I recently requested and Intrinsic Factor Antibody test with my GP and was told there's no need to do this test if my Parietal Cell antibody test was negative/normal. The Parietal Cell test was done in Jan 2021 and I assumed the IFAB was done at the same time and also came back normal. (I was unaware of the significance of IF testing as I was recently made aware of my low B12 status at the time and was in a state of confusion and ignorance of B12d/PA) I realise I have no record of IF testing, hence my request.
Can anyone confirm whether there is real value in having this test, considering the low accuracy of results and suggest how I can approach my GP again to demand this test. I have quoted the current BNF & BCHS guidelines in written correspondence but this seems to have been ignored.
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cloudspotting
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The IFAB (Intrinsic Factor Antibody test) also has its problems ~50% of the time, PA patients will test negative for IFAB, although a positive test confirms PA with >95% certainty. The problem is if you get two of these tests, test negative both times and the doctor may conclude you don't have PA. But Martyn Hooper, founder of PASOC, tested positive on his third test. You also need to be 2 weeks clear of a B12 injection for the IFAB test otherwise the results may be invalidated.
If you have P.A. you stand about a 50%chance of having a positive result . And similar odds for getting a negative result of course . Unfortunately the medical profession often think that a negative result always means no pernicious anaemia, which is totally wrong .
BUT symptoms are more important than anything else . If your GP does not want the test to be done , he will find a way not to do it . Privately, it is an expensive test , and needs a sample of venous blood , not a pin-prick .
It was hugely valuable to me , because I had been sent on my way when my B12 blood serum was very low , below range , ( I was not told this , and didn’t know then that I should be allowed to see my blood test results . ) I was so unwell that I went to see a private GP at a private hospital , and he did the IFAB test , which was positive . ….
Trouble is when you are feeling so unwell , it’s just too much to take up a fight with a doctor .
Doctors are trusted to do the very best for their patients , but I’m afraid that B12 deficient patients get a very poor deal . It’s a fight all the way . I had to give up the fight , which means I self-inject to keep myself well .
"If your GP does not want the test to be done , he will find a way not to do it" It feels like this is the motivation behind the 3 GP's I've seen over the past couple of years. I sense that's because my surgery is overstretched and cannot invest the time to 'listen & observe'. Even though they have run most of the standard B12 tests and it seems have come to their conclusion following restricted local health authority guidelines that does not allow to interpret and treat my B12/PA symptoms.
Yes I'm aware of Martyn's history of IFAB and how a positive IFAB test may not result in a diagnosis. The issue for me is how much energy I can muster to fight the system. I'm sure there must be a way to get through to my GP and would be interested in finding out how others in a similar situation have developed an approach to get a more positive outcome from their GP.
I am starting to wonder if PA comes and goes and that's why it takes so long for us to develop symptoms. Thats not to say I believe fully developed PA will suddenly reverse. Seems to me my symptoms followed a cyclic path with a gap of several years between each episode. It might also explain why some test can be unreliable. Perhaps they are highly reliable and that they are just showing what's really happening albeit in a cyclic form.
GPC and intrinsic factor antibodies are different but they can both cause b12 deficiency.
You can be positive in one and negative in the other or negative for both and still have clinical symptoms arising from b12 deficiency.
You asked if it’s worth testing. It’s only worth testing if the test gives you a positive and unlocks treatment. You can’t know that when making the decision to spend the money. A negative test doesn’t rule out anything.
It’s difficult to convince GPs to carry out more tests unless your B12 is very low and/or you are anaemic and you have symptoms. Have you had b12, iron and folate tests recently? If so, can you add your results and the reference range to your post?
Try to get hold of a copy of the local B12 deficiency guidelines for your ICB (Integrated Care Board) or Health Board as these are likely to mention testing for PA.
Try an online search or submit a FOI (Freedom of Information) request to ICB/Health Board asking what B12 deficiency guidelines are used locally and for a link to or copy of them.
Some local B12 deficiency guidelines have been posted on this forum.
It is possible to get IFA test privately in UK although some NHS doctors may not accept results of private blood tests.
It's possible to get a false positive in some IFA tests if blood is taken close to having a B12 injection. Doctors will usually leave at least two days and maybe up to two weeks after a B12 injection before testing IFA.
Thanks everyone for your input. My question is more about developing a strategy or direct approach towards the GP & neurologist to take my PA symptoms seriously. The B12 guidelines from my local ICB are pretty clear. I was first tested at 158 ng/L which is just above the local ICB 'severe deficiency' threshold.
The flowchart puts me in the mild category and I have been trying to highlight my debilitating neurological symptoms during the past year. I was eventually given a general referal to a neurologist in march this year but the waiting list is currently running at 12 months. I'm not confident that the neurology assesment will be a positive one from what I've read in some accounts on this forum but I'm hopeful for a good assessment if I'm able to represent my symptoms correctly. Unfortunately, I don't have the resources to go private with tests or treatment so looking to navigate the NHS as best I can. I'm fairly clear about what treatment I should be offered but finding it difficult to communicate with my GP who seems to be rigorously following the guidelines. I was refused loading doses which, I was told could only be offered following a neurology assessment!! I suspect the IFAB test is being refused for the same reason and perhaps if I manage to get a positive IFAB, I may be closer to an 'official' diagnosis?
