PA tests negative... how accurate are... - Pernicious Anaemi...

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PA tests negative... how accurate are they?

After my PA tests came back negative, my doctor was convinced I had celiac. Got my results yesterday and celiac was negative. It's my understanding these tests are pretty accurate. They tested endomysial antibodies, transglutaminase IGA and IGG and they were all negative.

The only odd thing that has ever shown up was MCH of 31.7 and alkaline phosphatase of 28. I am also heterozygous for MTHFR. And I have all the symptoms of a B12 deficiency, which are mostly relieved by B12 injections.

For PA, I had intrinsic factor and parietal cell antibodies tested. So what are the odds of false negatives on both these tests? If that's not likely, what could be causing the B12 deficiency?

10 Replies

Mine came back negative too for PA. I think I've read on here they can be 50% wrong. I still don't know the reason for being b12 defient. Just told will be on injections for life. At the present as still very poorly as long as i get the injections it's okay. As was on no medications or have another medical condition I can only assume for me age and too little stomach acid or PA.

There is a list of possible causes if you look through posts. Clivealive has often posted it. So was it a serum b12 test to find your low level?


I may ask to be tested again if nothing else turns up. I’m one of those people who has to know why. Maybe I never will, but I want to make sure they check everything. Serum B12 was borderline, but I took 10,000 mcg orally a few hours before the test (and had been taking that much daily for over a month). So, I was diagnosed based on that plus very classic symptoms.


Hi username7

Anyone at any age, can become B12 deficient. However, certain people are at an elevated risk. They include the following:

Vegetarians, vegans and people eating macrobiotic diets.

People aged sixty and over

People who’ve undergone any gastric and/or intestinal surgery, including bariatric surgery for weight loss purposes (Gastric bypass).

People who regularly use proton-pump- inhibitors. H2 blockers, antacids, Metformin, and related diabetes drugs, or other medications, or infections such as h-pylori that can interfere with B12 absorption.

People who undergo surgeries or dental procedures involving nitrous oxide, or who use the drug recreationally.

People with a history of eating disorders (anorexia or bulimia).

People with a history of alcoholism.

People with a family history of pernicious anaemia.

People diagnosed with anaemia (including iron deficiency anaemia, sickle cell anaemia and thalassaemia).

People with Crohn’s disease, irritable bowel syndrome, gluten enteropathy (celiac disease), Pancreatic insufficiency, or any other disease that cause malabsorption of nutrients.

People with autoimmune disorders (especially thyroid disorders such as Hashimoto’s thyroiditis and Grave’s disease) Type 1 diabetes, vitiligo, lupus, Addison’s disease, ulcerative colitis, infertility, acquired agammaglobulinemia, or a family history of these disorders.

Women with a history of infertility or multiple miscarriages.

Infants born to and/or breast fed by women who are symptomatic or are at risk for B12 deficiency.

Treatment for PA and non-dietary vitamin B12 deficiency is virtually the same.

The symptoms of PA are the symptoms of the B12 deficiency that it causes. If the cause isn't dietary then it is an absorption problem so you need to find another way of replenishing B12 initially. Most absorption problems aren't treatable but a few are - notably h pylori infection - which would mean that once that has been dealt with you would be able to absorb B12 from your diet so wouldn't need maintenance shots for life.

You could always ask for an MMA test if it is available where you are. Methylmalonic acid is a chemical used up in one of the cellular reactions mediated by B12. If there's not enough B12 in the cell then MMA levels will rise. If they're not high then it means your cellular levels of B12 are OK. High levels of plasma MMA (>0.75umol/L0 almost invariably indicate cobamalin deficiency.

However if you are supplementing with B12 you will need to stop for three months before the MMA or any other test to avoid skewing the result.

The IFA test is unreliable in that it gives false negatives in people with PA half the time. So a negative result doesn't mean that you don't have PA. However, a positive result is a sure-fire, 95% certain indicator of PA.

The British Society for Haematology guidelines say on the Diagnosis of B12 and Folate Deficiency "In the presence of discordance between the test result and strong clinical features of deficiency, treatment should not be delayed to avoid neurological impairment".

