Fecal Gluten Peptides Reveal Limitations of Serological Tests and Food Questionnaires for Monitoring Gluten-Free Diet in Celiac Disease Patients

Techno-Functions and Safety Concerns of Plant-Based Peptides in Food Matrices

Plant-based peptides (PBPs) benefit functional food development and environmental sustainability. Proteolysis remains the primary method of peptide production because it is a mild and nontoxic technique. However, potential safety concerns still emanate from toxic or allergenic sequences, amino acid racemization, iso-peptide bond formation, Maillard reaction, dose usage, and frequency. The main aim of this review is to investigate the techno-functions of PBPs in food matrices, as well as their safety concerns. The distinctive characteristics of PBPs exhibit their techno-functions for improving food quality and functionality by contributing to several crucial food formulations and processing. The techno-functions of PBPs include solubility, hydrophobicity, bitterness, foaming, oil-binding, and water-holding capacities, which subsequently affect food matrices. The safety and quality of foodstuff containing PBPs depend on the proper source of plant proteins, the selection of processing approaches, and compliance with legal regulations for allergen labeling and safety evaluations. The safety concerns in allergenicity and toxicity were discussed. The conclusion is that food technologists must apply safe limits and consider potential allergenic components generated during the development of food products with PBPs. Therefore, functional food products containing PBPs can be a promising strategy to provide consumers with wholesome health benefits.

Gluten-free diet adherence in pediatric celiac patients: Evaluating CDAT questionnaire and test for gluten detection in urine

OBJECTIVES

This study aimed to evaluate the contributions of the Adapted Celiac Dietary Adherence Test (CDAT) and the Rapid Urinary Gluten Detection Test (u-GIP) in assessing gluten-free diet adherence in children and adolescents with celiac disease.

METHODS

Fifty-four celiac patients from two pediatric gastroenterology outpatient clinics affiliated with university hospitals were evaluated. The original CDAT was adapted for children through a transcultural process, and the original cutoff point was adopted to define adherence. A single examiner carried out the u-GIP test in fresh urine samples. Sociodemographic and clinical factors and family food security status were also evaluated.

RESULTS

A total of 88.9% of participants (confidence interval [CI]: 77.4-95.8; p<0.001) adhered to the gluten-free diet, as determined by the adapted CDAT score, while 87.0% (CI: 75.1-94.6; p<0.001) had negative u-GIP results. Among the 48 children adhering to the CDAT, six exhibited positive u-GIP results in a urine sample. Of the six nonadherent participants, only one had a positive u-GIP result. Notably, none of the children and adolescents with celiac disease who tested positive for u-GIP reported symptoms on the day of testing, and their growth rates remained stable.

CONCLUSIONS

Even celiac children and adolescents adhering to the CDAT questionnaire may show a positive u-GIP in a single measurement without accompanying symptoms or growth impairment. The u-GIP could be helpful in complementary tests in specific situations, such as for patients who exhibit compliant behavior but still experience symptoms or maintain persistent positive serology.

Global Approach to Follow-Up of Celiac Disease

Celiac disease, an autoimmune disorder induced by the ingestion of gluten, affects approximately 1.4% of the population. Gluten damages the villi of the small intestine, producing symptoms such as abdominal pain, bloating and a subsequent loss of nutrient absorption, causing destabilization of the nutritional status. Moreover, gluten can trigger extra intestinal symptoms, such as asthma or dermatitis, but also mental disorders such as depression or anxiety. Moreover, people suffering from celiac disease sometimes feel misunderstood by society, mainly due to the lack of knowledge about the disease and the gluten-free diet. Thus, the treatment and follow-up of patients with celiac disease should be approached from different perspectives, such as the following: (1) a clinical perspective: symptomatology and dietary adherence monitorization; (2) nutritional assessment: dietary balance achievement; (3) psychological assistance: mental disorders avoidance; and (4) social inclusion: educating society about celiac disease in order to avoid isolation of those with celiac disease. The aim of this narrative review is to gain deep insight into the different strategies that currently exist in order to work on each of these perspectives and to clarify how the complete approach of celiac disease follow-up should be undertaken so that the optimum quality of life of this collective is reached.

