Diagnosis of Non-Celiac Gluten Sensitivity (NCGS): The Salerno Experts' Criteria

Non-Celiac Gluten Sensitivity: How Its Gut Immune Activation and Potential Dietary Management Differ from Celiac Disease

Non-celiac gluten sensitivity (NCGS) is a clinical entity triggered by the ingestion of gluten-containing grains leading to intestinal and/or extraintestinal symptoms that resolve once the gluten-containing foodstuff is eliminated from the diet, and it is diagnosed when celiac disease (CD) and wheat allergy (WA) have been ruled out. The limited knowledge about the pathophysiology of NCGS and the lack of validated biomarkers are still major limitations for clinical studies, making it difficult to differentiate NCGS from other gluten-related disorders (GRD). In the absence of clear-cut diagnostic criteria, NCGS is still mainly a diagnosis of exclusion. Several studies suggest that NCGS is an immune-mediated disease that likely activates an innate immune response. Moreover, it has recently been hypothesized that in addition to gluten, other components of wheat may be responsible for the symptoms observed in individuals without CD. This review aims at discussing available evidence related to the histological and immunological features in the gut mucosa of patients with NCGS and at outlining new dietary opportunities for these patients.

Prevalence of Self-Reported Gluten-Related Disorders and Adherence to a Gluten-Free Diet in Salvadoran Adult Population

Gluten-related disorders are not considered of relevance at public health level in Central America. The prevalence of gluten-related disorders, and adherence to a gluten-free diet, remain unknown in the Central American region. We conducted a cross-sectional survey of the Central American population from San Salvador, El Salvador, to estimate the prevalence rates of self-reported gluten-related disorders and adherence to a gluten-free diet. 1326 individuals were surveyed. Self-reported prevalence rates were (95% Confidence Interval): gluten sensitivity 3.1% (2.3–4.2); physician-diagnosed celiac disease 0.15% (0.04–0.5); wheat allergy 0.75% (0.4–1.3); non-celiac gluten sensitivity 0.98% (0.5–1.6). The prevalence rate of adherence to a gluten-free diet was 7.0% (5.7–8.5). Seven self-reported physician diagnosed gluten-sensitive cases informed the co-existence of non-celiac gluten sensitivity with celiac disease and/or wheat allergy. Among the non-self-reported gluten sensitivity individuals following a gluten-free diet, 50% reported that they were seeing a health professional for gluten-free dietary advice. Gluten sensitivity is commonly reported in Salvadoran population, but some health professionals acknowledge the coexistence of wheat allergy, celiac disease, and non-celiac gluten sensitivity. Among studies at population level, the prevalence of adherence to a gluten-free diet in Salvadoran population is the highest reported until now. However, just a few of the gluten-free diet followers were doing it for health-related benefits; the others reported weight control and the perception that the diet is healthier as the main motivation for adopting such a diet.

Influence of low FODMAP and gluten-free diets on disease activity and intestinal microbiota in patients with non-celiac gluten sensitivity

BACKGROUND & AIMS

Non-celiac gluten sensitivity (NCGS) is characterized by intestinal and extra-intestinal symptoms triggered by ingestion of gluten. However, non-gluten triggers have recently been implicated, and a FODMAP (fermentable oligo-, di-, monosaccharides and polyols)-reduced diet can partially improve symptoms in NCGS. Our aim was to analyze the effect of a low FODMAP versus a gluten-free diet (GFD) on clinical symptoms, psychological well-being, intestinal inflammation and integrity, and stool microbiota.

METHODS

Nineteen patients with NCGS and ten healthy controls consumed a gluten-containing standard diet before starting a two-week low FODMAP diet; after a five day transition period, participants ingested a GFD for another two weeks. The primary outcome measure was the improvement of clinical symptoms in NCGS patients under the different diets. Secondary outcomes were the determination of dietary effects on intestinal inflammation, psychological well-being, and differences in stool microbiota between NCGS patients and controls.

RESULTS

The low FODMAP diet and especially the GFD led to a significant improvement of clinical and psychological symptoms in NCGS. A clear reduction in duodenal intraepithelial lymphocytes and mucin-producing Goblet cells was found after the GFD in these patients. Significant microbial differences between NCGS patients and controls were noticed in stool samples at every time point. Both diets caused microbial shifts in all participants, with a greater variability on genus level and metabolisms groups in NCGS patients.

CONCLUSIONS

Our findings suggest a multifactorial etiology of NCGS, due to a functional effect caused by FODMAPs, combined with a mild gluten-triggered immune reaction, and a microbiota dysbalance. CLINICALTRIAL.

GOV ID

NCT03268720.

Challenges in the Standardization of Autoantibody Testing: a Comprehensive Review

Standardization and harmonization are complementary tools to achieve higher testing quality in laboratory medicine. Both are of great relevance and are strongly needed in autoimmune diagnostics, due to the impressive advance in basic research and technological development observed in this diagnostic field in recent years that has led to the introduction of many new tests and new analytical methods. It is, therefore, essential that this strong innovative thrust is translated into clinical practice in a coordinated way to avoid confusion and the risk of potentially harmful errors for the patient. However, while standardization of antibody assays is a very complex task, harmonization of procedures and behaviors is a more feasible target and should necessarily include all the phases of the total testing process-in the pre-analytical phase, appropriateness of test requests, harmonization of autoantibody terminology, and adoption of uniform nomenclature for laboratory tests; in the analytical phase, harmonization of measurements, and sharing of test profiles and diagnostic algorithms; and in the post-analytical phase, harmonization of data reporting, and criteria for interpreting immunoserological results, especially harmonization of units, reference intervals, decision limits, and definition and notification of critical values. We here provide and discuss some examples of harmonization initiatives related to anti-nuclear antibodies, TSH receptor, and anti-thyroid peroxidase antibodies and to antibodies associated with autoimmune hepatitis and with celiac disease. These initiatives could be the starting steps to achieve a wider consensus and a closer interaction among stakeholders in the path of autoimmune diagnostics harmonization to enhance clinical effectiveness and provide greater patient safety.

The effect of a controlled gluten challenge in a group of patients with suspected non-coeliac gluten sensitivity: A randomized, double-blind placebo-controlled challenge

BACKGROUND

Non-coeliac gluten-sensitivity (NCGS) has been proposed as a new entity with unknown prevalence and mechanisms, and there is a need for a standardized procedure to confirm the diagnosis. The objective of this study was to characterize the response to an oral gluten-challenge in patients with a symptom-relief when following a gluten free-diet (GFD).

METHODS

Twenty patients (14F/6M, age range: 21-62 years) with suspected NCGS, without coeliac disease and wheat-allergy, were included while on a gluten-free diet. All patients went through four periods of double-blinded provocation, two with gluten and two with placebo in randomized order. They consumed two muffins a day (11/0 g gluten) for 4 days, followed by a 3-day wash-out. Gastrointestinal symptoms were recorded with questionnaires at baseline and after each provocation. We also investigated whether patients were able to correctly identify periods with gluten-exposure.

