Get email alerts Get Celiac.com E-mail Alerts  




Celiac.com Sponsor:
Celiac.com Sponsor:




Ads by Google:






   Get email alerts  Subscribe to FREE Celiac.com email alerts

  • Announcements

    • admin

      Frequently Asked Questions About Celiac Disease   09/30/2015

      This Celiac.com FAQ on celiac disease will guide you to all of the basic information you will need to know about the disease, its diagnosis, testing methods, a gluten-free diet, etc.   Subscribe to FREE Celiac.com email alerts What are the major symptoms of celiac disease? Celiac Disease Symptoms What testing is available for celiac disease? - list blood tests, endo with biopsy, genetic test and enterolab (not diagnostic) Celiac Disease Screening Interpretation of Celiac Disease Blood Test Results Can I be tested even though I am eating gluten free? How long must gluten be taken for the serological tests to be meaningful? The Gluten-Free Diet 101 - A Beginner's Guide to Going Gluten-Free Is celiac inherited? Should my children be tested? Ten Facts About Celiac Disease Genetic Testing Is there a link between celiac and other autoimmune diseases? Celiac Disease Research: Associated Diseases and Disorders Is there a list of gluten foods to avoid? Unsafe Gluten-Free Food List (Unsafe Ingredients) Is there a list of gluten free foods? Safe Gluten-Free Food List (Safe Ingredients) Gluten-Free Alcoholic Beverages Distilled Spirits (Grain Alcohols) and Vinegar: Are they Gluten-Free? Where does gluten hide? Additional Things to Beware of to Maintain a 100% Gluten-Free Diet Free recipes: Gluten-Free Recipes Where can I buy gluten-free stuff? Support this site by shopping at The Celiac.com Store.

Blood Tests And False Negative Results
0

12 posts in this topic

I understand this is a difficult question to answer.

I am asking people to answer this based on their own experience and research.

Assume I have Celiac.

What is the percentage chance that I take a blood test and the result is a false negative?

0

Share this post


Link to post
Share on other sites


Ads by Google:

I have seen it written here, and elsewhere, that there is a 25% false negative rate. Other tests I've seen have said much lower but I'm afraid I am unsure what is correct. My tTg IgA and EMA were very positive so I wasn't faced with that issue.

I do know that if you are in the early stages of the disease, a child, or IgA deficient, you are much more likely to test negative. If you have the biopsy, some people have patchier damage than others and it would be easier to miss. Also some people do not present with intestinal symptoms, so they could have a "false negative" to the diet because some changes aren't noticeable for months (like new hair growing in or slow to heal neurological problems).

Good luck. :)

0

Share this post


Link to post
Share on other sites

Assume I have Celiac.

What is the percentage chance that I take a blood test and the result is a false negative?

You are asking a lot of good questions - this is a very helpful thing when going through the celiac diagnosis process.

Depending on which antibody test you are talking about this figure changes. I believe current numbers are as high as 30% false negative.

I also believe very strongly that these numbers will change as more and more people are tested for Celiac by both blood and endoscopic biopsy. To date there is a huge number of people that are never tested for Celiac Disease as most doctors are not looking for the Celiac in folks that present with many of the 300+ symptoms associated with Celiac, rather than the shorter list of "classic" symptoms. AND if they test sero-negative are told they do not have Celiac Disease without endoscopic biopsy.

It's all relative. In my family we currently have a 80% false negative blood test rate - if my arithmetic is correct this morning.

5 celiac = 4 sero negative + 1 weak/mild positive

plus one other NCGI or Celiac - to be determined someday - maybe - he is on the fence as to whether he wants to do a gluten challenge - mostly because the rest of us didn't show strong positive blood work.

0

Share this post


Link to post
Share on other sites

If I have Celiac and test false negative, would taking a blood test a second time increase the chance of an accurate diagnosis?

Or is there something in my blood that would cause a false negative making it not beneficial to take a second blood test.

0

Share this post


Link to post
Share on other sites

Here is some info that is easy to find from reputable sources:

http://www.celiaccen...q.asp#diagnosed

How accurate are the celiac blood tests?

The current diagnostic tests for celiac disease are very accurate, particularly when tTG and anti-endomysial antibodies are elevated. The isolated presence of anti-gliadin antibodies does not necessarily imply that the subject is affected by celiac disease, with the exception of children under the age of 2 in which tTG and EMA may not be present

 

http://www.curecelia...false-negatives

In blood tests, are false positives less common than false negatives?

