In vitro gliadin challenge: diagnostic accuracy and utility for the difficult diagnosis of celiac disease

The Compromised Intestinal Barrier Induced by Mycotoxins

Mycotoxins are fungal metabolites that occur in human foods and animal feeds, potentially threatening human and animal health. The intestine is considered as the first barrier against these external contaminants, and it consists of interconnected physical, chemical, immunological, and microbial barriers. In this context, based on in vitro, ex vivo, and in vivo models, we summarize the literature for compromised intestinal barrier issues caused by various mycotoxins, and we reviewed events related to disrupted intestinal integrity (physical barrier), thinned mucus layer (chemical barrier), imbalanced inflammatory factors (immunological barrier), and dysfunctional bacterial homeostasis (microbial barrier). We also provide important information on deoxynivalenol, a leading mycotoxin implicated in intestinal dysfunction, and other adverse intestinal effects induced by other mycotoxins, including aflatoxins and ochratoxin A. In addition, intestinal perturbations caused by mycotoxins may also contribute to the development of mycotoxicosis, including human chronic intestinal inflammatory diseases. Therefore, we provide a clear understanding of compromised intestinal barrier induced by mycotoxins, with a view to potentially develop innovative strategies to prevent and treat mycotoxicosis. In addition, because of increased combinatorial interactions between mycotoxins, we explore the interactive effects of multiple mycotoxins in this review.

A Peptide from Kiwifruit Exerts Anti-Inflammatory Effects in Celiac Disease Mucosa

Objective: Celiac disease is an immune-mediated disease of the intestine triggered by gluten. Gluten elicits, in genetically susceptible individuals, cytokine responses that are then transmitted to the immunocompetent cells. Vegetables and fruit have anti-inflammatory and antioxidant properties with a protective effect on intestinal epithelium. Kiwifruit is known to have beneficial effects on the intestinal tissues, and it is the only plant food containing the peptide kissper, with anti-inflammatory properties. The aim of this study was the evaluation of the kissper effect on the gluten-induced inflammation in celiac disease. Methods: We used an in vitro model of intestinal culture explant from celiac disease patients and non-celiac disease patients, cultured for 24 hours with the toxic gliadin peptide P31-43 and kissper preincubation. Results: Our data showed HLA-DR and TG2 reduction in the celiac disease mucosa pretreated with kissper, as well as a reduction of COX-2 in two patients. No differences we observed for the TGF-b1 and IL-15 levels in supernatants upon kissper pretreatment. Conclusions: The preliminary results suggest that kissper has a potential anti-inflammatory role in celiac disease.

The Role of a Low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyol Diet in Nonceliac Gluten Sensitivity

Background

Nonceliac gluten sensitivity (NCGS) is a recently defined clinical entity characterized by intestinal and extraintestinal symptoms associated with gluten ingestion in individuals in whom celiac disease (CD) or wheat allergy (WA) has been excluded. Despite its name and definition, gluten has been shown to precipitate symptoms in only 16–30% of these patients. In addition to gluten, other components of wheat, including fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs), alpha-amylase trypsin inhibitors (ATIs) and wheat germ agglutinin have been implicated in the causation of the symptoms of NCGS, with FODMAPs garnering the most attention. We present a review of the existing literature evaluating the role of FODMAPs in NCGS symptomatology.

Methods

A systematic review of PubMed, Cochrane, EMBASE, and Google Scholar for keywords fructans, non-celiac gluten sensitivity, NCGS, FODMAPs, and gluten-free diet (GFD) was conducted through a series of advanced searches. Articles related to the use of fructans or FODMAPs were analyzed.

Results

FODMAPs were found to be associated with gastrointestinal and extraintestinal symptoms in NCGS.

Conclusions

A low FODMAP diet has potential for improvement of clinical symptoms in NCGS. In addition, some evidence suggests an additional benefit to simultaneous adherence to both low FODMAP diet and GFD.

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.

