Back Again: Will These Tests Be Good Enough To Point To Celiac Or Not?

[VitaminDGirl]

So I did a saliva test some weeks ago that showed I am off the charts positive on this test: Gliadin Ab, SIgA (Saliva). (Borderline is 13-15 and I was 62!)~ Dr. said he calls this a "gluten allergy".

Sooooo yes, I will come off gluten, but I am still interested in learning if I am celiac or not so have remained on for now.

Today the dr. ordered these blood tests:

IgA Anti-tissue transglutaminase AND

IgA Anti-endomysium antibodies.

Will the above results be accurate enough to indicate celiac or not?

AND in case he decides to do an internal biopsy (and I accept) is it ok to be off gluten, or do I need to stay on it until that test is done as well?

Thanks.

Vitamin D Girl.

[ravenwoodglass]

Yes you do need to keep eating gluten until the biopsy is done. After the biopsy you can start a diet trial. False negatives are not uncommon with both blood and biopsy so do the trial even if the test results are negative.

Your doctor should also have ordered a total IGA and there are a couple of other tests that can be done but I can't think of the names of them right now, someone else will know and answer though and hopefully tell you them. If you total IGA is low that will cause a false negative on the IGA tests.

[VitaminDGirl]

Yes you do need to keep eating gluten until the biopsy is done. After the biopsy you can start a diet trial. False negatives are not uncommon with both blood and biopsy so do the trial even if the test results are negative.

Your doctor should also have ordered a total IGA and there are a couple of other tests that can be done but I can't think of the names of them right now, someone else will know and answer though and hopefully tell you them. If you total IGA is low that will cause a false negative on the IGA tests.

Thank you for your response.

I am not sure I quite understand all the testing.

I guess I"m fearing I've not ordered enough or the right tests (by my dr).

I mean, if these tests come back positive, it then means I probably have celiac, and only a biopsy could confirm?

But if it's negative, I may still have celiac and should get a biopsy?

If I know my antibodies are high already, would it have been better to just get the genetic celiac test? I mean, b/c if that was positive, chances are I have celiac with such high gluten antibodies, right?

Or maybe not.

I've been trying to research all of this, but am still left a bit confused.

[VitaminDGirl]

ps how many posts do we have to make before we don't have to go through the approval by the moderator anymore? Or are everyone's comments always moderated?

Just wondering.

[nora-n]

Hi I do not know anything about that, and my posts show up right away.

About the total IgA, here in Europe they automatically do that if they order the IgA celiac tests in most places.

[Jestgar]

If I know my antibodies are high already, would it have been better to just get the genetic celiac test? I mean, b/c if that was positive, chances are I have celiac with such high gluten antibodies, right?

There is no clearly defined "celiac gene". The genetic tests show associated genes only, so, no, the genetic test will not tell you if you have celiac disease.

[Jestgar]

ps how many posts do we have to make before we don't have to go through the approval by the moderator anymore? Or are everyone's comments always moderated?

Just wondering.

You're close.

[Gardening]

The celiac panel our local lab ran included:

anti-gliadin IGG

anti-gliadin IGA

TTG IGG

TTG IGA

anti-endomysial IGA

total IGA

Aside from total IGG, I can't think of anything else that could be included, and I thought it was pretty thorough.

You do need a total IGA, because if you don't make enough IGA in general, you can't make a high enough anti-gliadin IGA (or TTG, etc) to register as positive. Therefore, it could give you a false negative.

[nora-n]

Note that the EMA test is only IgA, since this is not an automated test.

they take a piece of monkey esophagus and incubate with the blood test, and look in an electronic microscope for flourescence which is caused by IgA.

There is no IgG version of that test.

Sometimes medical papers mention endomysium IgA and IgG, but obviously they then mean the ttg test.

[VitaminDGirl]

"Today the dr. ordered these blood tests:

IgA Anti-tissue transglutaminase AND

IgA Anti-endomysium antibodies."

Okkk....I'm still a bit confused.

The dr. ordered the above tests.

