Intrinsic Factor at top of range

[walbright]

My intrinsic factor antibody test came back at 1.1 (normal range 0-1.1). I was told that because my number is trending upward it should be considered positive. My B12 was 234 but many neuro symptoms including twitching, burning feet, ears ringing, anxiety. My question is....should this number be an indicator of pernicious anemia? I also have family history of PA.

[fbirder]

If you have been told that you have a positive test of the IF antibodies then there's a 95% chance that you do have PA, despite the normal B12 levels.

The gold test will be to see if a course of injections improves your symptoms.

[walbright in reply to fbirder]

Problem is that the doc says I do NOT have pernicious anemia though I am fairly confident that I do. I started weekly loading injections and my symptom were almost gone until I started monthly injections and they all came back. It is seriously maddening how hard we have to fight for this. Thank you so much for your input!

[fbirder in reply to walbright]

I would ask my doctor how a positive result for IFAB doersn't mean that I have PA.

[walbright in reply to fbirder]

I just read a response on this thread and he seems to know his stuff. He said my number is in the normal range. But I am not discouraged. Even after loading injections and then monthly injections - my numbers dropped again so this is a good indicator that I am not absorbing!

[Sleepybunny]

I think a positive IFA test result, a family history of PA and symptoms of b12 deficiency are pretty strong indicators.

I am not medically trained.

Have you considered joining PAS?

PAS (Pernicious Anaemia Society)

Based in Wales, UK. Has members in other countries.

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...

B12 Deficiency Info website

b12deficiency.info/

I wrote a very detailed reply on another forum thread with links to B12 deficiency symptoms lists, causes of b12 deficiency, info about tests for PA, B12 books, B12 websites, UK B12 documents, letters to GP about B12 deficiency and other B12 info which you might find helpful.

healthunlocked.com/pasoc/po...

If you're in UK, be warned that many UK forum members are reporting difficulty getting their B12 treatment due to impact of pandemic. Don't let GPs fob you off with oral tablets.

I left a long reply in this next thread with info on impact of pandemic on B12 treatment in UK.

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

It includes links to recent PAS news items and blog posts from B12 Deficiency Info which have suggestions on how to cope if injections stopped/delayed/swapped for oral tablets.

[walbright in reply to Sleepybunny]

Thank you for your response! I am in the US and do not yet have an official diagnosis. I have received weekly loading injections which made my symptoms almost disappear but then was dropped to monthly and they all came back. Ugh! Meeting with family doctor today to discuss this. Appreciate the information!

[Sleepybunny in reply to walbright]

Hi,

Some more info

B12 Awareness (US website)

b12awareness.org/

Stichting B12 Tekort (Dutch website with English articles)

stichtingb12tekort.nl/weten...

UK B12 Blogs

Martyn Hooper's blog about PA

martynhooper.com/

B12 Deficiency Info blog

b12deficiency.info/blog/

B12 books I found useful

"What You Need to Know About Pernicious Anaemia and B12 Deficiency" by Martyn Hooper

Martyn Hooper is the chair of PAS (Pernicious Anaemia Society).

"Living with Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper

Has several case studies.

"Could it Be B12?: An Epidemic of Misdiagnoses" by Sally Pacholok and JJ. Stuart (USA authors)

Very comprehensive with lots of case studies. There is also a paediatric version of this book "Could It Be B12? Paediatric Edition: What Every Parent Needs to Know".

"Vitamin B12 deficiency in Clinical Practice" (subtitle "Doctor, you gave me my life back!" by Dr Joseph Alexander "Chandy" Kayyalackakom and Hugo Minney PhD

[walbright in reply to Sleepybunny]

Thanks so much! I have the "Could It Be B12?" book already. That was a life saver!

[Hidden]

My intrinsic factor test was 0 (normal?)..B12 was 145 I most definitely have pernicious anaemia all the symptoms including neurological went away after my loading doses now they've come back. I'm going to self inject but I've also been told that the intrinsic factor test is very flawed so will will continue with self injecting monthly as per the pernicious anaemia website and not as the doctor says 3-monthly that won't be sufficient.

[Gambit62 Administrator]

the IFA test is not very sensitive. This means there is a 40-60% chance that a negative is a false negative (the exact probability depends on the test method). This means that a negative does not rule out PA as the cause of a B12 absorption problem. In the UK the BCSH (British Committee for Standards in Haematology) recognises IFAB-negative PA as a possibility because the test is so insensitive.

The IFA test is very specific which means that a positive is good evidence that PA is the cause of a B12 absorption problem.

The serum B12 test is a difficult one to interpret because the normal range is so large and different individuals tend to sit at different points in the range. If you have early test results that showed a significantly higher B12 level (>20% as that is the range that you would get from repeating the test on the same sample many times), that would be indicative of levels falling over time which is a good indicator of the presence of an absorption problem.

[FlipperTD]

I am a [retired] scientist and I have done many thousands of IFAb tests. It's a great test if a strong positive is reported, but otherwise it's not always that helpful.

If your laboratory reports a value of 1.1 and that's in their 'normal' range, then it's 'normal'. Typically, 'normal' ranges are 95% ranges, meaning that 95% of normal patients will be within that range, so 1 in 20 can be outside the range whilst still being 'normal'.

Of course, around 50% of patients with PA never have detectable IFAb either. You mention that your result is 'trending upward'. Given time it may well reach the 'abnormal' range but until then, it looks like it's 'normal'.

If your B12 level rises on oral therapy, you're absorbing it somehow, but some PA patients seem to be able to. If it doesn't rise on tablets but does rise on injections, then that makes PA much more likely. Do your own research, listen to what the experts on here say, and finally, be guided by your doctors; that's what they're there for!

Good luck.

[walbright in reply to FlipperTD]

Good information! Thank you!

[babylock]

My IF antibodies was high I was given a MMA (methylmalonic acid) test which also came back high. There go the diagnosis. Every three months b-12 and MMA are check.

Good Luck

[Sleepybunny]

Hi walbright,

Perhaps you could show your doctor this flowchart from UK guidelines which acknowledges that it is possible to have Antibody Negative PA

Flowchart from BSH Cobalamin and Folate Guidelines

stichtingb12tekort.nl/weten...

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

If you look at the fifth pinned post on this forum, the eighth link in the post is to the complete document the flowchart comes from.

[walbright in reply to Sleepybunny]

Thank you so much!