Patients with common variable immunodeficiency paradoxically have increased rates of autoimmune disorders

Common variable immunodeficiency (CVID), characterised by disordered B cell function, is one of the most common primary immunodeficiency disorders. Patients with CVID are at lifelong risk of recurrent infections, particularly of the respiratory and gastrointestinal tracts. Paradoxically, given their immunocompromised state, patients with CVID are also at significantly increased risk of autoimmune disorders, which are seen in almost 25% of cases. The authors report a 24-year-old female patient with CVID, manifested as severe hypogammaglobulinaemia with recurrent sinopulmonary infections and enterocolitis, who presented with transaminitis, chronic diarrhoea and haematemesis. No infectious aetiologies were identified. She was diagnosed with coeliac disease after a small bowel biopsy and positive response to gluten-free diet. Haematemesis was attributed to portal hypertension due to liver cirrhosis, which was confirmed via liver biopsy. Coeliac disease can be a cause of diarrhoea in patients with immunodeficiency disorders and is often underdiagnosed. It can also be the underlying source of liver disease and is an often under-recognised cause of cirrhosis. The case presented emphasises the paradoxical and challenging relationship that patients with CVID face between immunodeficiency and autoimmune disorders, and also highlights that coeliac disease is an under-recognised cause of liver disease.

Optimizing the diagnosis of celiac disease

PURPOSE OF REVIEW

The diagnostic approach in celiac disease is continuously evolving as our understanding of its pathophysiology improves. This review aims to provide a summary of contemporary work that supports optimization of the diagnosis of this common yet underdiagnosed condition.

RECENT FINDINGS

The recently updated National Institute of Clinical Excellence and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines and the contentious biopsy-free diagnostic approach will be discussed. We will review the evidence advocating optimal biopsy techniques such as single bite biopsy and controversial bulb biopsy sampling to increase diagnostic yield. Recent data providing phenotypical characterization and clinical outcomes of celiac subtypes such as potential celiac disease, seronegative celiac disease and ultrashort celiac disease will be covered. We will present emerging evidence on novel case finding strategies with point of care tests. Promising novel markers for celiac disease such as serum intestinal fatty acid binding protein and in-vitro gluten challenge will be included.

SUMMARY

Recent work has demonstrated the clinical significance of the celiac disease subtypes, emphasizing the importance of careful diagnosis and recognition. There is a move toward a less invasive and perhaps more cost-effective diagnostic approach in celiac disease, but duodenal biopsy remains the gold standard at present for all adults and the majority of pediatric patients.

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.

The culture of gut explants: A model to study the mucosal response

Various experimental model designs have been used to analyze the inflammatory pathways in human gastrointestinal illnesses. Traditionally, analytical techniques and animal models are popular experimental tools to study the inflammation process of intestinal diseases. However, the comparison of results between animal and human models is difficult for the inconsistency of outcomes. Although there are different animal models for studying the intestinal diseases, none of them fully represents the physiological and environmental conditions typical of the human species. Also, there is currently a concerted effort to decrease the experimental use of animals. On the converse, experimental protocols using the culture of gut mucosa had become popular with the advent of endoscopy which allows explanting multiple fragments from the intestine. The peculiar characteristic of this model is the ability to preserve in vitro the features that we found in vivo, thus also the response to various stimuli that differs from person to person. The aim of the present paper is to provide a review of some of the possible uses of the organ intestinal mucosa culture.

In Vitro Gluten Challenge Test for Celiac Disease Diagnosis

OBJECTIVES

The in vitro gluten challenge test is an important diagnostic modality in celiac disease (CD), especially in patients who begin treatment with a gluten-free diet before adequate diagnostic workup or in cases with atypical CD. Available literature was reviewed regarding the accuracy of the in vitro gluten challenge test for CD diagnosis.

METHODS

MEDLINE, Scopus, and Google Scholar were searched, and studies that used serology and bowel biopsy as the criterion standard for diagnosis were included in our study. Data on authors, publication year, characteristics of the patient and control groups, patients' diet, duration of the gluten challenge test, histology findings, endomysial antibody (EMA) and anti-tissue transglutaminase (tTG) levels, CD markers, and intercellular cell adhesion molecule-1, and human leukocyte antigens before and after the gluten challenge test were extracted.

RESULTS

Overall, 15 studies were included in this meta-analysis. Pooled sensitivity %/specificity % was 84/99 for EMA after the challenge, 52/96 for EMA without the challenge, 95.5/98.3 for anti-tTG after the challenge, and 95.1/98.3 for anti-tTG without the challenge test. Sensitivity/specificity for immunological markers were 89/97 for the percentage of CD25⁺-lamina propria lymphocytes, 96/91 for the percentage of CD3⁺-lamina propria lymphocytes, and 96.1/85.7 for the percentage of intercellular cell adhesion molecule-1-lamina propria lymphocytes. The factors that increased the sensitivity of EMA were longer test duration, and the evaluation of patients on a gluten-containing diet or short-term gluten-free diet.

CONCLUSIONS

The in vitro gluten challenge test can be a useful part of the diagnostic workup of CD, rather than only a model to evaluate its mechanisms.

