Celiac disease or non-celiac gluten sensitivity? An approach to clinical differential diagnosis

Nonallergic Diseases Associated With Foods

Clinicians are faced with evaluating real and alleged reactions to foods that may be allergic or nonallergic. Pathogenesis, diagnosis, and treatment of various non-IgE-mediated diseases are discussed in this review. These food-related conditions range from mild to severe. Referral for an allergy workup may be pursued despite the lack of IgE-mediated symptoms. Diagnostic testing is available for defined non-IgE-mediated food diseases that are either immunologic or nonimmunologic. These include celiac disease and related disorders, carbohydrate maldigestion, pancreatic insufficiency, and histamine intolerance. In contrast, there is a paucity of definitive studies to prove food intolerance diseases. There are no definitive diagnostic criteria or testing for nonceliac gluten sensitivity. Functional gastrointestinal disorders, such as irritable bowel syndrome, are better stratified diagnostically but still lack reliable testing. Both nonceliac gluten sensitivity and irritable bowel syndrome are linked to dietary triggers including fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Therefore, dietary alteration alone may be diagnostic and therapeutic when all other conditions are ruled out. These conditions are important considerations when evaluating a patient with history of a food reaction. There is little evidence that foods are causative in other ailments such as acne, migraines, and nasal congestion and hypersecretion.

The Gluten-Free Diet for Celiac Disease and Beyond

The gluten-free diet (GFD) has gained popularity beyond its main medical indication as the treatment for gluten-induced immune-mediated disorders such as celiac disease (CD), dermatitis herpetiformis, gluten ataxia, wheat allergy, and non-celiac gluten sensitivity. However, the diet carries some disadvantages such as elevated costs, nutritional deficiencies, and social and psychological barriers. The present work aims to review indications, proven benefits, and adverse events of a gluten-free diet. Close follow-up with patients following the diet is recommended. More data is needed to assess the effectiveness of the diet in managing mental and cognitive disorders and to establish a connection between the brain and gluten.

Self-reported Wheat Sensitivity in Irritable Bowel Syndrome and Healthy Subjects: Prevalence of Celiac Markers and Response to Wheat-free Diet

BACKGROUND/AIMS

Most patients with irritable bowel syndrome (IBS) report food-related aggravation of symptoms. Wheat/gluten is one of the most commonly incriminated. We studied the prevalence of self-reported wheat sensitivity in patients with IBS and in a healthy population from a region in India consuming mixed-cereal diets, correlated it with serological and human leukocyte antigen (HLA) markers of celiac disease, and evaluated the response to a wheat-free diet.

METHODS

We surveyed 204 patients with IBS and 400 healthy persons for self-reported wheat sensitivity. Testing for IgA anti-tissue transglutaminase and HLA DQ2 or DQ8 was done in individuals who reported wheat sensitivity. Consenting persons with wheat sensitivity were put on wheat-free diet and monitored for symptom change.

RESULTS

Twenty-three of 204 patients with IBS (11.3%) and none of the healthy subjects self-reported wheat sensitivity. Of 23 patients, 14 (60.9%) were positive for HLA DQ2 or DQ8 and none for anti-tissue transglutaminase antibody. After 6 weeks on wheat-free diet, all 19 participating patients reported clinical improvement; fewer patients had bloating, diarrhea, constipation, and easy fatigue.

CONCLUSIONS

Eleven percent of patients with IBS self-reported wheat sensitivity. None of them had positive celiac serology; 60.9% were positive for HLA DQ2 and DQ8, suggesting a possible genetic basis. All of them improved symptomatically on a wheat-free diet.

Wheat/Gluten-Related Disorders and Gluten-Free Diet Misconceptions: A Review

In the last 10,000 years, wheat has become one of the most important cereals in the human diet and today, it is widely consumed in many processed food products. Mostly considered a source of energy, wheat also contains other essential nutrients, including fiber, proteins, and minor components, such as phytochemicals, vitamins, lipids, and minerals, that together promote a healthy diet. Apart from its nutritional properties, wheat has a set of proteins, the gluten, which confer key technical properties, but also trigger severe immune-mediated diseases, such as celiac disease. We are currently witnessing a rise in the number of people adhering to gluten-free diets unwarranted by any medical need. In this dynamic context, this review aims to critically discuss the nutritional components of wheat, highlighting both the health benefits and wheat/gluten-related disorders, in order to address common misconceptions associated with wheat consumption.

Could it be gluten? Additional skin conditions associated with celiac disease

Celiac disease is a multifactorial, inflammatory disorder initiated and sustained by the ingestion of gluten. Occurring across a broad population, the intestinal and extraintestinal manifestations of celiac disease are variable in severity and may be nonspecific in presentation. Given that environmental, genetic, and immune factors involved in the pathogenesis of celiac disease that the digestive tract and skin share many characteristics, and with a prevalence of 0.5-1% in most populations, it is reasonable to consider varying presentations of skin conditions that are linked with celiac disease. The association between celiac disease and skin conditions has been discussed earlier, but new studies have emerged suggesting cutaneous involvement in addition to dermatitis herpetiformis. We review the current literature identifying the relationship and potential mechanisms between celiac disease and various skin conditions.

Celiac Disease: Fallacies and Facts

Our understanding of the pathophysiology of celiac disease has progressed greatly over the past 25 years; however, some fallacies about the clinical characteristics and management persist. Worldwide epidemiologic data are now available showing that celiac disease is ubiquitous. An elevated body mass index is common at the time of the diagnosis. The gluten-free diet (GFD) is an imperfect treatment for celiac disease; not all individuals show a response. This diet is widely used by people without celiac disease, and symptomatic improvement on a GFD is not sufficient for diagnosis. Finally, the GFD is burdensome, difficult to achieve, and thus has an incomplete efficacy, opening exciting opportunities for novel, nondietary treatments.

