Help understanding bloodwork

[Emma84]

these are my results. They’re proceeding with an endoscopy. What do these mean? Am I likely to have celiac? 
 

Celiac Disease Evaluation

Deaminated Gliadin Antibody, IgA    2.4    U/mL

Deaminated Gliadin Antibody, IgG    51.9    U/mL

IgA w/reflex to Tissue Transglutaminase IgG Ab    368.00    mg/dL

Tissue Transglutaminase (TTG) Antibodies IgA    <0.5

That’s copied from the blood test results and all the Celiac tests that were done. Do these make any sense to you?

[Emma84]

  On 4/25/2023 at 2:04 PM, Emma84 said:

these are my results. They’re proceeding with an endoscopy. What do these mean? Am I likely to have celiac? 
 

Celiac Disease Evaluation

Deaminated Gliadin Antibody, IgA    2.4    U/mL

Deaminated Gliadin Antibody, IgG    51.9    U/mL

IgA w/reflex to Tissue Transglutaminase IgG Ab    368.00    mg/dL

Tissue Transglutaminase (TTG) Antibodies IgA    <0.5

That’s copied from the blood test results and all the Celiac tests that were done. Do these make any sense to you?

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Oh also my MCHC was also slightly elevated, if that matters.

[Russ H]

  On 4/25/2023 at 2:04 PM, Emma84 said:

these are my results. They’re proceeding with an endoscopy. What do these mean? Am I likely to have celiac? 
 

Celiac Disease Evaluation

Deaminated Gliadin Antibody, IgA    2.4    U/mL

Deaminated Gliadin Antibody, IgG    51.9    U/mL

IgA w/reflex to Tissue Transglutaminase IgG Ab    368.00    mg/dL

Tissue Transglutaminase (TTG) Antibodies IgA    <0.5

That’s copied from the blood test results and all the Celiac tests that were done. Do these make any sense to you?

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Hello and welcome to the forum. Do you have the reference ranges for those results? As they vary between labs, they are needed to interpret the results.

[Emma84]

  On 4/25/2023 at 2:13 PM, Russ H said:

Hello and welcome to the forum. Do you have the reference ranges for those results? As they vary between labs, they are needed to interpret the results.

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Yes let me copy and paste below: 

MCHC: my result 34.9  range was 30.4-34.8 

 

 

Celiac Disease Evaluation 

Deaminated Gliadin Antibody, IgA2.4U/mL   Range <0.2 to 14.9

Deaminated Gliadin Antibody, IgG51.9U/mL.   Range <0.4 to 14.9

IgA w/reflex to Tissue Transglutaminase IgG Ab368.00mg/dL.    Range  70 - 400

Tissue Transglutaminase (TTG) Antibodies IgA<0.5U/mL.   Range   <0.5 to 14.9

 

 

 

 

[Russ H]

OK, so basically the blood tests for coeliac disease look for antibodies to deamidated gliadin (which derives from gluten)  and tissue transglutaminase (an enzyme that binds to gliadin in the gut). Two classes of antibodies are tested for (IgA and IgG), so this means 4 tests. Your tests show an isolated raised IgG deamidated  gliadin antibody. Because of this, you were also tested to see if you were IgA deficient (the result suggests that you are not). If you were IgA deficient, it would explain why you had an isolated positive IgG. So the results are equivocal.

[trents]

I would add to what Russ H said, some of the test results, but not all of them, indicate possible celiac disease. The positive ones are not particularly specific for celiac disease and could be the result of another disease process. The endoscopy with biopsy of the lining of the small bowel should provide some clarity. Do not start withdrawing gluten from your diet until the biopsy is complete.

[Russ H]

An isolated IgG DGP has poor predictive power for coeliac disease. Below is a study that suggests somewhere around 82% of isolated IgG DGP positive tests are false positives. Due to the small study size though, there is a wide uncertainty in that figure, and up to 97.7% could be false positives.

https://pubmed.ncbi.nlm.nih.gov/28161854/

[Emma84]

  On 4/25/2023 at 2:42 PM, Russ H said:

OK, so basically the blood tests for coeliac disease look for antibodies to deamidated gliadin (which derives from gluten)  and tissue transglutaminase (an enzyme that binds to gliadin in the gut). Two classes of antibodies are tested for (IgA and IgG), so this means 4 tests. Your tests show an isolated raised IgG deamidated  gliadin antibody. Because of this, you were also tested to see if you were IgA deficient (the result suggests that you are not). If you were IgA deficient, it would explain why you had an isolated positive IgG. So the results are equivocal.

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How do you know that I am not IgA deficient? From what I’m seeing my IgA seems quite low.

[Emma84]

  On 4/25/2023 at 3:19 PM, Russ H said:

An isolated IgG DGP has poor predictive power for coeliac disease. Below is a study that suggests somewhere around 82% of isolated IgG DGP positive tests are false positives. Due to the small study size though, there is a wide uncertainty in that figure, and up to 97.7% could be false positives.

https://pubmed.ncbi.nlm.nih.gov/28161854/

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Why did my doctor order an endoscopy? Should I not get that procedure? 

