Intrinsic factor antibody result

[Gecko22]

Hi all, I've only just seen the result of an Intrinsic Factor Antibody test that was done in December before I started SI which I don't know how to interpret. I got a result of 2 u/ml (reference range is 0-24 u/ml). Is that a positive or a negative result? Does that confirm PA or not?  Can someone explain please. Thank you!

[autumngreen]

I got exactly the same result on my IF test. I was told my the nurse I didn’t have PA though I’d had long term symptoms of low B12 (not due to diet). I’ve asked two health professionals to explain what the results mean but they haven’t, I don’t think they know. I’ve googled it and haven’t been able to find anything much.

I got B12 loading dose injections and now a B12 injection every 10 weeks, which makes a huge difference.

I don’t find health professionals very helpful. They are very dismissive and don’t seem keen to help with those health problems that aren’t fixed quickly or they want to prescribe pain killers or antibiotics for everything. It’s a real battle trying to get a GP to listen and hear what you’re saying. I wish you all the best.

[Gecko22 in reply to autumngreen]

Thank you! I couldn't agree more. I haven't been able to find anything online with that reference range either. I started loading doses in January regardless and now doing weekly injections. I can't say that I feel any better as yet but I have Long Covid and got infected again in early March so I've generally felt awful anyway and so many of the symptoms overlap.

Health professionals I've seen haven't been at all helpful and I've also been prescribed random things like antibiotics and Amytriptyline, which I didn't think I needed or would help so I decided not to take them. All the best!

[FlipperTD]

Scientist, not medic.

This is one where the laboratory performing the test should be consulted; actually issuing a reference range for a test, where it should be binary: Positive, or Negative, is a cop-out. Possibly due to the setup of the computer system that reports the result. ['Blaming the computer, not the folks operating it' is a disgrace.] Then reporting the result with no intelligent interpretation of it just makes it worse.

If anyone can explain why there should be a reference range quoted for something that shouldn't be there at all, I'd like to hear it. [It's down to the sensitivity of the test and cross-reaction.]

My humble interpretation is that the test is negative, but that still doesn't mean you don't have PA, as around 50% of PA patients don't display IFAb anyway.

PA is a clinical diagnosis, and requires the input of a medic who understands the condition. It's not something we should be left to work out ourselves!

Reporting u/ml is worth a challenge. Units of what, exactly?!

Keep on doing what you're doing.

[Gecko22]

Thank you! It's good to know what the result should have said and that even having a positive IFAb is not definitive. I won't worry too much about the result and will carry on SI as I have been, based on my symptoms. GPs I've seen don't seem to understand the condition at all, or believe how serious it is.

It's unfortunate that so many of us are left to work this all out for ourselves. I've been doing the same for my Long Covid for over 2 years now with the help of researchers, scientists and patient advocates who share their findings online. I don't know what I'd do without the internet and patient forums!

[Sleepybunny]

Your GP should know that a negative result in IFAb (Intrinsic Factor Antibody) test does not rule out PA. It's possible to have Antibody Negative PA.

Testing for PA

pernicious-anaemia-society....

Diagnostic flowchart from BSH Cobalamin and Folate Guidelines which mentions Antibody Negative PA.

stichtingb12tekort.nl/engli...

BSH Cobalamin and Folate Guidelines (aimed at researchers and health professionals)

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

[Gecko22]

Thanks Sleepybunny. I gave my GP all the info from the PA society before I started SI but he was patronising and dismissive of the possibility of PA as my B12 was "within range", ignoring my history of low folate and ID anaemia. I'll just keep on doing what I'm doing