Interpreting Test Results... Not sure if I have gluten sensitivity?

[AnnieBirdie]

Hello everyone. It's so nice to find a community of people who have or are going through the same thing.

A bit of a back story, since last year, I'v been experiencing a ton of GI issues. Symptoms ranging from diarrhea, constipation, abnormal stools, constant abdominal pain, accumulation of gas, chronic acid reflux, heartburn, etc... I saw a gastroenterologist and had a colonoscopy and endoscopy done. Colonoscopy was clear- they did not find any damage to the small intestine. For the endoscopy, they found inflammation but that was due to the acid reflux. I was also negative for H pylori and C Diff. A couple of months later, my doctor ordered a full blood panel for me. All my results came back normal- I was not deficient in any of my essential vitamins. Endomysial IgA Ab = negative, TTG IgA Ab = <1.0 U/ml, TTG IgG Ab = 2.0 U/mL, Total IgA = 271 mg/dL (also normal). I also got bloodwork done for Gliadin (Deamidated Peptide AB, IGA and IGG. Result for Gliadin (Deamidated Peptide Ab IgA) = 1.1 U/mL. BUT HERE'S THE WEIRD THING: my results for Gliadin (Deamidated Peptide Ab IgG) was flagged as high = 35.0 U/mL. I'm super confused because I tried cutting out gluten before (about a week) and I didn't feel any different. My stools still continued to look abnormal and my acid reflux was still very much present. I don't think it's celiacs, because my symptoms are not severe. When I eat a slice of bread, I don't feel extremely terrible or like I'm dying in pain. I just continuously have acid reflux and gassy stomach, either way. I'm also asian and I know its rare for us to have celiac's so I kind of ruled out genetic testing, plus no one in my family has it. So I'm completely lost. Is it possible there's some other autoimmune disease with these symptoms? I got tested for thyroid and my levels for TSH Reflex to free T4 are 3.10 mIU/L, which was in standard range. 

Any help is appreciated! 

Thank you! 

[trents]

Welcome to the forum, AnnieBirdie!

Not sure if you stated this inadvertently or if it was a real misconception, but a colonoscopy cannot be used to inspect the small bowel. A scope cannot go up that far from the bottom end. An endoscopy is used for examining the small bowel and for taking biopsies of the small bowel lining which would be necessary to check for celiac disease. Do you know if they took a biopsy of the small bowel villlous lining? Celiac disease damages the lining of the small bowel. The inflammation it causes wears the villi down which causes inefficiency in nutrient absorption. Looking for damaged villi in the small bowel is considered to be the gold standard test for celiac disease and is typically used to conform positive antibody tests. It is odd they did the scoping before the blood antibody testing unless they were not looking for celiac disease when the endoscopy was done, such that the blood antibody testing was an afterthought. This is why I wonder if they did a biopsy of the small bowel lining. Can you confirm this?

The high Deamidated Peptide Ab IgG could indicate celiac disease but the other blood antibodly tests were negative. Deamidated Peptide tests are secondary tests that are usually run when celiac-like symptoms are present but the tTG-IGA is negative. The tTG-IGA test is the most common test run and many times the only one ordered. It combines good sensitivity with good specificity and is inexpensive. However, the tTG-IGA is most reliable with people of white European dissent. Still,  it misses 20% of whites who actually do have celiac disease (as confirmed by biopsy) and 80% of those with black African dissent. So, I am not sure what impact on reliability your Asian descent might have on the tTG-IGA result. What we are finding is that as awareness about celiac disease and the variety of symptoms it produces has improved across the globe, and as better testing methodology has become available, that racial differences in celiac rates may not be as great as once thought. A good example of this is India where celiac diagnosis is trending upward and proving the incidence of celiac disease is much higher than once thought.

It is also unfortunate that you began a gluten free diet a week before the blood antibody testing was done as this could have driven the numbers down toward the negative range.