KEY RESULTS

Collectively the whole group reported the most severe symptoms after placebo (P = .012). Four out of twenty patients correctly identified the two periods when they received gluten, hence were diagnosed with NCGS. The diagnosed-group tended to show higher symptom scores than the not-diagnosed group both at baseline, after gluten exposure and after placebo, but no clear difference was seen between provocation with gluten and placebo. The not-diagnosed group showed more severe symptoms with placebo than with gluten (P = .029).

CONCLUSIONS AND INFERENCES

The present study showed that the majority of patients with suspected NCGS are not able to identify when challenged with gluten in a double-blind placebo-controlled food challenge, indicating that gluten is not the cause of their symptoms.

Randomized Double-Blind Placebo-Controlled Crossover Trial for the Diagnosis of Non-Celiac Gluten Sensitivity in Children

OBJECTIVES

Non-celiac gluten sensitivity (NCGS) is characterized by intestinal and extra-intestinal symptoms that are related to the ingestion of gluten in subjects who are not affected by either celiac disease (CD) or wheat allergy (WA). In this multicenter study, we aim for the first time to evaluate the prevalence of NCGS in pediatric subjects with chronic functional gastrointestinal symptoms associated with gluten ingestion using a double-blind placebo-controlled (DBPC) gluten challenge with crossover.

METHODS

Among 1,114 children with chronic gastrointestinal symptoms (negative CD and WA), those exhibiting a positive correlation between symptoms and gluten ingestion were eligible for a diagnostic challenge including the following phases: run-in, open gluten-free diet (GFD) and DBPC crossover gluten challenge. Patients were randomized to gluten (10 g/daily) and placebo (rice starch) for 2 weeks each, separated by a washout week. The gluten challenge was considered positive in the presence of a minimum 30% decrease of global visual analogue scale between gluten and placebo.

RESULTS

Out of 1,114 children, 96.7% did not exhibit any correlation with gluten ingestion. Thirty-six children were eligible; after the run-in and open GFD, 28 patients entered the gluten challenge. Eleven children (39.2%; 95% CI: 23.6-53.6%) tested positive.

CONCLUSIONS

This is the first demonstration of the existence of NCGS in children that reinforce the need for a DBPC for the diagnosis as the diagnosis is ruled out in >60% of cases. The registration identifier in ClinicalsTrials.gov is NCT02431585.

IL10 promoter haplotypes may contribute to altered cytokine expression and systemic inflammation in celiac disease

Celiac disease (CD) is an autoimmune/inflammatory condition triggered by dietary gluten intake in genetically predisposed individuals. Though associations with MHC class II HLA-DQ2 or -DQ8 are the primary and necessary genetic predisposition for CD, >97% of genetically predisposed individuals never develop CD. Cytokines were measured in the serum of CD patients and controls. Possible associations with IL10 promoter variants were investigated. Cytokine expression from PBMCs was monitored in response to gluten exposure, or CD3/TCR complex stimulation in the absence or presence of recombinant IL-10. Serum cytokines varied between patients with CD at the time of diagnosis, after dietary elimination of gluten, and healthy controls. Serum IL-17A reflected disease activity. Reduced IL-10 serum levels and altered IL-10 expression by PBMCs coincided with IL10 promoter haplotypes that encode for "low" IL-10 expression (ATA). Increased prevalence of ATA IL10 promoter haplotypes and subsequently reduced IL-10 expression may be an immunological cofactor in individuals genetically predisposed for the development of CD. Resulting cytokine imbalances may be utilized as disease biomarkers in CD.

Gluten sensitivity: fact or fashion statement?

PURPOSE OF REVIEW

In recent years, the concern over food sensitivities in general and gluten intolerance in particular has sharply increased. Patients and medical providers are awash in various claims about the potential implications of including or excluding gluten from the diet.

RECENT FINDINGS

Three main conditions are described with respect to gluten: wheat allergy, celiac disease, and nonceliac gluten sensitivity (NCGS). Wheat allergy is a type 1 hypersensitivity reaction to nongluten proteins within wheat. Celiac disease is an autoimmune reaction to the gluten protein resulting in damage to the small intestine with genetic associations. NCGS is a diagnosis of exclusion and, to date, no biomarkers have been identified for this condition.

SUMMARY

When evaluating and treating patients with potential reactions to gluten, it is important to distinguish among wheat allergy, celiac disease, and NCGS. Each condition has distinct dietary and treatment implications.

Fructan, Rather Than Gluten, Induces Symptoms in Patients With Self-Reported Non-Celiac Gluten Sensitivity

BACKGROUND & AIMS

Non-celiac gluten sensitivity is characterized by symptom improvement after gluten withdrawal in absence of celiac disease. The mechanisms of non-celiac gluten sensitivity are unclear, and there are no biomarkers for this disorder. Foods with gluten often contain fructans, a type of fermentable oligo-, di-, monosaccharides and polyols. We aimed to investigate the effect of gluten and fructans separately in individuals with self-reported gluten sensitivity.

METHODS

We performed a double-blind crossover challenge of 59 individuals on a self-instituted gluten-free diet, for whom celiac disease had been excluded. The study was performed at Oslo University Hospital in Norway from October 2014 through May 2016. Participants were randomly assigned to groups placed on diets containing gluten (5.7 g), fructans (2.1 g), or placebo, concealed in muesli bars, for 7 days. Following a minimum 7-day washout period (until the symptoms induced by the previous challenge were resolved), participants crossed over into a different group, until they completed all 3 challenges (gluten, fructan, and placebo). Symptoms were measured by Gastrointestinal Symptom Rating Scale Irritable Bowel Syndrome (GSRS-IBS) version. A linear mixed model for analysis was used.

RESULTS

Overall GSRS-IBS scores differed significantly during gluten, fructan, and placebo challenges; mean values were 33.1 ± 13.3, 38.6 ± 12.3, and 34.3 ± 13.9, respectively (P = .04). Mean scores for GSRS-IBS bloating were 9.3 ± 3.5, 11.6 ± 3.5, and 10.1 ± 3.7, respectively, during the gluten, fructan, and placebo challenges (P = .004). The overall GSRS-IBS score for participants consuming fructans was significantly higher than for participants consuming gluten (P = .049), as was the GSRS bloating score (P = .003). Thirteen participants had the highest overall GSRS-IBS score after consuming gluten, 24 had the highest score after consuming fructan, and 22 had the highest score after consuming placebo. There was no difference in GSRS-IBS scores between gluten and placebo groups.

CONCLUSIONS

In a randomized, double-blind, placebo-controlled crossover study of individuals with self-reported non-celiac gluten sensitivity, we found fructans to induce symptoms, measured by the GSRS-IBS. Clinicaltrials.gov no: NCT02464150.

