Advice Please - False Positive Blood Tests?

[sweethome]

Hello,

 

I'd love a little advice/information from people who probably know more about this than I do. Sorry for the slightly long post...

 

I am 32 and female. The only real health problem I have had is endometriosis, which was diagnosed and treated in 2002 and I have had no real problems with since. I am generally very healthy.

 

Last year, in May 2014, in began having some abdominal tenderness just above my belly button if the area was pressed (usually by my toddler's rather enthusiastic hugs!) and left-sided discomfort (waist level) at my back sort of radiating round to the side. I also felt quite full after eating only a little. My GP ordered an ultrasound, which was normal, and a whole range of blood tests, also all normal.

 

Things continued and in September, my GP ordered a coeliac screen which came back positive. My tTGA was 15.3 (normal range 0-6.9) and endomysial antibodies were positive. At the end of November I had an endoscopy and biopsy (4 samples were taken), which came back negative for coeliac disease.

 

In December I started experiencing problems with upper abdominal bloating and also constipation (sorry if tmi, but I could actually go four or five times a day, but just a couple of very tiny little pellets). I also began feeling lightheaded after eating and, with the exception of feeling hungry, felt so much better if I didn't eat or drink at all. So my GP repeated the coeliac screen to see if the first test was an anomaly. This time my tTGA was 35.7 (normal range 0-6.9) and endomysial antibodies were positive.

 

My gastroenterologist (who discharged me back to my GP after the normal biopsy) said I categorically do not have coeliac disease because of the negative biopsy and to continue as normal (with no guidance as to what was causing or would help my current symptoms). My GP agrees that I don't have coeliac disease.

 

So, my question: is there anything else that can cause a positive result on a tTGA blood test other than coeliac disease? My GP and the gastroenterologist both said false positives can occur.

 

My GP suggested I trial a gluten-free diet, but I'm concerned this is a very strict diet and unneccesary if I don't have coeliac disease and will delay/prevent an accurate diagnosis if I do. I have a two year old son, so if I do have coeliac diease, I understand he should be tested?

 

I don't know where to go with this now. Prior to all this starting last year, I had never even heard of coeliac disease. I also don't know if these blood tests are clouding the issue of what is actually causing my symptoms if they really are just false positives...

 

I would really appreciate any advice or insight... Many thanks in advance!

[kareng]

Your Celiac blood antibodies are going up.  Sounds like you have Celiac.  The GI just missed the damage when he biospied.

 

Open Original Shared Link

 

"if I have a positive blood test and a negative biopsy does that mean I have non-celiac gluten sensitivity?

This is not necessarily true. 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 (which is often defined as being a “potential celiac”). Please continue to work with a medical professional to eliminate celiac disease before pursuing another diagnosis."

 

 

 

Open Original Shared Link

 

 

"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 basicallyno false positives.

You could consider a Open Original Shared Link and Open Original Shared Link to assist with your diagnosis. In certain cases these can provide a strong enough indication to diagnose the disease when in conjunction with a positive response to a gluten-free diet."

 

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[MycasMommy]

If you do decide to do a trial run off of gluten, it will take a few months, at least, to get it all 100% perfect. You may notice relief right away though. Your small intestine is HUGE and the damage may have just been undetected.  That your GP and GI do not KNOW this is a warning sign that they do not know very much about celiac considering your blood work went UP and was twice positive, but they are still blaming the blood work for being inaccurate.  Anyway, if it were me, I would either find a new GI or as I am doing for my kid, going to a "fancy" doctor who deals with it as a specialization. Its out of pocket and worth it. People see having to go gluten free as some sort of horrible death sentence. It really isnt.  It is a change. If it makes you feel better, it is also worth it.  Also, it can cause fertility problems. If you already have endometriosis and are looking forward to another child someday, you will want to get it under control now.  You need no ones permission to go gluten free but it really is better to have a proper diagnoses BEFORE you do.

[sunny2012]

The blood test was supposed to eliminate the need for biopsy except in very rare cases. I was on the research to find an faster, more accurate, and less invasive method to diagnose Celiac. The biopsy can easily miss this disease for many reasons including biopsying places with no damage and taking biopsies incorrectly. 

I am not sure where the disconnect is with training physicians to understand the dangers of missing a Celiac diagnosis save perhaps they still believe it is no big deal just because it is controlled thru diet and they figure that is no big deal.

