Is This Blood Test Sufficient?

[tpchan85]

My brother suffers from celiac disease. I have suffered from lots of celiac symptoms for a long time, mostly bowel issues. Anyway, I got down to my local doctor who did some blood tests, they found some deficiencies (B12, folate), but the TTG IgA blood test came back negative (was on gluten at the time) so they said I can't possibly be celiac. I went gluten free anyway and felt quite a bit better. Anyway, I pushed them for a while and got a biopsy sorted and did the gluten challenge for 6 weeks they took 4 samples which came back negative for celiac but I'm not totally totally convinced. I want to have a full blood panel done to be absolutely certain, but here in the UK the NHS won't offer me anything but the TTG IGA so I have been searching for private hospitals that offer celiac panels.

 

The only one I have come across so far is Array 3 here Open Original Shared Link. I notice though it doesn't test Serum IGA or EMA, would this blood test be sufficient to say for certain whether I'm celiac or not? It's quite expensive so I want to be totally sure! Thanks.

[nvsmom]

There is a chance that you still have celiac disease because the sensitivity of the tTG IgA is somewhere between 75% and 95%, which means it can miss 5-25% of all celiacs.  We have more than a few board members who had a negative tTG IgA yet had other positive blood tests or a positive biopsy. It does happen sometimes, although it is not the norm.

 

The full celiac disease panel includes:

• tTG IgA and tTG IgG (tissue transglutaminase) - most common tests
• DGP IgA and DGP IgG (deaminated gliadin peptides) - newer tests often best at detecting early celiac disease
• EMA IgA (endomysial antibodies) - similar to the tTG IgA but detects damage as it becomes more advanced
• total serum IgA - a control test to detect IgA deficiency which can cause false negatives in IgA based  celiac tests (ex. tTG IgA)
• AGA IgA and AGA IgG (anti-gliadin antibodies) - older and less reliable tests that were largely replaced by the DGP tests

About 1 in 20 celiacs are deficient in IgA.  Was your total serum IgA tested?  You need to make sure you are not low in IgA or your IgA based test (tTG IgA) is meaningless.

 

I think the most useful tests for you would be the tTG IgG, DGP IgA and DGP IgG.  The EMA IgA is very similar to the tTG IgA and is rarely positive if the tTG IgA is not.  The AGA tests can miss many people but if you cant get the DGP tests, they might be good to get.

 

Pages 8 to 13 of this report discusses all the tests for celiac disease: Open Original Shared Link

 

The cyrex labs don't appear to use the above tests so I doubt their usefulness in getting you a diagnosis.  They won't tell you if you have celiac disease, and you already know that you are gluten sensitive... it could be a waste of money.

 

It is best if 6 or more samples are taken during a biopsy.  4 is the bare minimum and is sometimes not enough to detect damage in a celiac.  If the biopsy is not done right (not enough samples or samples not taken from the best locations) the sensitivity of the biopsy can fall to 80%, so 1 in 5 celiacs could be missed.... Do you have your biopsy report?  The people around here might be able to help you with it.  If there is Marsh 1 damage, you may be slipping into early celiac disease .

 

It is possible that you have non-celiac gluten sensitivity (NCGS), but since you have a sibling with celiac disease and have symptoms, I think you may be correct in suspecting celiac disease.  

 

Best wishes.

[tpchan85]

Thanks for your help!

 

I've spoken to a local private hospital and they are offering:

- TTG IGA + EMA IGA + Total IGA

- AGA IGA / IGG

- Genetic testing

 

Would this be a good course of action or should I try and find more comprehensive testing? Also if TTG IGA is normal and total IGA is normal, does that mean celiac is impossible?

[MsLindz]

Thanks for your help!

 

I've spoken to a local private hospital and they are offering:

- TTG IGA + EMA IGA + Total IGA

- AGA IGA / IGG

- Genetic testing

 

Would this be a good course of action or should I try and find more comprehensive testing? Also if TTG IGA is normal and total IGA is normal, does that mean celiac is impossible?

 

These would all be helpful testing, particularly the Total IGA and genetic testing. If you have the genes, it's much more likely that you could develop celiac disease. If the Total IGA test result is low, you would know that the other IGA tests will not be accurate for you.

 

As for the AGA test... I'm not sure how accurate or useful it would be.Open Original Shared Link:

 

 

 

Historically, a test for anti-gliadin antibody (AGA) was used in the evaluation of celiac disease. The 2013 American College of Gastroenterology guidelines recommend against this test for the primary detection of celiac disease due to concerns with its accuracy. It is inferior to the tests for anti-tTG and anti-DPG and should no longer be part of routine testing for celiac disease. The American Gastroenterology Association makes similar recommendations.

[nvsmom]

Thanks for your help!

 

I've spoken to a local private hospital and they are offering:

- TTG IGA + EMA IGA + Total IGA

- AGA IGA / IGG

- Genetic testing

 

Would this be a good course of action or should I try and find more comprehensive testing? Also if TTG IGA is normal and total IGA is normal, does that mean celiac is impossible?

 

The AGA IgA / IgG are older tests.  They aren't the best.  They will catch some celiacs but they can have a pretty high rate of false negatives.  The newer DGP tests are much better if you can get them.

 

Some celiacs' tTG IgA tests are negative.  Most will have a positive result but some don't - one of our moderators only had a positive DGP test.