A team of medicalresearchers recently set out to examine gene-environmental interactionsin the pathogenesis of celiac disease. The research team was made up ofA. Kondrashova, K. Mustalahti, K. Kaukinen, H. Viskari, V. Volodicheva,A. M. Haapala, J. Ilonen, M. Knip, M. Mäki, H. Hyöty, T. E. Group.Finland and nearby Russian Karelia have populations that eat about thesame amounts of the same grains and grain products. The two populationsalso have a high degree of shared genetic ancestry. The only majordifference between the populations of the two areas lies in theirsocioeconomic conditions.

The region of Russian Karelia ismuch poorer than the neighboring areas in nearby Finland. Thesanitation levels in Russian Karelia are also distinctly inferior thanthey are in Finland. The researchers compared the prevalence of celiacdisease and predisposing human leukocyte antigen (HLA) alleles inpopulations from Russian Karelia and Finland. The team performedscreening for tissue transglutaminase antibodies (tTG) and HLA-DQalleles on 1988 school-age children from Karelia and 3654 children fromFinland. Children with transglutaminase antibodies were encouraged tohave a duodenal biopsy.

Interestingly, the patients fromRussian Karelia showed tTG antibodies far less often than their Finnishcounterparts (0.6% compared to 1.4%, P = 0.005). The patients fromRussian Karelia also showed Immunoglobulin class G (IgG) antigliadinantibodies far less frequently than their Finnish patients (10.2%compared to 28.3%, P<0.0001).

The researchers confirmed adiagnosis of celiac disease by duodenal biopsy in four of the eighttransglutaminase antibody-positive Karelian children, for an occurrencerate of 1 in 496 versus 1 in 107 Finnish children.

In bothgroups, the same HLA-DQ alleles were associated with celiac disease andthe presence of transglutaminase antibodies. The patients from RussianKarelia showed a much lower prevalence of transglutaminase antibodiesand celiac disease than the Finnish children. 

The poorconditions and inferior hygienic conditions in Russian Karelia mightprovide some kind of protection against the development of celiacdisease. The value of studies like this aren’t to make us wax nostalgicfor poverty, or to encourage people to fend off celiac disease bybecoming poor and living in squalid conditions. The value of a studylike this lies in the idea that there may be more to the development ofceliac disease than simple biological factors. That environmentalconditions might play a key role in both the frequency ofceliac-related antibodies, and in the development of the disease itselfis quite intriguing and clearly warrants further and more comprehensivestudy.

Ann Med. 2008;40(3):223-31.

The mechanism by which these peptides move without being broken down has remained unknown. It now looks like scientists have isolated a culprit in the transport of gliadin peptides (in the form of intact gluten particles) across the intestinal barrier.

In people who can tolerate wheat well, gluten is completely broken down, or at least broken down to the point where it won’t provoke an adverse reaction from the person’s immune system. In celiac disease, it seems that certain types of gliadin proteins, notably peptide 31-49 (P31-41), trigger an adverse innate immune response. P31-41 is common to the N-terminus of the A-gliadins and is known to be toxic to people with celiac disease.

The movement of intact gluten particles, particularly peptide 31-49 (P31-41) and the 33-mer gliadin, across the gut barrier is a trigger for the abnormal immune response in celiacs. Until now, the exact mechanism responsible for the movement of undigested gliadin particles across the intestinal barrier remained unknown. The research team showed that a particular receptor, the transferrin receptor CD71 is responsible for the movement of intact gliadin fragments/peptides across the intestinal barrier.

The team of researchers was made up of Tamara Matysiak-Budnik,  Ivan Cruz Moura,  Michelle Arcos-Fajardo,   Corinne Lebreton, Sandrine Ménard, Céline Candalh, Karima Ben-Khalifa ,  Christophe Dugave,  Houda Tamouza, Guillaume van Niel, Yoram Bouhnik, Dominique Lamarque,  Stanislas Chaussade, Georgia Malamut,  Christophe Cellier,  Nadine Cerf-Bensussan, Renato C. Monteiro, and Martine Heyman.

