depend on?

Answer 7

Pernicious anaemia
2-3 monthly injections for life

Diet-related
Oral cyanocobalamin or twice yearly injections

Question 8

If B12 and Folate deficiency are present together what is treated first?

Answer 8

B12

Giving patients folic acid in B12 deficiency can lead to

Subacute combined degeneration of the cord

with demyelination in the spinal cord and severe neurological problems