Does High DGP IGA Typically Mean Celiac?

[Skg414228]

I went to the gastroenterologist for what I thought was IBS. They thought it sounded like celiac. I got a blood test with normal everything except a deamidated gliadine peptide iga of 688. Total iga was in normal range so not deficient. 
 

My question is with a dgp iga like that is it pretty much only celiac at that point. I haven’t seen anything else that would cause the dgp iga to be that high.

Already have the biopsy scheduled so nothing is going to change I’m just curious what else it could be and is the number high enough that I should really be preparing expecting a positive biopsy and it’s just a confirmation at this point? 

[trents]

Welcome to the forum, @Skg414228!

You say that your DGP-IGA score is high and you give the absolute test score but you do not give the scale or units used by the lab doing the analysis so we cannot comment further on your conclusion. Different labs use different reference ranges for the same tests. There is no industry standard for these celiac antibody tests. So, could you also post back with the scale and the units?

If you already have an endoscopy/biopsy scheduled, the important thing is to hold off on going gluten free until that is done. There are some things besides celiac disease that can cause elevated celiac disease antibody levels so it is still possible you may be looking at something else. This is especially true when you are not IGA deficient and the tTG-IGA is within normal range. But you are correct in saying that very high antibody scores strongly weight the probability in favor of celiac disease. Keep us posted.

By the way, kudos to your physician for ordering a more complete antibody panel. Many will only order the tTG-IGA.

Edited February 26 by trents

[Skg414228]

  On 2/26/2025 at 5:02 PM, trents said:

Welcome to the forum, @Skg414228!

You say that your DGP-IGA score is high and you give the absolute test score but you do not give the scale or units used by the lab doing the analysis so we cannot comment further on your conclusion. Different labs use different reference ranges for the same tests. There is no industry standard for these celiac antibody tests. So, could you also post back with the scale and the units?

If you already have an endoscopy/biopsy scheduled, the important thing is to hold off on going gluten free until that is done. There are some things besides celiac disease that can cause elevated celiac disease antibody levels so it is still possible you may be looking at something else. This is especially true when you are not IGA deficient and the tTG-IGA is within normal range. But you are correct in saying that very high antibody antibody scores strongly weight the probability in favor of celiac disease. Keep us posted.

By the way, kudos to your physician for ordering a more complete antibody panel. Many will only order the tTG-IGA.

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Oh sorry see I know nothing lol. Yes my doctor informed me to eat gluten up until the biopsy so squared away there. All of my questions here are just to get me in the right head space. I have put the actual values from the test. 

Deamidated Gliadin Peptide IgA Antibody, Quantitative Normal range: 0.0 - 14.9 U/mL - Value 688

Deamidated Gliadin Peptide IgA Antibody, Qualitative Normal value: Negative - Value: Positive (Abnormal)

Tissue Transglutaminase IgA Antibody, Quantitative Normal range: 0.0 - 14.9 U/mL - Value: <0.5

Tissue Transglutaminase IgA Antibody, Qualitative Normal value: Negative - Value: Negative

Deamidated Gliadin Peptide IgG Antibody, Quantitative Normal range: 0.0 - 14.9 U/mL - Value: 0.4

Deamidated Gliadin Peptide IgG Antibody, Qualitative Normal value: Negative - Value: Negative

Tissue Transglutaminase IgG Antibody, Quantitative Normal range: 0.0 - 14.9 U/mL - Value: <0.8

Tissue Transglutaminase IgG Antibody, Qualitative Normal value: Negative - Value: Negative

IgA Quantitative Normal range: 68 - 378 mg/dL - Value: 271

[trents]

You might find this interesting as it outlines the various antibody tests that can be ordered and rates them for their relative reliability:

What symptoms do you experience and how long have you been experiencing them? Do you have any other blood work parameters that are out of range from say a CBC or CMP. For those with celiac disease, the immune system misinterprets gluten as an invader and sends attacking cells into the lining of the small bowel, causing inflammation. Over time, this inflammation wears down the "villi" that line the small bowel, millions and millions of tiny finger-like projections that constitute the nutrient absorbing organ of the intestinal track. This can greatly reduce the efficiency with which nutrients are absorbed and often leads to other nutrient deficiency-related medical problems such as anemia and osteopenia/osteoporosis, just to name a couple. Celiac disease is an autoimmune disorder and is often found in association with other autoimmune disorders such as Hashimoto's thyroid disease and diabetes. There are over 200 symptoms/medical problems that have been associated with celiac disease, many of them not fitting into the classic category of GI distress.

