I was fortunate to be able to attend the International Celiac Disease Symposium (ICDS) in Chicago last week, during which I was able to hear lectures given by world expert doctors, researchers, and nutritionists. Although I got home 3 days ago, my mind is still spinning from all of the information that I learned and tried to absorb during the 22 hours of lectures. I was also fortunate to meet some awesome people from the Celiac internet community, including Erica from Celiac and the Beast, Rebecca from Pretty Little Celiac, G-Free Laura, and The Gluten-Free Professor. Although I was not one of the official bloggers from the conference, I did learn some information that I’d like to share with you.
Over the next few weeks I plan to summarize much of the information that I learned about both Celiac Disease and Non Celiac Gluten Sensitivity (NCGS) at the symposium, as well as to try to convince you to attend the next ICDS in Prague in 2015 with me, as my dear husband has already declined.
On Sunday night there was a pre-conference on NCGS with a panel of speakers who are world’s experts on NCGS. I am very interested in this topic as I have several family members who have NCGS and I am amazed by the lack of awareness of this condition in the medical community. There are many doctors who believe that you cannot get sick from gluten unless you have Celiac Disease (intestinal damage) and as you may already know, this is not true!
The experts who presented information about NCGS included Drs. Fasano, Green, Kelly, Mooney, Volta, Schuppan, and Leffler. Below is a summary of some of the information that was shared with the audience:
Patients with NCGS experience adverse symptoms after ingesting gluten but they do not meet the criteria for getting diagnosed with Celiac Disease (namely, they do not have the findings of Celiac Disease on small bowel biopsy). NCGS is a “diagnosis of exclusion” meaning that, ideally, Celiac Disease is ruled out before a diagnosis of NCGS is given. Despite this, many with NCGS are self-diagnosed.
Between 0.5 to 6% of U.S. population has NCGS, depending on which study is referenced. The average age of diagnosis is around 40 years, but the research on NCGS is really still in its infancy. Some patients with NCGS have abnormally high antibodies that are associated with Celiac Disease, such as TTG IgA and/or anti-gliadin antibodies, and others do not. About half of patients with NCGS have one of the two main Celiac genes (HLA-DQ2 and/or DQ8) and half do not. There are currently no biomarkers for NCGS, which plays a large part in the difficulty of diagnosis.
In a large Italian survey, the most common symptoms associated with NCGS included abdominal pain, bloating, diarrhea, fatigue, headache, anxiety, and a “foggy mind.” This mirrors the symptoms that have been described in previous studies.
Dr. Green introduced the acronym PWAWG which stands for People Who Avoid Wheat and Gluten. According to Dr. Green, not all PWAWGs have NCGS, and many have other problems such as small intestinal bacterial overgrowth (SIBO) and fructose intolerance. In one recent study, which has gotten a lot of attention, many NCGS patients’ reactions to gluten totally disappear when FODMAPs are also removed from the diet (see link to paper in references below). However, the researchers only looked for a resolution of abdominal and digestive symptoms and we do not know if other symptoms of NCGS, such as headaches and anxiety, also improved when FODMAPs were removed. More research is needed in this area. Although I will discuss FODMAPs more in the upcoming weeks, you can refer to Stanford’s website for more information on the low FODMAP diet if interested.
I learned that both autism and schizophrenia have been associated with anti-gliadin antibodies. There was a publication in 2011 that showed that there is subset of autistic children whose symptoms improve on a gluten free and casein free diet. There are also ongoing clinical trials to see if the GF diet can help improve symptoms associated with schizophrenia. The tissue transglutaminase antibody (TTG) type 6 looks to be a marker of neuroinflammation and is a possible biomarker for schizophrenia. TTG type 2 antibodies are what are currently measured in blood tests for Celiac Disease.
The pathogenesis of NCGS appears to involve the innate immune system and it is possible that wheat amylase trypsin inhibitors (ATIs), a totally different portion of wheat than the gluten proteins, may be involved. I wrote about this a bit last winter (see link) and the article referenced can be found in the references below.
During the panel discussion, we were reminded that the only way that a NCGS individual who is already GF can find out if he or she has Celiac Disease is to undergo a “gluten challenge.”
One of the last questions to the panel was, “Who should be avoiding gluten?” The answer given was patients with Celiac Disease, NCGS, and possibly autism and schizophrenia.
I also learned that Dr. Fasano recently published a book called “A Clinical Guide to Gluten-Related Disorders,” which I plan to purchase a copy of ASAP. It is available on Amazon.com (see here).
Dr. Fasano reminded us that there is currently more confusion than understanding of NCGS, and that it is similar where we were with understanding Celiac Disease 20 to 30 years ago. The great thing is NCGS is finally being recognized and properly studied!
For a great overview of NCGS, please check out the following abstract from PubMed by Dr. Volta, who was one of the experts on NCGS at the symposium:
Volta U, Caio G, Tovoli F, De Giorgio R.Cell Mol Immunol. Non-celiac gluten sensitivity: questions still to be answered despite increasing awareness. 2013 Sep;10(5):383-92. doi: 10.1038/cmi.2013.28. Epub 2013 Aug 10.
Recently, the increasing number of patients worldwide who are sensitive to dietary gluten without evidence of celiac disease or wheat allergy has contributed to the identification of a new gluten-related syndrome defined as non-celiac gluten sensitivity. Our knowledge regarding this syndrome is still lacking, and many aspects of this syndrome remain unknown. Its pathogenesis is heterogeneous, with a recognized pivotal role for innate immunity; many other factors also contribute, including low-grade intestinal inflammation, increased intestinal barrier function and changes in the intestinal microbiota. Gluten and other wheat proteins, such as amylase trypsin inhibitors, are the primary triggers of this syndrome, but it has also been hypothesized that a diet rich in fermentable monosaccharides and polyols may elicit its functional gastrointestinal symptoms. The epidemiology of this condition is far from established; its prevalence in the general population is highly variable, ranging from 0.63% to 6%. From a clinical point of view, non-celiac gluten sensitivity is characterized by a wide array of gastrointestinal and extraintestinal symptoms that occur shortly after the ingestion of gluten and improve or disappear when gluten is withdrawn from the diet. These symptoms recur when gluten is reintroduced. Because diagnostic biomarkers have not yet been identified, a double-blind placebo-controlled gluten challenge is currently the diagnostic method with the highest accuracy. Future research is needed to generate more knowledge regarding non-celiac gluten sensitivity, a condition that has global acceptance but has only a few certainties and many unresolved issues.
Additional References from ICDS pre-conference:
1. DiGiacomo, et al. Prevalence of gluten-free diet adherence among individuals without celiac disease in the USA: results from the Continuous National Health and Nutrition Examination Survey 2009-2010. Scand Journal Gastroenterol. 2013 Aug;48(8):921-5. doi: 10.3109/00365521.2013.809598. Epub 2013 Jul 8.
2. Biesiekierski JR, Newnham ED, Irving PM, Barrett JS, Haines M, Doecke JD, et al. Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial. Am J Gastroenterol 2011;106:508–14.
3. Biesiekierski JR., et al. No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates. Gastroenterology. 2013 Aug;145(2):320-8.e1-3. doi: 10.1053/j.gastro.2013.04.051. Epub 2013 May 4.
4. Junker, et al. Wheat amylase trypsin inhibitors drive intestinal inflammation via activation of toll-like receptor 4. J Exp Med. 2012 Dec 17;209(13):2395-408. doi: 10.1084/jem.20102660. Epub 2012 Dec 3.