Testing for Celiac Disease

There are a variety of tests available for celiac disease. Confirming a diagnosis of celiac disease is important, as there can be some implications of a confirmed diagnosis of celiac disease versus “gluten intolerance”. Patients with celiac disease are at risk for certain types of cancers, nutritional problems, and diminished bone density. Knowing for sure is very important as patients with a confirmed diagnosis of celiac disease require monitoring by a physician. Patients with celiac disease also need to be 100% gluten-free in regards to diet.

“Gluten intolerance”, also known as “non celiac wheat sensitivity”, causes people health issues or digestive distress when they are exposed to gluten. People with gluten intolerance do not have a confirmed diagnosis of celiac disease. Patients with gluten intolerance do not always need to be 100% gluten-free. Patients with gluten intolerance do not require the same level of monitoring that a patient with celiac disease would require. Both conditions can make people feel rather sick.  The symptoms of gluten intolerance can mimic other serious health issues, hence it is important to seek a formal opinion from a doctor.

Simply feeling better on a gluten-free diet does not constitute a diagnosis of celiac disease.

This has been shown in medical research. (Am J Gastroenterol 2011;106:508–514; Scand J Gastroenterol 2008;43:1311–1314.) Other health conditions including irritable bowel syndrome can improve on gluten-free diets.

Given these factors, formal testing is important. There are 2 types of tests for celiac disease. It is important to know that both are measuring the body’s response to gluten. In order for proper testing and confirmation of a diagnosis of celiac disease, the patient must be exposed to gluten.

1. Labs. A tissue transglutaminase antibody is most sensitive lab test for celiac disease. There are older antibody tests that are still available. We typically only use these older antibodies in certain clinical situations.

2. Biopsies of the small intestine. A biopsy of the small intestine enables the doctor to see how the small intestine is reacting to gluten. Biopsies of the small intestine are the most accurate test. The endoscopy will show breakdown of the intestine lining and the biopsy will show inflammation as well as breakdown of the intestine cells.  An adequate number of biopsies is required to make a proper diagnosis. Typically this is 6 specimens. Biopsies are taken during an upper endoscopy procedure.

I typically advise patients not to start a gluten-free diet until they have at least considered laboratory testing for celiac disease. If somebody is already on a gluten-free diet the standard labs and biopsies are rendered inaccurate. There is a genetic test we can do for celiac disease but this only rules out celiac disease it does not rule it in. Establishing a diagnosis of celiac in a patient already on a gluten-free diet requires the patient to ingest at least one serving of gluten per day for at least 4 weeks in order to measure the body’s response to gluten.

The bottom line is to consult with a physician on testing for celiac prior to starting a gluten free diet.

Video of me discussing these tests can be found here.