Then there is the variation factor in the immune system response from one person to another. For whatever reason, we know that the immune system response of some people is just atypical. Some who actually do have celiac disease will not throw positives on the tTG-IGA but will throw positives on other antibody tests that can be run for celiac disease. This the value of running a "full celiac panel" as was done in your case.

Finally, you could have NCGS (Non Celiac Gluten Sensitivity) rather than celiac disease. They share many of the same symptoms but NCGS does not damage the small bowel villi. However, it is 10x more common than celiac disease. And a one week hiatus from gluten may not be enough time to know if gluten is causing you issues or not, especially if you were only partially eliminating gluten. And there is also the possibility that some other food is causing the issue as opposed to gluten (or in addition to gluten), like dairy, oats, eggs, corn or soy. You would have a better idea if gluten was causing you issues if you were to totally eliminate it for several weeks.

Sorry to add to your confusion.

[Scott Adams]

I agree with @trents, and you should reach out to your doctor to get more detail about the endoscopy procedure that was done, and find out if they looked specifically for celiac disease and took biopsies for it. Also, this article may be helpful:

Quote

the IgG anti-gliadin antibodies are 91% specific and have an 87% sensitivity. This means that they will show positive results more readily but there is not as strong a correlation with celiac disease. It is less specific. Patients with other conditions but not afflicted with celiac disease will occasionally show positive results. IgG anti-gliadin antibodies are detectable in approximately 21% of patients with other gastrointestinal disorders. This test might yield false positive results but is less likely to yield false negative results.

 

[AnnieBirdie]

On 3/12/2023 at 8:01 PM, trents said:

Welcome to the forum, AnnieBirdie!

Not sure if you stated this inadvertently or if it was a real misconception, but a colonoscopy cannot be used to inspect the small bowel. A scope cannot go up that far from the bottom end. An endoscopy is used for examining the small bowel and for taking biopsies of the small bowel lining which would be necessary to check for celiac disease. Do you know if they took a biopsy of the small bowel villlous lining? Celiac disease damages the lining of the small bowel. The inflammation it causes wears the villi down which causes inefficiency in nutrient absorption. Looking for damaged villi in the small bowel is considered to be the gold standard test for celiac disease and is typically used to conform positive antibody tests. It is odd they did the scoping before the blood antibody testing unless they were not looking for celiac disease when the endoscopy was done, such that the blood antibody testing was an afterthought. This is why I wonder if they did a biopsy of the small bowel lining. Can you confirm this?

The high Deamidated Peptide Ab IgG could indicate celiac disease but the other blood antibodly tests were negative. Deamidated Peptide tests are secondary tests that are usually run when celiac-like symptoms are present but the tTG-IGA is negative. The tTG-IGA test is the most common test run and many times the only one ordered. It combines good sensitivity with good specificity and is inexpensive. However, the tTG-IGA is most reliable with people of white European dissent. Still,  it misses 20% of whites who actually do have celiac disease (as confirmed by biopsy) and 80% of those with black African dissent. So, I am not sure what impact on reliability your Asian descent might have on the tTG-IGA result. What we are finding is that as awareness about celiac disease and the variety of symptoms it produces has improved across the globe, and as better testing methodology has become available, that racial differences in celiac rates may not be as great as once thought. A good example of this is India where celiac diagnosis is trending upward and proving the incidence of celiac disease is much higher than once thought.

It is also unfortunate that you began a gluten free diet a week before the blood antibody testing was done as this could have driven the numbers down toward the negative range.

Then there is the variation factor in the immune system response from one person to another. For whatever reason, we know that the immune system response of some people is just atypical. Some who actually do have celiac disease will not throw positives on the tTG-IGA but will throw positives on other antibody tests that can be run for celiac disease. This the value of running a "full celiac panel" as was done in your case.