The team undertook the study to help them better understand how undigested gluten is able to migrate across the gut barrier. The size of the study was 53 individuals. The study group looked at 26 patients with active celiac disease, 13 patients who had been following a gluten-free diet for at least 12 months, 4 patients with refractory celiac sprue, and 10 people who were free of celiac disease.

In determining eligibility for the study, the standard for diagnosis of celiac disease was villous atrophy and positive serum tests for anti-gliadin, anti-Tgase, and endomysium IgA antibodies. The standard for refractory celiac sprue was resistance to a gluten-free diet, and persistence of villous atrophy when anti-gliadin IgA anti-bodies were not present. All control subjects were given a routine endoscopy, during which 4-6 consensual biopsy samples were taken, and determined to be free of celiac disease.

Even in people with celiac disease, larger gliadin peptides, like the p57-68 are completely broken down before being transported across the intestinal barrier. Smaller peptides like the like the peptides 31-49 (P31-41), and the 3-mer gliadin peptide, manage to cross the intestinal barrier intact.

Immuno-fluorescence studies revealed that patients with active celiac disease showed greater amounts of IgA at the apical pole of the surface epithelium, while control group and patients with treated celiac disease showed that IgA was isolated in the crypts, and did not appear in the villous epithelium. In people with active celiac disease, CD71 gets over-expressed on the apical pole, while on treated celiacs on a gluten-free diet show normal CD71 expression. For folks with refractory sprue, CD71 gets over-expressed in those individuals with flattened over-proliferation mucosa.

The high rates of binding at the apical surface of enterocytes in patients with active celiac disease indicate that the transferrin receptor CD71 plays a significant role in celiac disease.

JEM VOL. 205, January 21, 2008

Celiac.com 02/10/2008 - Researchers have found a 10mer durum wheat peptide capable of shifting a Th1 gluten-intolerant T cell response to a Th2 gluten-tolerant T cell response in intestinal T cell cultures derived from celiac disease children and incubated with deamidated gliadin peptides.  Durum wheat peptides could potentially treat celiac disease by causing celiac disease associated T cells to react tolerantly to gluten.

In the study, incubation of the T cell cultures with deamidated gliadin peptides resulted in a significant increase in T cell proliferation and interferon-gamma release.  Simultaneous exposure to duram wheat peptides totally abolished the cell proliferation and cytokine release while maintaining an elevated release of interleukin-10 (IL-10).

The workings of the immune system are too complex to discuss here in detail.  Basically when a "pre-helper" CD4-type T cell is presented with an epitope from an antigen (gliadin), the T cell becomes activated and responds to the stimulus by becoming either a type 1 or type 2 helper T cell which in turn releases different subsets of cytokines.  The Th1 path promotes mucosal tissue destruction in celiac disease while the Th2 path initiates proliferation of gluten and tTGase antibodies.  Th1 and Th2 cytokines each have properties which act in a feedback loop to suppress, limit, and regulate each other's cytokine secretions, i.e. Th1 cytokines suppress Th2 cytokine secretion and vice vesa.

Overactivity of either a Th1 or a Th2 response can result in an autoimmune condition.  Researchers theorize that balancing Th1/Th2 response can ameliorate and control symptoms and disease progression in at least some autoimmune diseases.  Th1 response includes release of the cytokine interferon-gamma which differentiates and activates macrophages.  Th2 response can include the release of IL-10, a cytokine which suppresses inflammation and promotes antigen tolerance.  Various molecules have been demonstrated to shift Th1/Th2 response in various autoimmune disorders.  In the durum wheat study, the presence of the durum wheat peptide in the gliadin peptide incubated celiac intestinal T cell culture increased Th2 IL-10 release and stopped T cell proliferation and Th1 interferon-gamma release.  Hence, this durum wheat peptide may be useful as a celiac disease therapy.  How effective this treatment may be is unknown at this time. 