Amylase-Trypsin Inhibitors in Wheat and Other Cereals as Potential Activators of the Effects of Nonceliac Gluten Sensitivity

Nonceliac gluten sensitivity (NCGS) is a gluten-related gastrointestinal disorder distinct from celiac disease (CD) and gluten allergy that is not easy to diagnose due to the lack of biomarkers. It is characterized by intestinal symptoms and extraintestinal manifestations with the consumption of gluten-containing foods. In contrast to CD, NCGS patients do not present a genetic predisposition or intestinal villi atrophy. Recent studies question the proinflammatory triggering activity of α-gliadin fraction contained in wheat, since it has been demonstrated that the amylase-trypsin inhibitors (ATIs) exert a strong activating effect on the innate immune response. We aimed to analyze the role of ATIs in the activation of innate immunity and in the development of the symptoms characteristic of NCGS. A systematic literature search was made using databases such as MEDLINE, SciELO, Science Direct, and Scopus, with focus on key words such as "amylase-trypsin inhibitors," "wheat," "gluten," and "celiac." Many studies are available on the structure, inhibition mechanism, and immune system effects of ATIs, mainly focused on IgE-mediated reactions. Recently, with the increase of NCGS interest, has increased the literature on the capacity of ATIs contained in wheat to activate the innate immune system. Literature published to date questions the relationship between activation of the innate immune system and gluten in NCGS. ATIs may have acted as interfering contaminant of gluten and appear as potential activator of innate immunity in NCGS patients. In view of their potential impact, more interventional studies are needed to demonstrate the proinflammatory effect of ATIs.

Biological markers for non-celiac gluten sensitivity: a question awaiting for a convincing answer

Non Celiac Gluten Sensitivity (NCGS) is characterized by immunological, morphological or symptomatic manifestations precipitated by gluten ingestion in individuals without celiac disease (CD). The most important challenge in NCGS is the diagnosis, currently based only on clinical observation. The "Salerno criteria" have been pointed out to achieve a reliable diagnosis even if they lack immediacy and practicality, thus making questionable patient's adherence. Therefore, biological indicators supporting the clinical diagnosis of NCGS are advisable. For these reasons, many attempts have been performed in order to identify possible serological, immunological, histopathological, immunohistochemical and pathophysiological aspects characterizing this condition with the aim of using them for diagnostic purposes. In the present narrative review, we carried out an update of the current scenario of potential markers of NCGS. The main fault of available studies is that, in most cases investigations have been pointed out towards molecules, which cannot be searched in the current laboratories of clinical analysis. Therefore, the matter has been confined within basic research. Additionally, in these studies, sensitivity and specificity of biological markers were not computable. This is a relevant limit, since an ideal test for NCGS should have a good discriminative power against both CD and other causes of microscopic enteritis. Until now, serological tests have failed, while the search for a soluble marker indicative of activation of innate immune system as well as immunohistochemistry could be the promising bases for the development of appropriate investigations in the future.

Post pancreatitis/cholecystectomy gluten intolerance

This case report describes the journey of a patient who suffered from life-limiting gastrointestinal symptoms after an acute bout of pancreatitis following ERCP for cholelithiasis bile following a ductal stone, and subsequent cholecystectomy. She was diagnosed and treated for IBS with medication without significant improvement. On implementation of a simple gluten and lactose exclusion diet she recovered to her premorbid state, and trials of gluten challenge triggered flares of symptoms. This case report will go on to discuss current evidence for use of gluten and lactose exclusion diets in some gluten sensitive patients misdiagnosed with IBS.

Non celiac gluten sensitivity and diagnostic challenges

Non-celiac gluten sensitivity (NCGS), also referred to as non-celiac wheat sensitivity (NCWS), is a clinical syndrome characterized by both intestinal and extra-intestinal symptoms responsive to the withdrawal of gluten-containing food from the diet. The aim of this review is to summarize recent advances in research and provide a brief overview of the history of the condition for the benefit of professionals working in gastroenterology. Academic databases such as PubMed and Google Scholar were searched using key words such as "non-celiac gluten sensitivity", "gluten related disorders", and the studies outlined in reference page were selected and analysed. Most of the analysed studiers agree that NCGS would need to be diagnosed only after exclusion of celiac disease and wheat allergy, and that a reliable serological marker is not available presently. The mechanisms causing symptoms in NCGS after gluten ingestion are largely unknown, but recent advances have begun to offer novel insights. The estimated prevalence of NCGS, at present, varies between 0.6 and 6%. There is an overlap between irritable bowel syndrome and NCGS with regard to the similarity of gastrointestinal symptoms. The histologic characteristics of NCGS are still under investigation, ranging from normal histology to slight increase in the number of T lymphocytes in the superficial epithelium of villi. Positive response to gluten free diet for a limited period (e.g., 6 weeks), followed by the reappearance of symptoms after gluten challenge appears, at this moment, to be the best approach for confirming diagnosis. The Salerno expert criteria may help to diagnose NCGS accurately in particular for research purposes but it has limited applicability in clinical practice.

T Helper Lymphocyte and Mast Cell Immunohistochemical Pattern in Nonceliac Gluten Sensitivity

Background and Aims

Nonceliac gluten sensitivity (NCGS) is a gluten-related emerging condition. Since few data about NCGS histopathology is available, we assessed the markers of lymphocyte and innate immunity activation.

Materials and Methods

We retrieved duodenal biopsy samples of patients with NCGS diagnosis according to the Salerno criteria. We selected specimens of positive (seropositive celiac disease/Marsh 1-2 stage) and negative (normal microscopic picture) controls. Immunohistochemistry for CD3 (intraepithelial lymphocytes-IELs), CD4 (T helper lymphocytes), CD8 (T cytotoxic lymphocytes), and CD1a/CD117 (Langerhans/mast cells) was performed. ANOVA plus Bonferroni's tests were used for statistical analysis.

Results

Twenty NCGS, 16 celiac disease, and 16 negative controls were selected. CD3 in NCGS were higher than negative controls and lower than celiac disease (18.5 ± 6.4, 11.9 ± 2.8, and 40.8 ± 8.1 IELs/100 enterocytes; p < 0.001). CD4 were lower in NCGS than controls and celiac disease (31.0 ± 22.1, 72.5 ± 29.5, and 103.7 ± 15.7 cells/mm²; p < 0.001). CD8 in NCGS were similar to negative controls, but lower than celiac disease (14.0 ± 7.4 and 34.0 ± 7.1 IELs/100 enterocytes, p < 0.001). CD117 were higher in NCGS than celiac disease and negative controls (145.8 ± 49.9, 121.3 ± 13.1, and 113.5 ± 23.4 cells/mm²; p = 0.009).

Conclusions

The combination of CD4 and CD117, as well as IEL characterization, may be useful to support a clinical diagnosis of NCGS.

Coeliac disease and gastrointestinal symptom screening in adult first-degree relatives

BACKGROUND AND AIM

The first-degree relatives (FDRs) of patients with coeliac disease are the main risk group for disease development. The study aims to evaluate the screening strategy in FDRs with negative coeliac serology based on human leukocyte antigen (HLA) genotyping, followed by duodenal biopsy, and to analyze the prevalence of gastrointestinal symptoms and the influence of gluten intake.