Autoimmunity Features in Patients With Non-Celiac Wheat Sensitivity

INTRODUCTION

Nonceliac wheat sensitivity (NCWS) is characterized by intestinal and extraintestinal manifestations consequent to wheat ingestion in subjects without celiac disease and wheat allergy. Few studies investigated the relationship between NCWS and autoimmunity. The aim of this study is to evaluate the frequency of autoimmune diseases (ADs) and autoantibodies in patients with NCWS.

METHODS

Ninety-one patients (13 men and 78 women; mean age of 40.9 years) with NCWS, recruited in a single center, were included. Seventy-six healthy blood donors (HBD) and 55 patients with a diagnosis of irritable bowel syndrome (IBS) unrelated to NCWS served as controls. Autoantibodies levels were measured. Human leukocyte antigen haplotypes were determined, and duodenal histology performed in all patients carrying the DQ2/DQ8 haplotypes. Participants completed a questionnaire, and their medical records were reviewed to identify those with ADs.

RESULTS

Twenty-three patients with NCWS (25.3%) presented with ADs; autoimmune thyroiditis (16 patients, 17.6%) was the most frequent. The frequency of ADs was higher in patients with NCWS than in HBD (P = 0.002) and in patients with IBS (P = 0.05). In the NCWS group, antinuclear antibodies tested positive in 71.4% vs HBD 19.7%, and vs patients with IBS 21.8% (P < 0.0001 for both). The frequency of extractable nuclear antigen antibody (ENA) positivity was significantly higher in patients with NCWS (21.9%) than in HBD (0%) and patients with IBS (3.6%) (P = 0.0001 and P = 0.004, respectively). Among the patients with NCWS, 9.9% tested positive for antithyroglobulin, 16.5% for antithyroid peroxidase, and 14.3% for antiparietal cell antibodies; frequencies were not statistically different from controls. The presence of ADs was related to older age at NCWS diagnosis, female sex, duodenal lymphocytosis, and eosinophil infiltration.

DISCUSSION

One in 4 patients with NCWS suffered from AD, and serum antinuclear antibodies were positive in a very high percentage of cases. These data led us to consider NCWS to be associated to ADs.

Estimating the Impact of Verification Bias on Celiac Disease Testing

GOAL

The goal of this study was to estimate the impact of verification bias on the diagnostic accuracy of immunoglobulin A tissue transglutaminase (IgA tTG) in detecting celiac disease as reported by an authoritative meta-analysis, the 2016 Comparative Effectiveness Review (CER).

BACKGROUND

Verification bias is introduced to diagnostic accuracy studies when screening test results impact the decision to verify disease status.

MATERIALS AND METHODS

We adjusted the sensitivity and specificity of IgA tTG reported by the 2016 CER with the proportion of IgA tTG positive and negative individuals who are referred for confirmatory small bowel biopsy. We performed a systematic review from January 1, 2007, to July 19, 2017, to determine these referral rates.

RESULTS

The systematic review identified 793 articles of which 9 met inclusion criteria (n=36,477). Overall, 3.6% [95% confidence interval (CI): 1.1%-10.9%] of IgA tTG negative and 79.2.2% (95% CI: 65.0%-88.7%) of IgA tTG positive individuals were referred for biopsy. Adjusting for these referral rates the 2016 CER reported sensitivity of IgA tTG dropped from 92.6% (95% CI: 90.2%-94.5%) to 57.1% (95% CI: 35.4%-76.4%) and the specificity increased from 97.6% (95% CI: 96.3%-98.5%) to 99.6% (95% CI: 98.4%-99.9%).

CONCLUSIONS

The CER may have largely overestimated the sensitivity of IgA tTG due to a failure to account for verification bias. These findings suggest caution in the interpretation of a negative IgA tTG to rule out celiac disease in clinical practice. More broadly, they highlight the impact of verification bias on diagnostic accuracy estimates and suggest that studies at risk for this bias be excluded from systematic reviews.

A Durum Wheat Variety-Based Product Is Effective in Reducing Symptoms in Patients with Non-Celiac Gluten Sensitivity: A Double-Blind Randomized Cross-Over Trial

Patients with non-celiac gluten sensitivity (NCGS) do not have celiac disease, but their symptoms improve after a gluten-free diet (GFD). However, to date, it is uncertain if gluten or other components of wheat are responsible for these symptoms. The aim of this study was to compare the effects of an organic durum wheat variety with those of standard commercial wheat in patients with known NCGS. We performed a double-blind randomized cross-over trial of 42 patients (mean age 45 years, 8 men) with NCGS diagnosed according to the Salerno criteria and adherence to GFD for at least 12 weeks from screening. Enrolled subjects were randomly assigned to one the following groups of treatment: (A) a two-week diet with Senatore Cappelli wheat variety pasta; (B) a two-week diet with standard commercial pasta. Then, after a two-week washout period on gluten-free diet, each patient crossed over to the other treatment group. Symptoms were assessed through a modified version of the Gastrointestinal Symptom Rating Scale (GSRS), tailored on NCGS. Between April 2018 and July 2018, 42 patients with NCGS were enrolled in the study (70.6% females), and 34 patients completed the study. Patients reported lower overall symptoms scores after eating Senatore Cappelli pasta than standard pasta (p = 0.03) and also significantly lower scores in several specific gastrointestinal and extra-intestinal symptoms after eating Senatore Cappelli pasta than standard pasta, specifically, bloating (p = 0.04), abdominal distention (p = 0.004), eructation (p = 0.01), flatus (p = 0.02), feeling of incomplete evacuation (p = 0.001), dermatitis (p = 0.01), and limb numbness (p = 0.03). In our study, patients with NCGS experienced lower gastrointestinal and extra-intestinal symptom scores after eating the Senatore Cappelli wheat variety than a standard commercial wheat. Should our preliminary results be confirmed by further studies, new dietary alternatives may be available to patients with NCGS, with consequent health, economic, and social benefits.

