Pernicious anaemia

Question 1

What is cause of pernicious anaemia:

Answer 1

• Cause of B12 deficiency
• Autoimmune condition where antibodies form against parietal cells OR intrinsic factor (causing overall lack of intrinsic factor)
• Lack of intrinsic cells prevents the absorption of B12

Question 2

Neurological symptoms of B12 deficiency:

Answer 2

Peripheral neuropathy - numbness OR paraesthesia

Loss of vibration sense or proprioception

Visual changes

Mood or cognitive changes

Question 3

Testing for pernicious anaemia:

Answer 3

Testing for auto-antibodies - used to diagnose

Intrinsic factor antibody - first line antibody

Gastric parietal cell antibody - can also be tested but is less helpful

Question 4

Dietary B12 deficiency treatment

Answer 4

can be treated with oral replacement (cyanocobalamin) unless deficiency is severe

Question 5

Pernicious anaemia treatment

Answer 5

1mg IM hydroxocobalamin 3x day - 2wks

–> then every 3 months

More intense regimens are used when neurological symptoms are present (1mg every other day until symptoms improve)

Question 6

Folate deficiency in addition to B12 deficiency:

Answer 6

Treat B12 deficiency first before correcting folate dificiency

• Treating patients with folic acid when they have B12 deficiency can lead to…

subacute combined degeneration of the cord

Question 7

How is B12 absorbed (where is it found in diet)

Answer 7

Found in fish

Intrinsic factor binds B12 so can be taken up in ileum

Intrinsic factor produced by parietal cells in stomach