Question About Ttg Iga

[Jdorrferball]

My daughter, 16, was having some extreme fatigue and the doc ran some tests and found her ferritin level to be only 3. I talked him into some tests for celiac since I am suspicious of celiac in myself. Her tTG IGA was 8.6. According to the lab value less than 20 is negative. I have seen other labs say less than 4 is negative and that 8.6 would be a weak positive. Can anyone shed some light on the difference in lab interpretations? We just don't have any explanation for such a low ferritin level in her. Thanks for your help!

[RMJ]

There are no official standards for the tTG IgA antibodies, so each lab prepares their own and assigns their own arbitrary units. I posted more about this in a different thread.

https://www.celiac.com/forums/topic/105883-comparing-results-with-difference-reference-ranges/

[Jdorrferball]

Hmm...I understand what you are saying in the post you linked to. But something about that just doesn't sit right. Still trying to wrap my brain around it

[Triomam]

Hmm...I understand what you are saying in the post you linked to. But something about that just doesn't sit right. Still trying to wrap my brain around it

Here in the UK I believe over 4 it becomes a possibility. Over 9 they start to consider a biopsy is considered....I'm not yet diagnosed as I'm waiting for my biopsy results....but my TTG IGA is over 300.

Hope you get sorted.

[GottaSki]

The reference ranges vary between labs.  The range indicates what is normal or negative for the method used to tests the antibodies.

 

If you fall higher than the reference range it is a positive.  As long as you have the ref range and result for your antibody tests, you have all the data needed.

 

You cannot compare your result to another lab's reference range.

 

Hope that is clear.

[pocahontas30]

My kids had some of the same results on their bloodwork. The pediatrician said they meant my daughter was negative for celiac, but the gastroenterologist looked at the results and said "we need to do more tests" because her results of IgA were too low to quantify anything. He said that some people who have celiac don't produce enough IgA to even test anymore. Hope that helps.

My daughter, 16, was having some extreme fatigue and the doc ran some tests and found her ferritin level to be only 3. I talked him into some tests for celiac since I am suspicious of celiac in myself. Her tTG IGA was 8.6. According to the lab value less than 20 is negative. I have seen other labs say less than 4 is negative and that 8.6 would be a weak positive. Can anyone shed some light on the difference in lab interpretations? We just don't have any explanation for such a low ferritin level in her. Thanks for your help!