Finally, you could have NCGS (Non Celiac Gluten Sensitivity) rather than celiac disease. They share many of the same symptoms but NCGS does not damage the small bowel villi. However, it is 10x more common than celiac disease. And a one week hiatus from gluten may not be enough time to know if gluten is causing you issues or not, especially if you were only partially eliminating gluten. And there is also the possibility that some other food is causing the issue as opposed to gluten (or in addition to gluten), like dairy, oats, eggs, corn or soy. You would have a better idea if gluten was causing you issues if you were to totally eliminate it for several weeks.

Sorry to add to your confusion.

Hi there, you’re right I forgot to mention. When my colposcopy was done, they were looking for evidence of IBD, so ulcerative colitis and crohns. Everything was normal. I also started the gluten free diet after the blood test showed a possible celiac diagnosis, so I think my results are somewhat accurate. However, now I’m wondering if it is a false positive because ever since writing my initial post, I’ve restarted a gluten free diet and can say that I do not feel any better. How long does it take before people start to feel improvement? I would assume some symptoms would clear up within days of not consuming gluten right? Im seeing a new doctor soon so I hope to get a second opinion! Thanks for your reply!

[AnnieBirdie]

On 3/13/2023 at 12:39 PM, Scott Adams said:

I agree with @trents, and you should reach out to your doctor to get more detail about the endoscopy procedure that was done, and find out if they looked specifically for celiac disease and took biopsies for it. Also, this article may be helpful:

 

Hi there, thanks for your response. Yes Im now thinking it might have been a false positive but I will definitely follow up with my doctor. 

[trents]

I believe you should start feeling better within a few weeks of abstinence from gluten if gluten is the problem or at least part of the problem.

But if you don't feel any better, I would go back on gluten and get restested after two months for antibodies. The timing of your testing with regard to gluten abstinence was out of phase since the initial antibody testing wasn't done for a week after you quit gluten.

[Scott Adams]

4 hours ago, AnnieBirdie said:

Hi there, you’re right I forgot to mention. When my colposcopy was done, they were looking for evidence of IBD, so ulcerative colitis and crohns. Everything was normal. I also started the gluten free diet after the blood test showed a possible celiac diagnosis, so I think my results are somewhat accurate. However, now I’m wondering if it is a false positive because ever since writing my initial post, I’ve restarted a gluten free diet and can say that I do not feel any better. How long does it take before people start to feel improvement? I would assume some symptoms would clear up within days of not consuming gluten right? Im seeing a new doctor soon so I hope to get a second opinion! Thanks for your reply!

Keep in mind that most celiacs may have no obvious symptoms, yet their health risks are the same if they continue eating gluten. You may be in this category, but testing would be the only way to be sure, and testing would not eliminate the possibility of non-celiac gluten sensitivity.

[Emma84]

On 3/13/2023 at 11:39 AM, Scott Adams said:

I agree with @trents, and you should reach out to your doctor to get more detail about the endoscopy procedure that was done, and find out if they looked specifically for celiac disease and took biopsies for it. Also, this article may be helpful:

 

I stumbled upon this thread and I’m glad I did. This is the anti-body that was elevated for me as well, but they said biopsy was negative. Do you know what other gastrointestinal disorders will also show a high igG gliadin result? 

[Scott Adams]

It's possible, but this info may be helpful:

Quote

DGP-IgA and DGP-IgG (Deamidated Gliadin Peptide) blood test for celiac disease - This test measures the levels of antibodies in the blood, but specifically targets deamidated gliadin peptides, which are a type of gluten protein that can trigger an immune response in people with celiac disease. The test is not always included in adults, but should be in cases with IgA deficiency. The test should always be included when screening children, especially if they are under 2 years old. The DGP test was created to detect celiac disease in those with IgA deficiency, as it tests for both IgA and IgG antibodies.

The sensitivity of the DGP-IgG test is reported to range from 75% to 85%, which means it can correctly identify individuals with the condition in about 75% to 85% of cases. The specificity of the DGP-IgG test is reported to range from 75% to 95%, which means it can correctly identify individuals without the condition in about 75% to 95% of cases.