Intrinsic factor antibody test - Pernicious Anaemi...

Pernicious Anaemia Society

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Intrinsic factor antibody test

Zazbag profile image
11 Replies

Hello,

My GP has agreed to test this antibody. I have Hashimoto's/hypothyroidism and take 150 mcg levothyroxine along with low dose naltrexone (currently 1 ml daily, titrating up 0.5 ml every two weeks), methyl-B12, methylfolate, vitamin D, ferrous fumarate, vitamin B6, zinc, magnesium and selenium. I imagine the answer is no but I wanted to check if I should discontinue any of these prior to the antibody test?

Many thanks,

Zara

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Zazbag profile image
Zazbag
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11 Replies
fbirder profile image
fbirder

The only one that might interfere is the methylcobalamin. To prevent any possible interference you would need to stop it for a period of a few days to two weeks (depending on the test type.

But if it does interfere it will give a false positive reault.

Zazbag profile image
Zazbag in reply to fbirder

Ok thank you, I'll discontinue that two weeks ahead. I'm taking the test in 6 weeks. What about the low dose naltrexone? Is it possible that could lower my antibodies if I have them?

Sleepybunny profile image
Sleepybunny

Hi,

If your GP suspects PA (Pernicious Anaemia) is a possibility, I hope they know that it is still possible to have PA even if you have a negative result in the Intrinsic Factor Antibody test .

If PA is suspected, I suggest you consider joining and talking to PAS who can offer support and info about PA.

PAS (Pernicious Anaemia Society)

Based in Wales, UK.

pernicious-anaemia-society....

There is a helpline number that PAS members can ring.

PAS support groups in UK

pernicious-anaemia-society....

No meetings during pandemic.

Blog post about how PAS can support PAS members seeking PA diagnosis

martynhooper.com/2017/06/24...

PA tests

Intrinsic Factor Antibody (IFA) test

labtestsonline.org/tests/in...

Parietal Cell Antibody (PCA) test

labtestsonline.org/tests/pa...

PCA is not recommended as a diagnostic test for PA in UK.

It is still possible to have PA with a negative result in IFA or PCA test.

About 50% of people with PA test negative on IFA test.

About 10% of people with PA test negative on PCA test.

UK B12 document

BSH Cobalamin and Folate Guidelines

b-s-h.org.uk/guidelines/gui...

Flowchart from BSH Cobalamin and Folate Guidelines

stichtingb12tekort.nl/weten...

Flowchart outlines process for diagnosing PA and Antibody Negative PA in UK

What are your serum B12 test results like?

Link about "What to do next" if B12 deficiency suspected

b12deficiency.info/what-to-...

I wrote very detailed replies on another forum thread with lots more info eg symptoms lists, causes of B12 deficiency, tests for PA, list of B12 books, list of B12 websites, more UK B12 documents, letters to GP about B12 deficiency and other B12 info including hints on dealing with unhelpful GPs, which you might find helpful.

healthunlocked.com/pasoc/po...

If you're in UK, be aware that the pandemic is impacting UK patients' B12 treatment.

I left a detailed reply about impact of pandemic on B12 treatment in UK in next link.

healthunlocked.com/pasoc/po.....

I am not medically trained.

Zazbag profile image
Zazbag

For autoimmunity. It's meant to be an effective off-label treatment for many autoimmune disorders.

Nackapan profile image
Nackapan

False positive

Zazbag profile image
Zazbag in reply to Nackapan

Please could you elaborate? Are you saying LDN will cause a false positive? That makes no sense since it lowers antibodies.

Nackapan profile image
Nackapan

As fbirder said. If the intrinsic antybody test done too close to b12 injections it can give a false positive. I dont know about LDN

In an earlier text it just said false negative when I think false positive was meant.

Zazbag profile image
Zazbag in reply to Nackapan

Thank you!

Zazbag profile image
Zazbag in reply to Nackapan

How far ahead should I discontinue B12? Two weeks?

Nackapan profile image
Nackapan in reply to Zazbag

I think that's right. Depends on the test it seems. So 2 weeks okay for any of them.

Nackapan profile image
Nackapan

If your b12 is low , below the bottom of the range. So b12 deficiency easy to find. As is aneamia although that does not need to be present.

The difficulty is the test used for Pernicios anaemia

If its positive you have it.

If its negative you could still have PA.

!

Folate usually tested at the same time as b12. Iron panel. Vitamin D FBC lover function celiac ect.

Yes lots of research still needed

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