What Are The Chances Of Blood Test Not Showing Celiac Disease

[hubicka]

Sorry, not a very well worded title. What I mean is, how reliable are blood tests - what is the chance that it would come back negative even if I did actually have celiac disease.

Having a blood test tomorrow, hoping it would be a simple yes or no (actually kind of hoping for a 'yes' so i can get on with sorting it out and feeling better/not having a horrible messed up digestive system!). I'm guessing it's definitely not going to be simple though!

I read somewhere that not many celiacs actually show up as celiac on a blood test, is this true?

[GottaSki]

No, that is not true. The best thing to do is make sure your doctor orders a complete celiac panel along with nutrient testing. If these come back negative and you have symptoms of Celiac Disease, the next step should be endoscopy.

The diagnosis process can be frustrating - but taken one step at a time armed with knowledge of proper testing procedures makes it go much more smoothly.

There are reasons for many negative tests - removing gluten is the most common. Being deficient in Total IgA or IgG or recently triggered Celiac Disease without significant damage are all reasons for negative results. Additionally, there is Non-Celiac Gluten Intolerance which has many of the same symptoms as Celiac Disease - NCGI does not trigger the immune system when gluten is ingested to produce the antibodies measured in celiac blood work.

For now get the blood work done and wait for the results.

Hang in there

[hubicka]

Thanks for the advice

I had stopped eating wheat for a few weeks (during which time my tummy was much better) and then started eating gluten again for the test (since 6 weeks ago). Symptoms seemed even worse than before for many many weeks (the bloating and gas was unreal!!) but is settling down a bit now so really not sure what to think. Hopefully the test will shed some light!

[kareng]

From the University of Chicago:

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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).

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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.

[GottaSki]

I find the term "screening" for celiac to be confusing. The University of Chicago and other celiac centers often run screening fairs to screen the general population. For this use the tTG-IgA with Total Serum IgA is excellent.

If a person presents with symptoms of Celiac Disease or demonstrated reactions to gluten, I strongly believe a full celiac panel should be run as the Deamidated Gliadin Peptide tests are often the first indication of gluten sensitivity.

I was "screened" with tTG IgA only and was barely/weak positive which triggered the rest of the panel. Personally, my IgG levels were higher in tTG, DGP and AGA than the IgA levels although my Total IgA was in "normal" range. Had my "screening" test been one point lower I would have likely not been referred to GI and it would have been chalked up to one more in a very long line of "normal" blood work.

The percentages of false negatives and false positives are based on different data - most are based on subjects diagnosed with Celiac Disease - those of us with severe symptoms and damage that go undiagnosed for decades are not counted in most data.

Bottom line - IMO...if you have symptoms you believe are gluten related - push for the complete/full celiac panel for the best opportunity for complete data.

[enoughalready]

I came back negative for celiac from tTG and and IgA (that's all my doctor ordered) but my recent endoscopy showed flattening. I'm still waiting for the biopsy results but they think it could be celiac.

Sorry, not a very well worded title. What I mean is, how reliable are blood tests - what is the chance that it would come back negative even if I did actually have celiac disease.

Having a blood test tomorrow, hoping it would be a simple yes or no (actually kind of hoping for a 'yes' so i can get on with sorting it out and feeling better/not having a horrible messed up digestive system!). I'm guessing it's definitely not going to be simple though!

I read somewhere that not many celiacs actually show up as celiac on a blood test, is this true?