Test interpretations

[MicG]

Test results as follows:

Deamidated Gliadin Abs, lgA 40 H (normal range 0-19)

Deamidated Gliadin Abs, IgG 4 (0-19)

t-Transglutaminase (tTG) IgA <2 (0-3)

t-Transglutaminase (tTG) IgG <2 (0-5)

Endomysial Antibody IgA Negative (Negative)

Immunoglobulin A, Qn, Serum 535 H (87-352)

Do I have celiac?

[trents]

Possibly. Your total IGA (Immunoglobulin A, Qn, Serum) is actually high so you are not IGA deficient. In the absence of IGA deficiency, the most reliable celiac antibody test would be the t-Transglutaminase (tTG) IgA for which your score is within normal range. There are other things besides celiac disease that might cause an elevated DGP-IGA (Deamidated Gliadin Abs, lgA) for which you do have a positive score. It might also be of concern that your total IGA is elevated as that can indicate some other health problems, some of which are serious. 

Had you been practicing a gluten free or a reduced gluten free diet prior to the blood draw?

Talk to your physician about these things. I would also seek an endoscopy/biopsy of the small bowel to check for damage to the villous lining, which is the gold standard diagnostic test for celiac disease.

[MicG]

I had been eating reduced gluten until about 3 days before the test. I did realize that wasn’t ideal, but it was experimental to see if gluten was actually bothering me. One slip up with soy sauce and it was quite clear to me that it was, lol. 

[trents]

Since you compromised the validity of the antibody testing by experimenting with gluten withdrawal ahead of the testing, you are faced with two options:

1. Reintroduce significant amounts of gluten into your diet for a period of weeks, i.e., undertake a "gluten challenge". The most recent guidelines are the daily consumption of at least 10g of gluten (about the amount found in 4-6 slices of wheat-based bread) for at least two weeks leading up to the day of testing. Note: I would certainly give it more than two weeks to be sure.

2. Be willing to live with the ambiguity of not knowing whether gluten causes you problems because you have celiac disease or NCGS (Non Celiac Gluten Sensitivity). There is no test for NCGS. Celiac disease must first be ruled out and we have tests for it. Celiac disease has an autoimmune base. NCGS does not. GI symptoms overlap. In the early stages of celiac disease, other body systems may not be showing stress or damage so, symptomatically, it would be difficult to distinguish between celiac disease and NCGS. Both conditions require elimination of gluten from the diet for symptom relief. Some experts feel that NCGS can be a precursor to celiac disease.

Edited March 5 by trents

[Scott Adams]

Based on those results alone, it’s not possible to say you have celiac disease. The test that is usually most specific for celiac, tTG-IgA, is negative in your results, and the endomysial antibody (EMA) is also negative, which generally argues against active celiac disease. However, your deamidated gliadin IgA is elevated, and your total IgA level is also high, which can sometimes affect how the other antibody tests behave. Another important factor is that you were reducing gluten before the test, which can lower antibody levels and make the results less reliable. Because of that, many doctors recommend a gluten challenge (eating gluten regularly for several weeks) before repeating blood tests or considering an endoscopy if symptoms and labs raise concern. It would be best to review these results with a gastroenterologist, who can interpret them in context and decide whether further testing is needed.

[Dr. Gunn]

Have you had celiac genetic risk testing? A celiac genetic test is accurate with or without gluten in your diet. If you don't carry the celiac risk genes you can effectively rule out celiac disease for life. 

[trents]

What Dr. Gunn states is essentially true. It is a rule out measure. But be aware that to possess either of the two primary genes that have been identified with celiac disease (or both) doesn't necessarily mean that you have or will develop celiac disease. Almost 40% of the general population carries one or both but only about 1% of the general population will develop active celiac disease. It remains latent until triggered by some stress event which may or may not occur. So, there is a genetic component to celiac disease but there is also an epigenetic component. 

[Dr. Gunn]

Exactly! Negative genetics can rule out celiac disease with close to 100% certainty. It takes tTg antibody testing and biopsy confirm the diagnosis in a genetically susceptible individual.