Antibodies and Active B12 Tests - Pernicious Anaemi...

Pernicious Anaemia Society
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Antibodies and Active B12 Tests


Hi everyone,

I've been searching for a diagnosis for a mystery illness for 8 years. Someone recently suggested checking for Pernicious Anemia, and whilst I assumed because my B12 levels had always been fine I didn't have anything to worry about, they mentioned there are antibodies that could be tested. They also said to get 'active B12' tested, which I'm guessing is different from regular B12. I just wondered if those would be worth doing, or with completely normal levels of B12 over a prolonged period of time make it pointless?

The other thing was that my grandmother had Pernicious Anemia, and actually died from it before I was born. I don't know what the chances of it being inherited or passed on in some genetic way, but I thought if I posted this here I might get some help from all you knowledgeable people!

So any advice or help you may have would be greatly appreciated. I'm more than happy to go into details about my illness, I only didn't as it's pretty complex and would have likely turned this post into a bit of an essay! But I realise you may need lots more info before being able to comment.


- Andy

5 Replies

What exactly do you mean by serum B12 levels being normal?

There is a huge grey area in which some people are suffering from B12 deficiency but because of the way reference ranges are given get told that there isn't a problem with B12

Also, do you know what your folate levels are like - if these are low then you won't be able to absorb B12

The antibody test for PA - PCA and IFA aren't particularly accurate tests.

Active B12 looks at specific forms of B12 - those that are used at the cell level - rather than all of the B12 in your body so can be more accurate but it still doesn't say what is happening at the cell level.

Most autoimmune problems are genetic - though in many cases the genes are latent and triggered by environmental issues. I get the impression that PA in the true sense isn't triggered by environmental issues, but I'm not entirely sure. It most definitely is genetic.

Many medics use the terms PA and B12 Deficiency interchangeably - though in fact the symptoms of 'pernicious anaemia' are actually the symptoms of a B12 deficiency caused by an autoimmune response that destroys the mechanisms in the ileum by which your body absorbs most of its B12 from your diet. However, it isn't the only potential cause of a B12 deficiency (leaving aside diets poor/lacking in B12). Lowering of stomach acid as you get older is another possibility - so if the problem for your grandmother developed late in her life then it was probably that rather than PA in the more formal sense, though difficult to gauge exact ages from your post.

Looking through some of your other post on the thyroid community there may be some overlap between your symptoms and B12 though on one you specifically mention that you don't have brain fogs and confusion and although I'm sure it is possible to have a B12 deficiency without these cropping up I get the impression from people's stories that it is quite rare.

Have you looked at the PAS symptom checklist - you can find it here,

to try and gauge exactly how close the overlap in symptoms is?


omron in reply to Gambit62

The last time I had my B12 levels tested they were 513 pg/ml, the range being 191 - 663. My folate was 16.9 ng/ml and the range 4.6 - 18.7. They seem good, being at the higher end of the "normal" ranges, but I know that this can be misleading in lots of tests.

I'm not entirely sure, although can find out, but I believe my grandmother developed it at a young age. She died of a heart attack in her late 40's, thought to be have been caused by the PA, so it definitely wasn't a case of old age being the reason for the PA.

You're right, I don't experience any brain fog. I don't forget names, or ask questions repeatedly etc. and my memory is still fine. However, having just looked at the PAS symptom checklist I do relate to the statements “I just want to be left alone” and “I just want the world to go away”, but those could just be from a long-term chronic illness making me feel rubbish, not specifically PA.

I do also have mood swings and irritability, but again I don't know how much that would be down to PA (if I had it) or just being ill.

In terms of the physical symptoms, I have the fatigue and weakness, and definitely the feeling tired after 8 or more hours of sleep. The same for feeling bloated and full - I have that constantly. However, I don't have pins and needles, shortness of breath, brittle or damaged nails, or pale yellow-tinged skin. Or at least I don't have yellow skin - I am very pale though!

Gambit62Administrator in reply to omron

unfortunately there is a huge overlap between symptoms of a B12 deficiency (whatever the cause) and a number of other conditions ... and its also true that one doesn't rule out there being more than one - quite the opposite if you have an autoimmune problem.

The problems with sleep and tiredness could be so many other things, though it does sound as if depression is a factor. Depression is actually a label for a cluster of symptoms that can have very diverse causes - one of which is B12D, but also thyroid and many of the other conditions you have looked at. The bloating does sound as if you could well have some sort of absorption problem going on in the background.

Reactive depression would tend to mean that you felt tired in the morning but things improved as you went through the day - though if I remember in one of your other posts you mention a dip in the early afternoon which wouldn't quite fit with reactive depression.

Have you looked at vitamin D?

Another possibility might be an MTHFR mutation - these affect your ability to convert some vitamins absorbed from food into methylated forms used at the cell level. This could leave you with high levels in serum but little usable at the cell level giving rise to symptoms of folate and cobalamin (B12) deficiency, but high levels in serum tests.

Hi, im newish to this site but have been helped by wonderful forebears in respect of their advice in what treatment i should hope to expect.

The PAS site is a must as a first port of call for symptoms related to pa. i personally had so many, but luckily not the extreme tiredness and only slight brain fog. Tummy issues and bad burning legs were the actual symptoms which took me to a gp. Diagnosed deficient and now on injections.

Definitely hereditary, my brother had autoimmune problems and more than likely my dad died undiagnosed as well.

Go to your gp with your concerns and symptoms and go from there.

If it is b12 related it can unfortunately go undetected/untreated for years.

Depending on your symptoms there are many conditions which overlap. i personally have taken to keeping a symptom/stress/food diary. That way i know when any symptoms seem unusual or flare up i have information i can relay to my gp.

Do check out the PAS symptoms list. Good luck

Hi Omron. I'm so sorry that you're having so many problems and cannot get to the bottom of your illness.

I notice from past posts that you have suspected coeliac, lupus, thyroid, etc. Many researchers believe leaky gut/intestinal disease is the ground zero of autoimmune disease and autoimmune/thyroid/PA/B12 def. are often interlinked with symptoms overlapping. Four members of my own family have autoimmune/B12issues. The fact that your grandmother died from PA and your sister also has similar problems means that there is a much higher risk of B12 deficiency (40% higher I believe) in the family, as B12 builds DNA.

What many GPs consider normal results are not, as "deficiencies begin to appear in the cerebral spinal fluid below 550 pg/ml." - 'Could it be B12?', by Sally Pacholok and Dr J.J. Stuart - a book I would thoroughly recommend. In any case the serum test only measures B12 in the blood and it does not show whether it is absorbed into the tissues.

Extreme anxiety, hair loss, weight loss, severe fatigue, etc. are neurological symptoms of severe B12 deficiency and should be treated with injections without delay according to the BNF and UKNEQAS guidelines below until no further improvement, as there is a short window of opportunity before they become irreversible. I hope this extract from the BCSH guidelines will help persuade your GP to begin injections as soon as possible.

"The BNF advises that patients presenting with neurological symptoms should receive 1000 ug i.m. on alternate days until there is no further improvement". : (List of symptoms and an excellent film) :

The above latest UK research document is supported by many research papers and has a useful summary if GP won't read full document, which indicates that there is no gold standard test. It also tells GP that, once b12 treatment is started, the test results don't mean anything and blood levels are not reflective of how effective the treatment is - it is the clinical condition of the patient that matters....

I'd also recommend Martyn Hooper's books, as well as 'The B12 Deficiency Survival Handbook' by Dr Aqsa Ghazanfar.

I hope all goes well but, If all else fails, many people on this site self inject successfully.

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