IGA deficiency?

[Cloe]

Hi everyone, I just recently had a blood test for celiac and my IGA level came back as  < 0.2 u/mL. Does anyone know if this is deficiency or in the normal range? Thanks!

[trents]

Welcome to the forum, Cloe!

Which IGA test do you refer to? There is more than one. Is this tTG-IGA you are referring to? DGP IGA? Total serum IGA? If so, we would need the range used by that lab to specify what is normal since every lab formulates their own tests and uses their own scale. There is no industry standard. Please post the information you have exactly as it is reported. Were there other tests non IGA tests run for celiac disease? If by some chance you live in the UK we can probably narrow that down.

Had you been eating regular amounts of gluten for weeks/months up to the time of the blood draw?

https://celiac.org/about-celiac-disease/screening-and-diagnosis/screening/

Edited July 27, 2023 by trents

[Cloe]

Thanks so much for your message! 

Yes it was the IgA Tissue Transglutaminase Ab and my result was:

< 0.2 U/ml

Range:0 - 10 U/ml

This is the only test I've had and I haven't heard anything from the doctor so wasn't sure what this meant? Thanks a lot for your help!

[trents]

It means you tested negative for celiac disease on that particular test.

Had you been eating regular amounts of gluten in the weeks and months leading up to the blood draw. Cutting back on gluten prior to testing will sabotage the test results.

If you don't have celiac disease but have celiac-like symptoms then you could have NCGS (Non Celiac Gluten Sensitivity).

[Scott Adams]

Did they do a Total IgA test as well? 

This article might be helpful. It breaks down each type of test, and what a positive results means in terms of the probability that you might have celiac disease. One test that always needs to be done is the IgA Levels/Deficiency Test (often called "Total IGA") because some people are naturally IGA deficient, and if this is the case, then certain blood tests for celiac disease might be false-negative, and other types of tests need to be done to make an accurate diagnosis. The article includes the "Mayo Clinic Protocol," which is the best overall protocol for results to be ~98% accurate.

 

 

[Cloe]

3 hours ago, trents said:

It means you tested negative for celiac disease on that particular test.

Had you been eating regular amounts of gluten in the weeks and months leading up to the blood draw. Cutting back on gluten prior to testing will sabotage the test results.

If you don't have celiac disease but have celiac-like symptoms then you could have NCGS (Non Celiac Gluten Sensitivity).

Ok thank you! Yes I had still been eating gluten leading up to the test so it should be accurate. It looks as though it could be  NCGS then, thanks again!

[Cloe]

31 minutes ago, Scott Adams said:

Did they to a Total IgA test as well? 

This article might be helpful. It breaks down each type of test, and what a positive results means in terms of the probability that you might have celiac disease. One test that always needs to be done is the IgA Levels/Deficiency Test (often called "Total IGA") because some people are naturally IGA deficient, and if this is the case, then certain blood tests for celiac disease might be false-negative, and other types of tests need to be done to make an accurate diagnosis. The article includes the "Mayo Clinic Protocol," which is the best overall protocol for results to be ~98% accurate.

 

 

Thanks so much for your message and the article! This is super helpful  They haven't done a Total IGA  I don't think. There was a comment under my result that said if I'm IGA deficient they'll do a total IGA, but I wasn't sure if that applied to me and what is considered IGA deficient? 

[trents]

21 minutes ago, Cloe said:

Thanks so much for your message and the article! This is super helpful  They haven't done a Total IGA  I don't think. There was a comment under my result that said if I'm IGA deficient they'll do a total IGA, but I wasn't sure if that applied to me and what is considered IGA deficient? 

I'm not sure if there is an industry standard range for total serum IGA. Each individual lab may develop it's own test for that one as is the case for the individual IGA antibody tests. So, you might need to ask that question of the lab that does the evaluation.

[RMJ]

The total IgA test is standardized and is reported as an absolute amount, although the normal ranges vary a little from lab to lab and are also different for children of different ages.

The only way to know if someone is IgA deficient is to do a total IgA test.

[Cloe]

5 hours ago, RMJ said:

The total IgA test is standardized and is reported as an absolute amount, although the normal ranges vary a little from lab to lab and are also different for children of different ages.

The only way to know if someone is IgA deficient is to do a total IgA test.

Thanks for your response! Recently they've changed it in the UK and this is the message they posted : 

 From 27/07/22 you will no longer automatically receive a total serum Immunoglobulin A concentration with every coeliac serology request.

Currently our first line screen consists of two assays: a total IgA serum concentration measurement [IgA] and an IgA-tissue Transglutaminase (IgA-tTG) antibody test.  We (and many others) have found that the IgA-tTG antibody assay data (RU value) can be used to predict which serum samples actually require a total serum IgA measurement (this data is available on request from Immunology).

Any serum sample that is flagged as having a low RU value will automatically receive a total IgA measurement. If the total serum IgA concentration is <0.2 g/L the usual IgG serology assays (IgG-tTG/IgG-EMA) will be reflexed, as already occurs for any patients with a serum total IgA concentration of <0.2g/L.

This will allow us to reduce unnecessary total IgA measurements by >95% resulting in significant efficiency savings.

[trents]

What is a "RU value"? Are they saying that any initial negative for the tTG-IGA will trigger a reflexive total serum IGA?

[RMJ]

RU might be something like relative units, since the units for the TTG-IgA aren’t absolute.

What’s strange is that you’re at the bottom of the range and they didn’t do total IgA. It could be that 0.2 RU in the TTG-IgA test is the limit of quantitation, and they do have a lower number that is between the limit of detection and the limit of quantitation, and they use that unreported number to decide whether or not to do the total IgA test.