Gluten sensitivity confirmed by genetics and blood tests in irritable bowel syndrome

Gluten sensitivity is very common, much more common than celiac disease. However, both celiac disease and gluten sensitivity are often missed, ignored or misdiagnosed. It is widely accepted celiac disease affects approximately 1% of people worldwide. It is commonly accepted that between 3-4% of people previously diagnosed with irritable bowel syndrome (IBS) have undiagnosed celiac disease. Dr’s. Rodney Ford, Ken Fine and I believe that many more than this are gluten sensitive. We believe that the presence of an elevated serum gliadin antibody is indicative of gluten sensitivity in most people. We concede that such individuals often do not have “true celiac disease” as it is now strictly defined by presence of HLA DQ2 or DQ8, a positive IgA endomysial antibody test or tissue transglutaminase IgA antibody with characteristic small bowel biopsy. However, our experience is that such individuals commonly present with symptoms identical to those with celiac disease and these symptoms respond to a gluten free diet. Now, researchers from Germany provide their scientific data that validates what we have observed and have been writing about. In the July 2007 issue of Clinical Gastroenterology and Hepatology, Wahnschaffe et al., from Germany report that gluten sensitivity causes symptoms meeting criteria for diagnosis of diarrhea predominant irritable bowel syndrome (d-IBS) that responds to a gluten-free diet.

They confirmed their earlier studies that found approximately one third of patients with d-IBS have IgG anti-gliadin and/or tissue transglutaminase antibodies in absence of villous atrophy and celiac disease specific antibodies. In this study they confirmed that those positive for HLA DQ2 with elevated AGA IgG or TTG IgG respond to a gluten-free diet with significant improvement of d-IBS symptoms. Also of interest is their mention in the paper that they had previously noted a subgroup of d-IBS identified by presence of DQ2 who had increased antibodies to gliadin or tissue transglutaminase in duodenal aspirate (similar to those Fine reports in stool). They state that these people “might actually have latent/potential celiac disease and could profit from a gluten free diet.” In conclusion I quote the authors as follows “…serum IgG antibodies against gliadin or tissue transglutaminase in combination with HLA DQ2 expression are useful markers to identify a subgroup of patients with d-IBS who are likely to respond to a gluten-free diet.”

This study published in the peer reviewed clinical journal of the American Gastroenterological Association is, in my opinion, a landmark article confirming the broader spectrum of gluten sensitivity and benefit of continuing to use gliadin antibodies as a screening blood test for both very early celiac disease as well as non-celiac gluten sensitivity. The paper also provides support for the concept that the presence of gliadin and tissue transglutaminase antibodies in the intestinal fluid (duodenal aspirate or stool) indicates gluten sensitivity. The presence of these antibodies appears to be sign of gluten sensitivity at a much earlier state than the presence of such antibodies or more specific celiac disease antibodies in the blood, before advanced intestinal injury has occurred.

In my clinical experience, if gliadin antibodies are also normal in the blood but the suspicion of gluten sensitivity is high, especially if the patient has HLA DQ2 or DQ8, then stool antibody testing may be helpful. Also, duodenal biopsy is often helpful, especially if any of the celiac disease related antibodies are elevated, the patient has risk factors, or they have suggestive symptoms of gluten sensitivity, regardless of the blood test results.

I have found many but not all of my patients with suggestive symptoms of gluten sensitivity who have “normal” celiac blood work have elevated stool gliadin IgA antibodies (Enterolab), with or without elevated tissue transglutaminase IgA antibodies, especially those with HLA DQ2 or DQ8. These individuals invariably respond to a gluten free diet. I myself am such a person. I have also found many of these individuals have intestinal biopsies demonstrating increased numbers of intraepithelial lymphocytes, the earliest finding in celiac disease.

I have submitted an abstract of my findings to one our national GI societies. Dr. Ford has also submitted such data for publication. However, since we are both clinically based and are reporting our single gastroenterologist experiences, and we are now known to have a bias that non-celiac gluten sensitivity exists, our reports lacks the power or impact of larger research center based studies such as this study from Germany. Since Dr. Ken Fine has yet to publish his experience with stool antibody testing, though he has publicly disclosed preliminary results, stool antibody testing is not widely accepted but instead is considered suspect or unproven by most “celiac experts”. However, we are now seeing more research, especially from Europe, that supports the existence of a distinct clinical entity we are calling non-celiac gluten sensitivity (NCGS). This condition clearly affects a much larger group of people than the “hidden epidemic of celiac disease” believed to occur in one in one hundred people in the world. The next questions may not be does NCGS exist but exactly how common is it? Is it one in ten or closer to one in three? Stay tuned to www.thefooddoc.com for more exiting news about celiac disease and non-celiac gluten sensitivity as we journey together in search of a healthy gut, healthy life.

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Reference:
Wahnschaffe U. et al. Predictors of Clinical Response to Gluten-Free Diet in Patients Diagnosed With Diarrhea-Predominant Irritable Bowel Syndrome. Clinical Gastroenterology and Hepatology July 2007 5; (7): 844-850.