Deamidated Gliadin Test And Ttg

[Mom2Will]

My daughter had her Deamidated Gliadin A test come back positive at 33 (normal is 0 - 19) but her tTG came back well within the normal range.

She isn't having many symptoms other than some constipation and eczema and her doctor is going to do a biopsy on her in a couple of weeks. She was tested because her brother has celiac disease confirmed with a biopsy. I guess I am resolved to her having celiac as well but can anybody explain to me why she would have a positive Deamidated Gliadin test but a negative tTG? If her tTG test is negative is a biopsy likely to turn anything up or is it maybe just too early for her to be properly diagnosed? She is 5 years old, if that makes a difference..

Thanks

Melissa

[Skylark]

Deamidated gliadin is the most sensitive test available. It is also 98% specific for celiac disease, meaning false positives are extremely rare. TTG is not particularly sensitive, especially in little kids. Your daughter is most likely celiac, and needs to be gluten-free to prevent damage even if the biopsy comes back OK.

[basilicious]

Hi mom2will, that sounds somewhat similar to my blood test experience. Has your daughter been eating gluten? That could help explain things. You mentioned that your son has celiac, so maybe you have changed your daughter's diet too?

I went very gluten-light prior to my blood tests -- stupidly, perhaps, but I was feeling so much better that I couldn't bring myself to eat much gluten. About a month and a half into the gluten-light diet, I had my blood tests, and at that time the only positive value was my DGP IgG, which was 72 with a normal reference range of 0-25. My biopsy was also negative, but on a puny gluten challenge, so I don't think it means much. Personally, I interpret it to mean that I was either lucky and caught this early or that I began to heal pretty rapidly. Since your daughter is school-age, it seems a bit more important for her to get an accurate biopsy reading and definitive diagnosis if she in fact has celiac. I would suggest double-checking that she is getting enough gluten in her diet. Then perhaps consider re-testing her blood in a few months if you think that she was not eating enough gluten leading up to the panel. If she has been getting plenty of gluten, then well...perhaps it is too early for a proper diagnosis. I don't know. But keep in mind that 20-30% of celiacs test negative in their blood work.

[alicewa]

Is the endoscopy even necessary if the DGP blood test is performed? I thought it was more specific for celiac disease than the endoscopy (i.e. positive biopsies can mean something else, can't they?). Didn't I hear somewhere that it may end up replacing the biopsy?

[ravenwoodglass]

Is the endoscopy even necessary if the DGP blood test is performed? I thought it was more specific for celiac disease than the endoscopy (i.e. positive biopsies can mean something else, can't they?). Didn't I hear somewhere that it may end up replacing the biopsy?

Yes you have heard correctly. Some doctors are skipping the endo when the blood work is positive. Don't know if they will all ever let it replace the biopsy as that is a real money maker but time will tell.

[Mom2Will]

Yes you have heard correctly. Some doctors are skipping the endo when the blood work is positive. Don't know if they will all ever let it replace the biopsy as that is a real money maker but time will tell.

Yeah, I was wondering about that. I thought that since she has a sibling with celiac and tested positive on the DGP that he would just diagnose her without the biopsy but he still says that nothing is definitive without a positive biopsy.....

[Skylark]

That's pretty common among GI doctors. The biopsy has been the "gold standard" for so long that they are continuing to do them. You know she needs to be off gluten, which is the important thing.

[ravenwoodglass]

Yeah, I was wondering about that. I thought that since she has a sibling with celiac and tested positive on the DGP that he would just diagnose her without the biopsy but he still says that nothing is definitive without a positive biopsy.....

If you are reluctant to have her go through a biopsy then talk to your ped and see if he will give her the 'official' diagnosis she will need for school. With a biopsy confirmed sibling and a positive blood test he might just diagnose.