Neg intrinsic factor and parietal cell antibodies

[anna1982]

Hi all

Is it possible to have negative intrinsic factor and parietal cell antibodies and normal gastrin and have PA? or would it be a run of the mill low b12?

[Galadriel1]

Yes, tests are unreliable and a neg result does not mean you don't have PA and I believe it is termed as ABnegPA. However it is caused 'run of the mill B12' will become PA if untreated. The anaemia is often unseen until late stage.

[Gambit62 Administrator]

interesting that you mention gastrin - my understanding is that, in relation to PA, this is quite a reliable indicator - and levels would be extremely high in a patient that had PA - however, PA is NOT the only absorption problem that can affect B12 absorption.

What exactly were your serum/active B12 results - with ranges and units, along with folate and full blood count if they were done?

Other absorption problems: coeliacs, crohn's, gastric surgery affecting the ileum, h pylori infection, and various drug interactions, including metformin used to treat type 2 diabetes, NSAIDs and PPIs.

[fbirder in reply to Gambit62]

Gastrin will be raised in people with Autoimmune Metaplastic Gastric Atrophy - the condition behind PA.

Gastrin secretion is switched on when for enters the stomach. It is switched off when the stomach pH drops due to secretion of hydrochloric acid. With AMGA there are no acid-secreting cells in the stomach, so gastrin production isn't switched off and levels become high.

But there are other possible causes. A gastronoma is a type of tumour (also called a Type 2 Gatric carcinoid) that secretes gastrin and results in high levels.

But high gastrin, in combination with other indicators, can be a good test for PA.