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Aitcher

False Positive Blood Tests

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Hello! I am in the middle of a possible celiac diagnosis and have a few questions. My doctor ran a celiac panel (along with a bunch of other tests) because I have persistent elevated liver enzymes. My IGA was 387 (normal range 66-433) and my TTG-IGA was 27.7 (normal range 0-15). My EMA was negative.  I had an endoscopy and biopsy yesterday. The doctor said he didn't see any obvious signs of celiac during the endoscopy and that my blood tests were likely a false positive. 

I have two other autoimmune diseases--rheumatoid arthritis and Sjogren's syndrome--and I have read that this makes false positive blood tests more likely. Has anyone else seen information about this?

I don't feel like I have any real symptoms. I am prone to diarrhea and loose stools, but they generally don't cause me any real distress or discomfort.  I have a sister that went gluten free a few months ago and says she feels a million times better. She refuses to get an official diagnosis though since it means going back on gluten for at least six weeks and she's not willing to do that.

Has anyone had elevated TTG-IGA but negative biopsy?  Or alternatively has anyone gotten a celiac diagnosis without any severe symptoms?  Mostly, I guess I'm just anxious waiting for the biopsy results and am interested in hearing other people's experiences getting diagnosed.

Thanks!

Heather

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Unfortunately this happens pretty often, however, in Europe and the UK you would likely have been diagnosed with celiac disease and not even given a biopsy, as their current diagnostic standards don't include a biopsy when the blood tests offer definitive results--the tTG test accurately diagnoses celiac disease 95% of the time.

There are some doctors, however, who might not offer you a formal diagnosis in your case, and some who might even say that you could still eat gluten, however, given your blood test results and the fact that you sister appears to also be gluten sensitive or may have celiac disease (44% of direct relatives also have celiac disease), it would surprise me if your doctor did not ask you to go gluten-free.

PS - it is more likely that your biopsy was not done correctly, or misinterpreted, than it would be for your blood tests to be false positive.


Scott Adams

Celiac.com - Celiac Disease Board Moderator

Founder Celiac.com

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Heather, elevated liver enzymes was what led to my Celiac Disease diagnosis almost 20 years ago. My liver enzymes returned to normal within about 3 months of stopping gluten. If nothing else, you could use that same criteria to evaluate whether or not gluten is causing your problems.

Edited by trents

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What did the biopsies reveal?  How many tissue samples were taken and from which locations?  You should get a copy of the pathologist’s and the endoscopy reports.  My GI told me right after the procedure that everything looked good when he went in.  The biopsies revealed the damage which was microscopic.  I think you need to wait for the biopsy results.  You can not rule out celiac disease yet.  
 
 

 

Edited by cyclinglady

Non-functioning Gall bladder Removal Surgery 2005

Diagnosed via Blood Test (DGP IgA only) and Endoscopy: March 2013

Hashimoto's Thyroiditis

Osteopenia/osteoporosis -- June 2013

Allergies and Food Intolerances

Repeat endoscopy/Biopsies: Healed

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5 hours ago, Scott Adams said:

Unfortunately this happens pretty often, however, in Europe and the UK you would likely have been diagnosed with celiac disease and not even given a biopsy, as their current diagnostic standards don't include a biopsy when the blood tests offer definitive results--the tTG test accurately diagnoses celiac disease 95% of the time.

There are some doctors, however, who might not offer you a formal diagnosis in your case, and some who might even say that you could still eat gluten, however, given your blood test results and the fact that you sister appears to also be gluten sensitive or may have celiac disease (44% of direct relatives also have celiac disease), it would surprise me if your doctor did not ask you to go gluten-free.

PS - it is more likely that your biopsy was not done correctly, or misinterpreted, than it would be for your blood tests to be false positive.

I politely disagree.  The EU guidelines for diagnosing patients without biopsies now includes adults (at least in the UK) who have a positive TTG,  but that result must be 10 times the cut off.    A slightly elevated TTG is not considered 10x the limit.  

