Celiac Disease and Gluten Intolerance Testing- Accurate or Misleading?

Monday, September 05, 2011 by: Julie McGinnis
Tags: celiac disease, gulten intolerance, health news

(NaturalNews) Jane G. made an appointment to see me after being diagnosed with Hashimoto's Thyroiditis (an autoimmune disease of the thyroid with links to celiac disease) and suffering from years of gastrointestinal issues. I reviewed Jane's medical history and found that not only does she have Hashimoto's and GI complaints, but she also suffers with inflammation in her joints and anemia (low iron). Suspecting that gluten intolerance was at the root of all these conditions, I suggested Jane adopt a gluten-free diet.

Immediately, I encountered resistance to this suggestion. Jane comes from an Italian-American family, and she lived for good Italian food. In order to even begin contemplating life without pasta and pizza, Jane really needed concrete medical evidence. I recommended that she undergo a new test from Cyrex Labs for gluten reactivity, complete with a comprehensive autoimmunity profile. Unfortunately, this test costs $369 and is not normally covered by insurance. Jane told me she could not afford that test or the appointment with a doctor outside her network. Instead, she made an appointment to get a Celiac Panel blood test done by her in-network physician.

When Jane's results came back negative, her physician told her that she did not need to follow a gluten-free diet. She was relieved and excited, but she also told me she knew something was still wrong because of her ongoing gastrointestinal symptoms. I convinced her to go gluten-free for two weeks and see if she felt any relief. By the end of the first week, her gastrointestinal symptoms had gone away. Her question to me then became, "Do I have gluten sensitivity? Was the test a false negative? What should I do?"

Blood Tests

The most common blood test requested by doctors is the Celiac Panel. This test measures both your immune system's response to gluten and whether there is damage to the intestinal tissue. The Celiac Panel consists of tests for the following: Anti-gliadin antibodies (AGA) for both IgA and IgG (IgA and IgG have a roll in controlling the immune system); anti-endomysial antibodies (EMA) -- IgA; anti-tissue transglutaminase antibodies (tTG) -- IgA, and total IgA level.

According to Dr. Thomas O'Bryan (an expert and lecturer about gluten intolerance), this test records a false negative 7 out of 10 times. These false negatives are due in part to the physician's interpretation as well as the patient's condition at the time of the test. Physicians may interpret the test as negative if the test for intestinal tissue damage (anti tTG and EMA) is negative -- even if the blood test results indicate a positive immune reaction. The intestinal tissue tests will only come back positive if there is severe damage or atrophy to this tissue -- the kind found in end-stage celiac disease. If there is only partial atrophy, the accuracy of this test goes down to 27-30 percent.

Another issue with the Celiac Panel test is that it does not account for those with IgA deficiency, which occurs 10 to 15 times more commonly among people with celiac disease than the general population. Patients with IgA deficiency will lack IgA antibodies, so this blood panel shows up negative. In addition, this panel only screens for one problematic portion of the gluten protein (alpha gliadin), when there are approximately 60 problematic portions. If you have an intolerance to one of the other 50+ proteins in gluten besides alpha gliadin, this test will also come back as negative. Dr. Vicki Petersen, author of The Gluten Effect, believes physicians are misdiagnosing 50 percent of the population according to these false negatives. As we are learning, there is a spectrum of gluten intolerance from slight to severe, and these tests do not pick up everyone's sensitivities.

Celiac Disease vs. Gluten Sensitivity

Dr. Alessio Fasano, MD, medical director of the Center for Celiac Research at the University of Maryland, does recommend that patients get blood tests for celiac disease; however, if those tests are negative, Dr. Fasano recommends getting tested for a traditional IgE-mediated allergy to wheat. If that test is also negative, he asks his patients to try a gluten-free diet for a period of 2-4 weeks and see if their symptoms abate. If they do, Dr. Fasano considers this lo-tech de facto positive result the best test of gluten sensitivity available today.

Dr. Fasano recently completed a research study that demonstrated gluten-sensitivity without the presence of celiac disease does exist. The research confirmed that gluten sensitivity is different from celiac disease at both the molecular level and in the immune system's response. Fasano and his co-authors have demonstrated that gluten sensitivity and celiac disease are part of a same spectrum of gluten-related disorders.