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.

Adaptive diagnosis of coeliac disease

Coeliac disease has for a long time simply been regarded as a gluten-dependent enteropathy and a duodenal biopsy was required in all patients for the diagnosis. It is now accepted that autoimmunity against transglutaminase 2 is an earlier, more universal and more specific feature of coeliac disease than histologic lesions. Moreover, high serum levels of combined anti-transglutaminase 2 and anti-endomysium antibody positivity have excellent predictive value for the presence of enteropathy with villous atrophy. This makes the histology evaluation of the gut no longer necessary in well defined symptomatic paediatric patients with compatible HLA-DQ2 and/or DQ8 background. The biopsy-sparing diagnostic route is not yet recommended by gastroenterologists for adults, and certain clinical circumstances (immunodeficiency conditions, extraintestinal manifestations, type-1 diabetes mellitus, age less than 2 years) may require modified diagnostic approaches. Coeliac patients with preserved duodenal villous structure do exist and these need a more extended evaluation by immunologic and molecular biology tools.

Assessing of Celiac Disease and Nonceliac Gluten Sensitivity

The publication of papers on the topic of gluten related disorders has substantially increased over the last few years. This has motivated healthcare professionals to pay attention not only to celiac disease and wheat allergy but also to a condition termed nonceliac gluten sensitivity (NCGS). Until now this condition has been diagnosed clinically on the basis of exclusion criteria and clinical response to gluten withdrawal. In addition, recent research in this field has shown that other food components distinct from gluten are implicated in NCGS cases, thereby changing our general understanding of NCGS diagnosis in either individuals on gluten containing diets or those already following a gluten-free diet with no proper diagnostic work-up of celiac disease. With this in mind, the assessment of NCGS will require extensive knowledge of celiac disease manifestations and the laboratory tests commonly performed during diagnosis of celiac disease.

The present and the future in the diagnosis and management of celiac disease

Celiac disease is an autoimmune enteropathy caused by gluten in genetically predisposed individuals. In celiac disease, adaptive and innate immune activation results in intestinal damage and a wide range of clinical manifestations. In the past, celiac disease was thought to result in signs and symptoms solely related to the gastrointestinal tract. Now, more than half of the adult population presents with extra-intestinal manifestations that can also be expected to improve on a gluten-free diet. For this reason, it is recommended that physicians have a low threshold of suspicion for celiac disease. Current knowledge of the immune pathogenesis of this autoimmune disease has served as a catalyst for the development of novel diagnostic tools and therapeutics. Over the years, highly sensitive and specific serological assays, in addition to genetic markers, have been found to target specific steps in the cascade pathway of celiac disease. Also the advent of the gluten challenge has enabled experts to design diagnostic algorithms and monitor clinical responses in clinical trials. The gluten challenge has provided substantial benefit in the advance of novel therapeutics as an adjuvant treatment to the gluten free diet. Generally, a strict gluten-free diet is highly burdensome to patients and can be limited in its efficacy. Alternative therapies-including gluten modification, modulation of intestinal permeability and immune response-could be central to the future treatment of celiac disease.

Modern diagnosis of celiac disease and relevant differential diagnoses in the case of cereal intolerance

At an incidence of 1:500, celiac disease (formerly sprue) is an important differential diagnosis in patients with malabsorption, abdominal discomfort, diarrhea and food intolerances. Celiac disease can induce a broad spectrum of both gastrointestinal and extraintestinal symptoms, e.g. dermatitis herpetiformis (Duhring's disease). A variety of oligo- and asymptomatic courses (e.g. anemia, osteoporosis, depression) through to refractory collagenic celiac disease are seen. In HLA-DQ2 and -8 predisposed individuals, celiac disease is provoked by contact with wheat gliadin fractions through a predominantly Th1 immune response and an accompanying Th2 response, which can eventually lead to villous atrophy. Using appropriate serological tests (IgA antibodies against tissue-transglutaminase, endomysium and deamidated gliadin peptides) under sufficient gluten ingestion, the diagnosis can be made more reliably today than previously. The same IgG-based serological tests should be used in the case of IgA deficiency. Diagnosis can either be made in children and adolescents with anti-transglutaminase titers exceeding ten times the standard for two of the above-mentioned serological markers and HLA conformity or it is made by endoscopy and histological Marsh classification in adults and in cases of inconclusive serology. If clinically tolerated, gluten challenges are indicated in patients that already have reduced gluten intake, in borderline serological results, discordance between serological and histological results or in suspected food allergy. The diagnosis of celiac disease needs to be definitive and robust before establishing a gluten-free diet, since lifelong abstention from gluten (gliadin < 20 mg/kg foodstuffs), cereal products (wheat, rye, barley and spelt) as well as from preparations and beverages containing gluten, is necessary. With effective elimination of gluten, the prognosis regarding complete resolution of small bowel inflammation is good. Refractory courses are seen only in rare cases, accompanied by enteropathy-associated T-cell lymphoma.

