I recently had a private diagnosis of Autoimmune Thyroiditis. This was given in the context of seeking a diagnosis of my B12 deficiency which was said to be linked with the above, Pernicious Anaemia, antibodies attacking thyroid and gastric parietal cells. I have been on levothyroxin for 15yrs. He based this partly on my raised Anti-Tg (67IU/ml). He recommended I get a parietal cell antibody test. Now for the confusion and uncertainty created in me. I requested a PCA antibody test from my GP who text me to inform me that the lab does not do it instead they do an Autoimmune Profile. This came back negative. I questioned if this was specific for PCA and was sent the follow message:
“Dear Mr xxxxxx
We contacted the laboratory and there is no test offered specifically called Gastric Parietal Cell Antibody. the lab's reply "I've spoken to Immunology Bench in Lab - forget the Gastric (its Parietal Cell antibodies)
Part of the AIP test.
Requesting Code PCA." they reassured us that the test formed part of an AIP - autoimmune profile - which you have had taken.
Thank you, Dr xxxxx”
What bothers me is that labs use different reference criteria. My diagnosis was given on the fact that, although showing in the ‘Normal’ range, nevertheless the antibodies were still raised in the results from a private thyroid test. Also I have no idea of what was included in the profile especially the Anti-Tg if it was included. Has anyone any insight into this type of testing as all seems very vague and confusing. I’m left with so many doubts as there seems there is no report just “HEp2-ANA screening test…..negative” on my blood test results. Sorry it’s long and may seem thyroid is but they’re linked so have posted in both. 🙂
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B12again
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Thanks Nackapan but this is what is on Klein’s report: “….the antibodies attack your thyroid and also your stomach [parietal cells] which impairs IF production and stops you absorbing B12 properly.” IF protein is produced by parietal cells in the stomach wall.
I'm not sure why they refuse to offer a standalone Parietal Cell Antibody test, perhaps FlipperTD will have some insight.
You can see in the autoimmune profile test description, one of the tests is called"Parietal Cell Antibody" which I suspect is why they seem to be splitting hairs over your use of the term "Gastric" (but as far as I know its the same test because gastric == stomach and the only place parietal cells are found is in the stomach). Seems like a tomAto/tomAHto issue 😆
I don't see a test for thyroid antibodies in the AIP test but I'm sure they can confirm that.
Finally a clarification on auto-immune antibodies, we may be talking about at least three types here - antibodies against the thyroid (not an expert on those) and in PA - two types of antibodies - antibodies against intrinsic factor and antibodies against the parietal cells.
Finally, as Nackapan mentioned, it is the IFAB test which, if positive, is diagnostic of PA, while the anti-parietal cell antibody test is not as helpful.
It's confusing. Parietal Cell Antibody [PCA] Testing is generally done in Immunology. Intrinsic Factor Antibody [IFAb] Testing is typically performed in either Haematology or possibly Biochemistry. These departments are in silos; they don't necessarily think that there's anyone else on the planet so it's possible that the test might be done, but in another department. PCA positivity is often seen in PA, but also in lots of other, unrelated conditions. IFAb positivity is much more specific, as a positive is found in around 50% of all PA cases, but not in anything else.
Each lab has its own reference ranges [or it should have] based on the population it serves. Plus there are numerous different methods involved, and each one may deliver different degrees of sensitivity. I realise this isn't helpful, but it might explain differences a bit.
In response to Technoid's input, the lab may have introduced a 'simplified' approach to test requesting, so if you want an apple, it comes with a banana and an orange, whether you like it or not. So I can see why they might not have a separately requestable PCA test, but that's as much down to the setup of the lab computer system as anything. Consider 'Serum B12' and 'Serum Folate'. In almost all circumstances the tests are run using separate automated assay kits, but the test requested on the computer is B12&Folate. There's some logic here, because if we find a macrocytic anaemia from the FBC, it's not possible to discriminate whether it'll be B12 or folate causing the problem, so we do both.
Thank you for your insights from your personal experiences. I was wondering if the ANA lab report contained more than just -N or +P but listed what actually was checked for, otherwise one is left wondering for as we know, regarding our illness journey experiences, confidence in many practices has been severely eroded. The autonomy of labs to dictate how they function is concerning too. If you could take a moment Flipper, to cast an eye over the below letter template I’ve cobbled together, for its accuracy, I would be grateful. I am aware of the specificity and sensitivity associated with various tests.🙏
Dear Dr [Doctor’s Surname],
I hope this letter finds you well. I am writing to express some concerns regarding a recent blood test. I had requested a test for Gastric Parietal Cell Antibodies (GPCA) to investigate the possibility of autoimmune gastritis or pernicious anaemia. However, I noticed that an Antinuclear Antibody (ANA) test was performed instead.
I understand that the ANA test is a valuable tool in diagnosing systemic autoimmune diseases, such as lupus, rheumatoid arthritis, or Sjogren’s syndrome, by detecting antibodies that attack components within the nucleus of cells. However, from my understanding and personal research, it appears that the ANA test does not specifically detect gastric parietal cell antibodies (GPC antibodies) or thyroid antibodies (TPOAb and TgAb). These specific antibodies are crucial in diagnosing autoimmune conditions like autoimmune gastritis, pernicious anaemia, or autoimmune thyroid diseases along with the clinical presentation of the patient, which were my primary concerns.
I wanted to clarify whether the ANA test was conducted due to a specific clinical reasoning or if there might have been a misunderstanding regarding the test I initially requested. I am keen to ensure that all relevant conditions are adequately investigated, especially if symptoms might suggest an autoimmune condition affecting the thyroid or gastric system.
I truly appreciate your expertise and guidance in managing my health. My intent in writing this letter is to advocate for my well-being and ensure that we are on the right path with the appropriate tests. If you think there is a more suitable approach or if additional tests are necessary, I am more than willing to discuss this further.
Thank you for taking the time to consider my concerns. I look forward to your guidance and any advice you may have on the next steps.
I think you cover the matter in a very polite and positive way. I'll be interested to see what happens next! As we're talking about Immunology, that's on the very edge of my experience. Lots of things we do are down to antibody and antigen reactions. Some are in automated systems, but some are down a microscope.
When they report these things, they're [probably] reporting the appearance of the test down a fluorescence microscope, and they may report the pattern observed, rather than just that something was 'positive'. So, 'speckled' is used as a term, but there are others.
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Assistance required with interpreting B12 and Pernicious Anaemia Blood Tests.....
Private Blood Tests for Pernicious Anaemia
I know a negative IF test result can be inaccurate but can a positive one be false?
GP didn't order intrinsic factor test!