METHODS

Adult FDRs with negative coeliac serology were invited to participate (n = 205), and a total of 139 completed the study protocol. HLA genotyping, transglutaminase antibody assessment, and duodenal biopsy were performed. Symptomatology was assessed using questionnaires during the various phases of dietary modification (baseline diet, gluten-free diet, and gluten overload).

RESULTS

The study included 139 participants (mean age, 42 years; 53.2% women). HLA-DQ2/8 was positive in 78.4% of the participants (homozygous, 15.1%; heterozygous, 63.3%). Histopathological alterations were noted in 37.1% of participants who underwent duodenal biopsy (Marsh I, 32.7%; Marsh IIIa, 4.4%). At baseline, symptoms were observed in 45.7% of the participants, and the proportion decreased to 24.5% after the gluten-free diet (P < 0.001). Symptoms were not associated with the presence of histological alterations or genetic risk. However, younger age (odds ratio [OR] = 0.91), female sex (OR = 2.9), and the presence of autoimmune disorders (OR = 2.8) were independently associated with a significant symptom response to the gluten-free diet.

CONCLUSIONS

Duodenal lymphocytosis and atrophy are frequently noted in FDRs, despite negative serological markers. In addition, gastrointestinal symptoms are commonly present and associated with gluten intake regardless of the histological pathology.

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.

Celiac Disease and Gluten Sensitivity

Celiac disease is an immune-mediated enteropathy triggered by gluten that affects genetically predisposed individuals, typically causing intestinal symptoms and malabsorption. Diagnosis requires stepwise evaluation with anti-tissue transglutaminase IgA and histologic analysis of the small bowel. Strict adherence to a gluten-free diet is the primary treatment. Patients with symptoms thought to be related to gluten but without evidence of celiac disease are difficult to diagnose and treat. Consider first advising general nutritional improvements. If symptoms persist, involve a trained dietitian for restrictive diets and consider evaluation for small intestinal bacterial overgrowth or other treatments for irritable bowel syndrome.

A New Proposal for the Pathogenic Mechanism of Non-Coeliac/Non-Allergic Gluten/Wheat Sensitivity: Piecing Together the Puzzle of Recent Scientific Evidence

Non-coeliac/non-allergic gluten/wheat sensitivity (NCG/WS) is a gluten-related disorder, the pathogenesis of which remains unclear. Recently, the involvement of an increased intestinal permeability has been recognized in the onset of this clinical condition. However, mechanisms through which it takes place are still unclear. In this review, we attempt to uncover these mechanisms by providing, for the first time, an integrated vision of recent scientific literature, resulting in a new hypothesis about the pathogenic mechanisms involved in NCG/WS. According to this, the root cause of NCG/WS is a particular dysbiotic profile characterized by decreased butyrate-producing-Firmicutes and/or Bifidobacteria, leading to low levels of intestinal butyrate. Beyond a critical threshold of the latter, a chain reaction of events and vicious circles occurs, involving other protagonists such as microbial lipopolysaccharide (LPS), intestinal alkaline phosphatase (IAP) and wheat α-amylase trypsin inhibitors (ATIs). NCG/WS is likely to be a multi-factor-onset disorder, probably transient and preventable, related to quality and balance of the diet, and not to the presence of gluten in itself. If future studies confirm our proposal, this would have important implications both for the definition of the disease, as well as for the prevention and therapeutic-nutritional management of individuals with NCG/WS.

Gluten-related disorders: certainties, questions and doubts

In the last decade, the ingestion of gluten, a heterogeneous complex of proteins present in wheat, rice, barley and probably in oats, has been associated with clinical disorders, such as celiac disease, wheat allergy and recently to non-celiac gluten sensitivity or wheat intolerance syndrome. Gluten-related disorders, which are becoming epidemiologically relevant with an estimated global prevalence of about 5%, require the exclusion of gluten from the diet. For the past 5 years, an important shift in the availability of gluten-free products, together with increased consumption in the general population, has been recorded and is estimated to be about 12-25%. Many people follow a self-prescribed gluten-free diet, despite the fact that the majority have not first been previously excluded, or confirmed, as having gluten disorders. They rely on claims that a gluten-free diet improves general health. In this review, we provide an overview of the clinical disorders related to gluten or wheat ingestion, pointing out the current certainties, open questions, possible answers and several doubts in the management of these conditions. KEY MESSAGE Incidence of gluten-related disorders is increased in the last decade and self-diagnosis is frequent with inappropriate starting of a gluten-free diet. Gluten and wheat are considered as the most important triggers to coeliac disease, wheat allergy and non-celiac gluten sensitivity. Pediatricians, allergologist and gastroenterologist are involved in the management of these conditions and appropriate diagnostic protocols are required.

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.

Non-coeliac gluten or wheat sensitivity: emerging disease or misdiagnosis?

Non-coeliac gluten or wheat sensitivity (NCG/WS) is a condition characterised by adverse gastrointestinal and/or extra-intestinal symptoms associated with the ingestion of gluten- or wheat-containing foods, in the absence of coeliac disease or wheat allergy. Up to one in 100 people in Australia may have coeliac disease but many more report adverse gastrointestinal and/or extra-intestinal symptoms after eating wheat products. In the absence of validated biomarkers, a diagnosis of NCG/WS can only be made by a double-blind, placebo-controlled, dietary crossover challenge with gluten, which is difficult to apply in clinical practice. Of people self-reporting gluten or wheat sensitivity, only a small proportion (16%) will have reproducible symptoms after a blinded gluten challenge of gluten versus placebo in a crossover dietary trial and fulfil the current consensus criteria for a diagnosis of NCG/WS. A wide range of symptoms are associated with NCG/WS, including gastrointestinal, neurological, psychiatric, rheumatological and dermatological complaints. The pathogenesis of NCG/WS is not well understood, but the innate immune system has been implicated, and there is overlap with coeliac disease and the functional gastrointestinal disorders (irritable bowel syndrome and functional dyspepsia). Identification of NCG/WS is important as gluten-free diets carry risks, are socially restricting and are costlier than regular diets.

Interfering with the high-affinity interaction between wheat amylase trypsin inhibitor CM3 and toll-like receptor 4: in silico and biosensor-based studies

Wheat amylase/trypsin bi-functional inhibitors (ATIs) are protein stimulators of innate immune response, with a recently established role in promoting both gastrointestinal and extra-gastrointestinal inflammatory syndromes. These proteins have been reported to trigger downstream intestinal inflammation upon activation of TLR4, a member of the Toll-like family of proteins that activates signalling pathways and induces the expression of immune and pro-inflammatory genes. In this study, we demonstrated the ability of ATI to directly interact with TLR4 with nanomolar affinity, and we kinetically and structurally characterized the interaction between these macromolecules by means of a concerted approach based on surface plasmon resonance binding analyses and computational studies. On the strength of these results, we designed an oligopeptide capable of preventing the formation of the complex between ATI and the receptor.

[Gluten: Is the information available on the Internet valid?]

BACKGROUND

Internet provides easy access to health information, but the quality and validity of this information vary.

OBJECTIVES

Evaluate the quality of website structures and the information provided on celiac disease (CD), gluten sensitivity (GS), and wheat allergy (WA).