Even though blood tests are quite accurate, they are falsely positive 1-3% of the time (i.e., being positive without the person having celiac) and, although less commonly, falsely negative 1-2% of the time (i.e., being normal when a person actually has celiac

 

http://www.curecelia...positive-biopsy

Is it possible to have a negative blood test, but a positive biopsy?

While rare, it is possible to have a negative blood test and still have celiac disease. tTG sensitivity is approximately 98%, which means that 2% of all celiacs may have a normal tTG level. Sometimes tTG antibodies are not produced enough to show up in the blood stream and can only be detected in the intestinal mucosa by special means.

IgA deficiency is a reason why you might have a negative blood test, but a positive biopsy.

Further medical evaluation is important for anyone still experiencing symptoms in order to establish the diagnosis or to rule out celiac disease as a part of establishing another diagnosis. In some cases, celiac disease is the wrong diagnosis as such conditions as Crohn’s Disease and food protein allergy share many of the same symptoms.

 

0

Share this post


Link to post
Share on other sites




I wonder if the figures above assume you are consuming a gluten full diet at time of testing?

It seems to get more complex if you throw in gluten-free and gluten light.

0

Share this post


Link to post
Share on other sites

I wonder if the figures above assume you are consuming a gluten full diet at time of testing?

It seems to get more complex if you throw in gluten-free and gluten light.

I think that is for an average person eating a diet with gluten. They have a recommendation for if you have been gluten-free.

http://www.cureceliacdisease.org/archives/faq/ive-heard-that-i-dont-necessarily-have-to-endure-12-weeks-of-eating-gluten-if-i-have-a-severe-reaction-is-that-true-how-does-it-work

I’ve heard that I don’t necessarily have to endure 12 weeks of eating gluten if I have a severe reaction. Is that true? How does it work?

The gut needs time to mount an antibody response that can be measured in the blood, which is why we recommend 12 weeks of eating gluten. If you experience symptoms immediately, it’s likely that the gut itself has quickly become damaged. In these cases, you and your medical professional could consider a shorter gluten challenge (3-4 days) and then have a biopsy.

Diagnosis is not an exact science, each person responds differently to the presence of gluten in the small intestine and the amount of time it has been there. Be sure to work with your medical professional to adjust your diet, if needed, during your gluten challenge.

0

Share this post


Link to post
Share on other sites

Here is some info that is easy to find from reputable sources:

http://www.celiaccen...q.asp#diagnosed

How accurate are the celiac blood tests?

The current diagnostic tests for celiac disease are very accurate, particularly when tTG and anti-endomysial antibodies are elevated. The isolated presence of anti-gliadin antibodies does not necessarily imply that the subject is affected by celiac disease, with the exception of children under the age of 2 in which tTG and EMA may not be present

 

http://www.curecelia...false-negatives

In blood tests, are false positives less common than false negatives?

Even though blood tests are quite accurate, they are falsely positive 1-3% of the time (i.e., being positive without the person having celiac) and, although less commonly, falsely negative 1-2% of the time (i.e., being normal when a person actually has celiac

 

http://www.curecelia...positive-biopsy

Is it possible to have a negative blood test, but a positive biopsy?

While rare, it is possible to have a negative blood test and still have celiac disease. tTG sensitivity is approximately 98%, which means that 2% of all celiacs may have a normal tTG level. Sometimes tTG antibodies are not produced enough to show up in the blood stream and can only be detected in the intestinal mucosa by special means.

IgA deficiency is a reason why you might have a negative blood test, but a positive biopsy.

Further medical evaluation is important for anyone still experiencing symptoms in order to establish the diagnosis or to rule out celiac disease as a part of establishing another diagnosis. In some cases, celiac disease is the wrong diagnosis as such conditions as Crohn’s Disease and food protein allergy share many of the same symptoms.

 

It looks like blood tests are more reliable than most people believe.

0

Share this post


Link to post
Share on other sites

It looks like blood tests are more reliable than most people believe.

I wish they would be more specific on which blood tests. I know some docs and labs are not always running the recommended tests and they may not be as accurate as some of the newer tests.

http://www.cureceliacdisease.org/archives/faq/which-blood-tests-should-i-have-to-screen-for-celiac-disease

'Which blood tests should I have to screen for celiac disease?

You should have both tTG-IgA and total serum IgA tests to screen for celiac disease. As long as you produce IgA (total serum IgA confirms you do), tTG-IgA is 98% accurate in measuring elevated antibodies. If IgA deficient, or if there is some other equivocating factor to potentially compromise the blood test, then an EMA blood test is also given.

Other gliadin antibody tests are not useful in screening for celiac disease."

Like I said before, this info is very easy to find . Just google "Celiac centers".

0

Share this post


Link to post
Share on other sites

I think another variable is which body systems are the most severely or earliest impacted. I showed false negative blood work repeatedly even after my GI system was severely compromised. I do not know if a total IGA was ever done as I was diagnosed many years ago and was seeing many different doctors for different system impacts. Since I had false negative blood tests (the older ones of course) doctors did not even consider doing an endo. I did however have brain lesions that would have been diagnostic if only the doctors had been savvy enough to recognize them for what they were.

I have DH so we know for sure that I have been celiac since childhood but the most severe symptoms that I had for years were neuro and skin related. I had celiac for over 30 years before gut impact became more than an occasional inconvience.

Since so many doctors consider celiac to mainly be a GI related disorder rather than the autoimmune disorder that it is there may be folks that are considered to have false positive tests because their biopsies are negative.

In my own family after I was finally diagnosed both children showed positive on blood work and one on the endo. They never would have even been checked for celiac if I hadn't insisted because I knew it was genetic.

1

Share this post


Link to post
Share on other sites

I think I read the 1-2% fasle negative statistic on the University of Chicago website but my general experience has not been that doctors test properly. I'd easily believe that half the doctors do the wrong tests or insufficient numbers of tests which would make this number a bit larger. My son was first flagged for celiac because of failure to thrive at 18 months and was told that he tested negative. After looking back through his records I see that he wasn't given a blood test at all for celiac (blood work was done for other things), they based it on assessing fats in the stool, which is not an accepted means. A second doctor did the same at age 2.5. This is a little more extreme, but plenty of adults are given the wrong or insufficient blood tests and told they are negative.

And then there is lab error, lack of skill in the technician. I think the reason these tests are sent out from most labs is that it takes some subjective skill at reading the tests, it's not as clear as a strep culture or something. So I suspect the 1-2% is what a researcher would find in a study of their patients tested by skilled pathologists, with results scored by skilled technicians. I'm very skeptical that this reflects most people's care.

1

Share this post


Link to post
Share on other sites

I think I read the 1-2% fasle negative statistic on the University of Chicago website but my general experience has not been that doctors test properly. I'd easily believe that half the doctors do the wrong tests or insufficient numbers of tests which would make this number a bit larger. My son was first flagged for celiac because of failure to thrive at 18 months and was told that he tested negative. After looking back through his records I see that he wasn't given a blood test at all for celiac (blood work was done for other things), they based it on assessing fats in the stool, which is not an accepted means. A second doctor did the same at age 2.5. This is a little more extreme, but plenty of adults are given the wrong or insufficient blood tests and told they are negative.

And then there is lab error, lack of skill in the technician. I think the reason these tests are sent out from most labs is that it takes some subjective skill at reading the tests, it's not as clear as a strep culture or something. So I suspect the 1-2% is what a researcher would find in a study of their patients tested by skilled pathologists, with results scored by skilled technicians. I'm very skeptical that this reflects most people's care.

Is it possible to take the test result to a second pathologist for a second opinion?

If so, how?

I wonder if their is a higher chance of accuracy if I have the blood test at a hospital lab as opposed to

a Lab Corp or Quest Diagnostics. I am wondering if the technicians and pathologists might be more skilled at a hospital.

Common sense tells me that the answer to this question is yes.