[Skg414228]

  On 2/26/2025 at 5:48 PM, trents said:

You might find this interesting as it outlines the various antibody tests that can be ordered and rates them for their relative reliability:

What symptoms do you experience and how long have you been experiencing them? Do you have any other blood work parameters that are out of range from say a CBC or CMP. For those with celiac disease, the immune system misinterprets gluten as an invader and sends attacking cells into the lining of the small bowel, causing inflammation. Over time, this inflammation wears down the "villi" that line the small bowel, millions and millions of tiny finger-like projections that constitute the nutrient absorbing organ of the intestinal track. This can greatly reduce the efficiency with which nutrients are absorbed and often leads to other nutrient deficiency-related medical problems such as anemia and osteopenia/osteoporosis, just to name a couple. Celiac disease is an autoimmune disorder and is often found in association with other autoimmune disorders such as Hashimoto's thyroid disease and diabetes. There are over 200 symptoms/medical problems that have been associated with celiac disease, many of them not fitting into the classic category of GI distress.

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I did read this article and all it helped me determine was that I am too dumb lol. Plus with DGP IGA 75-95 is a huge range. I was also confused on if it meant 75-95% of people with positive dgp iga have it or if it meant that of 100% of the people that have Celiac 75-95% this value will be positive. 

Most of my symptoms are GI related but the other one that stands out is inflammation. It almost felt like I had body aches and I have soreness right now that I don't have when I am on the paleo diet full time (which is gluten free when you never cheat on it, which I was occasionally). My doctor suspected Raynauds but never did a blood test for it, and then I have had ADHD which I can't remember if it was directly related or not. I have a healthy mix of a lot of stuff going on so honestly it would be a relief if it was celiac because I could at least manage that. Im a pretty healthy person exercise daily high intensity and endurance and a pretty good diet but I haven't been able to lose weight in like 7 years. 

[Skg414228]

  On 2/26/2025 at 5:02 PM, trents said:

Welcome to the forum, @Skg414228!

You say that your DGP-IGA score is high and you give the absolute test score but you do not give the scale or units used by the lab doing the analysis so we cannot comment further on your conclusion. Different labs use different reference ranges for the same tests. There is no industry standard for these celiac antibody tests. So, could you also post back with the scale and the units?

If you already have an endoscopy/biopsy scheduled, the important thing is to hold off on going gluten free until that is done. There are some things besides celiac disease that can cause elevated celiac disease antibody levels so it is still possible you may be looking at something else. This is especially true when you are not IGA deficient and the tTG-IGA is within normal range. But you are correct in saying that very high antibody scores strongly weight the probability in favor of celiac disease. Keep us posted.

By the way, kudos to your physician for ordering a more complete antibody panel. Many will only order the tTG-IGA.

Expand Quote  

It is interesting you mentioned that it could be other things because I asked my gastro and she literally said it means nothing else. That that value was only considered for Celiac which is kind of why I asked here because I didn't understand how a celiac only value could be high and it wasn't celiac. 

[trents]

The tests outlined in the article I linked are rated according to "sensitivity" and "specificity".

Sensitivity refers to how well the test does in not missing those who actually have the disease being tested for, in this case, celiac disease. The DGP-IGA test is estimated to have a sensitivity of 75% to 95%. 

Specificity refers to how well the test does in not producing a positive score to medical conditions other than the one being tested for, in this case, celiac disease.  The DGP-IGA test is estimated to have a specificity of 90% to 100%.

Obviously, in your case there is no issue with sensitivity. So, the only remaining question would be in relation to specificity. It is my observation from participating in this forum for many years and reading the posted test results from many, many forum contributors, that the likelihood of misdiagnosis due to a specificity issue diminishes greatly with high test score numbers. Still, there is a slight chance it could be due to something else. Think about it. If this were not so, why would your GI doc even be scheduling you for a biopsy?

Edited February 26 by trents

[Skg414228]

  On 2/26/2025 at 6:30 PM, trents said:

The tests outlined in the article I linked are rated according to "sensitivity" and "specificity".

Sensitivity refers to how well the test does in not missing those who actually have the disease being tested for, in this case, celiac disease. The DGP-IGA test is estimated to have a sensitivity of 75% to 95%. 

