Gluten Intolerance Test
by Sarah
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Why would you consider a gluten intolerance test? If you notice you don’t feel well after eating wheat or grain products, you may have an intolerance to gluten. You may also have a long list of unexplained problems from joint pain and headaches to weight loss, brain fog and lethargy; in which case, you need to encourage your doctor to test for celiac disease so you can at least eliminate it as a possible explanation for your suffering.
Gluten is a protein composite found in the triticeae family of grassy grains; the most common and potent forms of gluten are found in wheat, barley and rye. Even if you avoid these grains, gluten is added to so many products that it can be very difficult to completely remove it from your diet. To find out if gluten is causing your symptoms, consider a gluten intolerance test.
To understand gluten better and learn just how pervasive it is in the western diet, see my article: What Is Gluten?
What Forms of Gluten Intolerance Testing Exist?
Conclusive results for a broad gluten intolerance are usually found by putting patients on an elimination diet to see if eliminating gluten relieves their issues. Doctors like to do before and after intestinal biopsies to be certain intestinal villi are recuperating as a result of the gluten-free diet.
However, this is not the first step. Blood testing and allergen testing is done first, as elimination diets can be risky if other issues are present. In addition, a gluten-free diet can reduce the biomarkers doctors use to confirm the presence of celiac disease, making a complete diagnosis very difficult.
Basically, once you remove gluten from your diet, your body produces less of the harmful antibodies triggered by gluten and the villi along the wall of your small intestine begin to heal. If your villi are healthy and you don’t have raised antibodies in your blood, you may test negative for celiac disease. So if you take steps to eliminate celiac disease symptoms on your own, you may also make it difficult to have your celiac disease diagnosed.
A panel of blood tests is done to determine if the patient is in fact suffering from Celiac Disease, a severe gluten intolerance. The primary blood panel for celiac disease involves testing for several antibodies (see the list below).
In some situations a doctor may also suggest an intestinal biopsy instead of a blood panel, though this is rare. Usually the blood panel comes first, followed by the intestinal biopsy for diagnosis confirmation.
Clinical Gluten Intolerance Tests
Gluten Intolerance Test
The following blood panel, measuring serum antibodies, is a must to test for celiac disease:
- Endomysial antibodies (EMA)
- Tissue transglutaminase antibodies (tTG)
- IgG tissue transglutaminase
- Total IgA antibodies
A more recently developed test also thought to be highly accurate (when combined with the above antibody tests) is a measurement of deamidated gliadin peptides (DGP).
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In addition, the following tests are often conducted by thorough doctors when evaluating patients for a non-celiac gluten sensitivity, a gluten intolerance or a verified case of celiac disease:
- Stool Fat test, to determine malabsorption level (test for Steatorrhea).
- Complete Blood count (CBC), to determine anemia.
- Erythrocyte Sedimentation Rate (ESR) to look for inflammation.
- C-Reactive Protein (CRP) to further watch for chronic inflammation.
- Vitamins A, D, E and K (the fat-soluble vitamins) to check for vitamin deficiency relating to malabsorption in the proximal small intestine.
- Comprehensive Metabolic Panel (CMP) to analyze protein, calcium and electrolyte levels as well as to check liver and kidney functions.
I’ve also had readers inform me that they’ve had doctors test and confirm a Non-Celiac Gluten Sensitivity (NCGS) with the gliadin IgG non-deaminated antibody test. I think many doctors and researchers would consider this celiac disease test alone to be a little too over-simplified, but at least some anecdotal evidence suggests otherwise.
Another test gaining steam in the research community is the Fecal Anti-Gliadin Antibodies test (fAGA), most prominently conducted and promoted by the Enterolab. However, corroborating research in peer review journals hasn’t been done yet. Anecdotal evidence among my readers suggests a high rate of success with this test, but again note that you may test negative if you’ve already subscribed to a strict gluten-free diet.
Genetic Testing For Celiac Disease
The most established genetic test is specific to celiac disease and not necessarily for a wheat allergy, a non-celiac gluten sensitivity or a broader gluten intolerance. But it can help either verify the presence of celiac disease or identify people who may be predisposed to developing celiac disease. Because it can be done in a non-invasive manner (a saliva swab is often enough), this celiac disease genetic test is often done for at-risk children.
The test looks for the HLA-DQ2 and HLA-DQ8 genes. If one or both genes are present, the individual is at far greater risk of developing celiac disease at some point in his or her life.
Please note, however, that is still possible (though relatively rare), to have these genes and not develop celiac disease. So this test is usually either to take preliminary steps in identifying and helping at-risk individuals (people who have celiac disease in their immediate family) or to help confirm a diagnosis begun with some of the tests listed earlier in this article.
Celiac Disease Is More Common Than Most Doctors Realize
Many doctors still consider celiac disease to be relatively rare (although current gluten intolerance statistics may suggest otherwise), so if the patient tests negative for the clinical test for celiac sprue disease, an allergen test is then done.
But please note that just because you test negative for celiac disease does not mean with certainty that you still do not have some form of gluten intolerance. It also does not preclude the possibility for a wheat allergy. For more on these distinctions, please read gluten allergy symptoms.
Note that as of March 2011, a gluten sensitivity may exist as its own clinical entity, separate from celiac disease. The only way to distinguish this form of gluten intolerance from celiac disease is to do an intestinal biopsy. This has become widely known as NCGS, for non-celiac gluten sensitive.
What is an Allergen Test?
This is usually a skin prick test, which allows a doctor to test for a variety of food and other allergies at once. If the skin prick test comes back positive for a wheat allergy, an elimination diet is then the next step. If it does not come back positive, more testing is done to rule out other illnesses or conditions that could cause similar symptoms.
An allergy is a type 1 hypersensitivity, not an autoimmune disease, so it is possible to have a wheat allergy but not have celiac disease, and vice versa.
After those tests are complete, if gluten intolerance is still the most likely culprit, an elimination diet is used to confirm this diagnosis. To help with this process, I suggest you visit my gluten-free pantry.
Once a gluten sensitivity is confirmed, a dietitian can help you devise a meal plan that minimizes your allergic reactions or damage done by gluten while still providing your nutritional needs. Gluten intolerance doesn’t have to be painful or difficult to manage, and a gluten intolerance test can help you determine if this could be the cause of your discomfort.
