Hello. In the late 1990s I tested high positive for gastric parietal cell antibodies. Then again on three other occasions during recent years. However, last week I had a test for gastric parietal cell and intrinsic factor antibodies and to my surprise both came back negative. Is this usual? Can these antibodies come and go in this way? I’d assumed that once you have them they’d show up on a lab test, especially since my GPC antibodies have always been sky high previously. Folate well below range, B12 just in at the bottom of the range. Lots of symptoms over recent years which match PA symptom list, so I’ve been trying to get to the bottom of things. But now doctor is saying no PA due to lack of antibodies. I already have diagnosed with autoimmune thyroiditis/underactive since 2003. I haven’t eaten gluten in ten years. Does anyone have the same experience? And could I still have PA in these circumstances?
Had antibodies, now don’t: Hello. In... - Pernicious Anaemi...
Had antibodies, now don’t
I wonder why you were retested? Must be so confusing.
As far as I’m aware the antibodies don’t go away and so the answer is more likely to be the fact that the tests are not accurate. The IF antibodies test is notoriously unreliable (around 50% of the time).
I had a positive IF antibodies test and a couple of years later a negative test.
There are guidelines to say that a B12 deficiency should be treated by injections even if the antibodies test is negative.
Clearly your folate deficiency needs treating but as B12 treatment should begin first I would push for injections as per guidelines.
I’m sorry but I can’t provide you with a link to the guidelines but hopefully someone will be along who can. Otherwise, have a read of replies to posts by sleepybunny
Yes , if you test negative for the IFAB test , it’s about 50% wrong . ! So you can still have PA. Your symptoms should be treated , not a dodgy blood test . Surely the doctors know about the unreliability of a negative IFAB test .
Sorry, this is a technical response that won't actually add much to the debate, but here goes...
The IFAB test isn't simply 'a test'; there are several different tests on the market. They clearly don't all detect the same thing, or to the same degree. In general, antibody tests rely on the availability of an antigen to demonstrate the antigen:antibody reaction. What we call the 'Intrinsic Factor Antibody Test' doesn't actually work quite like that, as the methods used don't [as far as I'm aware] contain Intrinsic Factor. They certainly didn't when I used to test for IFAB. So the test demonstrates that there's something in the sample that is causing interference, and 'Antibody' is probably the easiest way to explain it. In summary, a positive IFAB is the best simple, quick test available, but only provides the answer in about 50% of cases of PA. Which I think is better than having no IFAB test available. The best test we had was the Schilling Test, but that hasn't been available for many years due to a range of technical issues, so IFAB is the best of what's left.
In my opinion it is unfair on the test to refer to it as either 'inaccurate' or 'unreliable'. If it was either of those then laboratories wouldn't offer it.
I think it's better to say that it provides a diagnosis in about 50% of cases of PA; a 'negative' IFAB result isn't necessarily 'wrong'.
It is important to follow the advice of the doctor delivering your care, and to treat the symptoms, whatever the underlying cause.
Thank you very much for that - I see what you mean . . It’s just a pity that the doctors don’t look at the IFAB test in that way . If it comes up negative, you don’t have PA , and don’t get treatment , in their book . That means terrible suffering for people whose condition deteriorates if they can’t afford a private doctor for injections , or don’t know about self injecting .
The Shilling test is available in the USA .
Thank you. I live and learn; I hadn't realised that the Schilling Test was available in the USA.
Maybe some of our readers will share their recent experiences of its use?
It was withdrawn in the UK for a variety of reasons, but it was one test we could rely on. It was a bit long-winded to use and not suitable for large numbers, but when done properly it worked a treat.
If you look araound, there are quite a few mentions of the Schilling test, but I could not find a single recent one, anywhere.
I would have expected at least some mentions from the USA if it were still in regular use. Maybe a few centres still somehow manage to get the requisite materials?
Currently, Schilling test is not readily available in most countries as a means of diagnosis for vitamin B12 deficiency.
ncbi.nlm.nih.gov/books/NBK5...
Among the reviewed methods, Schilling's test and/or its food-based version (using cobalamin-labeled egg yolk) were used for decades but have been discontinued, largely because they required radioactive cobalt.
pubmed.ncbi.nlm.nih.gov/299...
Unfortunately, the gold standard for clinical diagnosis, the Schilling test, has increasingly become unavailable, and replacement tests are only in their infancy.
pubmed.ncbi.nlm.nih.gov/216...
Several methods have been applied to diagnose vitamin B12 malabsorption, including Schillings test, which is now used rarely, but these do not quantify percent bioavailability.
pubmed.ncbi.nlm.nih.gov/214...
In their absence, since the disappearance of the Schilling tests, the gastric tubage currently used for the study of gastric acid secretion, is obligatory for the simultaneous study of intrinsic factor output.
pubmed.ncbi.nlm.nih.gov/212...
Technical details, and working from memory.
The Schilling Test as we performed it [DiCoPac] used two Cobalt Radioisotopes, 57Co and 58Co. These are both synthetic. 57Co has a half-life of 271 days and 58Co 71 days. Consequently it's not possible to stockpile these isotopes because they simply 'decay away'. A regular, reliable source is needed.
The two isotopes can be counted simultaneously due to their differing emission spectra, and consequently the test could be performed in a single visit. Done properly, it was a good test, but given that it involved a non-radioactive B12 injection, then swallowing radioactive vitamin B12 capsules and also swallowing animal intrinsic factor [probably sourced from slaughtered pigs] it was hardly surprising that it would eventually get withdrawn from the UK market. This leaves us in the current situation.
IFAB is better than nothing; it helps perhaps 50% of PA patients, but the remaining 50% aren't helped.
I believe the IF was bovine - and it was BSE that finally spelled the end of it in the UK.
That makes perfect sense! Thank you.
I don't have a 'pack insert' from the product but I'm fairly sure it would have said what the IF source was, and it was inevitably going to be slaughterhouse-sourced.
It must be over ten years since we had the test available. Using IF from any other species raises concerns regarding species specificity too.
The only case I know of using 'human IF' comes from William Bosworth Castle's famous experiment using 'raw hamburger meat treated with normal human gastric juice'.
Whh do the tests keep getting done? Thses tests are not definitive.
I tested negative for parietal cells. Csnt absorb b12 tablets it seems or iron well??
IFA test has lots of false negatives.
Havd tih had mma or homocysteine bloods done? I've not but useful tests if you read up on them. If tiy are still getting your b12 treatment i shouldn't worry too much. Go by symptoms wonder if ths ago was long enough after last I jection ?
Thanks so much for your replies. They are not, nor have they ever, offered any B12 treatment. All they’ve done is put me on folic acid 5mg daily. My ferritin is always in my boots, way below the range so I clearly have problems absorbing as I eat a healthy diet. As to why they keep testing me - I have no idea really!!! Different doctors over many years wanting to run their own bank of tests, all the while I continue feeling horrendous with no help. I’ve never had MMA or homocysteine tests done. What do they show? Got to dash, have more questions but my 9 yr old is whining!! Deep breaths
Can the GPC antibodies reduce or go below the range because they are no longer active, having done all the damage they can? The first time they were checked in a blood test was 1998 but of course they could have been active but not tested for well before then..... Do you think I should push for further tests (e.g. endoscopy) or just try to persuade the doctor to treat my symptoms with a trial of B12 injections?
By the way, my B12 level at last blood test in December was 270, reference range 180-1000. My IGg was at the top of the range. Folate well below range and ferritin barely there, well below range.
I felt a bit better after raising ferritin levels. I stopped shaking and wad not breathless any more.