Past, Present, and Future of Noninvasive Tests to Assess Gluten Exposure, Celiac Disease Activity, and End-Organ Damage

Although many biomarkers have been proposed, and several are in widespread clinical use, there is no single readout or combination of readouts that correlates tightly with gluten exposure, disease activity, or end-organ damage in treated patients with celiac disease. Challenges to developing and evaluating better biomarkers include significant interindividual variability-related to immune amplification of gluten exposure and how effects of immune activation are manifest. Furthermore, the current "gold standard" for assessment of end-organ damage, small intestinal biopsy, is itself highly imperfect, such that a marker that is a better reflection of the "ground truth" may indeed appear to perform poorly. The goal of this review was to analyze past and present efforts to establish robust noninvasive tools for monitoring treated patients with celiac disease and to highlight emerging tools that may prove to be useful in clinical practice.

Gluten-free diet for pediatric patients with coeliac disease: A position paper from the ESPGHAN gastroenterology committee, special interest group in coeliac disease

BACKGROUND AND OBJECTIVE

Coeliac disease is a chronic, immune-mediated disorder for which the only treatment consists of lifelong strict adherence to gluten-free diet (GFD). However, there is a lack of evidence-based guidelines on the GFD dietary management of coeliac disease. This position paper, led by the Special Interest Group in coeliac disease of the European Society of Pediatric, Gastroenterology Hepatology, and Nutrition, supported by the Nutrition Committee and the Allied Health Professionals Committee, aims to present evidence-based recommendations on the GFD as well as how to support dietary adherence.

METHODS

A wide literature search was performed using the MeSH Terms: "diet, gluten free," "gluten-free diet," "diets, gluten-free," "gluten free diet," and "coeliac disease" in Pubmed until November 8th, 2022.

RESULTS

The manuscript provides an overview of the definition of the GFD, regulations as basis to define the term "gluten-free," which foods are naturally gluten-free and gluten-containing. Moreover, it provides recommendations and educational tips and infographics on suitable food substitutes, the importance of reading food labels, risk of gluten cross-contact at home and in public settings, nutritional considerations as well as factors associated to dietary adherence based on available evidence, or otherwise clinical expertise.

CONCLUSIONS

This position paper provides guidance and recommendations to support children with coeliac disease to safely adhere to a GFD.

A Dedicated Celiac Disease Program Improves Celiac Quality Care Metrics and Short-Term Outcomes in Real Life

BACKGROUND AND AIMS

Dedicated multidisciplinary programs in gastroenterology are emerging with the goal to improve care. There is little information about the effects of a celiac disease program on disease-related quality care metrics and outcomes. We aimed to compare quality care metrics, symptom resolution, and serological response among patients diagnosed and treated in a celiac disease program with a standard of care cohort.

METHODS

We performed a retrospective cohort study with adult celiac disease patients. We divided patients into two groups: celiac disease patients treated in our program and those treated by gastroenterologists not affiliated with the program (standard of care). We abstracted data from electronical medical records and compared frequency at which guideline-driven quality care metrics were obtained, assessed symptom resolution, and serological response based on IgA anti-tissue transglutaminase levels.

RESULTS

We included 340 patients, 120 in the celiac disease program (89 women) and 220 (166 women) in the standard of care. Frequency of quality care metrics implementation in program patients was significantly greater for all variables (p < 0.0005). Diarrhea resolved in 38/46 (82.6%) in the CD program and 63/98 (64.2%) in the standard of care after starting a gluten-free diet (p = .025); bloating also resolved significantly more often in the former (26/34) than the latter (31/58; p = 0.03). Otherwise, there were no significant differences in resolution of clinical symptoms or serological response.

CONCLUSION

A celiac disease program improves celiac-related quality care metrics and may improve outcomes such as diarrhea resolution compared to standard of care.