 

It is a struggle to function on a gluten free diet. I had to stop eating out with friends who choose to consume the pre-meal bread while talking. I have found recognizable pieces of bread in my drink. NO telling how much of it ends up in my plate.

 

If you shop around the outside of the grocery store and cook from scratch, it will be much easier.

[Cthompson638]

I'm in a similar situation. My TTGA levels were low positive in my blood test but the GI has said that if there is no damage in my biopsies then I do not have Celiacs. She said it could just indicate gluten sensitivity, however from doing some research I have read that gluten sensitivity alone does not cause these antibodies to be produced.

[Cara in Boston]

A negative biopsy only means damage was not found, not that it was not there.  The biopsy can only confirm a celiac diagnosis, not rule it out.  If you have symptoms and a positive blood test, the "final test" would be to try the diet.  If your symptoms resolve (and your blood returns to normal) you can be 100% sure.

 

It is much more likely that your biopsy was falsely negative than your blood test falsely positive.

[nvsmom]

A low positive tTG IgA (not double or quadruple the normal upper limits like yours was) can be caused by thyroiditis, diabetes, liver disease, crohn's, colitis, or a serious infection.  Those causes only happen in about 5% of all positive results.  A false positive tTG IgA is not common; a positive result is caused by celiac disease 95% of the time.

 

The EMA IgA only gives a positive result for celiac disease.  I have never, in three years of researching celiac disease and being on this board, seen a false positive EMA IgA test.  They are specific to celiac disease 98-100% of the time.  Also, the EMA IgA tends to detect more advanced disease. After the tTG IgA has started to create problems, the EMA IgA appears and attempts to wipe out the upper layer of the intestines with the intention of killing off whatever is causing the problem.  

 

A positive EMA IgA in addition to a positive tTG IgA is celiac disease - that is how I was diagnosed.

 

See this report (pages 8-12) on the details of testing: Open Original Shared Link

 

The endoscopic biopsy has a sensitivity that can be as low as 80%.  That means it can miss up to 20% of celiacs, or 1 in 5.  I agree with the others that you are a celiac and the biopsy missed the damage, and because your small intestine has the surface area of a tennis court, I'm surprised it doesn't happen more often.

 

Also, those tests will not indicate non-celiac gluten sensitivity (NCGS).  The tTG and EMA tests are NEVER both positive in someone with NCGS.  Ever. It is barely possible that someone with NCGS has diabetes, thyroiditis, or some other problem that would cause a slightly elevated tTG IgA, but if it is accompanied by celiac disease symptoms then it's celiac disease.  As somone around here once said, if it looks like a duck and quacks like a duck....

 

Best wishes.

[MycasMommy]

A low positive tTG IgA (not double or quadruple the normal upper limits like yours was) can be caused by thyroiditis, diabetes, liver disease, crohn's, colitis, or a serious infection.  Those causes only happen in about 5% of all positive results.  A false positive tTG IgA is not common; a positive result is caused by celiac disease 95% of the time.

 

The EMA IgA only gives a positive result for celiac disease.  I have never, in three years of researching celiac disease and being on this board, seen a false positive EMA IgA test.  They are specific to celiac disease 98-100% of the time.  Also, the EMA IgA tends to detect more advanced disease. After the tTG IgA has started to create problems, the EMA IgA appears and attempts to wipe out the upper layer of the intestines with the intention of killing off whatever is causing the problem.  

 

A positive EMA IgA in addition to a positive tTG IgA is celiac disease - that is how I was diagnosed.

 

See this report (pages 8-12) on the details of testing: Open Original Shared Link

 

The endoscopic biopsy has a sensitivity that can be as low as 80%.  That means it can miss up to 20% of celiacs, or 1 in 5.  I agree with the others that you are a celiac and the biopsy missed the damage, and because your small intestine has the surface area of a tennis court, I'm surprised it doesn't happen more often.

 

Also, those tests will not indicate non-celiac gluten sensitivity (NCGS).  The tTG and EMA tests are NEVER both positive in someone with NCGS.  Ever. It is barely possible that someone with NCGS has diabetes, thyroiditis, or some other problem that would cause a slightly elevated tTG IgA, but if it is accompanied by celiac disease symptoms then it's celiac disease.  As somone around here once said, if it looks like a duck and quacks like a duck....

 

Best wishes.

 

 

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