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
0

  • Forum Statistics

    • Total Topics
      103,346
    • Total Posts
      917,410
  • Topics

  • Posts

    • Weird Reaction
      I think, if all this is caused by glutening, it could be that it takes a while to work its way out of your system. I should explain about what I said about organic broccoli.   I don't have a problem with organic food,  in fact, I buy organic milk and carrots all the time, but I don't want to try organic broccoli in case it is the broccoli that is the problem, not the insecticide.    I meant to ask, are you a coeliac or is it non-coeliac gluten intolerance that you have?   I wonder what sort of support you get in Australia for these conditions once diagnosed?   Here in the UK I think the understanding is that if new gastro symptoms have lasted for more than six weeks it needs to be investigated.   I have found this very helpful advice because I do get odd twinges of pain and sometimes changes in bowel movements (sorry if tmi) but they rarely last more than a couple of weeks.   If they do persist I mention it to my gastroenteroligist and he follows it up.  I recently had a sigmoidoscopy for left sided pain and they found nothing.  Turns out it was to do with lactose intolerance, but I always imagine the worse!    
    • Will my doctor test me? So many symptoms...
      Welcome, @iwillmoveamountain! Of course you are not wrong to pursue getting testing for celiac. My advice is to drop that doctor and find a new one, preferably one who is celiac savvy, and who will listen to you and test you for the disease.  
    • Will my doctor test me? So many symptoms...
      Hi! I was hoping some of you might be able to tell me if my symptoms seem like good reason to be tested for celiac disease... I actually asked my doctor to test me (years ago) and she told me she would not test me because the test is expensive... However, I am now desperate to figure out how to manage my health issues and am willing to find a doctor that WILL test me if my symptoms seem to point to celiac...Here they are:
      I have been diagnosed with all of the following over the last 12 years (I am 22 years old, and have always been a healthy weight/slightly underweight, and quite active):
      Irritable Bowel Syndrome Fibromyalgia Anorexia (started when I was 10, I have been mostly recovered since I was 14) Depression Anxiety Panic Attacks Horrible mood swings (from suicidal to totally fine in a matter of minutes)
        Chronic constipation and bloating Acne   HOWEVER, no one in my family has been diagnosed with celiac....am I wrong to think I have it??
    • Weird Reaction
      Yes, I was surprised about the MSG in broccoli as well. I just had a quick look now as I couldn't remember where I had read it but some mushrooms have it to. A Google search will bring up a few things. I always just thought MSG was an artificial food enhancer!! Insecticides are still a big possibility though. Why do you not want to try organic? We buy organic when we can and fruits and veges that are in season are usually the best and cheapest.  Thank you for the link, Cristiana. Very helpful. I have an appointment with my Naturopath in a couple of weeks and going to have a blood test done before that. She is excellent. Very knowledgeable and loves her work. Until then I'm not taking any supplements. I generally eat pretty well anyway so we'll see what she says. In the past I have used B12 injections (aka Neo Cytamen) which I found much better and safer than taken orally and very cheap. The energy boost was very noticeable. I didn't know it helped with anxiety though. She has also had me on Magnesium, Probiotics and Vitamin D3 and I also make my own Liver Tonic (Milk Thistle, Dandelion Root Powder, L-Glutamine, Taurine and Choline Bitartrate) which I use from time to time for a quick detox. Too much of anything can be bad but I think iron can be not real good in large amounts. Deficiencies can be related to gut health and/or competing for absorbtion with something else you may be taking I found. I'm no expert though but just a few things I've picked up during research. My normal GP told me to just eat some more red meat but I want to speak to my Naturopath first before supplementing. Her knowledge on nutrition is a bit more up-to-date.  I was just sitting there at lunch today after feeling great all morning and had a "weird feeling" come over me. Just a not quite right feeling. Very hard to describe and nausea seems to have returned to. It's funny that as I get older any little thing I get I seem to think it's life threatening even though all the tests I get back say I'm in good health. I guess that's part of that dread and doom and gloom feeling I mentioned earlier. Wish that would go away.  
    • Gluten and panic attacks
      There are great gluten-free pizza crusts out there, as well as good dairy free cheese. I find the key is to add good toppings, e.g. meats, carmelized onions, other veggies, white anchovies. Life goes on. Congrats. Hope the good feelings keep up. 
  • Upcoming Events

  • Blog Entries

  • Recent Status Updates

    • ChiaChick  »  Peaceflower

      Hi Peaceflower, Just wanted to say thank you for the chat.
      · 0 replies
    • ukuleleerika

      Hello! I am new to this Celiac website... Is there anyone out there with Celiac AND extensive food allergies? My allergies include shellfish, dairy, eggs, cantaloupe, kiwi, mango, nuts, oranges, red dye, and more I can't think of. I went to the allergist about a year ago to see why I wasn't feeling well, and once everything was eliminated, I still didn't feel well. We did more testing to find out I had celiac as well as allergies to cattle as well as rye grass (I live on a farm basically). This was back in January 2016. I recently had my endoscopy with the gastroenterologist a week ago. I have no idea what to do or what to eat... So fish and potatoes for me!
      · 2 replies
    • SLLRunner

      Week 4 of the gluten challenge- wheat cereal every morning, regular bread every day, and wheat tortillas for my lunch wraps. Right now, body aches that seem exercise related (weight lifting and running), even though I am doing the same intensity of weight lifting and running I've always done.  Just a few more weeks until my blood test. Counting down the days.
      · 0 replies
  • Who's Online (See full list)

  • Member Statistics

    • Total Members
      60,482
    • Most Online
      1,763

    Newest Member
    Jiifigment
    Joined