Gluten-Free Diet and Other Celiac Disease Therapies: Current Understanding and Emerging Strategies

A lifelong gluten-free diet (GFD) is the only treatment for celiac disease and other gluten-related disorders. Nevertheless, strict adherence to the GFD is often challenging due to concerns about social isolation, risk of gluten contaminations, high cost, poor quality and the taste of gluten-free products. Moreover, although the GFD is effective in achieving mucosal healing, it may lead to dietary imbalances due to nutrient deficiencies over a long period of time. To overcome these issues, several gluten-free wheat flours have been developed to create products that closely resemble their gluten-containing counterparts. Furthermore, given the critical importance of adhering to the GFD, it becomes essential to promote adherence and monitor possible voluntary or involuntary transgressions. Various methods, including clinical assessment, questionnaires, serology for celiac disease, duodenal biopsies and the detection of Gluten Immunogenic Peptides (GIPs) are employed for this purpose, but none are considered entirely satisfactory. Since adherence to the GFD poses challenges, alternative therapies should be implemented in the coming years to improve treatment efficacy and the quality of life of patients with celiac disease. The aim of this narrative review is to explore current knowledge of the GFD and investigate its future perspectives, focusing on technology advancements, follow-up strategies and insights into a rapidly changing future.

Monitoring patients with celiac disease on gluten free diet: different outcomes comparing three tissue transglutaminase IgA assays

OBJECTIVES

Tissue transglutaminase (tTG) IgA antibodies are a hallmark for celiac disease (CD). In CD patients on gluten free diet (GFD) these antibodies are transient. Few studies are available comparing the tTG-IgA assay characteristics for monitoring response to GFD. Since discrepant results were reported in patients on GFD after switching tTG-IgA assays, we conducted a retrospective observational study to monitor GFD response using three different tTG-IgA assays.

METHODS

Diagnostic samples from 44 adults and 17 children with CD were included. Of most patients two follow-up samples after introduction of GFD were available. In all samples tTG-IgA were assessed using one fluorochrome-enzyme immuno-assay (FEIA) and two chemiluminescence immuno-assays (CLIA) and intestinal fatty acid binding protein (i-FABP) as surrogate marker for intestinal epithelial damage was measured.

RESULTS

Using CLIA assays, normalization of antibody levels was delayed compared to FEIA (p<0.001). Of all samples taken after at least 6 months on GFD with elevated i-FABP indicating intestinal epithelial damage, 40 % had positive tTG-IgA according to the FEIA, 85 and 90 % according to the two CLIA.

CONCLUSIONS

Normalization of tTG-IgA in patients on GFD depends on the assay used. Both CLIA appear to be more sensitive in detecting suboptimal treatment response in CD-indicated by elevated i-FABP - when applying the manufacturer's recommended cut-off for the diagnosis of CD.

Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet

BACKGROUND

The gluten-free diet (GFD) has limitations, and there is intense research in the development of adjuvant therapies.

AIM

To examine the effects of orally administered Aspergillus niger prolyl endopeptidase protease (AN-PEP) on inadvertent gluten exposure and symptom prevention in adult celiac disease (CeD) patients following their usual GFD.

METHODS

This was an exploratory, double-blind, randomized, placebo-controlled trial that enrolled CeD patients on a long-term GFD. After a 4-wk run-in period, patients were randomized to 4 wk of two AN-PEP capsules (GliadinX; AVI Research, LLC, United States) at each of three meals per day or placebo. Outcome endpoints were: (1) Average weekly stool gluten immunogenic peptides (GIP) between the run-in and end of treatments and between AN-PEP and placebo; (2) celiac symptom index (CSI); (3) CeD-specific serology; and (4) quality of life. Stool samples were collected for GIP testing by ELISA every Tuesday and Friday during run-ins and treatments.

RESULTS

Forty patients were randomized for the intention-to-treat analysis, and three were excluded from the per-protocol assessment. Overall, 628/640 (98.1%) stool samples were collected. GIP was undetectable (< 0.08 μg/g) in 65.6% of samples, and no differences between treatment arms were detected. Only 0.5% of samples had GIP concentrations sufficiently high (> 0.32 μg/g) to potentially cause mucosal damage. Median GIP concentration in the AN-PEP arm was 44.7% lower than in the run-in period. One-third of patients exhibiting GIP > 0.08 μg/g during run-in had lower or undetectable GIP after AN-PEP treatment. Compared with the run- in period, the proportion of symptomatic patients (CSI > 38) in the AN-PEP arm was significantly lower (P < 0.03). AN-PEP did not result in changes in specific serologies.

CONCLUSION

This exploratory study conducted in a real-life setting revealed high adherence to the GFD. The AN-PEP treatment did not significantly reduce the overall GIP stool concentration. However, given the observation of a significantly lower prevalence of patients with severe symptoms in the AN-PEP arm, further clinical research is warranted.