If they are positive, I should for sure do the biopsy and it will show me if I have celiac?

And if the biopsy is negative, does it mean I"m not celiac?

And if the above tests are negative, do I order additional bloodwork of some sort?

If the biopsy is positive, but the tests above are negative, I have celiac?

Someone told me that getting the blood test to see if you carry the gene (which one of you said really doesn't do that?)... if positive means you probably will get it sometime in your life. If negative, I can't have it?

I hope my questions aren't too confusing and someone can help me out.

Thanks.

[nora-n]

These two tests are considered the most specifi tests for celiac nowadays, but recently the new deamidated gliadin test has been introduced several places and it is considered a bit better than the ttg test.

The endomysium test is the most specific one for celiac.

Note there are lots of false negatives, and the cutoffs are set very high as the doctor do not want any, ANY, false positives....so you might still be celiac despite of negative tests.

Or, you could still turn positive in the future.

these tests are really dependent on tissue damage, not just antibodies to gliadin like the antigliadin test.

most people with the gene will not develop celiac, as the gene is very common, like 30% or so of the population.

[VitaminDGirl]

These two tests are considered the most specifi tests for celiac nowadays, but recently the new deamidated gliadin test has been introduced several places and it is considered a bit better than the ttg test.

The endomysium test is the most specific one for celiac.

Note there are lots of false negatives, and the cutoffs are set very high as the doctor do not want any, ANY, false positives....so you might still be celiac despite of negative tests.

Or, you could still turn positive in the future.

these tests are really dependent on tissue damage, not just antibodies to gliadin like the antigliadin test.

most people with the gene will not develop celiac, as the gene is very common, like 30% or so of the population.

Ok, thanks for all of that. Very helpful!

I did the gliadin test by saliva and I was very high.

Supposedly my bloodwork above is 'in' now. I'm waiting for the dr's office to call with results. If they don't I plan to go pick them up from the lab myself tonight.

Stay tuned, and thanks again for all of the 'newbie' support! Much appreciated.

[VitaminDGirl]

Ok, thanks for all of that. Very helpful!

I did the gliadin test by saliva and I was very high.

Supposedly my bloodwork above is 'in' now. I'm waiting for the dr's office to call with results. If they don't I plan to go pick them up from the lab myself tonight.

Stay tuned, and thanks again for all of the 'newbie' support! Much appreciated.

Ok, so they just called and I'm negative on the bloodwork. So, the odds are equal still that I could be celiac even with negative bloodwork?

Is the biopsy the only other way to find out?

Or should I ask for other kinds of blood tests?

Thanks in advance.

[ravenwoodglass]

Ok, so they just called and I'm negative on the bloodwork. So, the odds are equal still that I could be celiac even with negative bloodwork?

Is the biopsy the only other way to find out?

Or should I ask for other kinds of blood tests?

Thanks in advance.

Yes you could still be celiac. The choice to biopsy is up to you but be aware that may come back a false negative also. If you are going to biopsy then stay on gluten until that is done. If your not going to biopsy then go ahead and get started on a strict trial of the diet. Your body know the answer.

[VitaminDGirl]

Do you have any idea of any research (or just from being on these boards) how often someone with negative blood results of IgA Anti-tissue transglutaminase ad IgA Anti-endomysium comes back with a positive internal biopsy?

Is it very common?

Thanks for any leads you can give. You all are such a blessing to me!

[VitaminDGirl]

PS would there be any other blood tests I could do before a biopsy that may give more ideas about if I have celiac?

Like is IgG testing what some follow-up with?

Thanks.

[nora-n]

Officially, 20% of biopsy-proven celiacs with villous atropy have negative bloodwork, and partial villous atrophy, patchy celiac, about half are negative.

[VitaminDGirl]

Officially, 20% of biopsy-proven celiacs with villous atropy have negative bloodwork, and partial villous atrophy, patchy celiac, about half are negative.

THank you again. Those numbers are bigger than I thought. I think I will try and have the biopsy done.