The kiwi fruit peptide kissper displays anti-inflammatory and anti-oxidant effects in in-vitro and ex-vivo human intestinal models

Literature reports describe kiwi fruit as a food with significant effects on human health, including anti-oxidant and anti-inflammatory activity. Fresh fruit or raw kiwi fruit extracts have been used so far to investigate these effects, but the molecule(s) responsible for these health-promoting activities have not yet been identified. Kissper is a kiwi fruit peptide displaying pore-forming activity in synthetic lipid bilayers, the composition of which is similar to that found in intestinal cells. The objective of this study was to investigate the kissper influence on intestinal inflammation using cultured cells and ex-vivo tissues from healthy subjects and Crohn's disease (CD) patients. The anti-oxidant and anti-inflammatory properties of kissper were tested on Caco-2 cells and on the colonic mucosa from 23 patients with CD, by challenging with the lipopolysaccharide from Escherichia coli (EC-LPS) and monitoring the appropriate markers by Western blot and immunofluorescence. EC-LPS challenge determined an increase in the intracellular concentration of calcium and reactive oxygen species (ROS). The peptide kissper was highly effective in preventing the increase of LPS-induced ROS levels in both the Caco-2 cells and CD colonic mucosa. Moreover, it controls the calcium increase, p65-nuclear factor (NF)-kB induction and transglutaminase 2 (TG2) activation inflammatory response in Caco-2 cells and CD colonic mucosa. Kissper efficiently counteracts the oxidative stress and inflammatory response in valuable model systems consisting of intestinal cells and CD colonic mucosa. This study reports the first evidence supporting a possible correlation between some beneficial effects of kiwi fruit and a specific protein molecule rather than generic nutrients.

Dyspepsia

PURPOSE OF REVIEW

Dyspepsia affects up to 40% of the general population and significantly reduces quality of life. A small proportion of patients have peptic ulcer disease as cause and this can be treated empirically with Helicobacter pylori eradication therapy in those that are infected. Approximately 20% have gastro-oesophageal reflux disease and this can be effectively treated with proton pump inhibitor therapy. Patients who remain symptomatic may warrant an endoscopy, but most will have functional dyspepsia. Treatment of functional dyspepsia remains a challenge.

RECENT FINDINGS

Recent large randomized trials suggest tricyclic antidepressant therapy may be effective in functional dyspepsia. A phase III randomized controlled trial reports that a new prokinetic, acotiamide, reduces dyspepsia symptoms in functional dyspepsia patients. There are also preliminary data that suggest buspirone, a drug that promotes gastric accommodation, is also effective in functional dyspepsia. There are also data to suggest that functional dyspepsia is caused by subtle manifestations of inflammation in the upper gastrointestinal tract, possibly caused by food sensitivity or a change in gut flora.

SUMMARY

The initial management of dyspepsia is well established, but managing those with continued symptoms is a challenge. Antidepressants and newer gastric motility agents show promise. Targeting the diet and gut microbiome is another area for future research in functional dyspepsia.

The kiwi fruit peptide kissper displays anti-inflammatory and anti-oxidant effects in in-vitro and ex-vivo human intestinal models

Literature reports describe kiwi fruit as a food with significant effects on human health, including anti-oxidant and anti-inflammatory activity. Fresh fruit or raw kiwi fruit extracts have been used so far to investigate these effects, but the molecule(s) responsible for these health-promoting activities have not yet been identified. Kissper is a kiwi fruit peptide displaying pore-forming activity in synthetic lipid bilayers, the composition of which is similar to that found in intestinal cells. The objective of this study was to investigate the kissper influence on intestinal inflammation using cultured cells and ex-vivo tissues from healthy subjects and Crohn's disease (CD) patients. The anti-oxidant and anti-inflammatory properties of kissper were tested on Caco-2 cells and on the colonic mucosa from 23 patients with CD, by challenging with the lipopolysaccharide from Escherichia coli (EC-LPS) and monitoring the appropriate markers by Western blot and immunofluorescence. EC-LPS challenge determined an increase in the intracellular concentration of calcium and reactive oxygen species (ROS). The peptide kissper was highly effective in preventing the increase of LPS-induced ROS levels in both the Caco-2 cells and CD colonic mucosa. Moreover, it controls the calcium increase, p65-nuclear factor (NF)-kB induction and transglutaminase 2 (TG2) activation inflammatory response in Caco-2 cells and CD colonic mucosa. Kissper efficiently counteracts the oxidative stress and inflammatory response in valuable model systems consisting of intestinal cells and CD colonic mucosa. This study reports the first evidence supporting a possible correlation between some beneficial effects of kiwi fruit and a specific protein molecule rather than generic nutrients.