I am not a medically trained person but I've had Pernicious Anaemia (one of many causes of B12 deficiency) for more than 47 years.

I wish you well.


Thank you for the wealth of info. I am seeing a gastroenterologist next week, as it appears to be an absorption issue. Oral B12 does not work, while shots do the trick every time.

1 like

Thank you! That’s exactly the info I was seeking. I thought I’d read that PC was very accurate, but could not find anything to back it up.


negative PC is 90% accurate but positive PC is somewhat more flaky

think the section on tests to investigate causes of cobalamin deficiency gives details of the accuracy of both IFA and PCA tests


PA is one cause of B12 Deficiency, also malabsorption and parasites, being vegan or not eating enough animal products. Intrinsic Factor is 30-40 percent accurate. I was told if your IF test comes back negative it does not rule out PA, but your are negative PA. Homocysteine test in light of B12 "normal" reading of B12 in your lab markers could show and support B12 deficiency as can MMA [methylmalonic acid] One or both of these are raised in people with not enough B12... Lab Markers for B12 deficiency are inadequate.


Just to add to your comment that coeliac tests are pretty accurate - big question mark.

Follow the work of Dr Tom O'Bryan (website: Renowned Gluten expert. Lots of info on his website, also video interviews. His books.

Dr Peter Osborne (website: Glutenology)

has a list of products in which gluten is found which is amazingly useful

Dr William Davis (cardiologist) his book Wheatbelly

And British Gastroenterologist (working at an NHS teaching hospital) Professor David Sanders book 'Gluten Attack'

All of which you can get from amazon (second hand v cheaply)

Did you know that NHS test for antibodies against 2 gluten proteins. There are actually 60+ that are known at this time.

It's also not all about Coeliac

Gluten Sensitivity (being far more widespread and serious ) totally different genes involved

Coeliac susceptibility - genes HLA DQ2 + 8

Gluten Susceptibility - genes often HLA DQ 1+ 3

And your genes don't rule out as only applies in 50% of cases so that's 50% where Genes prove nothing or our current knowledge of can't determine.

Dr O'Bryan has stated that 70% of coeliac tests are false negatives and explains why

I heard Professor Marsh speaking (Professor Marsh who developed the endoscopy test for coeliac disease = the Marsh Test, Marsh 1, Marsh 2, Marsh 3 Marsh 4) He stated the test was never meant to be definitive. That should determine from symptoms

Dr O'Bryan stated that at the time if we could have got into the brain as easy as we could get into and analyse the small intestines then Coeliac would be a label for brain disease.

Don't expect your GP to know any of this info

Dr O'Bryan also states that if anyone has any health concerns what so ever then they must rule out gluten issues. Not so easy to rule out when there are 70% false negatives with mainstream testing. You could always just give it up for 3-6 months and see if your health has improved. a 1/3rd of the size of a thumb nail of food containing gluten will trigger antibody attack for up to 6 months and so have to be clued up with gluten containing substances which is why I suggested Dr Peter Osborne's website list. For instance 'vegetable protein' found in stock cubes , soup is just one that springs to mind. Acetic acid often made from wheat is another.

There has been a private test now in the UK for probably about the last 5 yrs, previously only in the US. Cyrex Labs. Far more comprehensive testing. Can test currently for antibodies against 14 gluten proteins. But very expensive.

You can order the tests / see prices at Clinician Micki Rose can talk you through/interpret results and set you on a course of action

Dr Datis Kharrazian (renowned books Why Is My Thyroid Still Not Working and Why isn't My Brain Working ) involved in the formulation of the Cyrex tests along with cutting edge immunologist, states that the Elisa spot test is the only test worth using. Google Dr Datis Kharrazian and molecular mimicry.