Below is an example of sodium benzoate being used to shift Th1 to Th2 response in a mouse model of multiple sclerosis which improved symptoms and disease progression when fed to the mice orally.  This suggests that the durum wheat peptide could potentially treat celiac disease by simply being administered as an oral supplement.  However, if a probiotic bacteria could be genetically engineered to continuously secrete a form of this durum wheat peptide in the gut, this could result in essentially a "cure" for celiac disease if the durum wheat peptide proves effective.

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Am J Clin Nutr. 2008 Feb;87(2):415-23.
A 10-residue peptide from durum wheat promotes a shift from a Th1-type response toward a Th2-type response in celiac disease.
Silano M, Di Benedetto R, Maialetti F, De Vincenzi A, Calcaterra R, Trecca A, De Vincenzi M.
Division of Food Science, Human Nutrition and Health, Istituto Superiore di Sanita, Rome, Italy.
http://www.ajcn.org/cgi/content/abstract/87/2/415

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J Immunol. 2007 Jul 1;179(1):275-83.
Sodium benzoate, a food additive and a metabolite of cinnamon, modifies T cells at multiple steps and inhibits adoptive transfer of experimental allergic encephalomyelitis.
Brahmachari S, Pahan K.
Department of Neurological Sciences, Rush University Medical Center, 1735 West Harrison Street, Chicago, IL 60612, USA.
http://www.jimmunol.org/cgi/content/abstract/179/1/275

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According to the researchers, if a full-scale trial confirms the results, people with gluten intolerance and celiac disease might be able to safely stray from their strict gluten-free diets on occasion.

The enzyme is prolyl endoprotease isolated from Aspergillus niger and shows the power to quickly and effectively break down gluten peptides and proteins in a simulated human digestive tract. The enzyme has a similar pH level to that of the stomach, and remains intact in the stomach’s strongly acidic conditions.

The research team, led by Dr. C. Mitea from Leiden University Medical Center in the Netherlands tested the enzyme in a controlled system built to function in way that is nearly identical with the human gastrointestinal tract.

According to the report, the enzyme increased the digestion speed of the glutenins and gliadins that are found in white bread, and which people with gluten intolerance and celiac disease cannot properly break down. After 90 minutes, the gluten proteins treated with the enzyme were undetectable, whereas those glutens not treated with the enzyme, remained in the stomach for at least two hours.

The research team obtained similar results when they repeated the test on a fast food meal rather than just white bread alone, and showed that the enzyme treated food samples also eliminated adverse T-cell stimulatory activity that occurred in untreated samples. The tests showed that, in the same amount of time that food normally remains in the stomach, the enzyme brought about the total elimination of T-cell stimulatory peptides of gliadins and glutenins.

From the test results, the research team concluded that the enzyme is a solid choice for clinical trials to determine if it can eliminate 100% of gluten toxicity. They also noted that the enzyme is readily available in industrial quantities, and thus easy to tailor into a suitable treatment should trials prove fruitful.

Gut, Jan 2008; 57: 25 - 32.

Editor's Note: This is not a therapy that is designed to allow celiacs to eat gluten on a daily basis. At best it will allow them to not worry about cross-contamination when eating out.

Using data from the United States Department of Agriculture (USDA) about typical household food consumption, researchers assembled “market baskets” of regular and gluten-free foods. The availability and the difference in price between the 11 regular and gluten-free items in the market basket were compared according the type of store and the region in which the items were purchased.  Researchers surveyed local grocery stores, upscale grocery stores or regional chains, health food stores, and 4 online sites. Regions of the country were represented by New York City and Westchester County, Portland OR, Atlanta GA, Rapid City SD, and Chicago IL.

The researchers found that health food stores and online sites had the largest selection of gluten-free foods, carrying 94% and 100% of the market basket items respectively, compared to availability of 41% in upscale markets and 36% in local grocery stores. Although local grocery stores generally carried the smallest selection of gluten-free foods, Portland’s stores were unique with a relatively high availability of 82%. However, when considering availability in all types of stores, gluten-free foods were most available in the New York area (i.e., 73%).

