Help Interpreting Lab Results

[tpogo]

Hi all,

I was given a celiac panel last year and received a phone call that I'm 'positive' and i should go to a GI dr to get a biopsy. I didn't know much about the results and immediately went on a gluten-free diet as I just didn't want to go through the process of something so invasive (especially when I read of so many false negative results).

But over the last year of trying to be gluten-free, I've noticed some things w/ my children and wanted to get them tested also. So I've been doing research to understand what's involved w/children and also dug into my lab results to figure out if a genetic test would be a better alternative.

~Now that I have my results, I'm completely confused~

I could use some advice from this forum of experience in how exactly to interpret these results. My lab results report : For a Reference range of 0-15 U/ml, I basically have normal Gliadin IgA (8.92 U/ml) & Gliadin IgG (12.36 U/ml) but very high tTg IgA (22.41 U/ml) and normal tTg IgG (9.20 U/ml).

So my question - what does it mean to have a normal Gliadin IgA/IgG but high tTg Iga? Does this mean I have Celiac or gluten sensitivity, or would the levels indicate something else?

Thank you in advance for the opinions !

[Skylark]

Hi and welcome to the board.

Anti-gliadin is an old, inaccurate test that isn't very sensitive. It's negative in a lot of celiacs. TTG IgA is an autoimmune antibody directed at your intestine and assuming you don't have some other autoimmune disease like type 1 diabetes or rheumatoid arthritis, it indicates celiac disease. If you feel better and the TTG falls on the gluten-free diet, you definitely have celiac.

Be sure your kids are eating a full gluten diet for three months before you get them tested. They will have false negatives gluten-free.

[tpogo]

Hi and welcome to the board.

Anti-gliadin is an old, inaccurate test that isn't very sensitive. It's negative in a lot of celiacs. TTG IgA is an autoimmune antibody directed at your intestine and assuming you don't have some other autoimmune disease like type 1 diabetes or rheumatoid arthritis, it indicates celiac disease. If you feel better and the TTG falls on the gluten-free diet, you definitely have celiac.

Be sure your kids are eating a full gluten diet for three months before you get them tested. They will have false negatives gluten-free.

Thank you for the info! As far as I know, I don't have any autoimmune disease. I had some confusion over this because was that I was reading in one place that low IgA but high tTg could also indicate just general dietary allergies like eggs/milk/corn/etc.

Do you know if genetic tests are as reliable as the biopsy in diagnosis? i've read so much of false negatives in biopsy method and that Dr's today do not recommend the genetic testing yet. ...

[Skylark]

Thank you for the info! As far as I know, I don't have any autoimmune disease. I had some confusion over this because was that I was reading in one place that low IgA but high tTg could also indicate just general dietary allergies like eggs/milk/corn/etc.

Do you know if genetic tests are as reliable as the biopsy in diagnosis? i've read so much of false negatives in biopsy method and that Dr's today do not recommend the genetic testing yet. ...

I don't know what you've been reading but it's dead wrong. TTG is an enzyme in your body, not a food substance. If you have anti-TTG you definitely have autoimmunity. The only question is which kind of autoimmunity and most often TTG is a sign of celiac autoimmunity. Your GI doctor should be able to confirm what I'm telling you.

Genetic tests are not diagnostic. All they can do is stratify risk. 30% of the US population has a so-called celiac gene and 1% of celiacs do NOT have a so-called celiac gene. In a sense your kids already have positive genetic tests, since celiac runs in families and first-degree relatives of celiacs have at least a 1 in 20 chance of getting celiac. The chance of gluten intolerance is probably higher.

What you need to do with the kids is make sure they're eating a full gluten diet for three months and then get them celiac panels. Since you're positive for TTG, your kids have a little better chance of having TTG show up if they're celiac too. If your kids are tested, be sure they also get the newest deamidated gliadin IgG and IgA. It is much more sensitive and has a lower false negative rate.

There are false negatives by biopsy if 1) your doctor caught your celiac symptoms early and the autoimmune damage is very mild or 2) the biopsy simply misses patchy damage. People with anti-TTG have been followed in prospective studies and they almost invariably go on to develop positive biopsies, suggesting that sometimes anti-TTG precedes the onset of damage. They also usually have metabolic markers consistent with celiac disease. This is why there are a lot of medical papers now suggesting that celiac be diagnosed if a person has anti-TTG or anti-EMA, responds to a gluten-free diet, and the TTG antibodies go away gluten-free.