Nonceliac Wheat Sensitivity: An Immune-Mediated Condition with Systemic Manifestations

Non-celiac wheat sensitivity (NCWS) is characterized by gastrointestinal and extra-intestinal symptoms following the ingestion of gluten-containing cereals in subjects without celiac disease or wheat allergy. The identity of the molecular triggers in these cereals responsible for the symptoms of NCWS remains to be delineated. Recent research has identified a biological basis for the condition, with the observation of systemic immune activation in response to microbial translocation that appears to be linked to intestinal barrier defects. Ongoing research efforts are aimed at further characterizing the etiology, mechanism, and biomarkers of the condition.

Breaking bread!

Humankind has existed for 2·5 million years but only in the past 10 000 years have we been exposed to wheat. Therefore, it could be considered that wheat (gluten) is a novel introduction to humankind's diet! Prior to 1939, the rationing system had already been devised. This led to an imperative to try to increase agricultural production. Thus, it was agreed in 1941 that there was a need to establish a Nutrition Society. The very roots of the Society were geared towards necessarily increasing the production of wheat. This goal was achieved and by the end of the 20th century, global wheat output had expanded by 5-fold. Perhaps, as a result, the epidemiology of coeliac disease (CD) or gluten sensitive enteropathy has changed. CD now affects 1 % or more of all adults. Despite this, delays in diagnosis are common, for every adult patient diagnosed approximately three-four cases are undetected. This review explores humankind's relationship with gluten, wheat chemistry, the rising prevalence of modern CD and the new entity of non-coeliac gluten or wheat sensitivity. The nutritional interventions of a low fermentable oligo-, di- and mono-saccharides and polyols diet and gluten-free diet (GFD) for irritable bowel syndrome and the evidence to support this approach (including our own published work) are also reviewed. There appears to be a rising interest in the GFD as a 'lifestyler', 'free from' or 'clean eater' choice, causing concern. Restrictive diets may lead to potential nutritional implications, with long-term effects requiring further exploration.

[Non-celiac gluten/wheat sensitivity: still more questions than answers]

Non-celiac gluten/wheat sensitivity (NCG/WS) is a syndrome characterized by intestinal and extra-intestinal sym-ptoms elicited by gluten/wheat ingestion in the persons, who are not affected by celiac disease and wheat allergy. Due to the lack of established biomarkers, the diagnosis of NCG/WS is based on the clinical picture, and it is necessary to validate it in well-defined double-blind, placebo-controlled challenge (The Salerno Experts´ Criteria). In the article is discussed a current knowledge of NCG/WS in terms of pathogenesis, diagnosis and treatment. Key words: gluten - gluten-related disorders - non-celiac gluten/wheat sensitivity - wheat.

Hypoglycemic Mechanism of the Berberine Organic Acid Salt under the Synergistic Effect of Intestinal Flora and Oxidative Stress

Both alterations to the intestinal microflora and chronic systemic inflammation predispose towards type 2 diabetes (T2D). Changes in the composition of the intestinal microflora are associated with glucose metabolism changes in rats with T2D. Here, we demonstrate that a berberine fumarate (BF) has a hypoglycemic effect by regulating the intestinal microflora and metabolism of diabetic rats. The T2D rats had disorders of glucose and lipid metabolism, an abnormal intestinal microflora, fewer butyrate-producing and probiotic-type bacteria, larger numbers of potentially pathogenic and sulfate-reducing bacteria, and tissue inflammation. Administration of berberine fumarate significantly ameliorated the metabolic disorder; increased the populations of Bacteroidetes, Clostridia, Lactobacillales, Prevotellaceae, and Alloprevotella; and reduced those of Bacteroidales, Lachnospiraceae, Rikenellaceae, and Desulfovibrio. In addition, it reduced inflammation, inhibiting the overexpression of TLR4 and p-JNK and increasing the expression of PI3K, GLUT2, and other proteins, which are closely related to oxidative stress, thereby promoting the metabolism of glucose.

Office-Based Point of Care Testing (IgA/IgG-Deamidated Gliadin Peptide) for Celiac Disease

OBJECTIVES

Celiac disease (CD) is common yet under-detected. A point of care test (POCT) may improve CD detection. We aimed to assess the diagnostic performance of an IgA/IgG-deamidated gliadin peptide (DGP)-based POCT for CD detection, patient acceptability, and inter-observer variability of the POCT results.

METHODS

From 2013-2017, we prospectively recruited patients referred to secondary care with gastrointestinal symptoms, anemia and/or weight loss (group 1); and patients with self-reported gluten sensitivity with unknown CD status (group 2). All patients had concurrent POCT, IgA-tissue transglutaminase (IgA-TTG), IgA-endomysial antibodies (IgA-EMA), total IgA levels, and duodenal biopsies. Five hundred patients completed acceptability questionnaires, and inter-observer variability of the POCT results was compared among five clinical staff for 400 cases.

RESULTS

Group 1: 1000 patients, 58.5% female, age 16-91, median age 57. Forty-one patients (4.1%) were diagnosed with CD. The sensitivities of the POCT, IgA-TTG, and IgA-EMA were 82.9, 78.1, and 70.7%; the specificities were 85.4, 96.3, and 99.8%. Group 2: 61 patients, 83% female; age 17-73, median age 35. The POCT had 100% sensitivity and negative predictive value in detecting CD in group 2. Most patients preferred the POCT to venepuncture (90.4% vs. 2.8%). There was good inter-observer agreement on the POCT results with a Fleiss Kappa coefficient of 0.895.

CONCLUSIONS

The POCT had comparable sensitivities to serology, and correctly identified all CD cases in a gluten sensitive cohort. However, its low specificity may increase unnecessary investigations. Despite its advantage of convenience and rapid results, it may not add significant value to case finding in an office-based setting.