In general, the price of the gluten-free foods was about 79% greater than their normal counterparts. gluten-free cereals were the exception with a small and statistically insignificant increase in cost compared to the non-gluten-free cereals. The internet appears to be the most expensive place to buy gluten-free foods, followed by health food stores and upscale markets. However, these differences were not statistically significant due to the small number of stores and internet sites surveyed. Interestingly, even though availability of gluten-free foods varied widely among the geographic locations, cost did not.

The economic burden of a gluten-free diet has important implications for people with celiac disease. Compliance with a gluten-free diet is made more difficult by the low availability and relatively high cost of packaged gluten-free foods. Noncompliance with a gluten-free diet is associated with an increased mortality rate and worse quality of life.

Resources

Lee, A., Ng, D., Zivin, J., and Green, H. (2007) Economic burden of a gluten-free diet. J. Hum. Nutr. Diet. 20, 423-430.

The team conducted a denaturing gradient gel electrophoresis analysis of fecal samples from both the celiac and the control groups. They found that children with celiac disease had a more diverse profile of intestinal microbiotic bacteria than did the healthy control subjects.

The children with celiac disease were characterized by the presence of Lactobacillus curvatus, Leuconostoc mesenteriodes, and Leuconostoc carnosum, whereas the members of the healthy control group were characterized by the presence of Lactobacillus casei. Conversely, the bifidobacterium population was much greater in the members of the healthy control group than among the children with celiac disease.

The healthy control group showed particularly high populations of bifidobacterium adolescentis compared to the celiac patients. The team has called for more research into which populations of the various gut microbial are affected by celiac disease. This may lead to a possible role for probiotics and/or prebiotics in returning the balance of the gut microbes in those with celiac disease.

FEMS Immunol Med Microbiol. 2007 Dec;51(3):562-8

The study findings appear in the Journal of Gastroenterology & Hepatology. The research team looked at forty-two children with celiac disease.

The team chronicled weight and height as weight for height (WFH) and height standard deviation scores (HSDS) deviation scores. 25 of the 42 children underwent duodenal biopsies after 1 and 2 years, while 14 of the children underwent a third biopsy after being on a gluten-free diet for 3-7 years. The research team measured compliance with a gluten-free diet in the children using regular interviews & IgA anti-endomysial antibody estimation (EMA).

The average HSDS was 3.3 + 1.6 with 76% showing an HSDS of <-2, with 60% of the children undernourished, with an average WfH of 81.6 + 5.7.

Over an average follow-up span of 3.7 years, the HSDS improved significantly to -1.3 + 1.7, with 84% of cases achieving normal nutrition. The average growth rate was 13.9 cm for the first year, and 5.6 cm in the following years.

The small bowel biopsies conducted upon diagnosis revealed Marsh IIIb subtotal villous atrophy in 18, or 72%, of the patients, and partial villous atrophy in 7, or 28%. Follow-up biopsy after 1-2 years revealed a change to partial villous atrophy in 17 of the 18 who originally showed Marsh IIIb subtotal villous atrophy. One patient showed a normal biopsy. All 7 patients who originally showed partial villous atrophy showed improvement.

81% of the patients showed negative results for IgA endomysial antibody. Follow-up biopsies conducted after 5 years of Gluten-free Diet showed improvement to Marsh I-II, but no normalization.

From these results, the team concluded that most children with celiac disease exhibit normal nutritional uptake and growth patterns with the introduction of a gluten-free diet, and that most also show significant improvement in small bowel histology, but none show normalization, even after 5 years of a dedicated gluten-free diet.

Journal of Gastroenterology Hepatology. 2007; 22(8): 1300-1305

Recently, a team of doctors led by Dr. Daniel Leffler conducted a study of the factors that are most important in increasing the success rates for people trying to maintain a gluten-free diet. Dr. Leffler is a clinical fellow in gastroenterology at Boston’s Beth Israel Deaconess Medical Center. Dr. Leffler presented the results of that study recently at the 2007 American College of Gastroenterology’s Annual Scientific Meeting and Postgraduate Course. The results of the study indicate that support groups seem to have an important role to play.

A team of doctors, dietitians, psychologists, and patients created a study questionnaire that included 155 questions designed to measure ten areas important to success in living with celiac disease, including the burden of the disease, knowledge specific to celiac, health care access, mood and stress factors, perceptions about adherence, reasons for adherence, social support, symptoms.