Specificity refers to how well the test does in not producing a positive score to medical conditions other than the one being tested for, in this case, celiac disease.  The DGP-IGA test is estimated to have a specificity of 90% to 100%.

Obviously, in your case there is no issue with sensitivity. So, the only remaining question would be in relation to specificity. It is my observation from participating in this forum for many years and reading the posted test results from many, many forum contributors, that the likelihood of misdiagnosis due to a specificity issue diminishes greatly with high test score numbers. Still, there is a slight chance it could be due to something else. Think about it. If this were not so, why would your GI doc even be scheduling you for a biopsy?

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Okay yeah that helps! To answer your last bit my understanding was that you need to have multiple tests to confirm celiac. Blood, biopsy, dna, and then I think symptoms is another one. Either way I think everything has to be confirmed with the biopsy because that is the gold standard for testing (Doctors words). You also answered another question I forgot to ask about which is does a high value push to a higher % on those scales. I truly appreciate your answers though and just like hearing what other people think. Digging into forums and google for similar stuff has been tough. So thank you again!

[trents]

No, you don't necessarily need multiple testing methods to confirm celiac disease. There is an increasing trend for celiac diagnoses to be made on a single very high tTG-IGA test score. This started in the UK during the COVID pandemic when there was extreme stress on the healthcare system there and it is spreading to the US. A tTG-IGA score of somewhere between 5x and 10x normal is good enough by itself for some physicians to declare celiac disease. And mind you, that is the tTG-IGA, not the DGP-IGA. The tTG-IGA is the centerpiece of celiac antibody testing, the one test most commonly ordered and the one that physicians have the most confidence in. But in the US, many physicians still insist on a biopsy, even in the event of high tTG-IGA scores. Correct, the biopsy is considered "confirmation" of the blood antibody testing. But what is the need for confirmation of a testing methodology if the testing methodology is fool proof?

As for the contribution of genetic testing for celiac disease, it cannot be used to diagnose celiac disease since 40% of the general population has the genetic potential to develop celiac disease while only 1% of the general population actually develops celiac disease. But it can be used to rule out celiac disease. That is, if you don't have the genes, you don't have celiac disease but you might have NCGS (Non Celiac Gluten Sensitivity).

[Skg414228]

  On 2/26/2025 at 6:56 PM, trents said:

No, you don't necessarily need multiple testing methods to confirm celiac disease. There is an increasing trend for celiac diagnoses to be made on a single very high tTG-IGA test score. This started in the UK during the COVID pandemic when there was extreme stress on the healthcare system there and it is spreading to the US. A tTG-IGA score of somewhere between 5x and 10x normal is good enough by itself for some physicians to declare celiac disease. And mind you, that is the tTG-IGA, not the DGP-IGA. The tTG-IGA is the centerpiece of celiac antibody testing, the one test most commonly ordered and the one that physicians have the most confidence in. But in the US, many physicians still insist on a biopsy, even in the event of high tTG-IGA scores. Correct, the biopsy is considered "confirmation" of the blood antibody testing. But what is the need for confirmation of a testing methodology if the testing methodology is fool proof?

As for the contribution of genetic testing for celiac disease, it cannot be used to diagnose celiac disease since 40% of the general population has the genetic potential to develop celiac disease while only 1% of the general population actually develops celiac disease. But it can be used to rule out celiac disease. That is, if you don't have the genes, you don't have celiac disease but you might have NCGS (Non Celiac Gluten Sensitivity).

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Fair enough! I very easily could have misread somewhere. Celiac is very confusing lol but I should know in a little over a month what the final verdict is. Just thought chatting with people smarter than myself would get me in the right mindset. I just thought that DGP IGA was pretty high compared to some stuff I had seen and figured someone on here would be more willing to say it is more than likely celiac instead of my doctor who is trying to be less direct. She did finally say she believes it is celiac but wanted to confirm with the biopsy. I did figure it wouldn't hurt seeing what other people said too just because not all doctors are the best. I think mine is actually pretty good from what I have seen but I don't know what I don't know lol. Sorry lot of rambling here just trying to get every thought out. Thanks again!

[trents]

Keep us posted and let us know the results of the biopsy. Your case is atypical in a way in that you have this high DGP-IGA but normal TTG-IGA so knowing how it turns out will give us more data for similar situations that may be posted in the future. 