Non-celiac gluten/wheat sensitivity (NCGS)-a currently undefined disorder without validated diagnostic criteria and of unknown prevalence: Position statement of the task force on food allergy of the German Society of Allergology and Clinical Immunology (DGAKI)

Within the last decade, non-celiac gluten/wheat sensitivity (NCGS) has been increasingly discussed not only in the media but also among medical specialties. The existence and the possible triggers of NCGS are controversial. Three international expert meetings which proposed recommendations for NCGS were not independently organized and only partially transparent regarding potential conflicts of interest of the participants. The present position statement reflects the following aspects about NCGS from an allergist's and nutritionist's point of view: (A) Validated diagnostic criteria and/or reliable biomarkers are still required. Currently, this condition is frequently self-diagnosed, of unknown prevalence and non-validated etiology. (B) Gluten has not been reliably identified as an elicitor of NCGS because of high nocebo and placebo effects. Double-blind, placebo-controlled provocation tests are of limited value for the diagnosis of NCGS and should be performed in a modified manner (changed relation of placebo and active substance). (C) Several confounders hamper the assessment of subjective symptoms during gluten-reduced or gluten-free diets. Depending on the selection of food items, e.g., an increased vegetable intake with soluble fibers, diets may induce physiological digestive effects and can modify gastrointestinal transit times independent from the avoidance of gluten. (D) A gluten-free diet is mandatory in celiac disease based on scientific evidence. However, a medically unjustified avoidance of gluten may bear potential disadvantages and risks. (E) Due to a lack of diagnostic criteria, a thorough differential diagnostic work-up is recommended when NCGS is suspected. This includes a careful patient history together with a food-intake and symptom diary, if necessary an allergy diagnostic workup and a reliable exclusion of celiac disease. We recommend such a structured procedure since a medically proven diagnosis is required before considering the avoidance of gluten.

Celiac disease is uncommon in irritable bowel syndrome in the USA

BACKGROUND AND AIMS

Routine serologic testing for celiac disease (CD) may be useful in irritable bowel syndrome (IBS) patients, but this is controversial. We aimed to compare the prevalence of unrecognized CD in a large cohort of patients with and without IBS.

PARTICIPANTS AND METHODS

This is a family case-control IBS study conducted at a single US academic medical center. Stored serum and DNA were available. Tissue transglutaminase (TTg) immunoglobulin A was performed, followed by indirect immunofluorescence testing for endomysial antibodies with positive or weakly positive TTg results. Individuals were considered to have CD if both results were positive. χ and Fisher's exact tests were used to compare prevalence between the two groups.

RESULTS

Serum samples were studied from 533 cases and 531 controls. In all, 80% of participants were female, with a median age of 50 years; 65% of cases and 0% controls met the Rome criteria for IBS. Previous serological testing for CD had occurred in 142 (27%) cases and 13 (2%) controls, but none had CD on subsequent testing. Six (1.1%) cases versus five (0.9%) controls had positive or weakly positive TTg test. Six cases (1.1%) versus three (0.6%) controls were confirmed to have CD by endomysial antibody (P=0.51).

CONCLUSION

No difference in the prevalence of CD between patients with IBS and patients without IBS at a tertiary medical center was observed. Our findings do not support routine celiac serologic or genetic testing in patients with IBS in all US populations.

The Gut Microbiota and the Emergence of Autoimmunity: Relevance to Major Psychiatric Disorders

BACKGROUND

Autoimmune phenotypes are prevalent in major psychiatric disorders. Disequilibria of cellular processes occurring in the gastrointestinal (GI) tract likely contribute to immune dysfunction in psychiatric disorders. As the venue of a complex community of resident microbes, the gut in a homeostatic state equates with a functional digestive system, cellular barrier stability and properly regulated recognition of self and non-self antigens. When gut processes become disrupted as a result of environmental or genetic factors, autoimmunity may ensue.

METHODS

Here, we review the issues pertinent to autoimmunity and the microbiome in psychiatric disorders and show that many of the reported immune risk factors for the development of these brain disorders are in fact related and consistent with dysfunctions occurring in the gut. We review the few human microbiome studies that have been done in people with psychiatric disorders and supplement this information with mechanistic data gleaned from experimental rodent studies.

RESULTS

These investigations demonstrate changes in behavior and brain biochemistry directly attributable to alterations in the gut microbiome. We present a model by which autoantigens are produced by extrinsicallyderived food and microbial factors bound to intrinsic components of the gut including receptors present in the enteric nervous system.

CONCLUSION

This new focus on examining activities outside of the CNS for relevance to the etiology and pathophysiology of psychiatric disorders may require new modalities or a re-evaluation of pharmaceutical targets found in peripheral systems.

The Overlapping Area of Non-Celiac Gluten Sensitivity (NCGS) and Wheat-Sensitive Irritable Bowel Syndrome (IBS): An Update

Gluten-related disorders have recently been reclassified with an emerging scientific literature supporting the concept of non-celiac gluten sensitivity (NCGS). New research has specifically addressed prevalence, immune mechanisms, the recognition of non-immunoglobulin E (non-IgE) wheat allergy and overlap of NCGS with irritable bowel syndrome (IBS)-type symptoms. This review article will provide clinicians with an update that directly impacts on the management of a subgroup of their IBS patients whose symptoms are triggered by wheat ingestion.

Non-celiac gluten sensitivity: All wheat attack is not celiac

Currently, 1% of the United States population holds a diagnosis for celiac disease (CD), however, a more recently recognized and possibly related condition, "non-celiac gluten sensitivity" (NCGS) has been suggested to affect up to 6% of the United States public. While reliable clinical tests for CD exist, diagnosing individuals affected by NCGS is still complicated by the lack of reliable biomarkers and reliance upon a broad set of intestinal and extra intestinal symptoms possibly provoked by gluten. NCGS has been proposed to exhibit an innate immune response activated by gluten and several other wheat proteins. At present, an enormous food industry has developed to supply gluten-free products (GFP) with GFP sales in 2014 approaching $1 billion, with estimations projecting sales to reach $2 billion in the year 2020. The enormous demand for GFP also reflects a popular misconception among consumers that gluten avoidance is part of a healthy lifestyle choice. Features of NCGS and other gluten related disorders (e.g., irritable bowel syndrome) call for a review of current distinctive diagnostic criteria that distinguish each, and identification of biomarkers selective or specific for NCGS. The aim of this paper is to review our current understanding of NCGS, highlighting the remaining challenges and questions which may improve its diagnosis and treatment.