[Emma84]

  On 4/25/2023 at 3:11 PM, trents said:

I would add to what Russ H said, some of the test results, but not all of them, indicate possible celiac disease. The positive ones are not particularly specific for celiac disease and could be the result of another disease process. The endoscopy with biopsy of the lining of the small bowel should provide some clarity. Do not start withdrawing gluten from your diet until the biopsy is complete.

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So if it’s not Celiac, does that mean for sure there is something else going on? Or is it not concerning that my IgG was elevated? 

[trents]

  On 4/25/2023 at 3:33 PM, Emma84 said:

How do you know that I am not IgA deficient? From what I’m seeing my IgA seems quite low.

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There are two IGA measures in your test results. tTG-IGA is the low one and this is the most commonly relied upon antibody test for celiac disease. There are other IGA tests that can also be run. All the individual IGA components combined make up "total IGA" which is the one you scored 368 on and it falls within the normal range. The tTG-IGA fraction is normal for you. Low total IGA can skew the individual IGA tests downward toward the negative range and that is why they run that one.

[trents]

  On 4/25/2023 at 3:38 PM, Emma84 said:

So if it’s not Celiac, does that mean for sure there is something else going on? Or is it not concerning that my IgG was elevated? 

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Yes. For instance, another bowel disease such as Crohn's. No one is saying it's definitely not celiac. Your IgG positive indicates possible celiac disease but possible other medical issues. IGG is not as specific for celiac disese as the tTG-IGA and the EMA tests.

[Emma84]

  On 4/25/2023 at 3:39 PM, trents said:

There are two IGA measures in your test results. tTG-IGA is the low one and this is the most commonly relied upon antibody test for celiac disease. There are other IGA tests that can also be run. All the individual IGA components combined make up "total IGA" which is the one you scored 368 on and it falls within the normal range. The tTG-IGA fraction is normal for you. Low total IGA can skew the individual IGA tests downward toward the negative range and that is why they run that one.

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Gotcha, thank you. 
 

 

can you help me understand the link below? The way it reads to me it sounds like the IgG being elevated is accurate 84% of the time? Unless I’m misreading this ? 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440671/

  On 4/25/2023 at 3:42 PM, trents said:

Yes. For instance, another bowel disease such as Crohn's. No one is saying it's definitely not celiac. Your IgG positive indicates possible celiac disease but possible other medical issues. IGG is not as specific for celiac disese as the tTG-IGA and the EMA tests.

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Gotcha. Celiac seems to be the only thing that makes sense, as it only appears to be gluten that causes problems and cutting out gluten seems to be the only solution.
 

anyways, I guess I’ll find out tomorrow morning. I’m so sick of pooping and sleeping all the time. Hopefully if it’s not celiac, they’ll see something else that will tell me what it is.  

[Emma84]

  On 4/25/2023 at 2:42 PM, Russ H said:

OK, so basically the blood tests for coeliac disease look for antibodies to deamidated gliadin (which derives from gluten)  and tissue transglutaminase (an enzyme that binds to gliadin in the gut). Two classes of antibodies are tested for (IgA and IgG), so this means 4 tests. Your tests show an isolated raised IgG deamidated  gliadin antibody. Because of this, you were also tested to see if you were IgA deficient (the result suggests that you are not). If you were IgA deficient, it would explain why you had an isolated positive IgG. So the results are equivocal.

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Can you elaborate on this? What do you mean by the results of equivocal? 

[trents]

You are correct in your understanding of the IgG being 84% accurate for celiac disease but compared to the tTG-IGA which is 98% accurate, the igG is less specific. You need to go forward with the endoscoy/biopsy to clarify whether or not you have celiac disease. Don't withdraw gluten until the endoscopy/biopsy is complete.

Your test results also could mean you have NCGS (Non Celiac Gluten Sensitivity).

[Emma84]

  On 4/25/2023 at 3:11 PM, trents said:

I would add to what Russ H said, some of the test results, but not all of them, indicate possible celiac disease. The positive ones are not particularly specific for celiac disease and could be the result of another disease process. The endoscopy with biopsy of the lining of the small bowel should provide some clarity. Do not start withdrawing gluten from your diet until the biopsy is complete.

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Ok so there’s enough reason to proceed with endoscopy then? 

  On 4/25/2023 at 3:48 PM, trents said:

You are correct in your understanding of the IgG being 84% accurate for celiac disease but compared to the tTG-IGA which is 98% accurate, the igG is less specific. You need to go forward with the endoscoy/biopsy to clarify whether or not you have celiac disease. Don't withdraw gluten until the endoscopy/biopsy is complete.

Your test results also could mean you have NCGS (Non Celiac Gluten Sensitivity).

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Gotcha thank you! 84% plus my symptoms is enough for me to justify the endoscopy. Just wanted to make sure that it was like a 10% chance or something way low because an endoscopy doesn’t seem fun lol 

[Emma84]

  On 4/25/2023 at 3:39 PM, trents said:

There are two IGA measures in your test results. tTG-IGA is the low one and this is the most commonly relied upon antibody test for celiac disease. There are other IGA tests that can also be run. All the individual IGA components combined make up "total IGA" which is the one you scored 368 on and it falls within the normal range. The tTG-IGA fraction is normal for you. Low total IGA can skew the individual IGA tests downward toward the negative range and that is why they run that one.

