8 replies to this topic

[Marlie]

I am not so patiently awaiting results of my teen's biopsy today. My question is regarding the labs prior to the biopsy. She tested positive with the dgp igg and iga but negative with the ttg iga and ema. Anybody else had results like this? Doctor told me only way to diagnose was biopsy. These tests are just a screening and nothing more. However I read that this new dgp test was highly accurate in diagnosis. Hence I am now confused. Why positive on dgp and negative on other tests.

[Lisa]

Can you post the results with the lab ranges. That will help.

I was not familiar with the DGP testing, but I found this easily.
http://www.celiac.co...ting/Page1.html

"The results of these tests clearly demonstrate that IgA DGP does not offer any advantages to the IgA tTG antibodies, and is actually less accurate and more expensive. However, IgG DGP antibodies present an invaluable tool in screening for celiac disease in cases where IgA tTG tests fail. Eventually, a new antibody screening will hopefully be designed which combines IgA tTG and IgG DGP, and reduces the number of tests currently used in celiac screening. However, intestinal biopsy is always required to confirm the presence of celiac disease no matter what serological tests are involved."

[Marlie]

Can you post the results with the lab ranges. That will help.

I was not familiar with the DGP testing, but I found this easily.
http://www.celiac.com/articles/22043/1/Is-DGP-Serological-Test-the-Wave-of-the-Future-for-Celiac-Disease-Testing/Page1.html

"The results of these tests clearly demonstrate that IgA DGP does not offer any advantages to the IgA tTG antibodies, and is actually less accurate and more expensive. However, IgG DGP antibodies present an invaluable tool in screening for celiac disease in cases where IgA tTG tests fail. Eventually, a new antibody screening will hopefully be designed which combines IgA tTG and IgG DGP, and reduces the number of tests currently used in celiac screening. However, intestinal biopsy is always required to confirm the presence of celiac disease no matter what serological tests are involved."

I don't have the labs but looked at them at hospital today. I believe a positive level was like 1.6 and her score was like a 4.9. Unfortunately I can't remember if that was the igg or iga score for the dgp and I can't recall the other dgp score except it was definitely positive. I was told it was a high positive.

I know there is less written about this newer test but in multiple places it is rated an extremely good test.

[Skylark]

That Celiac.com article was based on one study and sadly the self-designated experts writing there often overinterpret single articles. I've read all the studies on DGP and the IgG version is considered more sensitive than TTG, and comparably specific to EMA, at 95%-98%.

Was she tested for IgA deficiency? That could explain low results on the IgA tests. Also, the autoimmunity has to be pretty severe for TTG and EMA antibodies (which is also thought to be TTG) to be in the bloodstream. IgG is more typically found in the blood, and the deamidated form of gliadin is only made by people somewhere in the process of developing celiac, which is what makes the DGP IgG a better test.

[orangez28cam]

All of these new tests can be so confusing. I also had the DGP tests done along with complete celiac panel. My DGP IGA was a high positive, and my TTG IGG was a weak positive. All other tests were negative. I did the endoscopy and they took 6 biopsies which were all negative. I was still put on the gluten free diet and it has made a world of difference. My understanding is that some doctors will diagnose celiac based on DGP tests alone, where others still believe a positive biopsy
is the gold standard. Its all very frustrating.

[Skylark]

I just put a link to new research you might find interesting in this other thread.
http://www.celiac.co...-back-negitive/

[Mari]

I had elevated anti alpha gliadin antibodies (positive) but the anti ttg was not elevated (negative). From what I read there were 2 reasons for this result, one was that I had been eating very little gluten for several years and the other was that I had significant sprue indicating that most of my villi were damaged and in that case the anti ttg is sometimes not elevated.

[Marlie]

That Celiac.com article was based on one study and sadly the self-designated experts writing there often overinterpret single articles. I've read all the studies on DGP and the IgG version is considered more sensitive than TTG, and comparably specific to EMA, at 95%-98%.

Was she tested for IgA deficiency? That could explain low results on the IgA tests. Also, the autoimmunity has to be pretty severe for TTG and EMA antibodies (which is also thought to be TTG) to be in the bloodstream. IgG is more typically found in the blood, and the deamidated form of gliadin is only made by people somewhere in the process of developing celiac, which is what makes the DGP IgG a better test.

Thanks for the info. My daughter was in fact determined to test positive in the biopsy. Her total IgA was 67 which is in normal range but on the low side. It was the DGP IgG that was the high number. Maybe she is somewhat IgA deficient? Just trying to understand as many people get tested using only the EMA and TTG and if we were not lucky enough to have a GI doctor in the hospital run this test we'd continue running around for years trying to figure out what was wrong. I'm very grateful for this new test and feel lucky that they found out what is wrong with her. However, I have found little written on this test and in my humble opinion it has without a doubt proved to be a very important test. The doctor's office said she has early stages of Celiac disease which goes along with what you said. Does anyone know how long early stages of Celiac go on for? She's been sick for years with multiple ailments first beginning with sinus issues, then severe chronic headaches, multiple fractures amongst other things. Could this all be traced to this disease? Also, does this disease cause weird things with blood work like low lymphocytes, high SEG rates, and stuff like that off and on? Also, what about pulse rates that seem abnormal?

[Skylark]

I'm glad to hear you got a firm diagnosis and are over the wondering. You were lucky to get a good doctor and your daughter was very lucky to have her celiac diagnosed in her teens rather than her thirties like me.

Her low-normal IgA would make it a little harder to get positive results on EMA and TTG. The lower the total IgA is, the higher the chance of a false negative because of how the test works. "Early stages" is a little bit of an assumption on your doctor's part. The biopsy only looks at a tiny bit of the intestine and celiac damage is patchy so you don't really know the state of her whole intestine. Also, not all celiacs even secrete TTG and EMA into the bloodstream even if they have severe villous damage. Remember, IgA is primarily a mucosal antibody and the bulk of the TTG and EMA is in the intestine. That's part of why the DGP IgG test is so good. IgG is mostly a bloodstream antibody.

Celiac disease can cause all sorts of weird things. Malnutrition from malabsorption can affect almost any system in the body depending on the deficiencies, and the autoimmunity is not limited to the intestinal lining either. The immune activity can make people feel generally ill, with fatigue, depression, headaches and so forth. The multiple fractures would be from calcium malabsorption causing weak bones. The blood work abnormalities may be from celiac as well -- we've seen just about anything around here.

I hope she starts feeling better over the next few months as she heals.