Stool Gluten Peptide Detection Is Superior to Urinary Analysis, Coeliac Serology, Dietary Adherence Scores and Symptoms in the Detection of Intermittent Gluten Exposure in Coeliac Disease: A Randomised, Placebo-Controlled, Low-Dose Gluten Challenge Study

Monitoring adherence to a gluten-free diet is an important goal of coeliac disease management. Urine and stool gluten immunogenic peptide (GIP) assays provide an objective readout of gluten ingestion, with the former favoured due to its convenience and acceptability. This study assessed stool GIP excretion after low-dose gluten challenge designed to mimic accidental gluten exposure. A total of 52 coeliac participants undertook a randomised, double-blind gluten (50-1000 mg) or placebo challenge. Stool and urinary GIP, serology, dietary adherence and symptoms were assessed. Stool GIP was 100% sensitive for gluten intake ≥250 mg and 71% for 50 mg. Peak GIP detection was 12-36 h after gluten exposure. The mean stool GIP after 1000 mg gluten ingestion remained above the limit of quantification for 5 days. Urine GIP assessment had poor sensitivity for GIP excretion compared to stool. Serology, dietary adherence score and symptoms did not correlate with gluten excretion during lead-in. We conclude that stool GIP detection is highly sensitive, with levels related to gluten dose and time from ingestion. Weekly or bi-weekly testing will detect low-level exposure more effectively than urine GIP assessments or traditional methods. In this seronegative, apparently well-treated cohort, a high frequency of baseline-positive GIP suggests ongoing gluten exposure, but the assessment of patient behaviour and assay specificity is needed.

Identification of RNAi hypoallergic bread wheat lines for wheat-dependent exercise-induced anaphylaxis patients

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is one of the most severe forms of wheat allergy. It occurs in patients when they exercise after ingesting wheat-containing foods. Nowadays, the only possible alternative for WDEIA patients is to avoid such foods. This study investigated the potential of six RNA of interference (RNAi) wheat lines with low-prolamin content as alternatives for WDEIA patients. For that purpose, a high performance-liquid chromatography (HPLC) analysis was performed to evaluate differences in gluten protein fractions among these lines. Next, western blots were conducted to measure the immunoglobulin E (IgE) reactivity to wheat proteins in sera from five WDEIA patients. Additionally, monoclonal antibodies (moAb) recognition sites and the IgE binding sites were searched in all peptides identified by LC-MS/MS after protein digestion. The results showed a 61.4%-81.2% reduction in the gliadin content of the RNAi lines, accompanied by an increase in their high-molecular weight (HMW) glutenin content compared to the wild type bread wheat line (WT). In all cases, the reduction in gliadin content correlated with a decrease in IgE reactivity observed in the sera of WDEIA patients, highlighting the E82 and H320 lines. These two RNAi lines exhibited a ≤90% reduction in IgE reactivity. This reduction could be attributed to an absence of IgE binding sites associated with α- and ω5-gliadins, which were present in the WT. Overall, these lines offer a potential alternative for foodstuff for individuals with WDEIA.

Assessing mucosal recovery in celiac disease - Time to diagnosis and histological severity as determining factors

Study background and objectives: There is great disparity in mucosal recovery among celiac patients on a gluten-free diet. We report a study to identify associated factors.

METHODS

Celiac patient cases were collected that had positive celiac serology and villous atrophy at diagnosis, and had undergone a control biopsy after at least 12 months of follow-up.

RESULTS

We included 70 celiac patients. They had experienced symptoms for 9.05 ± 9.48 years before being diagnosed. After follow-up for 2.93 ± 1.94 years, 34.3 % had complete mucosal recovery and 57.1 % had partial mucosal recovery. In the comparative analysis we found no relationship between mucosal recovery and sex, age, clinical manifestations or follow-up time from diagnosis to second biopsy. Time with clinical manifestations before diagnosis was associated with a worse outcome: 2.64 years in patients with full recovery, 4.61 years in patients with partial recovery, and 14.26 years in patients with persistent villous atrophy. Higher transglutaminase antibody titers both at diagnosis and during follow-up were associated with poorer histologic outcomes. We observed higher mucosal recovey rates in patients with mild atrophy versus severe atrophy at diagnosis.