Participants of the study were all found through biopsy to have celiac disease. A professional nutritionist assessed each of the participants for dietary adherence. Of the 154 participants, 76% were Caucasian women. Nearly 70% had at least a college-level education. The average age was 50, and they had followed gluten-free diets for an average of 5 years.

Concerns over cost and changes in stress levels and shifts in mood were among the reasons that contributed not following a gluten-free diet. Being a member of a celiac support group (P=.008), the ease of eating gluten-free while traveling (P=.012), or while attending social functions were important factors in successfully following the gluten-free diet.

Demographic factors like age, sex, and age at diagnosis had no bearing on successfully remaining on a gluten-free diet.

A total of 61 patients were evaluated with a bowel biopsy. 13 of the subjects exhibited no indications of the disease, a condition known as latent celiac disease. 48 of the patients without symptoms showed celiac-related intestinal damage, a condition known as silent celiac disease.

The study team observed that a similar ratio of patients with both latent celiac and silent celiac disease exhibited minor symptoms of celiac disease. Both patients with symptoms and those without symptoms had similar indications of malabsorption and similar body mass idices.

Loss of bone density was more common in those with silent celiac disease than in those with latent celiac disease. Patients with silent celiac disease more regularly showed elevated levels of celiac-positive antibodies. As far as clinical symptoms of celiac disease, such as blood and antibody tests, the two groups showed no major differences.

The researchers concluded that even with no symptoms, most people diagnosed with celiac disease as children go on to develop active celiac disease as adults. Such patients should undergo screening for villous atrophy, and osteopenia, and should be encouraged to resume their gluten-free diet in the event that villous atrophy is detected.

Colleagues at Finland’s University of Tampere go so far as to say that even patients with latent celiac disease should follow a strict gluten-free diet. They feel that villous atrophy is only a small part of the equation, and a sign of well-advanced celiac, and that the use of mucosal damage as a standard for diagnosing celiac disease is incomplete and can lead to missed diagnosis and otherwise preventable damage.

Gut 2007; 56: 1379-1386, 1339-1340

It is possible a vitamin D deficiency early in life could be a factor in triggering the onset of celiac disease as well as slowing the recovery of the mucosa after celiac disease is diagnosed and treated.  Reduced sun exposure due to modern changing life styles might account for an increasing incidence celiac disease and other autoimmune disorders.  Vitamin D deficiency at the time gluten is introduced into an infant's diet could also play a role in celiac disease onset.  A previous study performed in Sweden found babies born in summer more susceptible to celiac disease than babies born in winter.  If gluten is first introduced to babies some 6 months after birth, seasonal variation of vitamin D levels might account for the difference, i.e. summer-born babies would receive their first gluten in midwinter when sun exposure is minimal.  Since breastfed babies obtain vitamin D from mother's milk, nursing mothers need to be sure to maintain high vitamin D levels during winter months.

A study just released by the National Cancer Institute examined the relationship between serum 25(OH)D levels and total cancer mortality in 16818 participants and concluded "results do not support an association between 25(OH)D and total cancer mortality."  However, the study did find "colorectal cancer mortality was inversely related to serum 25(OH)D level, with levels 80 nmol/L or higher associated with a 72% risk reduction compared with lower than 50 nmol/L."  The fact that vitamin D appears to lower colon cancer mortality risk is consistant with the preservation role vitamin D appears to play in maintaining the intestinal mucosal barrier.  Note that this study does not consider whether receiving daily doses of vitamin D supplements much higher than current recommendations would provide a cancer risk benefit.

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Am J Physiol Gastrointest Liver Physiol. 2007 Oct 25.
Novel Role of the Vitamin D Receptor in Maintaining the Integrity of the Intestinal Mucosal Barrier.
Kong J, Zhang Z, Musch MW, Ning G, Sun J, Hart J, Bissonnette M, Li YC.
Medicine, The University of Chicago, Chicago, Illinois, United States; Chicago, Illinois, United States.
Open Original Shared Link .

