Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be

talking to you about Pinnicious Anemia. And you can find written notes on this topic at

zero to finals.com slash penitious anemia or in the hematology section of the second edition of the zero to finals medicine book.

So let's get straight into it.

Vitamin B12 deficiency causes macroscopic anemia with large red blood cells.

The key causes of a low vitamin B12 are penitious anemia,

insufficient dietary B12, for example on a vegan diet as B12 is mostly found in animal products,

and medications that reduce B12 absorption, for example, proton pump inhibitors and metformin.

Panicious anemia is an autoimmune condition involving antibodies against the parietal cells or intrinsic factor.

So let's talk in more detail about the pathophysiology of panicious anemia.

The parietal cells of the stomach produce a protein called intrinsic factor.

Intrinsic factor is essential for the absorption of vitamin B12 in the distal ileum.

In pernicious anemia, auto-antibodies target either the parietal cells or intrinsic factor,

resulting in a lack of intrinsic factor and a lack of absorption of vitamin B-12.

Vitamin B-12 deficiency can cause neurological symptoms, such as peripheral neuropathy with numbness

or paristhesia, or pins and needles, a loss of vibration sense, a loss of proprioception, visual changes and mood and cognitive

changes. A tom tip for you, for your exams, remember to test for a vitamin B12 deficiency and

pernicious anemia in patients presenting with peripheral neuropathy,

particularly with pins and needles in the hands and feet.

Next let's talk about auto-antibodies.

Auto-antibodies used to diagnose penitious anemia are intrinsic factor antibodies,

which are the first line investigation,

...