How Looking for Celiac‐Safe Wheat Can Influence Its Technological Properties

Because of the continuous increase in the prevalence of gluten‐related disorders, selection of wheat with a low content of immunogenic gluten epitopes could be an innovative alternative for prevention. In this review, the focus is on literature data concerning the deallergenization tools of wheat, which are mainly related to breeding approaches (classic and advanced) and processing operations (germination and fermentation). Until now, no safe wheat genotype has been identified, whereas decreasing wheat allergenicity is possible. On the other hand, the decrease of gluten or some of its epitopes can strongly affect technological properties. Thus, obtaining celiac‐safe gluten without affecting the technological properties of wheat could be considered as a new challenge that scientists will be facing. Celiac‐safe wheat‐based product development could be a great revolution in the market of foods for special medical purposes. The present paper is aiming to: (a) review the strategies and the approaches used, or that can be used, for developing low allergenic wheat: their utilities and limits were also discussed and (b) screen the impact of gluten reduction or removal on the quality of wheat end‐use products.

Celiac Disease and Nonceliac Gluten Sensitivity

Gluten-related disorders include celiac disease (CD), wheat allergy, and nonceliac gluten sensitivity. CD is an autoimmune enteropathy caused by damage to small intestinal mucosa when gluten is ingested in genetically susceptible individuals. Currently, the only available treatment of CD is gluten-free diet. Several potential treatments are being researched. Wheat allergy is a hypersensitivity reaction caused by IgE-mediated and/or non-IgE-mediated immune response, and can involve the gastrointestinal tract, skin, or respiratory tract. Nonceliac gluten sensitivity is one of a variety of immunologic, morphologic, or symptomatic manifestations precipitated by ingestion of gluten in individuals in whom CD and wheat allergy are excluded.

Nomenclature and diagnosis of gluten-related disorders: A position statement by the Italian Association of Hospital Gastroenterologists and Endoscopists (AIGO)

BACKGROUND

"Gluten-related disorders" is a term that encompasses different diseases induced by the ingestion of gluten-containing food. Because of their incidence the scientific community has been intensively studying them.

AIM

To support gastroenterologists with a correct nomenclature and diagnostic approach to gluten-related disorders in adulthood.

METHODS

The Italian Association of Hospital Gastroenterologists and Endoscopists (AIGO) commissioned a panel of experts to prepare a position statement clarifying the nomenclature and diagnosis of gluten-related disorders, focusing on those of gastroenterological interest. Each member was assigned a task and levels of evidence/recommendation have been proposed.

RESULTS

The panel identified celiac disease, wheat allergy and non-celiac gluten sensitivity as the gluten-related disorders of gastroenterological interest. Celiac disease has an autoimmune nature, wheat allergy is IgE-mediated while the pathogenesis of non-celiac gluten sensitivity is still unknown as is the case of non-IgE mediated allergy. Diagnosis should start with the serological screening for celiac disease and wheat allergy. In case of normal values, the response to a gluten-free diet should be evaluated and a confirmatory blind food challenge carried out.

CONCLUSIONS

Gluten-related disorders are clinically heterogeneous. Patients should be carefully managed and specific protocols applied for a correct differential diagnosis in gastroenterological setting.

Non-coeliac gluten/wheat sensitivity: advances in knowledge and relevant questions

Non-coeliac gluten/wheat sensitivity (NCG/WS) is a syndrome characterized by intestinal and extra-intestinal symptoms occurring a few hours or days after the ingestion of gluten and wheat proteins in patients testing negative for coeliac disease and wheat allergy. Areas covered: The present review deals with recent scientific acquisitions of this gluten-related syndrome, including pathogenetic mechanisms, clinical picture, symptom score, biomarkers and double-blind placebo-controlled trial for diagnosis, and treatment. The methodology used was a literature search on NCG/WS using Medline and Premedline from 1970 to August 2016. Expert commentary: We discussed the pathogenesis of symptom generation and altered gut physiology in NCG/WS. Possible mechanisms include innate and adaptive immune activation, impaired intestinal epithelial barrier and changes in gut microbiome. These interlinked factors may be exploited for their clinical relevance as possible biomarkers. A systemic immune response to microbial and wheat antigens, together with intestinal cell damage, occurs in patients with NCG/WS. Due to the lack of established biomarkers, it is mandatory to validate the diagnosis of the syndrome by means of a well-defined work-up involving dietary challenge. Finally, dietary and other therapeutic indications have been thoroughly reviewed.

Non Celiac Gluten Sensitivity

PURPOSE OF REVIEW

A new syndrome responding to gluten-free diet and defined non-celiac gluten sensitivity entered the spectrum of gluten-related disorders, together with celiac disease and wheat allergy. However, its definition, prevalence, diagnosis, pathogenesis, treatment, and follow up are still controversial. The purpose of the review is to summarize the evidence and problems emerging from the current literature.

RECENT FINDINGS

Direct implication of gluten in the onset of symptoms is often unproved as a low fermentable oligo-, di- and mono-saccharides and polyols diet or other components of cereals as wheat amylase trypsin inhibitor could be similarly involved. To date, no specific biomarkers or histological abnormalities confirm diagnosis, and only the self-reported response to gluten-free diet as well as a positive double blind placebo-gluten challenge characterizes these non-celiac, non-wheat allergic patients. Critical revision of published studies can offer practical indications in approaching this clinical topic and useful suggestions to standardize scientific researches.

Nonceliac gluten sensitivity: an approach to diagnosis and management

PURPOSE OF REVIEW

Symptoms attributed to gluten consumption are frequently reported evoking the need for differentiating nonceliac gluten sensitivity (NCGS) from other gluten-related disorders such as celiac disease and wheat allergy. This review discusses diagnostic criteria and research to date on the pathogenesis and diagnosis of NCGS.