CONCLUSIONS

In spite of gluten-free diet a significant proportion of patients have persistent histologic changes. Time with clinical manifestations before diagnosis is key for histological severity and recovery.

Comparison of weekly gluten immunogenic peptide measurement and conventional tools to assess adherence to the gluten-free diet in celiac disease: An observational prospective study

BACKGROUND

Adherence to the gluten-free diet (GFD) is critical to achieving symptom control and mucosal healing in celiac disease (CeD), but its assessment is difficult.

OBJECTIVES

We sought to compare stool gluten immunogenic peptides (GIPs) measurements over a 4-wk period with conventional tools commonly used to monitor compliance with a GFD.

METHODS

Consecutive adult patients with CeD attending the Small Bowel Section of the Buenos Aires Gastroenterology Hospital were invited to this observational study and were instructed to collect stool samples on Fridays for 4 consecutive weeks. Weekly mean stool GIP concentration was measured was estimated. GIP results were compared with a self-assessment scale of adherence, specific CeD serology, the celiac symptom index, and the assessment by an expert dietitian.

RESULTS

Fifty-three CeD patients were enrolled and those with stool GIP ≥0.65 μg/g/wk (n = 13; 24.5%) had higher serum concentrations of IgA deamidated gliadin peptides (DGPs) antibodies [69 (29-109) compared with 14 (13-29); P = 0.0005] and IgA tissue transglutaminase [42 (14-200) compared with 10 (7-16); P = 0.02], higher proportion of cases with IgA DGP antibodies >20 AU/mL (84.6% compared with 33.3%; P = 0.002), and a higher self-estimated adherence score [5 (4-9) compared with 9 (7-10); P = 0.003]. GIP did not correlate with celiac symptom index scores (55.6% compared with 30.8%; P = 0.9). Expert dietitian assessment identified 69% [odds ratio (OR): 5.25; 95% CI: 1.1-27.2; P = 0.01] of nonadherent cases when high stool GIP. Logistic regression analysis determined that IgA DGP (adjusted OR: 1.1; 95% CI: 1.01-1.11; P = 0.02) and males (adjusted OR: 28.3; 95% CI: 1.1-722.6; P = 0.04) were independently associated with excessive gluten exposure.

CONCLUSIONS

Weekly stool GIP identifies gluten exposure that is not always detected by commonly used GFD adherence assessment methods. The higher the concentration of stool GIP, the better the predictive value of serology and dietitian interviews. Stool GIP is a useful and practical test for GFD monitoring, particularly for risky gluten exposure in real-life scenarios.

Refractory celiac disease and its mimickers: a review on pathogenesis, clinical-pathological features and therapeutic challenges

Refractory celiac disease (RCD) and enteropathy-associated T-cell lymphoma (EATL) are rare, yet severe complications of celiac disease (CD). Over the last decades, several studies have addressed the biology and clinical-pathological features of such conditions, highlighting unique disease patterns and recurrent genetic events. Current classification proposals identify two forms of RCD, namely: (i) type 1 RCD (RCD-I), characterized by phenotypically normal intra-epithelial lymphocytes (IELs); and (ii) type 2 RCD (RCD-II), featuring phenotypically aberrant IELs. While RCD-I likely represents a gluten-independent dysimmune reaction against small bowel epithelial cells, RCD-II is better considered an in situ aggressive T-cell lymphoma, with high rates of progression to overt EATL. The diagnosis of RCD and EATL is often challenging, due to misleading clinical-pathological features and to significant overlap with several CD-unrelated gastro-intestinal disorders. Similarly, the treatment of RCD and EATL is an unmet clinical need for both gastroenterologists and hematologists. Moving from such premises, this review aims to provide a comprehensive view of RCD and EATL, specifically considering their pathogenesis and the many still open issues concerning their diagnosis and clinical management.

