Confusion about testing

[SammyProd]

Hello, 

Is a 'positive and then a negative' a consistent 'no' for celiac disease? 

I was tested 7 or 8 years ago for issues with iron deficiency anemia and other symptoms, weight loss and trouble with eating. I am at a healthy weight now but have persisting anemia and other issues.

The results that have always confused me are as follows: 

COELIAC DISEASE SEROLOGY

"Although screening by multiplex immunoassay for IgG antibodies to deamidated gliadin peptide was positive, confirmatory testing with a second, more specific method (Phadia ELIA) was negative. In the absence of IgA antibodies to tissue transglutaminase, coeliac disease is unlikely. False negative results may occur in affected individuals compliant with a gluten-free diet."

-end of copy from results- 

Now of course I understand that the results say that coeliac disease is unlikely, and I was not on a gluten free diet at the time, so it should be correct.

Is this usual to test by a second more specific method if igG is positive by a less specific method? I am not sure why they mentioned it on the results at all. It has made me think there could be a mistake due to the positive then negative thing. 

I have asked the doctor to explain it to me and they didn't clarify anything other than that it is indeed negative. 

Sorry if it's a silly question.

I still suffer with iron deficiency anemia and other issues which is why I am always wondering about causes. I do feel better when eating gluten free but have never stuck to it for long enough to know if it's worth trying (because I know my celiac testing was negative, so I assume there isn't a valid reason to try gluten free.)

I posted here because I have seen other helpful answers with others confused about testing. 

Thanks for any kind responses!

Samantha 

[trents]

Welcome to the forum, Samantha!

First, I disagree with your statement that you were negative for celiac disease in your testing. A positive GDP with a negative tTG-IGA can certainly indicate celiac disease and this is not an uncommon combination in our celiac community. Why else would they even run the DGP if they were testing for celiac disease? One thing that can cause a negative for the tTG-IGA is low total IGA which can cause individual IGA tests to trend toward the negative range. But you do not report a total IGA result so I assume that test was not run.

There is also the possibility that you have NCGS (Non Celiac Gluten Sensitivity) which shares many of the same symptoms with celiac disease but for which there are no tests. An NCGS diagnosis is made when celiac disease is first ruled out but celiac-like symptoms persist. Both require a whole-hearted commitment to life-long gluten free eating. And in either case you can do permanent damage to body systems by not being faithfully gluten-free. It is can be a tragic assumption that you don't need to be as careful with NCGS as you do with celiac disease.

Your symptoms are certainly consistent with celiac disease.

You need to get serious about jumping on the gluten-free bandwagon and staying on it. And it is shameful that the doctor did not give you more guidance about this. The fact is, many doctors, especially general practitioners are terribly lacking in their knowledge about gluten disorders. We see this all the time on this forum.

[knitty kitty]

Welcome to the forum, @SammyProd,

Anemia can affect tTg testing, causing false negatives.

Hemolysis and IgA‐antibodies against tissue transglutaminase: When are antibody test results no longer reliable?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6816937/

You would be better off getting genetic testing to see if you have any of the common genes for Celiac Disease.  If you've got even one of the genes for Celiac Disease, you would benefit from going gluten free.  

Hope this helps!

[jaggirl47]

10 hours ago, SammyProd said:

Hello, 

Is a 'positive and then a negative' a consistent 'no' for celiac disease? 

I was tested 7 or 8 years ago for issues with iron deficiency anemia and other symptoms, weight loss and trouble with eating. I am at a healthy weight now but have persisting anemia and other issues.

The results that have always confused me are as follows: 

COELIAC DISEASE SEROLOGY

"Although screening by multiplex immunoassay for IgG antibodies to deamidated gliadin peptide was positive, confirmatory testing with a second, more specific method (Phadia ELIA) was negative. In the absence of IgA antibodies to tissue transglutaminase, coeliac disease is unlikely. False negative results may occur in affected individuals compliant with a gluten-free diet."

-end of copy from results- 

Now of course I understand that the results say that coeliac disease is unlikely, and I was not on a gluten free diet at the time, so it should be correct.

Is this usual to test by a second more specific method if igG is positive by a less specific method? I am not sure why they mentioned it on the results at all. It has made me think there could be a mistake due to the positive then negative thing. 

