Normal levels for intrinsic factor antibody?

[Jenkinsaj]

Hi, I was told a couple of weeks ago that despite having a normal b12 ( approx300, I had been taking oral B12) I had pernicious anaemia. My intrinsic factor is 2.1 which has caused a great deal of confusion, one Dr said that it was positive and on the blood result form did state abnormal, however all other Drs are saying it is in within normal limits and have stopped my B12 injections. I am totally confused. What is the normal range for intrinsic factor antibody, the only information I could find suggested that less than 1.2 is negative, 1.21-1.52 is equivocal and above 1.53 is positive indicating PA, am I going mad? Would appreciate any help or advice. Will ring the PA society later to ask their advice. Thank you.

[fbirder]

Different labs use different tests on different equipment and may give the results in different units.

The ranges you’ve quoted are from South Tees NHS. Other labs may have different ranges. I know there’s one lab that used to use <6 as normal.

You need to get your test results with the range for the lab that did the test.

However, as the test result says ‘abnormal’ I’m going to guess that the ‘other doctors’ are using that older test range.

But get a copy. They’re your results and you’re entitled to have them.

[Jenkinsaj in reply to fbirder]

Thank you so much. I did get a copy and it said my levels are 2.1 u/ml and the labs range is 0.00-6.00u/ml. So when Drs look at it it’s in range but it says abnormal so everyone is confused. Nice guy at PA society says ignore results and just look at symptoms, not easy convincing the Drs however. Thank you for taking the time.

[Gambit62 Administrator]

the IFA test is notoriously insensitive - and gives false negatives 40-60% of the time so can't really be used to rule out PA.

If you are UK based I would refer GPs to the BCSH guidelines on diagnosis and treatment of cobalamin and folate deficiencies which you can find here

onlinelibrary.wiley.com/doi...

but your GP can access through the BNF

The standards give quite a good run down of the limitations of the various tests related to B12 and provides a few protocols for diagnosing B12 deficiency. It also refers to IFAB negative PA as a recognition of the extreme limitations of IFA test.

On the other hand it is quite a specific test and (although there are some circumstances in which it can give false positives, ie too close to a B12 shot) it rarely gives false positives.

[Jenkinsaj in reply to Gambit62]

Thank you very much.

[Hmc449]

Have you been tested for a MTHFR gene mutation? If you have this, you’ll have problems with “regular” b12 and folate supplements. I have a MTHFR 677T mutation and have to take methylated folate and methylated b12. I had to take a lot of both together just to get my levels in the range and then continue with that to get in the optimum range. Having regular b12, regular folic acid in diet etc seems to cancel it out. I haven’t been tested for intrisic factor- so I don’t know about that. But until I was tested for MTHFR I couldn’t get my b12 and folate up- my body just couldn’t convert the regular supplements. I don’t know your ranges for your b12- but 300 seems low. My Dr. said optimal ranges are between 600-1200 and being above that range for b12 is not harmful.

mthfrgenehealth.com/mthfr-v...

[fbirder in reply to Hmc449]

Half the people in the world have the C677T MTHFR mutation.

If you have one copy of this (heterozygous) then your MTHFR enzyme works at about 70% efficiency. The body can easily get round this by making more of the enzyme.

If you have two copies (homozygous, like 9% of the population) then the enzyme works at 30% efficiency. For the vast majority of those people that, too can be compensated.

A very small minority will find that supplementing with methylfolate may do them some good, and won’t do any harm.

There is zero point in supplementing with methylcobalamin.

B12 levels should be above 600 pmol/L means maintaining levels higher than around the levels where 90% of the population are ok.

[Hmc449 in reply to fbirder]

My labs say the ranges on them should be 200-1100 pg/mL...which appears to be a different calculated range than your describing.

My Dr said optimal range is 600-1200 in that case.

You obviously have your own thoughts about gene mutations. In my case, taking non-methylated folate and b12 did nothing for me.

[fbirder in reply to Hmc449]

Yes, I have my ideas on gene mutations. They’re shared by a vast number of experts on the subject. Including the largest gene testing company on the planet.

Our Take on The MTHFR Gene, is a 23andMe blog posting (January 5, 2017), a meta-analysis finding that the past two decades of scientific evidence as it relates to specific MTHFR-influenced health conditions to be inconclusive or conflicting, with two exceptions, 1. women with two copies of C677T variant, 2. a very rare variant that may cause homocystinuria. Their takeaway, "Based on the existing data, scientists at 23andMe have concluded that people should not interpret their genotypes at the common MTHFR variants as having an effect on their health."

[fbirder]

This article summarises some research in relation to MTHFR

quora.com/How-do-we-know-if...

[Gambit62 Administrator]

Jenkinsaj Please note responses to this post have been edited and in some cases removed as they included responses not directly relating to the original post and some responses were not framed with the level of consideration that we would like to see on this forum

[Jenkinsaj in reply to Gambit62]

Thank you