Celiac Disease Dietary Adherence on the Rural-Urban Continuum

Poor adherence to a gluten-free diet for those with celiac disease is a well-established risk factor, leading to gastrointestinal symptoms, malabsorption of nutrients, and psychiatric complications. Previous studies have shown that those outside urban areas encounter unique barriers to dietary adherence and are less likely to engage in health management behaviors than those in urban regions. This study aimed to examine the relationship between gluten-free dietary adherence and individual, relationship, and community factors, including the geographic location of residence on the rural-urban continuum, for 253 adults with celiac disease living in the United States. Those with celiac disease residing in urban regions had significantly better dietary adherence than those residing in nonurban areas (p < 0.05). Those living in nonurban communities had, on average, poor enough adherence scores to suggest ongoing intestinal damage from gluten consumption. Geographic location, age, years since diagnosis, and annual income significantly predicted compliance with a gluten-free diet for those with celiac disease, accounting for nearly 20% of the variance. Those living outside urban areas with a lower income, younger age, and more recent diagnosis of celiac disease had the worst dietary adherence, placing them at the most risk for ongoing disease progression and complications.

More Than Three Years for Normalisation of Routine Laboratory Values after Gluten Withdrawal in Paediatric Coeliac Patients

The assessment of the nutritional and inflammatory status of paediatric patients with coeliac disease is an interesting approach to early diagnosis and functional follow-up. Most authors agree that the normalisation of symptoms takes about one year. The aim of the study was to evaluate the clinical manifestation and normalisation of routine analytics in Spanish children diagnosed with celiac disease.

METHODS

We performed a retrospective case-control study in Spanish paediatric patients, including 21 celiac patients and 20 healthy controls. The 21 patients selected in the case-control study were followed for 5 years after starting a gluten-free diet (GFD). All patients had type 3 villous atrophy according to the Marsh-Oberhuber classification. A total of 39 blood samples were taken before the start of the GFD, and 109 were taken after. Twenty control sera from healthy donors were used for comparison.

RESULTS

We found that patients had a subclinical but statistically significant increase in blood calcium, transaminases, and white blood cells, and a decrease in serum iron, at the time of diagnosis. Our study also shows that analytical values normalise within five years on a gluten-free diet.

CONCLUSIONS

The use of a combination of subclinical changes, including low iron, high calcium, elevated leukocytes, lymphocytes, and ALT levels in blood samples, together with a low growth percentile, is pertinent in detecting coeliac disease. This set of parameters could help in the diagnosis of patients without clinical symptoms. We can also show that the levels of Fe, Ca, transaminases, and leucocytes remain subclinically altered after 3 years, despite the gluten-free diet.

The Gluten-Free Diet for Celiac Disease: Critical Insights to Better Understand Clinical Outcomes

The gluten-free diet (GFD) remains a complex paradigm in managing celiac disease (CeD) in children and adults, and there are many reasons why GFD adherence should be strict to improve outcomes. However, this is a challenging task for patients, since they need to have access to quality healthcare resources that facilitate optimal GFD adherence. Understanding the strengths and weaknesses of the GFD, tackling coexisting nutritional deficiencies, and dealing with complex situations, such as seronegative CeD or non-responsive CeD, all require the involvement of a multidisciplinary team. The short- and long-term follow-up of CeD patients should preferably be performed by a combined Gastroenterology and Nutrition service with well-defined quality standards and the multidisciplinary involvement of physicians, nurses, dietitians, and psychologists. Nutritional advice and counseling by an experienced dietitian can reduce the costs associated with long-term follow-up of CeD patients. Likewise, psychological interventions may be essential in specific scenarios where implementing and sustaining a lifelong GFD can cause a significant psychological burden for patients. This manuscript aims to provide guidelines to improve clinical practice in the follow-up and monitoring of CeD patients and provide information on the nutritional risks of an ill-advised GFD. Clinicians, biochemists, food technologists, dietitians, and psychologists with a global view of the disease have been involved in its writing.

Gluten Immunogenic Peptides Are Not Correlated With Reported Adherence to Gluten-Free Diet in Children With Celiac Disease

OBJECTIVE

There is no gold standard to assess adherence to gluten-free diet (GFD) among patients with celiac disease (CeD). Gluten immunogenic peptides (GIPs) in urine and stool were suggested as novel markers for evaluating adherence to GFD. Our aim was to assess the presence of GIP in pediatric patients with CeD, and to compare the results with alternative methods for evaluating GFD adherence.