Celiac disease: a comprehensive current review, published July 2019

Authors:  Giacomo Caio, Umberto Volta, Anna Sapone, Daniel A. Leffler, Roberto De Giorgio, Carlo Catassi & Alessio Fasano K

“The gold standard for celiac disease diagnosis is represented by the combination of mucosal changes detected by duodenal biopsy and by positivity of serological tests (anti-tTG antibodies, anti-endomysium antibodies (EmA), and deamidated gliadin peptide (DGP) antibodies). Despite the progress made in serology, no antibody test currently available provides a sensitivity and specificity of 100% (Table 3) [96, 97], thus requiring intestinal biopsy as a key adjunct for establishing a correct diagnosis [98]. Pediatric patients with high titers (over 10 times the cut-off) of anti-tTG antibodies, detectable EmA, HLA-DQ2/HLA-DQ8 positivity, and signs/symptoms suggestive of celiac disease may skip duodenal biopsy as recommended by recent guidelines by the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) [99]. Although a large multicenter European study showed diagnostic accuracy of ESPGHAN criteria in identifying celiac disease in children [100], it should be pointed out that these criteria are not followed worldwide. In fact, in some countries such as the USA, ESPGHAN criteria are not recommended because of the poor reproducibility of the anti-tTG assays [101].“

https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-019-1380-z

Edited by cyclinglady

Non-functioning Gall bladder Removal Surgery 2005

Diagnosed via Blood Test (DGP IgA only) and Endoscopy: March 2013

Hashimoto's Thyroiditis

Osteopenia/osteoporosis -- June 2013

Allergies and Food Intolerances

Repeat endoscopy/Biopsies: Healed

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@cyclinglady, you are leaving out the part about her sister possibly also having undiagnosed CD, which would dramatically increase her risk in this case (if her sister has it the odds increase to ~44%). 

Let us know how things turn out!


Scott Adams

Celiac.com - Celiac Disease Board Moderator

Founder Celiac.com

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5 hours ago, Scott Adams said:

@cyclinglady, you are leaving out the part about her sister possibly also having undiagnosed celiac disease, which would dramatically increase her risk in this case (if her sister has it the odds increase to ~44%). 

Let us know how things turn out!

That is true!  The old 1 in 10 chance seems to be no longer the case.  


Non-functioning Gall bladder Removal Surgery 2005

Diagnosed via Blood Test (DGP IgA only) and Endoscopy: March 2013

Hashimoto's Thyroiditis

Osteopenia/osteoporosis -- June 2013

Allergies and Food Intolerances

Repeat endoscopy/Biopsies: Healed

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My biopsy results showed up in my health app today. It says several irregular fragments were taken from the "duodenum/proximal duodenum" and that they measured in aggregate 0.6 x 0.4 x 0.1 cm. The "biopsy shows fragments of enteric mucosa with intact villi and no intraepithelial lymphocytosis."  If I'm understanding correctly, this means the biopsy showed no indication of celiac disease. I have not talked to my doctor yet but assume that he'll tell me that I do not need to go gluten free.

I really thought it was going to come back positive. I didn't mention it in my earlier post, but I was diagnosed with both a vitamin B12 deficiency and iron deficiency anemia in the last two years. Between that, the bloodwork, the elevated liver enzymes, and my sister, I was pretty convinced I had celiac. I'm having an ultrasound of my liver this week so that may provide some additional clues about the elevated liver enzymes at least.

What other conditions can cause an elevated TTG-IGA besides celiac?

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2 hours ago, Aitcher said:

My biopsy results showed up in my health app today. It says several irregular fragments were taken from the "duodenum/proximal duodenum" and that they measured in aggregate 0.6 x 0.4 x 0.1 cm. The "biopsy shows fragments of enteric mucosa with intact villi and no intraepithelial lymphocytosis."  If I'm understanding correctly, this means the biopsy showed no indication of celiac disease. I have not talked to my doctor yet but assume that he'll tell me that I do not need to go gluten free.

I really thought it was going to come back positive. I didn't mention it in my earlier post, but I was diagnosed with both a vitamin B12 deficiency and iron deficiency anemia in the last two years. Between that, the bloodwork, the elevated liver enzymes, and my sister, I was pretty convinced I had celiac. I'm having an ultrasound of my liver this week so that may provide some additional clues about the elevated liver enzymes at least.

What other conditions can cause an elevated TTG-IGA besides celiac?

It is possible that your GI missed damaged areas.  I think your other autoimmune  diseases (Sjogrens and RA) can cause the slightly elevated TTG IgA.  

