QUESTION ABOUT TESTING AND DIAGNOSIS

[CPV]

Hello. After months of tummy trouble, finally got (blood) tested this week.

All the tests were negative or in the normal range except for the T-TRANSGLUTAMINASE (TTG) IGA.

That was a 4, which put me on the low side of a weak positive.

Also, my IMMUNOGLOBULIN A was 420 (a bit on the high side).

Will talk with my doctor next week, but wanted to see if anyone had any thoughts about

whether I have Celiac or not.

Thanks.

[trents]

First, it needs to be asked, were you already trying to eat gluten free when you had the test done? If so, that can cause negative results.

Second, the TTG_IGA is considered to be the best serum antibody test for celiac disease. It is the most specific but not the most sensitive. So, generally, when that one is positive, even a weak positive, it means you do have celiac disease. But you may also have NCGS (Non Celiac Gluten Sensitivity).

You need to consider the gold standard test for disease and that is an endoscopy with a biopsy of the small bowel lining. Celiac disease damages the lining of the small bowel (the "villi") whereas NCGS does not, even though symptomatically they are very similar. So, the biopsy is used to distinguish between the two. But again, if you decide to pursue an endoscopy/biopsy you must still be eating gluten for the results to be valid.

[CPV]

9 minutes ago, trents said:

First, it needs to be asked, were you already trying to eat gluten free when you had the test done? If so, that can cause negative results.

Second, the TTG_IGA is considered to be the best serum antibody test for celiac disease. It is the most specific but not the most sensitive. So, generally, when that one is positive, even a weak positive, it means you do have celiac disease. But you may also have NCGS (Non Celiac Gluten Sensitivity).

You need to consider the gold standard test for disease and that is an endoscopy with a biopsy of the small bowel lining. Celiac disease damages the lining of the small bowel (the "villi") whereas NCGS does not, even though symptomatically they are very similar. So, the biopsy is used to distinguish between the two. But again, if you decide to pursue an endoscopy/biopsy you must still be eating gluten for the results to be valid.

Thank you for your timely and highly informative answer. Wasn't on a gluten free diet at the time of the testing. Suspect you are right and that a biopsy may be in my future. Again, much appreciated 🙏