how likely is it to get a false negative test? NCGS?

[chim]

Hi everyone! I recently got tested for Celiac disease and Crohns with the results coming back negative. I was really hoping this would name all the symptoms that have been troubling me for the past 2 years. My question is how likely is it to get a false negative test? 

I am 37 years old and for the past two years I have been having the following symptoms:

• numbing, tingling and burning sensation on my hands and legs.
• Soft yellow stools with mucus, and maybe 3-4 times a month diarrhea.
• bloating and gas and rarely light abdominal cramps
• Low iron even when taking supplements (feritine is normal)
• joint pain
• upset stomach (rarely)
• brain fog in the morning
• fatique
• nausea
• mouth ulcers
• easy bruising

Do you thing NCGS would be a possibility?

First I visited a neurologist, who gave me alpha lipoic acid and magnesium supplements, that did improve (almost eliminated at first) the neuropathy symptoms but then they returned. I was then tested for carpal tunnel syndrome which was positive with a moderate result, and had an MRI. Yesterday I finally had an appointment with a neurosurgeon who said that degeneration on my spine is very mild and does not justify my neurological symptoms and should look for other reasons. Carpal tunnel justifies numbing and tingling on hands but not on the legs. I read that carpal tunnel can be a celiac disease symptom, so was hoping that with a gluten free diet I would avoid surgery on my hands.

In three weeks I am having a colonoscopy which will hopefully give some answers. 

[Scott Adams]

What tests were done for celiac disease?

Unfortunately test results for celiac disease are not always definitive, and many errors can be made when doing an endoscopy for celiac disease, and they can happen in many ways, for example not collecting the samples in the right areas, not collecting enough samples, or not interpreting the results properly and giving a Marsh score. 

Many biopsy results can also be borderline, where there may be certain damage that could be associated with celiac disease, but it just doesn't quite reach the level necessary to make a formal diagnosis.

The same is true for blood test results. Over the last 10 years or so a new "Weak Positive" range has been created by many labs for antibody results, which can simply lead to confusion. There is no "Weak Negative" category, for example. Many people are not routinely given a total IGA blood test when doing a blood screening, which can lead to false negative interpretations if the patient has low IGA. We've seen on this forum many times that some doctors who are not fully up on how interpret the blood test results can tell patients that the don't need to follow a gluten-free diet or get more testing because only 1 of the 2 or 3 tests done in their panel is positive (wrong!). 

Dermatologists often don't know how to do a proper skin biopsy for dermatitis herpetiformis, and when they do it wrongly their patient will continue to suffer with terrible DH itching, and all the risks associated with celiac disease. For many, the DH rash is the only presentation of celiac disease.

Unfortunately many people will continue to suffer and eat gluten due to these errors in performing or interpreting the tests for celiac disease. Some will find out about the majority here who fall into the non-celiac gluten sensitivity zone and go gluten-free and recover, but many will continue suffer needlessly. Consider yourself lucky if you've figured out that gluten is the source of your issues and you've gone gluten-free, because many people never figure it out.

Approximately 10x more people have non-celiac gluten sensitivity than have celiac disease, but there isn’t yet a test for NCGS. If your symptoms go away on a gluten-free diet it would likely signal NCGS.

 

[Scott Adams]

PS - Were you eating at least two slices of bread daily for 6-8 weeks before your blood test, or 2 weeks before your endoscopy? We've heard over and over in this forum from people who were not told to eat at least two slices of bread daily for 6-8 weeks before a blood test for celiac disease--which is the standard protocol for the tests. Many people go gluten-free before their blood tests are taken, which can create false-negative results.

[chim]

Hello Scott thank you so much for taking the time to answer my question! I really appreciate it!

These were the celiac tests I had done:

1. Endomysium IgA Ab [Titer]in Serum or Plasma by Immunofluorescence EMA IgA[IIF] 

Results: 1.5

Reference value: <1/10

Method: Immunofluorescence

 

2. Tissue transglutaminase IgA Ab [Units/volume]in Serum or Plasma by Immunoassay (anti tTG-IgA)

Results: 1.5 U/ml

Reference value: Negative (-):<10, Positive (+): >=10

Method: Elisa

The truth is I don't know if I was eating 2 slices of bread daily. I was never on a gluten free diet, but also didn't track my intake so not sure... I most probably did eat 2 slices of bread or equivalent. 

I will have a colonoscopy in 3 weeks. I will do this for these 3 weeks and we'll find out and then I will see if I will try and go on with a gluten free diet to see if my symptoms subside. 

 

 

 

[RMJ]

A colonoscopy cannot detect celiac disease, it looks at the wrong part of the intestines. Might you be having an endoscopy?

[Scott Adams]

12 hours ago, chim said:

Hello Scott thank you so much for taking the time to answer my question! I really appreciate it!

These were the celiac tests I had done:

1. Endomysium IgA Ab [Titer]in Serum or Plasma by Immunofluorescence EMA IgA[IIF] 

Results: 1.5

Reference value: <1/10

Method: Immunofluorescence

For your Endomysium IgA Ab results, the reference range says <1/10, and your score was 1.5. This is somewhat confusing. Was that test negative as well? Is over 1 positive? I just can't tell by how this is shown. Perhaps positive would be over 10?

Approximately 10x more people have non-celiac gluten sensitivity than have celiac disease, but there isn’t yet a test for NCGS. If your symptoms go away on a gluten-free diet it would likely signal NCGS.

[RMJ]

2 hours ago, Scott Adams said:

For your Endomysium IgA Ab results, the reference range says <1/10, and your score was 1.5. This is somewhat confusing. Was that test negative as well? Is over 1 positive? I just can't tell by how this is shown. Perhaps positive would be over 10?

Approximately 10x more people have non-celiac gluten sensitivity than have celiac disease, but there isn’t yet a test for NCGS. If your symptoms go away on a gluten-free diet it would likely signal NCGS.

If that’s the typical EMA test the results are given as a dilution.  In that case, it would have to be more dilute than 1:10 to be positive, so 1:5 would be negative.

[chim]

9 hours ago, RMJ said:

A colonoscopy cannot detect celiac disease, it looks at the wrong part of the intestines. Might you be having an endoscopy?

Hello RMJ! No my GI booked me for a colonoscopy. I guess because the gluten test came back negative... maybe she suspects something else at this point... I am not sure....

[chim]

3 hours ago, Scott Adams said:

For your Endomysium IgA Ab results, the reference range says <1/10, and your score was 1.5. This is somewhat confusing. Was that test negative as well? Is over 1 positive? I just can't tell by how this is shown. Perhaps positive would be over 10?

Approximately 10x more people have non-celiac gluten sensitivity than have celiac disease, but there isn’t yet a test for NCGS. If your symptoms go away on a gluten-free diet it would likely signal NCGS.

I really don't understand either. But the doctor said it was negative... I will ask her when I see her again. I will wait for the colonoscopy and the results and depending on that I will talk with my doctor about the possibility of NCGS and try a gluten free diet.

1 hour ago, RMJ said:

If that’s the typical EMA test the results are given as a dilution.  In that case, it would have to be more dilute than 1:10 to be positive, so 1:5 would be negative.

So possibly the 1.5 stated is meant as 1:5? The doctor said it was negative but she did not explain. We talked on the phone. I will ask her to specify when I see her in person in 3 weeks. Thank you!