RECENT FINDINGS

There is recent evidence to support NCGS as a distinct clinical entity. The symptoms attributed to NCGS are nonspecific, overlapping with those reported in patients with celiac disease and irritable bowel syndrome. In contrast to celiac disease and wheat allergy, the diagnosis of NCGS is more challenging because there are no specific clinical biomarkers and because the pathogenesis of NCGS is largely not well understood. The pathogenesis of NCGS may reflect alterations in innate immunity to gluten or other components of wheat, may be linked with autoimmunity, or is a result of a reaction to gluten as a fermentable carbohydrate.

SUMMARY

NCGS is a newly characterized and evolving clinical entity that requires ruling out other causes of wheat-related or gluten-related gastrointestinal symptoms, including celiac disease and wheat allergy, coupled with double-blind placebo-controlled crossover challenge with gluten.

Autoimmune diseases, gastrointestinal disorders and the microbiome in schizophrenia: more than a gut feeling

Autoimmunity, gastrointestinal (GI) disorders and schizophrenia have been associated with one another for a long time. This paper reviews these connections and provides a context by which multiple risk factors for schizophrenia may be related. Epidemiological studies strongly link schizophrenia with autoimmune disorders including enteropathic celiac disease. Exposure to wheat gluten and bovine milk casein also contribute to non-celiac food sensitivities in susceptible individuals. Co-morbid GI inflammation accompanies humoral immunity to food antigens, occurs early during the course of schizophrenia and appears to be independent from antipsychotic-generated motility effects. This inflammation impacts endothelial barrier permeability and can precipitate translocation of gut bacteria into systemic circulation. Infection by the neurotropic gut pathogen, Toxoplasma gondii, will elicit an inflammatory GI environment. Such processes trigger innate immunity, including activation of complement C1q, which also functions at synapses in the brain. The emerging field of microbiome research lies at the center of these interactions with evidence that the abundance and diversity of resident gut microbiota contribute to digestion, inflammation, gut permeability and behavior. Dietary modifications of core bacterial compositions may explain inefficient gluten digestion and how immigrant status in certain situations is a risk factor for schizophrenia. Gut microbiome research in schizophrenia is in its infancy, but data in related fields suggest disease-associated altered phylogenetic compositions. In summary, this review surveys associative and experimental data linking autoimmunity, GI activity and schizophrenia, and proposes that understanding of disrupted biological pathways outside of the brain can lend valuable information regarding pathogeneses of complex, polygenic brain disorders.

Celiac disease: advances in diagnosis

Celiac disease (CD) is characterized by small intestinal damage, which is mediated by a gluten-driven inflammatory response. Establishing a robust diagnosis is critical for improved quality of life and prevention of co-morbidities, although treatment is associated with a substantial life-long burden of care for patients and families. Unfortunately, CD remains a challenging diagnosis. As awareness of the disease increases, more diagnoses of CD are being made by primary care physicians. In fact, many patients may not present to a gastroenterologist because their symptoms are not clearly linked to a gastrointestinal pathology. Also, many patients are starting a gluten-free diet without prior testing, a circumstance that leads to even more confusion. Lastly, the number of serologic and genetic tests, and the role of endoscopy, can be confusing. The purpose of this review is to examine diagnostic testing strategies, focusing on published guidelines, for the evaluation of patients with suspected CD.

Management of Nonceliac Gluten Sensitivity by Gastroenterology Specialists: Data from an Italian Survey

BACKGROUND AND AIM

Nonceliac gluten sensitivity is syndrome characterized by symptoms disappearing after a gluten-free diet. Its existence is still argument of discussion among specialists. Our aim was to evaluate the knowledge about nonceliac gluten sensitivity among gastroenterology specialists.

METHODS

During October 2013 a questionnaire was sent through a medical newsletter to Italian gastroenterologists. Twelve questions investigated their knowledge on nonceliac gluten sensitivity, including their diagnostic and therapeutic approach.

RESULTS

A total of 212 gastroenterologists filled in the questionnaire. The 98.6% were aware of the existence of a syndrome called "nonceliac gluten sensitivity" and 77% believe in its existence. However, only 56% gave a correct definition of the term. The majority of specialists diagnosed gluten sensitive patients and the number of diagnoses was not statistically different from that of celiac disease. Moreover, a gluten-free diet was prescribed by 64% of the specialists and among them the 73% noted an increase of gluten sensitive patients attending their outpatient services.

CONCLUSIONS

Our study indicated that most of the specialists recognize nonceliac gluten sensitivity and prescribe gluten-free diet, although 44% of the specialists are not able to give its correct definition; underlining the necessity of medical education on this topic is needed.

Genetic differentials of child abuse: Is your case rare or real?

The clinical geneticist can be called upon to play a role in the medical evaluation of children with clinical findings concerning for child abuse. This Introduction describes a case of suspected child abuse in an 8-month-old baby referred to clinical genetics to exclude osteogenesis imperfecta. The experience from this case raised medical and ethical considerations and prompted consideration of the role of the clinical geneticist in distinguishing rare mimics of child abuse from real cases. From this single case, and a discussion regarding similar cases, arose the idea of this issue in Seminars in Medical Genetics, Genetic Differentials of Child Abuse: Is Your Case Rare or Real? In thinking about child abuse from a clinical genetics perspective, we categorize clinical presentations into fractures, skin lesions, hemorrhage, growth disturbances, and concern for caregiver-fabricated illness (previously known as Munchausen syndrome by proxy). In this Introduction, we also discuss recent questions regarding Ehlers-Danlos syndrome and infantile fractures and concerns about caregiver-fabricated illness in the context of mitochondrial or other rare diseases. The goal is that this issue on child abuse and genetics will serve as a resource to help distinguish the rare causes from the real cases of child abuse, and those critical distinctions and correct diagnoses may be life-saving for some infants and children.