MATERIALS AND METHODS

The websites addressing CD, GS, and WA appearing on the first two pages of Google, Yahoo, and Bing from seven selected queries were investigated. We initially assessed the website structures with one instrument (Netscoring) and the presence of certification (quality label Health On the Net (HON code)). Then we evaluated the content of each website concerning the information about CD, GS, and WA. Our repository was based on the most recent guidelines of the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) and the World Gastroenterology Organization (WGO) published in 2012. The websites were classified into eight categories.

RESULTS

One hundred and five websites were included. Twenty-one websites obtained a sufficient score with the Netscoring instrument (average 113.6/312). There was a significant correlation between the referenced websites analyzed and the grades obtained with the Netscoring instrument (Pearson=0.39, P=0.2×10^-5): websites of scientific societies (11.8/18), community websites (9.44/18), and website associations (9.4/18). There was a significant correlation between the results obtained for the websites on CD, GS, and WA and the results obtained for the websites with the Netscoring instruments (Pearson=0.41, P=2.6×10^-6). Only three websites were consistent with the guidelines on CD, GS, and WA.

CONCLUSION

The websites were partially in agreement with the guidelines. To date, the pediatrician remains the main actor in parental guidance concerning gluten information.

Re-challenge Studies in Non-celiac Gluten Sensitivity: A Systematic Review and Meta-Analysis

Background: Non-celiac gluten sensitivity (NCGS) is a clinical entity characterized by intestinal and/or extra-intestinal symptoms related to the ingestion of gluten in individuals that are not affected by either celiac disease (CD) or wheat allergy (WA). Since we do not have specific biomarkers for NCGS, the diagnosis is based on the evidence of a clear relationship between the ingestion of gluten (re-challenge) and clinical symptoms, after a remission during the gluten-free diet (GFD). Several re-challenge studies have been published so far to evaluate the real prevalence of NCGS, reporting conflicting results. In the present article, we provide a systematic review with meta-analysis of the existing literature on re-challenge studies to evaluate prevalence figures of NCGS after re-challenge procedures. Methods: All clinical trials performing a gluten re-challenge with or without a placebo control in patients with a suspected diagnosis of NCGS were included. Search results were limited to studies published in English language. No publication date or publication status restrictions were imposed. Results: Eleven studies were included in the meta-analysis. There was a considerable heterogeneity related to different sample size, type, and amount of gluten administered, duration of challenge and different type of placebo. The overall pooled percentage of patients with a diagnosis of NCGS relapsing after a gluten challenge was 30%, ranging between 7 and 77%. The meta-analysis showed a not significant relative risk (RR) of relapse after gluten challenge as compared to placebo (RR = 0.4; 95% CI = -0.15-0.9; p = 0.16). The overall pooled percentage of patients with a diagnosis of NCGS relapsing after a gluten challenge performed according to the recent Salerno criteria was significantly higher as compared to the percentage of patients relapsing after placebo (40 vs. 24%; p = 0.003), with a significant RR of relapse after gluten challenge as compared to placebo (RR = 2.8; 95% CI = 1.5-5.5; p = 0.002). Conclusions: The prevalence of NCGS after gluten re-challenge is low, and the percentage of relapse after a gluten or a placebo challenge is similar. However, a higher number of patients will be correctly classified with NCGS if applying the recent Salerno criteria.

Coeliac disease: review of diagnosis and management

Coeliac disease is an immune-mediated systemic disease triggered by exposure to gluten, and manifested by small intestinal enteropathy and gastrointestinal and extra-intestinal symptoms. Recent guidelines recommend a concerted use of clear definitions of the disease. In Australia, the most recent estimated prevalence is 1.2% in adult men (1:86) and 1.9% in adult women (1:52). Active case finding is appropriate to diagnose coeliac disease in high risk groups. Diagnosis of coeliac disease is important to prevent nutritional deficiency and long term risk of gastrointestinal malignancy. The diagnosis of coeliac disease depends on clinico-pathological correlation: history, presence of antitransglutaminase antibodies, and characteristic histological features on duodenal biopsy (when the patient is on a gluten-containing diet). Human leucocyte antigen class II haplotypes DQ2 or DQ8 are found in nearly all patients with coeliac disease, but are highly prevalent in the general population at large (56% in Australia) and testing can only exclude coeliac disease for individuals with non-permissive haplotypes. Adhering to a gluten free diet allows duodenal mucosal healing and alleviates symptoms. Patients should be followed up with a yearly review of dietary adherence and a health check. Non-coeliac gluten or wheat protein sensitivity is a syndrome characterised by both gastrointestinal and extra-intestinal symptoms related to the ingestion of gluten and possibly other wheat proteins in people who do not have coeliac disease or wheat allergy recognised by diagnostic tests.

Self-Reported Non-Celiac Wheat Sensitivity in High School Students: Demographic and Clinical Characteristics

BACKGROUND

Non-Celiac Wheat Sensitivity (NCWS) has recently been included among the gluten-related disorders. As no biomarkers of this disease exist, its frequency has been estimated based on self-reported symptoms, but to date no data are available about self-reported NCWS in teenagers.

AIM

To explore the prevalence of self-reported NCWS in a group of high school students and to study their demographic and clinical characteristics.

METHODS

The study was performed between April 2015 and January 2016 in two high schools of a coastal town in the south of Sicily (Italy). A total of 555 students (mean age 17 years, 191 male, 364 female) completed a modified validated questionnaire for self-reported NCWS. The subjects who self-reported NCWS were then compared with all the others.

RESULTS

Seven individuals (1.26%) had an established diagnosis of CD. The prevalence of self-reported NCWS was 12.2%, and 2.9% were following a gluten-free diet (GFD). Only 15 out of 68 (23%) NCWS self-reporters had consulted a doctor for this problem and only nine (14%) had undergone serological tests for celiac disease. The NCWS self-reporters very often had IBS symptoms (44%).

CONCLUSIONS

Self-reported NCWS was found to be common in teenagers, with a frequency of 12.2%; the frequency of GFD use was 2.9%, which was much higher than the percentage of known CD in the same population (1.26%). A greater awareness of the possible implications on the part of the subjects involved, and a more thorough medical approach to the study of self-reported wheat-induced symptoms are required.

The enteric toxicity of gluten enhances graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Pro-inflammatory peptides present in wheat and related grains are associated with celiac disease and non-celiac gluten sensitivity. We hypothesize that these peptides induce enteric responses that may exacerbate the gastrointestinal manifestations of graft-versus-host disease after an allogeneic hematopoietic stem cell transplant. Therefore, we propose that a gluten free diet should be tested as a prophylactic and/or therapeutic intervention against gastrointestinal graft-versus-host disease for patients undergoing an allogeneic hematopoietic stem cell transplant.