I have asked the doctor to explain it to me and they didn't clarify anything other than that it is indeed negative. 

Sorry if it's a silly question.

I still suffer with iron deficiency anemia and other issues which is why I am always wondering about causes. I do feel better when eating gluten free but have never stuck to it for long enough to know if it's worth trying (because I know my celiac testing was negative, so I assume there isn't a valid reason to try gluten free.)

I posted here because I have seen other helpful answers with others confused about testing. 

Thanks for any kind responses!

Samantha 

My son’s DGA IgG is positive and his tTG IGA is negative. He has suffered from anemia most of his life.

He has now been diagnosed with “highly suspected celiac disease” and sees the specialist on September 26 to schedule his endoscopy for confirmation.

[Scott Adams]

This article might be helpful. It breaks down each type of test, and what a positive results means in terms of the probability that you might have celiac disease. One test that always needs to be done is the IgA Levels/Deficiency Test (often called "Total IGA") because some people are naturally IGA deficient, and if this is the case, then certain blood tests for celiac disease might be false-negative, and other types of tests need to be done to make an accurate diagnosis. The article includes the "Mayo Clinic Protocol," which is the best overall protocol for results to be ~98% accurate.

 

 

[joelkeys0519]

Hello! I’m new here and am equally confused based on test results, Mayo Clinic articles, and the nurse practitioner saying I’m in a “gray area” after my bloodwork came back.

DGA, IgA was 33 and moderate to strong positive is >30 (and out of reference range). Other markers were negative or borderline, and DQ2 was positive so I know there is a genetic marker to be concerned about. 

I’ve already resorted to eating gluten-free but I also want to have a more concrete diagnosis. I suspect endoscopy is next but she also called for stool analysis just in case. 

Has anyone found similar results yielded a diagnosis of Celiac’s or NCGS? I’m also happy to answer any questions about missing info from the results of it helps clarify things!

Thanks in advance!

[trents]

Welcome to the fourm, joelkeys0519!

When did you start the gluten free diet in relation to the antibody testing you have already had? You should hold off on the gluten free effort until all testing, including the endoscopy/biopsy is complete. Otherwise, you will compromise the results  and push them in the negative direction.

[SammyProd]

Thanks everyone - very helpful! 

 

The mayo clinic article makes sense. I don't think I have IGA deficiency because it isn't mentioned on results, but it looks like the results were low enough for them to check the other antibodies. 

 

My IGA results from the above panel: 

Deamidated gliadin peptide igA: 2 U/mL. (<15)

Total igA: 0.94 g/L.

(0.40-3.50)

Trans glutaminase igA: <1 U/mL.

(<15)

 

Then it says: 

Confirmatory testing IgG antibodies to deamidated gliadin peptide was performed by a second method (Phadia ELiA).

Deamidated gliadin peptide igG (ELiA) 1.7 U/mL.

(<7)

And then the text from my original posting is under those results. 

So because all the results were in reference range, I was confused why they mentioned all the stuff in my first post. 

But.. I think the mayo clinic article explains why the second testing was done. 

Do the results above explain better what he doctors are certain that it is a negative result ? This test was ordered and interpreted by a gastroenterologist. 

 

Thanks again,

Samantha 

 

Ps. 

It is definitely worth mentioning that remembered I had a repeat test in 2020 with a different doctor and different lab, when I had low B12 and low iron after pregnancy, and they ran a less specific test without serum IgA (I think) but was also negative.

TTG IgA Ab: 4 IU/mL. (0-19)

Gliadin IgA Ab: 5 units (0-19)

"Negative results for both TTG and Gliadin are likely to exclude active coeliac disease, provided serum IgA and gluten intake are normal." 

 

[Scott Adams]

It looks like all of your celiac disease blood tests are negative, and you are not IgA deficient:  Total igA: 0.94 g/L. (0.40-3.50).

Approximately 10x more people have non-celiac gluten sensitivity than have celiac disease, but there isn’t yet a test for NCGS. If your symptoms go away on a gluten-free diet it would likely signal NCGS.

[SammyProd]

Yes this makes sense, I think it may be worth seeing if non-celiac gluten sensitivity may be an issue and see if there are any improvements.

Thanks everyone for the good answers.