Maize prolamins could induce a gluten-like cellular immune response in some celiac disease patients

Celiac disease (CD) is an autoimmune-mediated enteropathy triggered by dietary gluten in genetically prone individuals. The current treatment for CD is a strict lifelong gluten-free diet. However, in some CD patients following a strict gluten-free diet, the symptoms do not remit. These cases may be refractory CD or due to gluten contamination; however, the lack of response could be related to other dietary ingredients, such as maize, which is one of the most common alternatives to wheat used in the gluten-free diet. In some CD patients, as a rare event, peptides from maize prolamins could induce a celiac-like immune response by similar or alternative pathogenic mechanisms to those used by wheat gluten peptides. This is supported by several shared features between wheat and maize prolamins and by some experimental results. Given that gluten peptides induce an immune response of the intestinal mucosa both in vivo and in vitro, peptides from maize prolamins could also be tested to determine whether they also induce a cellular immune response. Hypothetically, maize prolamins could be harmful for a very limited subgroup of CD patients, especially those that are non-responsive, and if it is confirmed, they should follow, in addition to a gluten-free, a maize-free diet.

Gliadin does not induce mucosal inflammation or basophil activation in patients with nonceliac gluten sensitivity

BACKGROUND & AIMS

Nonceliac gluten-sensitive (NCGS) patients report intestinal and extra-intestinal symptoms shortly after ingesting gluten; these symptoms disappear on gluten-free diets, although these patients have no serologic markers of celiac disease or intestinal damage. In fact, there is no evidence for mucosal or serologic modifications in those individuals. We investigated immunologic responses of duodenal mucosa samples and peripheral blood basophils, isolated from NCGS patients, after exposure to gliadin.

METHODS

Participants underwent a complete clinical evaluation to exclude celiac disease while on a gluten-containing diet, a skin prick test to exclude wheat allergy, and upper endoscopy (n = 119) at 2 tertiary medical centers in Italy. Patients were considered to have NCGS based on their symptoms and the current definition of the disorder. Subjects were assigned to the following groups: patients with celiac disease on gluten-free diets (n = 34), untreated patients with celiac disease (n = 35), patients with NCGS (n = 16), or controls (n = 34). Duodenal biopsy samples collected during endoscopy were incubated with gliadin peptides, and levels of inflammatory markers were assessed. Peripheral blood basophils were extracted and incubated with gliadin peptides or a mix of wheat proteins; activation was assessed based on levels of CD203c, CD63, and CD45.

RESULTS

Duodenal mucosa samples collected from 69 patients with celiac disease showed markers of inflammation after incubation with gliadin. Some, but not all, markers of inflammation were detected weakly in biopsy samples from 3 controls and 3 NCGS patients (P = .00 for all markers). There were no significant increases in the levels of CD63 and CD203c in NCGS patients.

CONCLUSIONS

Unlike the duodenal mucosa from patients with celiac disease, upon incubation with gliadin, mucosa from patients with NCGS does not express markers of inflammation, and their basophils are not activated by gliadin. The in vitro gliadin challenge therefore should not be used to diagnose NCGS.

Kinetics of the histological, serological and symptomatic responses to gluten challenge in adults with coeliac disease

OBJECTIVE

Coeliac disease is defined by gluten responsiveness, yet there are few data on gluten challenge (GC) in adults on a gluten-free diet. Lack of data regarding the kinetics of responses to gluten is a limitation in clinical practice and research when GC is performed.

DESIGN

20 adults with biopsy-proven coeliac disease participated. The study included two run-in visits followed by a 14-day GC at a randomly assigned dose of 3 or 7.5 g of gluten/day. Study visits occurred 3, 7, 14 and 28 days after starting GC. Duodenal biopsy was performed during the run-in and at days 3 and 14 of GC. Villous height to crypt depth ratio (Vh:Cd) and intraepithelial lymphocyte (IEL) count/100 enterocytes were measured by two pathologists. Antibodies to tissue transglutaminase and deamidated gliadin peptides, lactulose to mannitol ratio (LAMA) and symptoms were assessed at each visit.