I feel I'm in the place that Martyn Hooper describes as 'no man's land' when it comes to diagnosis and unable to speed up the process where the medical professionals are quite intransigent and not open to discussion. I fear this will go on for another year or more and looking for other strategies to help move things along. On a more positive note, I have managed to get my GP to agree a temporary 8 weekly appointment for Hydroxo as a trial. I'm also SI every 3 days which seems to keep my symptoms from getting worse.
3) Might be worth discussing risks of developing SACD, sub acute combined degeneration of the spinal cord with your doctors.
I'm not saying you have this, I'm not a health professional but I am saying your doctors should be aware that SACD is a possible consequence if treatment for B12 deficiency is delayed or inadequate.
Mentioning SACD may make them take more notice of you.
PAS article about SACD, sub acute combined degeneration of the spinal cord
1&2) Yes, I wrote to the practice manager on the advice of PAS shortly after becoming a member, outlining the guidelines you mention and requested loading doses. My GP did not engage with me and suggested the benefits of my B12 injections were due to a placebo. I'm trying a different GP at the surgery in the hope that I may get a more understanding response. 3) I will follow up with mentioning SACD at my forthcoming appt and when I finally have my neurology assessment.
I requested and was tested positive for H Pylori and Gastritis (mild) via gastroscopy. I also requested a re-testing for serum THF (normal). Homocysteine & MMA levels were within range after testing last year. My GP consulted with the local Haematology dept who recommended the Hcy and MMA but Gp did not refer me to the Haematologist. The NICE Guidelines suggest this is recommended if neurology symptoms are present. My blood tests are within range but RBC has been persistently just over the max level of 5.5 10*9/L for a couple of years. Not sure if this is an issue?
I suspect this is a waiting game and I can progress my diagnosis after the neurology examination before taking my case further via complaints. Thanks for your suggestions.
"I'm hopeful for a good assessment if I'm able to represent my symptoms correctly"
I'm sure you'll be well prepared for the neurology appointment.
I saw several neurologists and only one thought B12 deficiency might be a possibility but I didn't get a diagnosis from him as the serum B12 result was normal range. I had numerous typical symptoms and they all missed the diagnosis.
I wish I'd challenged my neurologists more but I was hardly able to function physically or mentally at the time.
Have you got a complete symptoms list with all your neurological symptoms especially any affecting your spinal area to pass to neurologist?
Symptoms of B12 Deficiency (folate deficiency also mentioned)
It suggests that doctors should consider continuing treatment if patients improve on B12 treatment even if tests such as MMA/Homocysteine are within normal range.
I tried everything I could think of to get treatment but in the end realised it was not going to happen and had to resort to self injection. I've since managed to get some NHS treatment but it's not enough for me.
I have never had a confirmed diagnosis, more of a tacit agreement that I have B12 deficiency symptoms which are helped by B12 injections.
I do think it's worthwhile to get a confirmed diagnosis if possible.
Thanks for this encouraging reply. Like you, I don't always function mentally or physically when the appointment time arrives but I've learned to go in with a script & checklist of questions. This can be difficult with an allocated 10 min GP appointment.
Main symptoms are extreme fatigue and brain fog - concentration/memory. As well as the usual pins & needles in feet & arms, balance & dizziness comes and goes. What is particularly worrying is that I've recently developed a strange tingling down my spine like water flowing. I'm hoping this is not a signal for emerging SACD and one for the neurologist to explain. Have about 5 more neuro symptoms and keeping a diary. I know when to increase SI frequency when my Tinnitus becomes a problem.
Good suggestion to go in with printouts. Gp's sometime react adversly when discussing medical matters so I'm learning 'patient tact' and hopefully reading the situation better and not being intimidated.
I'm also keen to promote patient stories as a way of representing the unspecific nature of PA symptoms in the hope this will change medical practice & culture within the profession. Martyn at PASOC is doing some excellent work with his CPD programme, hence my interest in patient - doctor relationships. 👍
The IFAb test is useful in that if it comes back positive, it tells you and your GP fairly reliably that you actually have PA. If it comes back negative, it only tells you you're IFAb negative, but doesn't tell you anything about PA status. That's where clinical judgement comes in, doctor!
It would be good if we had a 100% sensitive and specific test for PA, but we don't. Even when we had our long-lamented Schilling Tests, it was still possible to get misleading results.
The Parietal Cell Antibody test may be positive in PA, but it's also positive in many other conditions, so it's not a useful indicator of PA status.
.... Confirming my feelings at the moment, on the importance of this merry-go-round of testing and diagnosis, where clinical judgement seems in short supply. Feel like I need to keep positive and work a bit more on my relationship with the GP in these trying times at the surgery.
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Parietal cell antibodies and ifa testing questions 
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Positive IFAB results just in.