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J Epidemiol Community Health. 2003 Jan;57(1):36-9.
Children born in the summer have increased risk for coeliac disease.
Ivarsson A, Hernell O, Nystrom L, Persson LA.
Department of Public Health and Clinical Medicine, Epidemiology, Umea University, Umea, Sweden.
Open Original Shared Link .

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J Natl Cancer Inst. 2007 Oct 30.
Prospective Study of Serum Vitamin D and Cancer Mortality in the United States.
D. Michal Freedman, Anne C. Looker, Shih-Chen Chang, Barry I. Graubard.
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD; National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD.
Open Original Shared Link .

The medical journal GUT recently published a paper by Matysiak-Budnik et al. concerning the natural history of celiac disease, which indicates that classic celiac damage to the intestinal lining may take years or decades to develop in some cases. A team of researchers looked at 61 adults who had been diagnosed with celiac disease as children, and who felt themselves to be asymptomatic for anywhere from 3 to 21 years, with a group average of 11 years. An exam revealed that 48 of the 61 test subjects indeed showed villous atrophy with crypt hypoplasia. The 13 other patients showed no celiac-associated intestinal damage.

Strangely, 2 of the 13 patients with no signs of damage had showed such damage a short time after gluten was reintroduced into their diets, only to return to normal as they continued to consume gluten. From this, the researchers concluded that some people might actually become truly latent and tolerate gluten with no adverse effects. It’s also possible that such people actually still have celiac disease and that the intestinal damage has yet to recur, as villous atrophy occurs only at the tail end of celiac disease.

In fact, delayed relapse of celiac disease after gluten reintroduction supports the notion that people with normal mucosa may in fact have celiac disease. Still, it is highly uncommon for patients with celiac disease to show no clinical symptoms on a long-term gluten-inclusive diet. The level of celiac disease+ intraepithelial lymphocytes has proven to be more useful than mucosal Marsh Type 1 lymphocytes in revealing early developing celiac disease in such cases and in general.

Reliable diagnosis of celiac disease is important, as untreated celiac disease carries a broad range of associated risks including markedly higher rates of certain cancers. A recent study also suggests celiac disease may also adversely impact both the peripheral the central nervous systems.

However, regarding the 13 asymptomatic patients, the original diagnosis of celiac would seem to be accurate in each case, as each had celiac-type HLA, either HLA DQ2 or DQ8, and their follow-up exam results showed that 5 of those patients had positive serum antibody results and higher densities of small bowel mucosa celiac disease+ and CD3+ intraepithelial lymphocytes than did the non-celiac control groups. Two of the 13 patients developed symptoms of a relapse during the follow-up.

The study team concluded that the “2 year rule” for reintroducing gluten is invalid and supports the view that celiac disease exists beyond villous atrophy. As villous atrophy of the small intestine is only one manifestation of genetic gluten intolerance, and that the present diagnostic guidelines based on mucosal damage and ignoring early developing celiac disease and dermatitis herpetiformis is only one incarnation of celiac disease.

GUT 2007; 56:1339-1340

Katri Kaukinen, Pekka Collin, Medical School, University of Tampere and Department of Gastroenterology and Alimentary Tract Surgery, Tampere University Hospital, Tampere, Finland Markku Ma¨ki, Medical School, University of Tampere and Department of Paediatrics, Tampere University Hospital, Tampere, Finland

The team used mass spectrometry to analyze enzyme modifications of immuno-dominant a-gliadin peptide P56-58 and modeling studies to determine the extent of peptide binding to HLA-DQ2.The team treated wheat flour with microbial transglutaminase and lysine methylesther. They then extracted, digested and deaminated the gliadin.

They used biopsy specimens from 12 adults with known celiac disease to generate gliadin-specific intestinal T-cell lines (iTCLs), which they then challenged in vitro with various antigen solutions.

The results showed that tissue TG-mediated transamidation with lysine methylesther of P56-58, or gliadin in alkaline conditions inhibited the interferon expression in iTCLs.

Gastroenterology, Volume 133, Issue 3, September 2007; p780-789