METHODS

Pediatric patients diagnosed with CeD, who were on GFD for at least 1 year, were enrolled and followed prospectively between November 2018 and January 2021. Study visits included clinical assessment, a dietitian interview, Biagi score, food questionnaires, anthropometric and laboratory measurements, and urine and stool samples obtained for laboratory GIP analysis.

RESULTS

The study included 74 patients (63.5% females), with median (interquartile range, IQR) age of 9.9 (7.8-11.7) years, and median (IQR) duration on GFD of 2.5 (2-5.5) years. Good GFD adherence, assessed by Biagi score, was reported in 93.1% of cases. GIP was evaluated during 134 visits, with GIP detected in 27 of 134 (20.1%) of the visits (16.3% of stool samples and 5.3% of urine samples). Positive GIP results were significantly more common in males compared to females (30.6% vs 14.1%, respectively, P < 0.05). Detection of positive GIP was not associated with dietary assessment of GFD adherence, celiac serology results, or reported symptoms.

CONCLUSIONS

Stool and urine GIP can be detected in children with CeD, even when dietary assessment indicate good adherence to GFD. The role of GIP testing in clinical practice should be further explored.

Current evidence for dietary therapies in irritable bowel syndrome

PURPOSE OF REVIEW

Diet appears to trigger symptoms in the majority of individuals with irritable bowel syndrome (IBS) and is associated with a reduced quality of life. There has been a recent focus on the role of dietary therapies to manage individuals with IBS. The aim of this review is to discuss the utility of traditional dietary advice (TDA), low-FODMAP diet (LFD) and gluten-free diet (GFD) in IBS.

RECENT FINDINGS

Several recent randomized controlled trials (RCTs) have been published demonstrating the efficacy of the LFD and GFD in IBS, with the evidence base for TDA being predominantly based on clinical experience, with emerging RCTs evaluating TDA. Only one RCT has been published to date comparing TDA, LFD and GFD head to head, with no difference noted between diets in terms of efficacy. However, TDA has been noted to be more patient-friendly and is commonly implemented as a first-line dietary therapy.

SUMMARY

Dietary therapies have been demonstrated to improve symptoms in patients with IBS. In view of insufficient evidence to recommend one diet over another currently, specialist dietetic input in conjunction with patient preference is required to determine implementation of dietary therapies. Novel methods of dietetic delivery are required in view of the lack of dietetic provision to deliver these therapies.

Standard addition method (SAM) in LC-MS/MS to quantify gluten-derived metabolites in urine samples

A tight adherence to a gluten-free diet (GFD), the most effective treatment currently available for celiac disease, is important to reduce symptoms, avoid nutritional deficiencies and improve quality of life in celiac patients. The development of analytical methods allowing detecting gluten exposure due to occasional or involuntary food transgressions could represent a useful tool to monitor patient habits and conditions and prevent long-term complications. The aim of this work was to develop and validate an approach based on the standard addition methodology (SAM) for the detection and quantification of two main metabolites of alkylresorcinols, 3,5-dihydroxybenzoic acid (DHBA) and 3-(3,5-dihydroxyphenyl)-propanoic acid (DHPPA), whose presence in urine samples is related to the intake of gluten-containing foods. Analytically, the method consisted of a protein precipitation step followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis. The chromatographic method involved the use of a hydrophilic interaction liquid chromatography (HILIC) in a direct phase approach; LC-MS/MS analyses were performed in selected reaction monitoring (SRM) mode. Manipulation and instrumental errors were normalised using stable isotopic standards (ISs). The SAM approach here described requires less than 1 mL of urine per sample, thus greatly reducing the sample volume needed. Noteworthy, despite the small cohort of samples analysed, our data allowed to identify a potential "threshold" value, around 200 ng/mL for DHBA and 400 ng/mL for DHPPA, to discriminate between a GFD and a gluten rich diet (GRD).