"Imagine gluten ingestion on a spectrum, said Dr. Fasano. At one end, you have people with celiac disease, who cannot tolerate one crumb of gluten in their diet. At the other end, you have the lucky people who can eat pizza, beer, pasta and cookies -- and have no ill effects whatsoever. In the middle, there is this murky area of gluten reactions, including gluten sensitivity. This is where we are looking for answers about how to best diagnose and treat this recently identified group of gluten-sensitive individuals."

Genetic Components

As an autoimmune disease, celiac disease is the consequence of the interplay between genes and the environment (gluten). Two genes, HLA DQ2 and/or HLA DQ8 are absolutely necessary to develop celiac disease. Since one third of the general population have one of these genes, the presence of DQ2 or DQ8 does not, by itself, mean that the person will develop celiac disease; rather, that they have a genetic predisposition for celiac disease. Dr. Kenneth Fine's research at Enterolab shows that there are several more genes linked to the possible development of celiac disease, gluten sensitivity, and other gluten-related conditions.

Stool and Salivary Tests

Other ways to test for celiac disease and gluten sensitivity include stool test and salivary tests. These tests can be ordered on-line and performed at home without a doctor ordering the test. Enterolab's unique test screens for gluten sensitivity, as well as for many other antigenic food sensitivities. Enterolab's method uses stool rather than blood as the testing substrate because the immunologic reactions to gluten proteins occur in the intestinal tract, and not in the blood. Enterolab's salivary test also identifies the presence of genes associated with celiac disease and gluten sensitivity. All you have to do is swab the inside of your cheek and send it in.

Small Intestine Biopsy

A more invasive test for celiac disease is small intestine biopsy. With other, less invasive, methods of testing available today, I do not recommend biopsies. In a recent study, Adherence to biopsy guidelines increases celiac disease diagnosis, led by Dr. Benjamin Lebwohl, MD, MS, a gastroenterologist at the Celiac Disease Center at Columbia University Medical Center, in New York found that 65 percent of patients undergoing a biopsy of the small intestine do not have the recommended number of samples (4) to diagnose celiac disease. The study, published in the July 2011 issue of Gastrointestinal Endoscopy, analyzed a national database of biopsy specimens. More than 100,000 patients had a biopsy of the small intestine, but only 35 percent of them had at least four samples taken, which is the number recommended by the American Medical Association. Adhering to the recommended four biopsy samples increases the rate of diagnosis of celiac disease seven-fold. According to Dr. Peter Green, Director of the Celiac Center Columbia University Medical Center, who was also a co-author on the paper, "In this study, we identified just one of the factors contributing to the high rate of under-diagnosis of celiac disease in the United States. We plan on studying other physician-related factors that may also be operative."

Jane G.

Today, Jane G. is doing well. Her GI complaints cleared up after one week on a gluten-free diet. She continued on the diet, and within a month, her energy levels improved and her joint pain was significantly reduced. She began to embrace her new way of life and realized that her anemia would take a little longer to resolve as her intestines healed and began properly absorbing nutrients again. However, her thyroid condition will remain, because once that sort of damage is done to an organ via an autoimmune response, it is hard to recover. Still, in most cases, preventing the body from attacking itself will stop the condition from getting worse.

To Test or Not to Test: Let Your Body Be Your Guide

If testing for gluten sensitivity helps you feel confident that you are doing the right thing and not overlooking any additional health problems, then test away; however, if going gluten-free makes you feel better, then don't worry about your test results. The slightest sensitivity to gluten can cause many health problems and the only definitive way to rid yourself of them is to stop eating gluten.

If you think you might be gluten sensitive, but you're not sure, there is a useful questionnaire at Health Now Medical that can help you get started. Also, visit thegluten free girl for a complete list of safe and forbidden foods plus a list of medications and health problems associated with gluten sensitivity.

About the author:
Julie McGinnis, M.S., R.D., certified herbalist holds a Master's degree in nutrition from the University of Bridgeport in Connecticut and has been involved in the field of nutrition for twenty years. Upon completion of her herbal certification she began her career in complementary health and worked for years in research and development for a professional line of nutrition supplements. She has written professional nutrition and health literature for national retailers and other small businesses. She is one of three owners of The Gluten Free Bistro in Boulder, CO a manufacturer of gluten-free pizza, pasta and flour.www.theglutenfreebistro.com