blood tests for celiac

[Judi Magner]

My ND did a blood test that shows I am positive for both DQ2 and DQ8. It says greater than 95% of celiac patients are positive for either of these. I have been gluten free for about 10 years so an endoscopy always shows negative for celiac. Is there a genetic test that would confirm this diagnosis?

[trents]

56 minutes ago, Judi Magner said:

My ND did a blood test that shows I am positive for both DQ2 and DQ8. It says greater than 95% of celiac patients are positive for either of these. I have been gluten free for about 10 years so an endoscopy always shows negative for celiac. Is there a genetic test that would confirm this diagnosis?

Welcome to the forum, Judi Magner!

The only genetic test available at this time for celiac disease is the one you have already had done. It does not diagnose active celiac disease but only establishes the potential to develop active celiac disease. About 40% of the population have one or more of these two genes but only about 1% of the population experience the active form. There are two test modes available at this time to establish the presence of active celiac disease. One test mode involves the detection of serum antibodies that celiac disease inflammation in the small bowel lining typically produces. The other is the biopsy with microscopic examination of the small bowel lining for damage caused by that inflammation. Typically, the biopsy is done in response to positive antibody scores and serves the purpose of confirmation. However, it is sometimes the case that individual immune systems respond atypically and active celiac disease does not produce the expected antibodies such that the disease is confirmed by biopsy if celiac symptoms warrant further investigation. Both test modes can be and often are invalidated by beginning the gluten free diet for some weeks previous to testing since this allows for the abatement of the inflammation and healing of the SB lining to take place.

It is unfortunate that many doctors neglect (or don't know enough) to advise their patients to continue to consume regular amounts of gluten for 6-8 weeks preceding the serum antibody testing and for two weeks preceding the endoscopy/biopsy. It is also the case that many seeking a diagnosis are made so ill by gluten that they medically and physically cannot continue consuming gluten before testing is complete.

At this point, your only option would be to resume the consumption of gluten for 6-8 weeks if you want to distinguish whether or not you have celiac disease or NCGS (Non Celiac Gluten Sensitivity).

[Scott Adams]

A genetic test would give you your probability for having celiac disease, and I to am positive for DQ2 and DQ8--I believe people with both markers have an ~15% of getting celiac disease--but to confirm the diagnosis would require a gluten challenge for at least 6-8 weeks for the blood tests, and at least 2 weeks for a biopsy: