Post Celiac Diagnosis - Follow Up Labs

[MegS123]

Hi all! 
 

I was diagnosed with celiac disease in Oct of 2023 through blood work & then an endoscopy. At the time of diagnosis, my Endomysial Antibody IgA came back positive abnormal,  t-Transglutaminase (tTG) IgA was at 90 (negative 0-3, weak positive 4 - 10, positive >10) & Immunoglobulin A serum was 385 (normal range 87-352). 
 

I had a follow up set of labs done ~7 months into a gluten-free diet and my Endomysial Antibody IgA came back negative, my t-Transglutaminase (tTG) IgA was at 40 (> 15 = antibody detected) & Immunoglobulin A was 378 (normal range 47-310). 
 

I just had a second set of follow up labs done on Monday (~11 months into gluten-free diet) and received the below results. 
- TISSUE TRANSGLUTAMINASE AB, IGA = 16.5 (> 15 = antibody detected)

- IMMUNOGLOBULIN A = 366 (47-310 normal range) 

- TISSUE TRANSGLUTAMINASE AB, IGG = <1 (<15 no antibody detected) 

I haven’t been able to speak with my doctor yet so was wondering what others peoples thoughts / experiences have been with the below. 
 

1. My immunoglobulin A serum results are decreasing but in comparison to the other markers, it seems like it’s been taking longer to drop. Is this normal? 
 

2. The labs on Monday were the first time I’ve been tested for TISSUE TRANSGLUTAMINASE AB, IGG, which obviously came back negative. Has anyone else tested negative for this but still confirmed celiac? Maybe wishful thinking but wondering if there’s any way this could indicate I don’t have celiac 🙃???

 

Thanks!

[trents]

Welcome to the forum, @MegS123!

First, the immunoglobulin A is not a celiac diagnostic test per se. This is a measure of total IGA and if it is abnormally low, aka, "IGA deficiency", it will suppress individual celiac antibody test values such as the TTG-IGA and which can potentially result in false negatives. I do not know that there are any particular health issues associated with elevated immunoglobulin A. The important point from this score in the immediate context is that you are not IGA deficient so your individual IGA celiac antibody test scores should be reliable.

Second, IGG antibody tests are second tier celiac antibody diagnostic tests which can be helpful in catching those who actually do have celiac disease but who respond atypically to the IGA antibody tests which are considered first tier. But to your question, it is typical to not produce positive scores for all the various kinds of celiac antibody tests. If this were not so, why would we need more than one kind of test?

The big picture is that it seems you are being successful in eating gluten free.

Here is a primer for understanding the various kinds of antibody tests that can be used to detect celiac disease: 

 

[MegS123]

Thank you @trents!! This is helpful!