Blood Tests......what Is Correct?

[bobtom]

My 11 year old son has been complaining of stomach aches, off and on, for the last 8-10 months. Pediatrician ordered gliadin IGA (deamidated peptide) which came back 67 (<20 normal). Referred to GI and he said that test isn't very reliable and ordered a tTG IGA and total serum IGA (which I am assuming is normal since he had an elevated gliadin to begin with). I was under the impression from what I have been reading that the gliadin test he had done is pretty reliable. Just wondering thoughts on that and is it common to have that test be high and the tTG IGA be low? If so, what would that indicate? This is all very confusing. Thank you!!

[nvsmom]

I think gliadin IgA is considered innaccurate because it has a higher false negative rate than ttg IgA... I think.

I think gliadin IgA indicates celiac. If it has a low specificity (meaning it could test positive for other problems) I would have the GI or pediatrician explain what those possible causes are instead of brushing it off as he he did.

He sounds like the type of GI that you'll need to see with a list of documented info on the test results to get the doctor on board. Your son is way above normal...what else does he think it is?

Good luck.

[GottaSki]

From what I understand that your son's high DGP IgA indicates Celiac Disease even if the tTG IgA is currently negative.

Here is one journal article that talks about DGP IgA as a useful tool in children because the DGP antibodies may show up before tTG antibodies in blood and is better at monitoring compliance once gluten free.

Open Original Shared Link

It is a small study - used this to illustrate my point. There are other studys with much larger sampling groups that you can find with a simple google search.

Your situation is the exactly the reason doctors should run the ENTIRE Celiac Blood Panel when there are symptoms in children. Looking at one test at a time prolongs an already difficult diagnosis process.

It was correct for your GI to order more Celiac blood tests, but it looks like your still hasn't had an Endomysial IgA or any IgG testing. Did the GI order any nutrient tests? Does he have direct experience with Celiac Disease? This can make a big difference if you decide to proceed with endoscopy/biopsy.

I have the same question as nvsmom - if the GI doesn't think the DGP IgA indicates Celiac Disease, what does he think the test means?

[bobtom]

Thanks for your replies. He did not order any nutrient tests and he didnt offer any explanation to the high result if it isn't celiac. He pretty much blew off that he thought it could be celiac, but he said we needed to "contend" with the high DGP. He did very briefly mention that if the tTG comes back negative, he may do a biopsy, but he said it so quickly and brushed over it and on to other things. My son had his tTG drawn this weekend, I will let you know what is was. I am very interested to see what it is and where we proceed from there. Can and elevated DGP indicate anything else?? Thanks for your time!

[frieze]

My 11 year old son has been complaining of stomach aches, off and on, for the last 8-10 months. Pediatrician ordered gliadin IGA (deamidated peptide) which came back 67 (<20 normal). Referred to GI and he said that test isn't very reliable and ordered a tTG IGA and total serum IGA (which I am assuming is normal since he had an elevated gliadin to begin with). I was under the impression from what I have been reading that the gliadin test he had done is pretty reliable. Just wondering thoughts on that and is it common to have that test be high and the tTG IGA be low? If so, what would that indicate? This is all very confusing. Thank you!!

the IgA version is more sensitive, but less specific, than the IgG version. So they should be ordered together.

[GottaSki]

Can and elevated DGP indicate anything else?? Thanks for your time!

Gliadin is one of two proteins in gluten. Upon digestion proteins are broken down into peptides. A positive DGP IgA shows that antibodies are being created to fight these peptides specific to gluten.

I don't know of anything other than a problem with gluten being the cause of a positive DGP IgA. Anyone else?