Persistence of Nonceliac Wheat Sensitivity, Based on Long-term Follow-up

We investigated how many patients with a diagnosis of nonceliac wheat sensitivity (NCWS) still experienced wheat sensitivity after a median follow-up time of 99 months. We collected data from 200 participants from a previous study of NCWS, performed between July and December 2016 in Italy; 148 of these individuals were still on a strict wheat-free diet. In total, 175 patients (88%) improved (had fewer symptoms) after a diagnosis of NCWS; 145 of 148 patients who adhered strictly to a gluten-free diet (98%) had reduced symptoms, compared with 30 of 52 patients who did not adhere to a gluten-free diet (58%) (P < .0001). Of the 22 patients who repeated the double-blind, placebo-controlled challenge, 20 reacted to wheat. We conclude that NCWS is a persistent condition. Clinicaltrials.gov registration number: NCT02823522.

The Effects of a Gluten-free Diet Versus a Hypocaloric Diet Among Patients With Fibromyalgia Experiencing Gluten Sensitivity-like Symptoms: A Pilot, Open-Label Randomized Clinical Trial

BACKGROUND AND AIMS

Patients with fibromyalgia frequently present with symptoms similar to those experienced by patients with gluten-related disorders, raising the possibility that a subgroup of these patients could be experiencing underlying gluten sensitivity. This study aimed to evaluate the effects of a gluten-free diet (GFD) compared with a hypocaloric diet (HCD) among patients with fibromyalgia.

METHODS

Adult patients diagnosed with fibromyalgia were randomly allocated to receive a GFD or a HCD over a 24-week period. The primary outcome measure was the change in the number of gluten sensitivity symptoms. The following secondary outcomes were evaluated: body mass index, Revised Fibromyalgia Impact Questionnaire, Pittsburgh Sleep Quality Index, Brief Pain Inventory, Beck Depression Inventory-II, State-Trait Anxiety Inventory, Short-Form Health Survey, Patient Global Impression Scale of Severity, Patient Global Impression Scale of Improvement, and adverse events.

RESULTS

Seventy-five subjects were randomly allocated to receive either a GFD (n=35) or an HCD (n=40). The least squares mean change in the total number of gluten sensitivity symptoms from baseline did not differ significantly between the GFD and HCD groups (-2.44±0.40 for the GFD; -2.10±0.37 for the HCD; P=0.343). Similarly, the 2 dietary interventions did not differ in any of the remaining measured secondary outcomes. Both dietary interventions were well tolerated.

CONCLUSIONS

Both dietary interventions were associated with similar beneficial outcomes in reducing gluten sensitivity symptoms and other secondary outcomes. However, despite its specificity, GFD was not superior to HCD in reducing the number of gluten sensitivity symptoms or secondary outcomes.

Review paper. Gluten-related disorders and schizophrenia - potential linking mechanisms, diagnostic and therapeutic challenge

More and more evidence confirms the theory that the intake of cereal products containing gluten may play an important role in the pathogenesis of many diseases. There are also premises indicating the relationship between the so-called gluten-related diseases and the development and course of mental disorders, including schizophrenia.

The aim of this article is to review the literature on the potential relationship between the consumption of gluten and schizophrenia, considering the etiopathogenesis and the role of gluten-free diet in the treatment of schizophrenia.

Methods: There were analysed available research papers in PubMed and Google Scholar with the key words: schizophrenia, gluten- related disorders, allergy to grain products, celiac disease, microbiota, immune system, exorphins and time span: 1960-2016 .

Conclusions: Existing research results indicate a possible relationship between diet rich in grain products with high gluten content and the occurrence or exacerbation of schizophrenia symptoms. However, further studies are necessary to: 1) identify groups of patients for whom the consumption of cereal products (gluten) is associated with a particular risk of schizophrenia exacerbation, 2) determine the mechanisms relating the consumption of gluten with the mental state of schizophrenic patients, 3) get the possible benefits of implementing gluten-free diet in patients with schizophrenia.

Responses of blood mononucleated cells and clinical outcome of non-celiac gluten sensitive pediatric patients to various cereal sources: a pilot study

Non-celiac gluten sensitivity (NCGS) is a clinical entity recently documented by the scientific community in pediatric patients. Nevertheless, its triggering mechanisms remain largely unsettled. We studied 11 children with NCGS who were diagnosed based on a clear-cut relationship between wheat consumption and development of symptoms, after excluding celiac disease (CD) and wheat allergy, matched with 18 children with active CD. Sixteen pediatric patients were also enrolled as controls. Cultured peripheral blood mononucleated cells (PBMCs) obtained from NCGS, CD and control patients were cultured in the presence of wheat proteins extracted from ancient and modern cultivars. Results demonstrated that wheat proteins induced an overactivation of the proinflammatory chemokine CXCL10 in PBMC from NCGS pediatric patients and that this overexpression also depended on the wheat cultivar from which proteins were extracted. Proteins from modern wheat cultivar activated CXCL10 to a greater extent than those extracted from ancient wheat genotypes.

Nutritional Wheat Amylase-Trypsin Inhibitors Promote Intestinal Inflammation via Activation of Myeloid Cells

BACKGROUND & AIMS

Wheat amylase-trypsin inhibitors (ATIs) are nutritional activators of innate immunity, via activation of the toll-like receptor 4 (TLR4) on myeloid cells. We aimed to characterize the biologic activity of ATIs in various foods and their effect on intestinal inflammation.

METHODS

We selected 38 different gluten-containing and gluten-free products, either unprocessed (such as wheat, rye, barley, quinoa, amaranth, soya, lentils, and rice) or processed (such as pizza, pasta, bread, and biscuits). ATIs were extracted and their biological activities determined in TLR4-responsive mouse and human cell lines. Effects of oral ATIs on intestinal inflammation were determined in healthy C57BL/6 mice on a gluten-free or ATI-free diet and in mice given low-level polyinosinic:polycytidylic acid or dextran sodium sulfate to induce colitis. Parameters of innate and adaptive immune activation were determined in duodenum, ileum, colon, and mesenteric lymph nodes.

RESULTS

Modern gluten-containing staples had levels of TLR4-activating ATIs that were as much as 100-fold higher than in most gluten-free foods. Processed or baked foods retained ATI bioactivity. Most older wheat variants (such as Emmer or Einkorn) had lower bioactivity than modern (hexaploid) wheat. ATI species CM3 and 0.19 were the most prevalent activators of TLR4 in modern wheat and were highly resistant to intestinal proteolysis. Their ingestion induced modest intestinal myeloid cell infiltration and activation, and release of inflammatory mediators-mostly in the colon, then in the ileum, and then in the duodenum. Dendritic cells became prominently activated in mesenteric lymph nodes. Concentrations of ATIs found in a normal daily gluten-containing diet increased low-level intestinal inflammation.

CONCLUSIONS

Gluten-containing cereals have by far the highest concentrations of ATIs that activate TLR4. Orally ingested ATIs are largely resistant to proteases and heat, and increase intestinal inflammation by activating gut and mesenteric lymph node myeloid cells.

