My Intrinsic Factor came back negativ... - Pernicious Anaemi...

Pernicious Anaemia Society

32,672 members24,065 posts

My Intrinsic Factor came back negative, with a range 0-25, does it have to be over 25 to be positive please?

Jo5454 profile image
6 Replies

Hi, My result was 4 AU for the IF test and just wondering if this needs to be over 25 to be positive please? I'm gathering the AU stands for what it's measured in? I presumed it would be a positive or negative result as I thought you either have them or don't? Does 4 mean they are present in a low amount?

Many thanks Jo

Written by
Jo5454 profile image
Jo5454
To view profiles and participate in discussions please or .
Read more about...
6 Replies
fbirder profile image
fbirder

AU, as far as I understand, AU means 'Arbitrary Units'. Often test results are reported as 'Positive', Negative' or 'Indeterminate' without any numbers. I'll guess that they sometimes add the numbers just because doctors really, really like them.

Yes, 4 means your test is negative. Which tells you nothing as many people with PA get negative results. 

Jo5454 profile image
Jo5454 in reply tofbirder

Thanks, so guess given the range it would need to be more than 25 to be considered positive. I just assumed you either had the antibodies or don't, so don't really understand the number. 

It's a bit of a lottery that test, isn't  it! 

I requested the parietal cell antibody test, but doesn't look like that was done, I guess it's because it isnt considered to be as useful in diagnosing PA?

Thanks...

fbirder profile image
fbirder in reply toJo5454

In any test there will be some background noise. Even a supposedly zero sample might give a small positive response. For most tests that are Yes/No/Maybe a 'Yes' is a big response.

Yes, the anti-IF test is a bit rubbish, but there doesn't seem to be much of an alternative.

Hi. I'm waiting for this result too. You can still have pernicious anemia even with a negative result as only about 50% of PA patients are positive. Look on the mother site and you'll see documents that confirm this.

Jo5454 profile image
Jo5454 in reply to

Yes, thanks still searching. My Drs first words were that I haven't got PA because negative IF and my Active B12 wasn't low enough- although it was 27, bottom of the range and the MMA was 430 more than top of the range! 

Have you got your result yet?

in reply toJo5454

Not yet. He told me it takes two weeks, so 4 days to go. He didn't accept the private test results for b12.  Are you going to show him the evidence? NICE  no longer recommend the parietel cell test. Look at bcshguidelines.com for evidence. 

Not what you're looking for?

You may also like...

GP stopping my B12 injections despite a positive intrinsic factor antibody result

I was diagnosed with rheumatoid arthritis in 2007. In 2010 I suffered a numb tongue and extreme...

Doctor not accepting my Intrinsic factor A test, wants to do her own.

How will that work? Next time it could say negative as unreliable. Also said that test doesn't...
SunnyWorld profile image

Intrinsic factor

I seem to be at a sticking point with the findings of the intrinsic factor test. This is due to the...

Intrinsic factor antibodies

Can someone explain this test to me please. I got a numerical result and reference range rather...
Hsss7 profile image

INTRINSIC FACTOR ANTIBODY TEST . Has any member with P.A. had to have more than one IFAB test to get a positive reading ?

Is it a fact that the Intrinsic Factor antibodies come and go continually ? Or do they not appear...
wedgewood profile image

Moderation team

See all
Gambit62 profile image
Gambit62Administrator
Foggyme profile image
FoggymeAdministrator
taka profile image
takaAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.