Noncoeliac gluten sensitivity: a diagnostic dilemma

PURPOSE OF REVIEW

Noncoeliac gluten sensitivity (NCGS) has gained attention as an emerging clinical entity. Data regarding the epidemiology, pathogenesis, and management of NCGS are scattered in view of the diagnostic uncertainty surrounding the disorder. We aim to provide a current perspective of NCGS and its associated controversies.

RECENT FINDINGS

NCGS consists of a spectrum of intestinal and extraintestinal symptoms related to the ingestion of gluten-containing food, yet in the absence of coeliac disease or wheat allergy. To date, no specific biomarker exists for NCGS, thereby leaving the diagnosis to be confirmed by dietary elimination followed by double-blind placebo-controlled gluten-based rechallenges. Unfortunately, this technique is cumbersome, not readily-available in routine clinical practise, and can still leave the diagnosis of NCGS open to debate as to whether the effects demonstrated can be specifically attributed to the gluten-protein per se or rather coexisting nongluten components, such as fermentable carbohydrates and amylase-trypsin inhibitors.

SUMMARY

Physicians are increasingly being posed with the dilemma of patients presenting with self-reported NCGS. However, this appears to be the tip of the iceberg and future studies are in need of delineating which gluten-based component is responsible for each individual patient's complaint.

High Proportions of People With Nonceliac Wheat Sensitivity Have Autoimmune Disease or Antinuclear Antibodies

BACKGROUND & AIMS

There is much interest in wheat sensitivity among people without celiac disease (CD), but little is known about any risks associated with the condition. We evaluated the prevalence of autoimmune diseases (ADs) among patients with nonceliac wheat sensitivity (NCWS), and investigated whether they carry antinuclear antibodies (ANA).

METHODS

We performed a retrospective study of 131 patients diagnosed with NCWS (121 female; mean age, 29.1 years) at 2 hospitals in Italy from January 2001 through June 2011. Data were also collected from 151 patients with CD or irritable bowel syndrome (IBS) (controls). Patient medical records were reviewed to identify those with ADs. We also performed a prospective study of 42 patients (38 female; mean age, 34 years) diagnosed with NCWS from July 2011 through March 2014 at 3 hospitals in Italy. One hundred age- and sex-matched subjects with CD or IBS served as controls. Serum samples were collected from all subjects and ANA levels were measured by immunofluorescence analysis. Participants completed a questionnaire and their medical records were reviewed to identify those with ADs.

RESULTS

In the retrospective analysis, similar portions of subjects with NCWS (29%) and CD (29%) developed ADs (mainly Hashimoto's thyroiditis, 29 cases), compared with a smaller proportion of subjects with IBS (4%) (P < .001). In the prospective study, 24% of subjects with NCWS, 20% of subjects with CD, and 2% of subjects with IBS developed ADs (P < .001). In the retrospective study, serum samples tested positive for ANA in 46% of subjects with NCWS (median titer, 1:80), 24% of subjects with CD (P < .001), and 2% of subjects IBS (P < .001); in the prospective study, serum samples were positive for ANA in 28% of subjects with NCWS, 7.5% of subjects with CD (P = .02), and 6% of subjects with IBS (P = .005 vs patients with NCWS). ANA positivity was associated with the presence of the HLA DQ2/DQ8 haplotypes (P < .001).

CONCLUSIONS

Higher proportions of patients with NCWS or CD develop autoimmune disorders, are ANA positive, and showed DQ2/DQ8 haplotypes compared with patients with IBS.

The spectrum of noncoeliac gluten sensitivity

The past 5 years have seen an increase in the use of a gluten-free diet outside a diagnosis of coeliac disease or IgE-mediated wheat allergy. This trend has led to the identification of a new clinical entity termed noncoeliac gluten sensitivity (NCGS). In this Review, we discuss the evidence for NCGS as demonstrated by the results of double-blind, placebo-controlled dietary rechallenge studies. Furthermore, the characteristic phenotype of individuals with NCGS is described as well as the symptom manifestations commonly reported after gluten exposure, which include intestinal symptoms consistent with IBS, and extraintestinal symptoms such as neurological dysfunction, psychological disturbances, fibromyalgia and skin rash. Moreover, emerging evidence suggests that NCGS can be associated with organic gastrointestinal pathologies, such as IBD, in which its presence might be a reflection of severe or stricturing disease. However, NCGS is not without its controversies and uncertainties, in particular pertaining to whether it is gluten or nongluten components of the grain evoking symptoms; evidence suggests that fermentable carbohydrates, amylase trypsin inhibitors and wheat-germ agglutinin can also be responsible culprits. Finally, we discuss the novel techniques that might help diagnose NCGS in the future.

Nonceliac Gluten Sensitivity

Nonceliac gluten sensitivity (NCGS) is the clinical term used to describe gastrointestinal (GI) and/or extraintestinal symptoms associated with gluten ingestion. The prevalence of NCGS is unknown. The condition has clinical features that overlap with those of celiac disease (CD) and wheat allergy (WA). The pathophysiologic process in NCGS is thought to be through an innate immune mechanism, whereas CD and WA are autoimmune- and allergen-mediated, respectively. However, dietary triggers other than gluten, such as the fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, have been implicated. Currently, no clinical biomarker is available to diagnose NCGS. Exclusion of CD and WA is necessary in the evaluation of a patient suspected to have NCGS. The onset of symptoms in patients with NCGS can occur within hours or days of gluten ingestion. Patients with NCGS have GI and extraintestinal symptoms that typically disappear when gluten-containing grains are eliminated from their diets. However, most patients suspected to have NCGS have already initiated a gluten-free diet at the time of an evaluation. A gluten elimination diet followed by a monitored open challenge of gluten intake to document recurrence of GI and/or extraintestinal symptoms can sometimes be helpful. If NCGS is strongly suggested, then a skilled dietitian with experience in counseling on gluten-free diets can provide proper patient education. Additional research studies are warranted to further our understanding of NCGS, including its pathogenesis and epidemiology, and to identify a biomarker to facilitate diagnosis and patient selection for proper management.