[Celiac disease : Pathogenesis, clinics, epidemiology, diagnostics, therapy]

Celiac disease is induced by the consumption of gluten containing cereals (wheat, spelt, barley, rye). With a prevalence of ~ 1 %, it is the most common non-infectious chronic inflammatory intestinal disease worldwide. It manifests in all age groups, either classically with abdominal pain, diarrhoea and growth failure or weight loss, more commonly with indirect consequences of malabsorption, such as anaemia and osteoporosis, or with associated autoimmune diseases like type 1 diabetes, autoimmune thyroiditis or dermatitis herpetiformis. The pathogenesis of celiac disease is well explored. Gluten, the cereal storage protein, is not completely digested and reaches the intestinal mucosa where it activates inflammatory T cells, which cause atrophy of the resorptive villi. This T‑cell activation requires a genetic predisposition (the molecules HLA-DQ2 or -DQ8 on antigen-presenting immune cells). Moreover, the enzyme tissue transglutaminase (TG2) which is released in the mucosa increases the immunogenicity of the gluten peptides by a deamidation reaction. The test for serum antibodies to the autoantigen TG2 is one of the best diagnostic markers in medicine, which in combination with endoscopically obtained biopsies, secures the diagnosis of celiac disease. Despite these tools celiac disease is severely underdiagnosed, with 80-90 % of those affected being undetected. The untreated condition can lead to grave complications. These include the consequences of malabsorption, cancers (especially intestinal T‑cell lymphoma), and likely also the promotion of autoimmune diseases. The therapy of celiac disease, a strict gluten-free diet, is difficult to maintain and not always effective. Alternative, supporting pharmacological therapies are urgently needed and are currently in development.

New insights into the pathogenesis and treatment of irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders (FGID), characterized by abdominal pain and a change in stool form that cannot be explained by structural abnormalities. Its prevalence ranges from 9 to 23% of the worldwide population. The pathophysiology of IBS is diverse and not well understood. Biopsychosocial concept assumes that the disease is a product of psychosocial factors and altered at multiple levels of gut physiology interactions. Some aetiological factors have been identified, yet. One of the most important is the disruption of brain-gut mutual communication that leads to visceral hypersensitivity. Also genetic and epigenetic factors are involved. Chronic stress may predispose to IBS as well as exacerbate its symptoms. Both quantitative and qualitative disorders of the gut microbiota are observed. There is also a relationship between the IBS symptoms and the intake of a specific type of food products. In the diarrhoea type of IBS the role of previous gastrointestinal infection is demonstrated. Recent studies have suggested that visceral hypersensitivity in patients with IBS may be secondary to the activation of the immune cells and low-grade inflammation. Clinical symptoms of IBS include abdominal pain and change in bowel habits as well as somatic and psychiatric comorbidities. IBS is diagnosed on the basis of Rome Diagnostic Criteria. Recently, their newest version (Rome IV) has been presented. The aim of this review is to summarize the past decade progress in IBS diagnosis, main pathophysiological aspects and therapeutic management strategy.

Suspected Nonceliac Gluten Sensitivity Confirmed in Few Patients After Gluten Challenge in Double-Blind, Placebo-Controlled Trials

A double-blind, placebo-controlled, gluten challenge has been proposed to confirm a diagnosis of nonceliac gluten sensitivity (NCGS) in patients without celiac disease who respond to a gluten-free diet. To determine the accuracy of this approach, we analyzed data from 10 double-blind, placebo-controlled, gluten-challenge trials, comprising 1312 adults. The studies varied in the duration of the challenge (range, 1 d to 6 wk), daily doses for the gluten challenge (range, 2-52 g; 3 studies administered <8 g/d), and composition of the placebo (gluten-free products, xylose, whey protein, rice, or corn starch containing fermentable carbohydrates). Most of the studies found gluten challenge to significantly increase symptom scores compared with placebo. However, only 38 of 231 NCGS patients (16%) showed gluten-specific symptoms. Furthermore, 40% of these subjects had a nocebo response (similar or increased symptoms in response to placebo). These findings reveal heterogeneity and potential methodology flaws among studies of gluten challenge, cast doubt on gluten as the culprit food component in most patients with presumptive NCGS, and highlight the importance of the nocebo effect in these types of studies.

Contact Dermatitis Due to Nickel Allergy in Patients Suffering from Non-Celiac Wheat Sensitivity

Background: Non-celiac wheat sensitivity (NCWS) is a new clinical entity in the world of gluten-related diseases. Nickel, the most frequent cause of contact allergy, can be found in wheat and results in systemic nickel allergy syndrome and mimics irritable bowel syndrome (IBS). Objective: To evaluate the frequency of contact dermatitis due to nickel allergy in NCWS patients diagnosed by a double-blind placebo-controlled (DBPC) challenge, and to identify the characteristics of NCWS patients with nickel allergy. Methods: We performed a prospective study of 60 patients (54 females, 6 males; mean age 34.1 ± 8.1 years) diagnosed with NCWS from December 2014 to November 2016; 80 age- and sex-matched subjects with functional gastrointestinal symptoms served as controls. Patients reporting contact dermatitis related to nickel-containing objects underwent nickel patch test (Clinicaltrials.gov registration number: NCT02750735). Results: Six out of sixty patients (10%) with NCWS suffered from contact dermatitis and nickel allergy and this frequency was statistically higher (p = 0.04) than observed in the control group (5%). The main clinical characteristic of NCWS patients with nickel allergy was a higher frequency of cutaneous symptoms after wheat ingestion compared to NCWS patients who did not suffer from nickel allergy (p < 0.0001). Conclusions: Contact dermatitis and nickel allergy are more frequent in NCWS patients than in subjects with functional gastrointestinal disorders; furthermore, these patients had a very high frequency of cutaneous manifestations after wheat ingestion. Nickel allergy should be evaluated in NCWS patients who have cutaneous manifestations after wheat ingestion.

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.

Wheat challenge in self-reported gluten sensitivity: a comparison of scoring methods

BACKGROUND

The condition non-coeliac gluten sensitivity (NCGS) is clinically similar to coeliac disease, but lack objective diagnostic criteria. Symptom relief on gluten-free diet followed by gluten containing food challenge may confirm the condition in clinical settings.

AIM

To describe the results of an open bread challenge in patients with suspected NCGS, and to compare the results with recently suggested cut-offs for symptom change.

MATERIAL AND METHODS

Fifty-six patients (12 males) self-instituted on gluten-free diet with negative coeliac disease diagnostics were examined for NCGS by an open bread challenge. Symptoms were reported by Gastrointestinal Symptom Rating Scale, IBS-version (GSRS-IBS) and visual analogue scale (VAS). Results were retrospectively compared to the Salerno and Monash cut-offs for symptom change.

RESULTS

Forty-seven patients were diagnosed with NCGS. Total GSRS-IBS score and overall symptoms by VAS increased significantly in NCGS (p < .001), but not in non-NCGS patients (p < .12 and p = .08, respectively). Total GSRS-IBS challenge score and overall symptoms by VAS were significantly higher in NCGS than in non-NCGS patients (53 vs. 37, p = .004 and 76 vs. 39 mm, p = .02, respectively). Applying the Salerno and Monash cut-offs, 63 and 75% would be classified with NCGS, respectively. According to total GSRS-IBS absolute agreement was lowest between clinician's diagnosis and Salerno cut-off (63%) and highest between Salerno and Monash cut-offs (88%).

