Gastric parietal cell antibodies OR IFAB? Do I need both??

[Suffering_sunny]

Hi there,

I tested negative for GPCA, but I haven't done IFAB.

Having done GPCA, is that enough?

Should I also do IFAB? I am on eod si injections, but for my peace of mind and for my GP to stop upsetting me/scaring me with their lack of b12 knowledge. I'd really like to at least TRY for a confirmatory test.

Should I do IFAB? And if so, how long after injecting, so that I don't get a false positive or something (if that's even a thing)...

I know that there are lots of reasons for b12 issues, and this is only one. But, I want to try everything, if it would be useful.

Thanks,

S

[Nackapan]

IFAB test is ususlly the test used to confirm PA.It's possible to have a false positive with alot of b12 in your bloodstream.

Ususlly done before b12 injections start.

False negatives seem more common though.

IFAB test picks up about 50% with PA

With the parietal cell antibody test can be positive for many reasons . Not recommended to diagnose PA

There is not a conclusive test for PA.

Some have several IFAB tests before a

positive one .

It's the 'clinical picture '

Other things need to be ruled out

Symptoms and response to b12 treatment.

I'm 5 yesrs in .

Nothing else to date found to treat.

Menopause my trigger.

Very low serum b12 discovered only when symptoms were severe.

Nothing else significant before .

An absorbtion issue .

Not diet related

Not clouded by any other medical issues .

Its B12 that's got me better via regular injections.

A trial on oral b12 failed.

Can be fine with a dietary b12 deficiency as you can absorb but simply not getting enough from food.

[FlipperTD]

Scientist, not medic.

Parietal Cell Abs negative? That's a start! However, IFAb ought to be done, and probably best to do it immediately before your next B12 jab. However, if you're EOD, then that's not going to make much difference. So long as the lab running the test is aware, then they can make the call of whether or not it is worth testing the sample.

Perhaps it's time to ask what exactly makes you, or your GP, think you actually have PA? It's a confusing time. Good luck.

[Sleepybunny]

Hi,

I think it's possible to have PA even if GPCA and IFA test results are negative/normal range.

If a person has lost most of their parietal cells then GPCA test may come back negative or normal range.

About half of people with PA test negative/normal range on IFA test.

See Background Information section in this UK document "NICE CKS Anaemia - B12 and Folate deficiency".

May also be info in new "NICE guideline B12 deficiency" published on 6th March 2024.

Some labs say to leave at least 48 hours after a b12 injection before having IFA test and some say leave up to two weeks.

Has your GP ordered a gastrin test? May need to see a specialist doctor for this.

Thread about tests for PA and B12 deficiency

healthunlocked.com/pasoc/po...

I'm not medically trained.

[ReallyWondering]

Yes, get the IFAB test. But like others have said, negative could be false. Consider getting an endoscopy, as well.