Cost and availability of gluten-free food in the UK: in store and online

OBJECTIVE

Coeliac disease (CD) is a lifelong condition requiring strict adherence to a gluten-free (GF) diet and good availability of GF foods is critical to this. Patients with CD from lower socioeconomic groups are recognised to have higher treatment burden and higher food costs may impact this. Therefore, we aimed to assess the availability and cost of GF food in supermarkets and via the internet.

DESIGN

Supermarkets and internet shops delivering to homes in a single city (UK) were analysed between February and March 2014. Stores were identified with comprehensive internet searches. Ten commonly purchased items were analysed for cost and compared with standard non-GF alternatives. Direct measurement of the number of GF foods available was compared between stores which were categorised according to previously published work.

SETTING

Supermarkets covering the whole of Sheffield, UK.

RESULTS

None of the budget supermarkets surveyed stocked any GF foods. Quality and regular supermarkets stocked the greatest range, each stocking a median of 22 (IQR 39) items (p<0.0001). All GF foods were at least four times more expensive than non-GF alternatives (p<0.0001). GF products are prevalent online, but 5/10 of the surveyed products were significantly more expensive than equivalents in supermarkets.

CONCLUSIONS

There is good availability of GF food in regular and quality supermarkets as well as online, but it remains significantly more expensive. Budget supermarkets which tend to be frequented by patients from lower socioeconomic classes stocked no GF foods. This poor availability and added cost is likely to impact on adherence in deprived groups.

Diagnosis of gluten related disorders: Celiac disease, wheat allergy and non-celiac gluten sensitivity

Cereal crops and cereal consumption have had a vital role in Mankind’s history. In the recent years gluten ingestion has been linked with a range of clinical disorders. Gluten-related disorders have gradually emerged as an epidemiologically relevant phenomenon with an estimated global prevalence around 5%. Celiac disease, wheat allergy and non-celiac gluten sensitivity represent different gluten-related disorders. Similar clinical manifestations can be observed in these disorders, yet there are peculiar pathogenetic pathways involved in their development. Celiac disease and wheat allergy have been extensively studied, while non-celiac gluten sensitivity is a relatively novel clinical entity, believed to be closely related to other gastrointestinal functional syndromes. The diagnosis of celiac disease and wheat allergy is based on a combination of findings from the patient’s clinical history and specific tests, including serology and duodenal biopsies in case of celiac disease, or laboratory and functional assays for wheat allergy. On the other hand, non-celiac gluten sensitivity is still mainly a diagnosis of exclusion, in the absence of clear-cut diagnostic criteria. A multimodal pragmatic approach combining findings from the clinical history, symptoms, serological and histological tests is required in order to reach an accurate diagnosis. A thorough knowledge of the differences and overlap in clinical presentation among gluten-related disorders, and between them and other gastrointestinal disorders, will help clinicians in the process of differential diagnosis.

Coeliac disease - from genetic and immunological studies to clinical applications

Coeliac disease is a common and important gastrointestinal disease. It affects at least 1%, most Western European populations and in Nordic countries it is even more frequent. It is strongly associated with certain Human Leukocyte Antigen-DQ genes and triggered by ingestion of wheat gluten and related cereals from rye and barley. The diagnosis relies on a combination of clinical signs, serology and small intestinal biopsy. Work during the last couple of decades has shown that gluten-specific, Human Leukocyte Antigen-DQ-restricted T-cells in the intestinal mucosa are of paramount importance in the disease process. The gluten peptides are chemically modified by the endogenous enzyme transglutaminase 2, the same enzyme that serves as target in today's sensitive serological tests for coeliac disease. The increasing knowledge on the disease process allows for development of improved diagnosis, patient care and new treatment modalities.

Wheat-related disorders reviewed: making a grain of sense

Wheat-related disorders have become a growing area of clinical and scientific interest and can be categorized broadly as: autoimmune-mediated; allergic; and non-autoimmune/non-allergic conditions. Non-celiac gluten sensitivity (NCGS) and non-celiac wheat sensitivity (NCWS) present on this spectrum as disorders associated with adverse gastrointestinal and extra-intestinal manifestations following exposure to gluten and/or other wheat-related constituents. NCGS/NCWS is increasingly considered in patients with unexplained symptoms after the exclusions of celiac disease and wheat allergy. As objective diagnostic data and specific biomarkers are lacking, response to a gluten-free/wheat-free diet can confirm the presence of NCGS/NCWS. An association with irritable bowel syndrome has been detected, and the effects of other food components, such as fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, may contribute. Our organization and synthesis of extant knowledge pertaining to wheat-related disorders may advance current practice and research efforts toward an improved understanding of NCGS/NCWS as an evolving clinical entity.

Non-celiac gluten sensitivity: a work-in-progress entity in the spectrum of wheat-related disorders

Non-celiac gluten sensitivity is an undefined syndrome with gastrointestinal and extra-intestinal manifestations triggered by gluten in patients without celiac disease and wheat allergy. The pathogenesis involves immune-mediated mechanisms requiring further research. Symptoms disappear in a few hours or days after gluten withdrawal and recur rapidly after gluten ingestion. Besides gluten, other wheat proteins as well as fermentable oligo-, di-, mono-saccharides and polyols (FODMAPs) may contribute to this syndrome. This syndrome occurs mainly in young women, being rare in children. Its prevalence ranges from 0.6% to 6%, based on primary or tertiary care center estimates. No biomarker is available, but half of patients tests positive for IgG anti-gliadin antibodies, which disappear quickly after gluten-free diet together with symptoms. Also, genetic markers are still undefined. Although currently limited to a research setting, double-blind, placebo-controlled, cross-over trial strategy is recommended to confirm the diagnosis. Treatment is based on dietary restriction with special care to nutrient intake.