Following up on my previous posts (low B12, started on B12 loading shots - had second today so too early to tell results on symptoms)
Finally got my IF antibody test back today
Results: 2.9 U/mL (Normal: < 6 U/mL)
I'm aware of the inherent reliability of the test (40-60%) so realise that it doesn't rule out PA.
I'm not entirely clear how the test works though - I could understand it being zero, but I thought that 'normal' people don't have the antibodies at all? I guess this is to do with the way they test and that they pick up some things that aren't the antibodies, but above a certain level they can be sure that at least SOME of them are?
Or does everyone have a small number of antibodies, that just aren't able to affect things?
I'm in the process of writing a letter to my GP to try to get everything clear and documented for a way forward.
If the test is accurate and I don't have the antibodies, the BJH chart seems to suggest calling it 'anti-body negative PA' - but is that because PA can occur without the antibodies, or is that because the test isn't accurate enough to be sure either way?
Are there other tests I should be considering seeking? Are the homocysteine and MMA level tests likely to be valuable and show something up if the IF antibodies test didn't . Similarly, is there any benefit to a parietal cell antibody test as I've read that it can be less specific as a PA guide (and perhaps would be unlikely to show anything if the IF antibody test doesn't?)
The other things I am considering raising as possibilities with the doctor:
1. Ferrite test (My blood cells are seemingly not megaloblastic (normal MCV) so worth ruling out iron deficiency combined with the B12 (Though RDW is normal)
2. Possibly tests for coeliac/chrohns (I have had mostly mild IBS symptoms for some years - have previously tried gluten-free diet and not seen much difference - and followed a FODMAP diet with some improvement)
3. Test for Helicobacter pylori to rule that out as cause.
From some recent changes I've made, it would appear that I may have low stomach acid, which I understand is common in PA, but also can be common in other causes, so not sure that helps the diagnosis, but may do with my own management. I've been taking apple cider vinegar before meals - and Betaine HCL tablets with Pepsin and do appear to have noticed an improvement, although it is early days.
I have already been seen by a neurologist and am awaiting brain MRI and SSEP, though I am now less sure they will show up anything (I guess it will be better if they don't!)
Am I missing anything else that I should be enquiring about? (Folate was normal, albeit lower within the scale so I am taking supplements while I am on the B12 shots as seems to be the advice. Also on Vitamin D daily - The rest of the full blood count I had recently was normal)
Sorry - lots of info in there, but any advice welcomed!
Gavin
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Test range: Most tests will have a range where the test will produce a result even when the sample was 'blank'.
I don't think it is important to be able to explain to your GP why the test is inaccurate - you just need a reference that they will consider reliable
This is what the BCSH guidelines on diagnosis and treatment of cobalamin and B12 deficiencies says about the IFA test
The finding of a low total serum cobalamin level may be further evaluated by testing for anti-IFAB. If positive, the test has a high positive predictive value (95%) for the presence of pernicious anaemia (Toh et al, 1997), with a concurrent low false positive rate (1–2%) i.e. a high specificity. It identifies those patients with a need for lifelong cobalamin replacement therapy. IFAB is positive in 40–60% of cases (Ungar et al, 1967), i.e., low sensitivity, and the finding of a negative IFAB assay does not therefore rule out pernicious anaemia (hereafter referred to as AbNegPA). In addition, the positivity rate increases with age (Davidson et al, 1989) and in certain racial groups [Latino-Americans and African-Americans; (Carmel, 1992)].
Your GP can access the guidelines through the BNF and they can also be accessed here
MMA and homocysteine are markers that can help clarify if a B12 deficiency is present - they won't tell you anything about the cause.
macrocytic anaemia isn't present in about 25% of people who are B12 deficient. whilst this might be down to an iron deficiency also being present that isn't the only reason. If you have both macrocytic and microcytic anaemia going on then the RDW (Red blood cell distribution width) should be above the normal range.
Tests to help rule out anti-body negative PA (which is just a way of saying IFA hasn't given a positive but PA is the probable cause) as different conditions have different consequences, but it sounds as if coeliacs may have been ruled out already.
Thanks Gambit. I will definitely be including that reference, as well as the full BJH guidelines and the NICE CKS.