[Skg414228]

  On 2/26/2025 at 7:26 PM, trents said:

Keep us posted and let us know the results of the biopsy. Your case is atypical in a way in that you have this high DGP-IGA but normal TTG-IGA so knowing how it turns out will give us more data for similar situations that may be posted in the future. 

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I forgot to mention that I wasn’t prepared to take a celiac test so when I took this test I was pretty gluten free except for some cheat meals here and there. But I was about 98% gluten free at that point except I had gluten a few times a few days before this test by coincidence. So I probably skewed the numbers a bit by accident. 

[trents]

How long had you been practicing a reduced gluten diet by the time you had the blood draw?

[Skg414228]

  On 2/26/2025 at 10:22 PM, trents said:

How long had you been practicing a reduced gluten diet by the time you had the blood draw?

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Honestly it was like a solid couple of months. I started sometime in early December and the blood draw was on the 18th of Feb. Again it was almost all the time except a few days here and there with a cheat meal or even a whole day. Overall those it was a paleo diet like 98% of that time. I didn't go gluten free on purpose I was avoiding all grains and felt some aches and pains go away so I kept doing it, but then kept telling myself I needed more fiber which is why I had those cheat meals every now and then lol. 

[trents]

It is certainly possible that had you not been eating essentially gluten-free at the time of the blood draw, you would have tested positive for the TTG-IGA. That one seems to not have a lot of staying power once you begin to withdraw gluten. That is the value of some of these other tests. They can still throw up "celiac" flags further out from withdrawing gluten. It is very common for people to experiment with the gluten free diet before getting formally tested. They don't know any better and it seems some doctors don't know enough to tell them not to.

Edited February 26 by trents

[Skg414228]

  On 2/26/2025 at 10:37 PM, trents said:

It is certainly possible that had you not been eating essentially gluten-free at the time of the blood draw, you would have tested positive for the TTG-IGA. That one seems to not have a lot of staying power once you begin to withdraw gluten. That is the value of some of these other tests. They can still throw up "celiac" flags further out from withdrawing gluten. It is very common for people to experiment with the gluten free diet before getting formally tested. They don't know any better and it seems some doctors don't know enough to tell them not to.

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Yeah I had zero thoughts on celiac it was an ibs referral. She suspected celiac when she started questioning me and I already needed a colonoscopy which I guess is why she didn’t care that I had been fairly gluten free up to that point. Because they would have just done the biopsy when doing the colonoscopy. I don’t know we will see just figured I’d put that info on the forum in case someone finds it interesting later. I’ll update in April when I find out. 

[trents]

The biopsy for celiac disease is done of the small bowel lining and in conjunction with an "upper GI" scoping called an endoscopy. A colonoscopy scopes the lower end of the intestines and can't reach up high enough to get to the small bowel. The endoscopy goes through the mouth, through the stomach and into the duodenum, which is at the upper end of the intestinal track. So, while they are scoping the duodenum, they take biopsies of the mucosal lining of that area to send off for microscopic analysis by a lab. If the damage to the mucosa is substantial, the doc doing the scoping can often see it during the scoping.

Edited February 26 by trents

[Skg414228]

  On 2/26/2025 at 10:48 PM, trents said:

The biopsy for celiac disease is done of the small bowel lining and in conjunction with an "upper GI" scoping called an endoscopy. A colonoscopy scopes the lower end of the intestines and can't reach up high enough to get to the small bowel. The endoscopy goes through the mouth, through the stomach and into the duodenum, which is at the upper end of the intestinal track. So, while they are scoping the duodenum, they take biopsies of the mucosal lining of that area to send off for microscopic analysis by a lab. If the damage to the mucosa is substantial, the doc doing the scoping can often see it during the scoping.

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Well I’m going on the gluten farewell tour so they are about to find out lol. I keep saying biopsy but yeah it’s a scope and stuff. I’m a dummy but luckily my doctor is not. 

[trents]

It is a biopsy but it's not a colonoscopy, it's an endoscopy.

[Skg414228]

  On 2/26/2025 at 10:55 PM, trents said:

It is a biopsy but it's not a colonoscopy, it's an endoscopy.

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 Correct. I’m doing both in the same go though. Thanks for clarifying before I confused someone. I’m doing a colonoscopy for something else and then they added the endoscopy after the test. 

[trents]

Gotcha!

[trents]

Current "gluten challenge" recommendations are the daily consumption of at least 10g of gluten (about the amount found in 4-6 slices of wheat bread) daily leading up to the day of the biopsy.