RESULTS

Significant reduction in Vh:Cd (2.2-1.1, p<0.001) and increase in IELs (32.6-51.8, p<0.001) were seen from baseline to day 14. Antibody titres increased slightly from baseline to day 14 of GC but markedly by day 28. LAMA did not change significantly. Gastrointestinal symptoms increased significantly by day 3 and returned to baseline by day 28. No differences were seen between the two gluten doses.

CONCLUSIONS

14 day GC at ≥ 3 g of gluten/day induces histological and serological changes in the majority of adults with coeliac disease. These data permit accurate design of clinical trials and indicate that many individuals will meet coeliac diagnostic criteria after a 2-week GC.

Usefulness of the organ culture system when villous height/crypt depth ratio, intraepithelial lymphocyte count, or serum antibody tests are not diagnostic for celiac disease

The existence of mild forms of celiac disease (CD) can make the histology-based diagnosis difficult to reach. Since anti-endomysium (EMA) and anti-tissue transglutaminase (anti-tTG) are detectable in culture supernatants of duodenal biopsies from CD patients, our aim was to assess if this system can support the histology in the diagnostic work-up. A total of 559 suspected CD patients underwent serum EMA/anti-tTG detection, upper endoscopy with duodenal biopsy sampling, histologic analysis, and organ culture to detect EMA/anti-tTG in supernatants. A subgroup of 30 patients with organ culture positive results were put on a gluten-free diet (GFD). Their gluten-dependency was evaluated by the psychological general well-being and beck depression inventory indexes. Statistical analysis was performed by Cohen k inter-test, Friedman test, and Dunn multiple comparison. Two hundred forty-one out of 559 (43.1%) patients showed intestinal villous atrophy, whereas serum and organ culture EMA/anti-tTG were positive in 293/559 (52.4%) and 334/559 (59.7%) patients, respectively. The strength of agreement resulted good for serology vs histology (k = 0.730), good for organ culture vs histology (k = 0.662), and very good for serology vs organ culture (k = 0.852). After 12 months of GFD, psychological general well-being index significantly increased, and beck depression inventory index significantly decreased (P < 0.001 for each one). Data highlight the organ culture system as a useful tool to assist the histology in diagnosing CD, mainly in cases without villous atrophy or in seronegative patients. The marked improvement in quality of life after a GFD further supports the reliability of this system in diagnosing CD.

Difficult diagnosis of celiac disease: diagnostic accuracy and utility of chromo-zoom endoscopy

BACKGROUND

Chromo-zoom endoscopy has been demonstrated to be valuable in assessing the degree of intestinal villous atrophy in patients with suspected celiac disease.

OBJECTIVE

To evaluate the diagnostic accuracy of chromo-zoom endoscopy in patients with difficult diagnosis because of nonconcordant test results and/or the confounding of a gluten-free diet initiated before an appropriate diagnosis of celiac disease and to compare the findings to a recent reference standard, the in vitro gliadin challenge test.

DESIGN

Prospective, case-control study.

SETTING

Tertiary-care referral hospital.

PATIENTS

Patients without celiac disease (negative control group, n = 9), patients with celiac disease (positive control group, n = 41), and patients with difficult diagnosis (n = 27).

INTERVENTION

Chromo-endoscopy with indigo carmine and endoscopic zoom-magnification were performed. Duodenal fragments were collected for the in vitro gliadin challenge test. The area under the receiver operating characteristic curve (ROC) was used for statistical analyses on accuracy.

MAIN OUTCOME MEASUREMENTS

Diagnostic accuracy of chromo-zoom endoscopy for detection of mucosal abnormalities in patients with difficult diagnosis.

RESULTS

Chromo-zoom endoscopy had a high accuracy for celiac disease diagnosis in analyses on negative controls and positive controls (area under roc = 0.99). In the difficult diagnosis group, the accuracy of chromo-zoom endoscopy was lower (area under roc = 0.83), but it increased after exclusion of patients with celiac disease on gluten-free diet (area under roc = 0.88).

LIMITATIONS

There was a 4% failure rate in the ability to cultivate biopsies. Also, the study was done at an academic medical center.

CONCLUSION

Chromo-zoom endoscopy has high accuracy for cases of difficult diagnosis of celiac disease but only in untreated patients with celiac disease.