Coeliac hasn't been tested for as far as I know, though its possible the gastro referral I had a year or so back did, I did have some blood taken, but not sure I ever saw the results (so assume what they tested was 'normal' ).
From my research, it looks like PA is the most common cause of B12 deficiency, but I've not seen relative figures for how likely that is compared to h pylori or the various gastric issues.
I'm waiting for the neurologist to come back with a guidance on the B12 injections, which hopefully will ensure that is in place at the right frequency - from then it's more a case of trying to rule things out and see how things settle down symptoms wise, but hopefully a forward journey now!
Thanks sleepybunny - I did reference the NICE and BSH guidelines in my letter to the neurologist. Letter has arrived apparently, but won't see it till tomorrow. From what I gather, she didn't consider my neuropathy significant enough to treat on the higher scale, but I'll read it tomorrow before deciding on next approach. Her tests on consultation with needles etc on hands did not show anything, and the nerve conduction studies I had also showed normal, although I've had some numbness and tingling for a year.
At the moment, it doesn't appear that she will be helpful in obtaining the higher dose, so will have to go back to GP when she returns from holiday - I guess by then I'll know if my symptoms have improved or not.
The neurologist appears to reference the Royal United Hospital Bath guidelines (ruh.nhs.uk/For_Clinicians/d... and their algorith chart, which appears to differ in places from the NICE guidelines (particularly when Macrocytosis is not present)
It's also not clear whether they are as up to date, as the version I link references 2010, but I've not had time to investigate further as yet. The document does list the PAS as a reference though.
Confused generally at the moment and felt lethargic all day so will leave it until I have a clearer mind. 3rd loading dose tomorrow, so hopefully that will improve things.
"neurologist appears to reference the Royal United Hospital Bath guidelines"
The BSH Cobalamin and Folate Guidelines were published in 2014. It's possible that neurologist has not read complete BSH document. I too have come across the problem of local area b12 deficiency guidelines not being updated.
I gave a copy of whole set of BSH Cobalamin guidelines to my GPs. Do you think the neurologist would like a copy?
There are some useful quotes from B12 documents that might be of use, in fbirder 's summary of B12 documents. Link to summary in third pinned post.
Some people on forum have pointed out the consequences of undertreatment of neuro symptoms in b12 deficiency to their doctors.
On PAS website there is an article about SACD sub acute combined degeneration of the spinal cord available to PAS members.
If you are not given the correct level of treatment, it's possible that further deterioration will occur. I'm sure your doctors do not want to risk that happening.
Link about writing letters to Gps about B12 deficiency. Point 1 is about undertreatment of neuro symptoms.
Thank you for all those links - I have so many links now it's getting hard to find the one I want at any one time, but they are all useful info! From some of the reading I don't seem to be at the severe end of the scale, but of course that just makes me recognise how much worse it must be for some people.
The guidelines she seems to be taking her clinical pathway from still mention the schilling test, which I gather hasn't been around for some time. All the references are from 2010 too, which suggests to me it's not been updated to reflect the new guidelines. Not entirely sure why they use it either, given that I live in Kent, not Bath!
doesn't even mention 2 monthly injections as an option for anyone, so my guess is that it's based on the previous guidelines and hasn't been updated.
Given that in her letter she says this (sic - clearly the NHS can't afford spellcheck)
"In your case there is no damage seen on the brain, spinal cord nor delayed nerve conduction studies confirmed. This excludes severe or significant nerval involvement."
and this:
"Even with severe cases where we have a long extended spinal cord lesions l usually only
substitute with 1 mg for a maximun of 5 days before then slowing down the speed to a normal substitution regime. l therefore think it would be an over treatment if we treat as you line out in your letter."
then I'm not sure that I am going to get very far with her and may be better spent concentrating on my GP with info related to the other symptoms, or possibly seek a haematologist referral..... pick your battles and all that.
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Intrinsic factor antibody test result
Antibody test was normal...
Help with diagnosis?
If taking B12 supps skew's PA Intrinsic Factor test, does it do the same for Gastric Parietal Cell AB too?
What is test for 'active b12' 