CONCLUSION

Clinician diagnosed 85% with NCGS. The proportion of NCGS was lower according to the Salerno and Monash cut-offs. The Salerno cut-off should be the starting point for a common definition of symptom change.

Intraepithelial lymphocytes, scores, mimickers and challenges in diagnosing gluten-sensitive enteropathy (celiac disease)

The upper digestive tract is routinely scoped for several causes of malabsorption, and the number of duodenal biopsy specimens has increased notably in the last 10 years. Gluten-sensitive enteropathy (GSE) is an autoimmune disease, which shows an increasing prevalence worldwide and requires a joint clinico-pathological approach. The classical histopathology of GSE with partial or total villous blunting is well recognized, but the classification of GSE is not straightforward. Moreover, several mimickers of GSE with intraepithelial lymphocytosis have been identified in the last 20 years, with drug interactions and medical comorbidities adding to the conundrum. In this review, we report on the normal duodenal mucosa, the clinical presentation and laboratory diagnosis of GSE, the duodenal intraepithelial lymphocytes and immunophenotype of GSE-associated lymphocytes, the GSE mimickers, the differences "across oceans" among guidelines in diagnosing GSE, and the use of a synoptic report for reporting duodenal biopsies in both children and adults in the 21st century.

Role of capsule endoscopy in suspected celiac disease: A European multi-centre study

AIM

To analyze the diagnostic yield (DY), therapeutic impact (TI) and safety of capsule endoscopy (CE).

METHODS

This is a multi-centre, observational, analytical, retrospective study. A total of 163 patients with suspicion of celiac disease (CD) (mean age = 46.4 ± 17.3 years, 68.1% women) who underwent CE from 2003 to 2015 were included. Patients were divided into four groups: seronegative CD with atrophy (Group-I, n = 19), seropositive CD without atrophy (Group-II, n = 39), contraindication to gastroscopy (Group-III, n = 6), seronegative CD without atrophy, but with a compatible context (Group-IV, n = 99). DY, TI and the safety of CE were analysed.

RESULTS

The overall DY was 54% and the final diagnosis was villous atrophy (n = 65, 39.9%), complicated CD (n = 12, 7.4%) and other enteropathies (n = 11, 6.8%; 8 Crohn’s). DY for groups I to IV was 73.7%, 69.2%, 50% and 44.4%, respectively. Atrophy was located in duodenum in 24 cases (36.9%), diffuse in 19 (29.2%), jejunal in 11 (16.9%), and patchy in 10 cases (15.4%). Factors associated with a greater DY were positive serology (68.3% vs 49.2%, P = 0.034) and older age (P = 0.008). On the other hand, neither sex nor clinical presentation, family background, positive histology or HLA status were associated with DY. CE results changed the therapeutic approach in 71.8% of the cases. Atrophy was associated with a greater TI (92.3% vs 45.3%, P < 0.001) and 81.9% of the patients responded to diet. There was one case of capsule retention (0.6%). Agreement between CE findings and subsequent histology was 100% for diagnosing normal/other conditions, 70% for suspected CD and 50% for complicated CD.

CONCLUSION

CE has a high DY in cases of suspicion of CD and it leads to changes in the clinical course of the disease. CE is safe procedure with a high degree of concordance with histology and it helps in the differential diagnosis of CD.

Prevalence of Self-Reported Gluten Sensitivity and Adherence to a Gluten-Free Diet in Argentinian Adult Population

Background: Previous studies suggest that the prevalence of wheat/gluten sensitivity and adherence to a gluten-free diet (GFD) are high in Latin population despite a poor diagnosis of celiac disease. However, these prevalence rates still remain unknown in most Latin American countries. Methods: A cross-sectional survey study was conducted in Santa Fe, Argentina. Results: The estimated self-reported prevalence rates were (95% Confidence Interval [CI]): self-reported gluten sensitivity (SR-GS) 7.61% (6.2–9.2), SR-GS currently following a GFD 1.82% (1.2–2.7), celiac disease 0.58% (0.3–1.2), wheat allergy 0.33% (0.12–0.84), self-reported non-celiac gluten sensitivity (SR-NCGS) 6.28% (5.1–7.8), SR-NCGS currently following a GFD 0.91% (0.5–1.6), and adherence to a GFD 6.37% (5.1–7.9). SR-GS was more common in women (6.0%; p < 0.001) and associated with irritable bowel syndrome (p < 0.001). Among the GFD followers, 71.4% were doing it for reasons other than health-related benefits and 50.6% without medical/dietitian advice. In the non-SR-GS group, the main motivations for following a GFD were weight control and the perception that a GFD is healthier. Conclusion: In Argentina, gluten sensitivity is commonly reported and it seems that physicians/gastroenterologists are aware of celiac disease diagnosis. Trustable information about the benefits and potential consequences of following a GFD should be given to the general population.

New insights in IBS-like disorders: Pandora's box has been opened; a review

The most complained gastrointestinal symptoms are chronic diarrhea, bloating and abdominal pain. Once malignancies and inflammatory bowel diseases are excluded, irritable bowel syndrome (IBS) and the so called "IBS-like disorders" should be taken into account. The relationship between IBS as defined by Rome IV criteria and these clinical conditions is sometimes obscure, since many IBS patients identify food as a possible trigger for their symptoms. Here, we discuss IBS and the most common IBS-like disorders (celiac disease, non-celiac gluten sensitivity, fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), lactose intolerance, small intestinal bacterial overgrowth (SIBO), α-amylase/trypsin inhibitor (ATIs), nickel allergic contact mucositis), focusing on epidemiologic, clinical, diagnostic and therapeutic aspects. Given the lack of specificity of symptoms, clinical investigation will be facilitated by awareness of these disorders as well as new specific diagnostic tools.

Celiac Disease and Wheat Intolerance Syndrome: A Critical Update and Reappraisal

Since the first description of celiac disease (CeD) by Samuel Gee in 1888 and the later "miraculous discovery" that bread was responsible for this condition following World War II in Europe, there has been an exponential growth of knowledge regarding CeD. Just when we thought that we knew everything there was to know about it, the disease is, however, offering new challenges, with its presentation having significantly morphed over the years from cases of overt gastrointestinal symptoms, malnutrition, and atrophic villi on duodenal biopsies to that of largely extraintestinal, subtle, or mild symptoms. Along with these changes, unexpectedly a new parallel entity appeared a few years ago and is gaining ground: the so-called nonceliac gluten sensitivity, an improper name because it should actually be referred to as wheat intolerance syndrome given that the role of gluten in all such cases is far from demonstrated and the implication of an immune involvement suggested by the term "sensitivity" is still unfounded. Lastly, wheat can be an offender also through an immunoglobulin E-mediated allergy, whose presence must also be evaluated and ruled out in selected cases.The practicing physician is therefore now challenged with the task of discerning which patients need to be assessed for one or the other of these disorders, and how.This review aims at providing an updated, critical reassessment of these 2 entities.