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Thank you for explaining! Wish I had asked more questions on the phone 

[Russ H]

  On 4/25/2023 at 3:43 PM, Emma84 said:

can you help me understand the link below? The way it reads to me it sounds like the IgG being elevated is accurate 84% of the time? Unless I’m misreading this ? 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440671/

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That paper does not measure isolated IgG DGP. Most of the positives for IgG DGP were also positive for IgA tTG, which you were not. Recent studies suggest that an isolated IgG DGP positive has poor predictive value (much less than 84%). Your test results neither confirm nor exclude coeliac disease.

 

Here are some studies on isolated IgG DGP. Most are for people under the age of 18 but there is one on adults.

This study suggests a positive predictive vale of 3.9% (94.1% false positives) in patients under the age of 18:

https://onlinelibrary.wiley.com/doi/full/10.1111/jpc.16071

This study suggests a positive predictive vale of 2.5% (97.5% false positives) in patients under the age of 18:

https://journals.lww.com/jpgn/Fulltext/2019/01000/In_Screening_for_Celiac_Disease,_Deamidated.6.aspx

This study suggests a positive predictive vale of 2.8% (97.2% false positives) in patients under the age of 18:

https://www.sciencedirect.com/science/article/abs/pii/S0009898122011421?via%3Dihub

This study suggests a positive predictive value of 15.5% in adults (although could be much smaller due to low numbers in study):

https://link.springer.com/article/10.1007/s10620-017-4474-5

 

 

[Emma84]

  On 4/25/2023 at 4:47 PM, Russ H said:

That paper does not measure isolated IgG DGP. Most of the positives for IgG DGP were also positive for IgA tTG, which you were not. Recent studies suggest that an isolated IgG DGP positive has poor predictive value (much less than 84%). Your test results neither confirm nor exclude coeliac disease.

 

Here are some studies on isolated IgG DGP. Most are for people under the age of 18 but there is one on adults.

This study suggests a positive predictive vale of 3.9% (94.1% false positives) in patients under the age of 18:

https://onlinelibrary.wiley.com/doi/full/10.1111/jpc.16071

This study suggests a positive predictive vale of 2.5% (97.5% false positives) in patients under the age of 18:

https://journals.lww.com/jpgn/Fulltext/2019/01000/In_Screening_for_Celiac_Disease,_Deamidated.6.aspx

This study suggests a positive predictive vale of 2.8% (97.2% false positives) in patients under the age of 18:

https://www.sciencedirect.com/science/article/abs/pii/S0009898122011421?via%3Dihub

This study suggests a positive predictive value of 15.5% in adults (although could be much smaller due to low numbers in study):

https://link.springer.com/article/10.1007/s10620-017-4474-5

 

 

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Now I’m wondering why the doctor ordered an endoscopy

[Russ H]

Do you have other symptoms?

[Emma84]

  On 4/25/2023 at 5:04 PM, Russ H said:

Do you have other symptoms?

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Bad GI issues that seemed only tied to gluten from what I can tell, and fatigue. Possibly some Weight loss but that could just be because of the diarrhea. Yellow poop when eating gluten. Anxiety and depression that gets better off gluten. Some bloodwork suggesting a potential liver issue with no history of liver problems and no obvious risk for liver issues. 

  On 4/25/2023 at 5:04 PM, Russ H said:

Do you have other symptoms?

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Also I get rashes when I eat gluten although none of them look like DH. 

[Russ H]

It is quite possible to have coeliac disease with negative or equivocal blood results. Make sure you keep eating gluten up to the endoscopy. In the UK, NICE recommends eating at least one gluten containing meal a day for 6 weeks prior to the endoscopy although they don't recommend how much gluten.

[KennaH]

  On 4/25/2023 at 3:11 PM, trents said:

I would add to what Russ H said, some of the test results, but not all of them, indicate possible celiac disease. The positive ones are not particularly specific for celiac disease and could be the result of another disease process. The endoscopy with biopsy of the lining of the small bowel should provide some clarity. Do not start withdrawing gluten from your diet until the biopsy is complete.

Expand Quote  

I would agree because after my endoscopy results posted before I talked to doctor I stopped eating gluten. I had to “gluten up” before blood work for baseline. Biopsy was best way to know severity and best options for me moving forward. 

[Emma84]

  On 4/25/2023 at 5:14 PM, Russ H said:

It is quite possible to have coeliac disease with negative or equivocal blood results. Make sure you keep eating gluten up to the endoscopy. In the UK, NICE recommends eating at least one gluten containing meal a day for 6 weeks prior to the endoscopy although they don't recommend how much gluten.

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I’ve been gluten free for 2 years, then ate for 5 weeks prior to bloodwork and it will be 6 weeks for endoscopy. Should that be accurate? 

[Russ H]

The Mayo clinic says 2 slices of bread a day for 6-8 weeks prior to blood test and just 2 weeks prior to endoscopy. It is probably enough. I have seen testing centres recommending from 4 weeks all the way up to 12 weeks prior to blood testing.