If you have problems /symptoms there's also the intestinal make up of your own microbiome and intestinal permeability (leaky gut) to be taken into account

There are greater minds than ours or our GP's working on this, we just have to learn from them :) x


VERY interesting. I ate gluten-free for a week, awaiting my celiac results. Ate 2 slices of pizza to celebrate NOT having celiac on Friday. Then I was up half the night with heartburn and abdominal pain, which lasted through yesterday (plus diarrhea, yay!). I took activated charcoal, probiotics, l-glutamine and curcumin, plus drank some organic coconut water. Only then did I begin to feel slightly better, but I'm still not 100%. I then concluded that I must at least have a sensitivity to gluten (or glyphosate-- I'm in the US and it's pervasive, even in our organic food supply).

I have not been genetically tested, but my mother was recently tested and has the "celiac gene".

I will look into all of the extremely helpful information you provided. Thank you very much.


Just because it is named gluten sensitivity - do not be under the impression as the name might imply that you are just a bit sensitive to gluten. As Dr O'Bryan often says, you can't be alittle bit pregnant, you either are or you aren't. It's probably more serious to have gluten sensitivity than coeliac. More so as at least coeliac is recognised as an autoimmune condition by the mainstream medical profession. Gluten sensitivity is not always recognised. Accepted science takes on average 17 years to filter down to the practising medical profession. Gluten Sensitivity is where you don't necessarily have intestinal issues but gluten proteins get through the gut lining and your immune system creates antibodies against. Organs/tissue often are caught up in the war and blasting of the antibody attack against the gluten proteins, every time gluten gets through. So your organs suffer damage as they happen to be in the way , close proximity. Also gluten proteins as they damage the gut lining let other proteins through from whatever you have eaten /taken (eg meds) and antibodies are created also to whatever - tomatoes, broccoli etc. Once the antibodies are created they will always be triggered and attack.

In addition to this there is molecular mimicry that is the proteins that come through the intestinal lining will be similar in structure to some tissue, the immune system sees this tissue as the enemy and will attack. Gluten looks very similar to thyroid tissue and brain tissue so you get antibody attack against your brain and thyroid. Or dependant on antibody formation to other stuff getting through, constant attack on your liver or heart or kidneys etc.

Gluten is known to destroy the intestinal lining cells (similar to holes /ladders in a pair of tights) in everyone but the cellsof the lining are the quickest growing cells to repair the lining. But eventually some people (maybe due to the health of their microbiome or parasites, or the amount of LPS (negative gram bacteria waste) or genetic triggering etc they reach what is called oral tolerance and damage starts to happen and eventually becomes noticeable re symptoms.

You can have such antibody attack without coeliac or as well as coeliac

It sounds as though you do possibly have intestinal issues and so maybe the damage is not bad enough yet to pick up on the limited testing.

However all grain flours digest rapidly to sugar (for instance 1 slice of toast is equivalent to 12 teasp sugar) in addition sugar makes the small intestines very acidic. which can attract bacteria/ micro organisms up into the small intestines that should live and feed further down in the large colon. These tend to be gas producing organisms when feeding. This can cause bloating of the small intestine and uncomfortable symptoms/improper digestion etc. this is called SIBO (small intestinal bacterial overgrowth)

Either way the best course of action is to give up all wheat, and other grains and sugar and re balance your microbiome. the good bacteria and positive micro organisms keep the less desireable ones in check and prevent from reproducing out of control. Organisms that should live in the colon will retreat back when healthy conditins don't suit. Remember you are not feeding yourself when you eat, you are feeding your micro organisms for good or poor health.

Microbiologists see humans as bags of bacteria covorting about having a human experience. Our micro organisms influence our brain, our personalities who we are.

We may think that we just can't resist that last biscuit in the packet but it is our gut bacteria messaging our brain cells influencing our choices. If you have predominently an acid loving micro organism community then they want to survive and will do anything to survive and manipulate you their host. If you feed the positive to your health micro organisms then the environment they live in will change and they will reproduce and take over the balance

Whether it's an unbalanced microbiome, SIBO, Coeliac antibody attack on your intestinal villi and lining, whether it's a leaky gut and gluten sensitivity, the answer is the same

If you are in the US you are very lucky and can choose a functional doctor - (Institute of Functional Medicine IFM registered) who will understand all this.

Good Luck xx


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