The University of Chicago:

Yes, blood work can be falsely positive, as can any test in medicine, especially at low titers. However, it may be that the biopsy was done or read incorrectly or that there’s not yet enough damage in the small intestine to diagnose celiac disease. A second opinion at a celiac center can help clarify a diagnosis. False positives vary between the tests and also between the populations considered. For instance, tTG is falsely positive in about 2-3% of people in general, but in about 20% of those with Type 1 Diabetes or other autoimmune conditions. EMA, on the other hand, has basically no false positives. You could consider a genetic and EMA test to assist with your diagnosis.”

http://www.cureceliacdisease.org/faq/is-it-possible-to-have-a-positive-blood-test-but-not-have-celiac-disease/

 I certainly hope that you do not have a 3rd AI! 
I can share that my 3rd AI is AI Gastritis which can cause B-12 and iron deficiencies just like celiac disease.  Did they biopsy your stomach?  If not, there is a specific antibodies test for it.  
 

Still lots of people are sensitive to gluten.  You might consider trialing the diet.  

Edited by cyclinglady

Non-functioning Gall bladder Removal Surgery 2005

Diagnosed via Blood Test (DGP IgA only) and Endoscopy: March 2013

Hashimoto's Thyroiditis

Osteopenia/osteoporosis -- June 2013

Allergies and Food Intolerances

Repeat endoscopy/Biopsies: Healed

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10 hours ago, cyclinglady said:

It is possible that your GI missed damaged areas.  I think your other autoimmune  diseases (Sjogrens and RA) can cause the slightly elevated TTG IgA.  

The University of Chicago:

Yes, blood work can be falsely positive, as can any test in medicine, especially at low titers. However, it may be that the biopsy was done or read incorrectly or that there’s not yet enough damage in the small intestine to diagnose celiac disease. A second opinion at a celiac center can help clarify a diagnosis. False positives vary between the tests and also between the populations considered. For instance, tTG is falsely positive in about 2-3% of people in general, but in about 20% of those with Type 1 Diabetes or other autoimmune conditions. EMA, on the other hand, has basically no false positives. You could consider a genetic and EMA test to assist with your diagnosis.”

http://www.cureceliacdisease.org/faq/is-it-possible-to-have-a-positive-blood-test-but-not-have-celiac-disease/

 I certainly hope that you do not have a 3rd AI! 
I can share that my 3rd AI is AI Gastritis which can cause B-12 and iron deficiencies just like celiac disease.  Did they biopsy your stomach?  If not, there is a specific antibodies test for it.  
 

Still lots of people are sensitive to gluten.  You might consider trialing the diet.  

Thanks for the information. I knew I had read somewhere that having other autoimmune diseases increased the chance of false positives but I couldn't find it again.  I don't think they biopsied my stomach but my doctor did say that I have a hiatal hernia, esophagitis, and minor erosions in the bulb of the duodenum.  He recommended that I start taking Prilosec. I have lots of questions for him next time we talk (and I'm not just coming out of sedation) :)

I am considering trying to go gluten free for a few months to see if I see improvement in any of my symptoms. 

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I would strongly suggest you go gluten free.  You did have a positive TTG.   Like I said, it can be easy to miss damaged areas or you could just be starting to develop celiac.  The AIP diet has helped so many people who have autoimmune disease and it is gluten free.  Which is telling.  Gluten is not good for everybody.  Even celiac disease researchers know that Non-celiac Gluten Sensitivities exist, they just can not test for it.  
 

In my case, I know that going gluten free not only treated my celiac disease, but my thyroid enlargement and nodules disappeared within a year.  It is one of the reasons so many doctors who treat autoimmune Thyroiditis (e.g. Hashimoto’s) recommend a gluten free diet.  It works for so many.  
 

Getting a diagnosis can be hard.  My nieces’s fourth GI finally ordered a pill camera which found her Crohn’s which was beyond the reach of both scopes.  Some cases do not meet the normal algorithms.  
 

Bottom line?  You need to figure out how to stop the autoimmune attack. Diet can certainly help!  


Non-functioning Gall bladder Removal Surgery 2005

Diagnosed via Blood Test (DGP IgA only) and Endoscopy: March 2013

Hashimoto's Thyroiditis

Osteopenia/osteoporosis -- June 2013

Allergies and Food Intolerances

Repeat endoscopy/Biopsies: Healed

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