Help understanding results - weak positive

[leah91]

Hi there, 

I recently had tests run for likelihood of coeliacs. My brother got diagnosed in 2022 and my mother and sister suffer from an intolerance. My sister since birth and my mother only during the time of pregnancy with my sister. 

I have had symptoms, bloating, change in stool, gas etc. and had an endoscopy done almost 2 years ago which found stomach damage (erosion). 

I got my TTG IgA - 4.6, but all references are slightly different saying this is immediately a negative, or a weak positive. Then TTg IgG - 3.8 which I believe is an immediate negative. 

With my family history and symptoms is it worth retesting? Or accepting this as a weak positive / negative ? 

As there are so many different references out there, I'm not sure what to make of it. 

 

Thank you!

[trents]

Welcome to the forum, @leah91!

Each lab uses different reference ranges for determining what negative vs. positive is for the celiac antibody blood tests since they each concoct the tests a little differently. So, in order to interpret the results you would have to know the reference range used by the lab who analyzed the blood sample.

Another factor here is that you do not mention if a "total IGA" test was run. If total IgA is low, it will suppress the value of the TTG-IGA test. A total IGA test should, therefore, always be run but it often isn't. I would ask for a total IGA to be done. Make sure you are eating plenty of gluten for weeks ahead of time.

You also mention that an endoscopy was done that found "erosion" in your stomach. Celiac disease damages the lining of the small bowel and the duodenum, the first part of the small bowel just below the stomach. The do use an endoscopy for that and take biopsies of the villous lining which are then sent to a lab for microscopic analysis to look for damage. If the damage is severe, it can often be seen with the scope, however. But it is damage of the small bowel lining that is the key, not of the stomach.

[leah91]

Hi, thanks you for your response and thank you for clarifying everything. I didn't have a total IGA test, but will definitely go do one now you've mentioned. Is it worth doing a retest of TTG at the same time? 

I don't remember them mentioning if they examined my small bowel, I believe they only went as far as my stomach at that time as we encountered some difficulties during the process, so it was quickly over and done. 

How much gluten a day is recommended to eat in the weeks running up? 

[leah91]

Sorry I forgot to answer. The results are only >10 positive and anything below negative for celiacs 

[trents]

The pretest gluten challenge recommended daily amounts of gluten consumption is 10g of gluten for at least 2 weeks leading up to the day of testing. That's the equivalent of 4-6 slices of bread and I would go for at least 3 weeks to be sure to get a valid test.