The Importance of an Early Evaluation after Establishing a Gluten-Free Diet in Children with Celiac Disease

A gluten-free diet (GFD) is the only treatment available for celiac disease (CD); hence, it is important to ensure correct adherence to the diet and adequate monitoring of the diet. The present study aims to assess the importance of an early follow-up of celiac patients after diagnosis of the disease, identify the role of stool gluten immunogenic peptides (GIPs) in the assessment of GFD adherence, and analyze possible nutritional imbalances or deficiencies in the GFD. This is a cross-sectional study carried out in pediatric patients with newly diagnosed CD in a tertiary hospital in Spain. Of the 61 patients included, 14% had positive stool GIPS at 4 months after CD diagnosis, Among them, 88% had negative stool GIPS at 9 months after diagnosis, following dietary advice. We found nutritional deficiencies in the GFD, such as vitamin D (with only 27% of patients with adequate intakes), folate, calcium, magnesium, and fiber. Similarly, we found imbalances: excess protein and fat intakes and a high percentage of total daily energy intake came from ultra-processed foods (UPF). These findings emphasize the importance of early follow-up of children after diagnosis of CD. It is also crucial to identify patients with poor GFD compliance based on stool GIPS and analyze GFD nutritional imbalances and deficits. Our findings may contribute to the development of specific strategies for the early follow-up of patients with CD, including appropriate nutritional counselling.

Evaluation of the Usefulness of an Automatable Immunoassay for Monitoring Celiac Disease by Quantification of Immunogenic Gluten Peptides in Urine

A gluten-free diet (GFD) is currently the only treatment available for patients with celiac disease (CD). However, adherence to a GFD can be challenging because gluten is present in many foods. A lifelong follow-up of patients with CD must be performed to promote adherence to a GFD and to identify the appearance of symptoms and the associated diseases. Therefore, the development of tools to analyze gluten exposure in these patients is important. This study proposes the development of the first automatable ELISA to monitor adherence to a GFD through the quantification of urine gluten immunogenic peptides (u-GIP). Seven healthy volunteers without suspicion of CD and 23 patients with CD were monitored as part of this study to optimize, validate, and apply this assay. Non-interference was found in the urine matrix, and the recovery percentage for spiked samples was 81–101%. The u-GIP was stable for up to 16 days when the samples were stored at different temperatures. Overall, 100% of the patients had detectable u-GIP at diagnosis (range of 0.39–2.14 ng GIP/mL), which reduced to 27% after 12 months on a GFD. Therefore, this highly sensitive immunoassay would allow the analysis of u-GIP from a large battery of samples in clinical laboratories of specialized healthcare centers.

Clinical utility of urinary gluten immunogenic peptides in the follow-up of patients with coeliac disease

BACKGROUND

Gluten-free diet (GFD) is the only treatment for patients with coeliac disease (CD) and its compliance should be monitored to avoid cumulative damage.

AIMS

To analyse gluten exposures of coeliac patients on GFD for at least 24 months using different monitoring tools and its impact on duodenal histology at 12-month follow-up and evaluate the interval of determination of urinary gluten immunogenic peptides (u-GIP) for the monitoring of GFD adherence.

METHODS

Ninety-four patients with CD on a GFD for at least 24 months were prospectively included. Symptoms, serology, CDAT questionnaire, and u-GIP (three samples/visit) were analysed at inclusion, 3, 6, and 12 months. Duodenal biopsy was performed at inclusion and 12 months.

RESULTS

At inclusion, 25.8% presented duodenal mucosal damage; at 12 months, this percentage reduced by half. This histological improvement was indicated by a reduction in u-GIP but did not correlate with the remaining tools. The determination of u-GIP detected a higher number of transgressions than serology, regardless of histological evolution type. The presence of >4 u-GIP-positive samples out of 12 collected during 12 months predicted histological lesion with a specificity of 93%. Most patients (94%) with negative u-GIP in ≥2 follow-up visits showed the absence of histological lesions (p < 0.05).

CONCLUSION

This study suggests that the frequency of recurrent gluten exposures, according to serial determination of u-GIP, could be related to the persistence of villous atrophy and that a more regular follow-up every 6 months, instead of annually, provides more useful data about the adequate adherence to GFD and mucosal healing.

Evaluation of a Single Determination of Gluten Immunogenic Peptides in Urine from Unaware Celiac Patients to Monitor Gluten-Free Diet Adherence

INTRODUCTION AND AIM

Usually, adherence to the gluten-free diet (GFD) in celiac patients is indirectly assessed through serological analysis, questionnaires, or invasive methods such as intestinal biopsy. The detection of gluten immunogenic peptides in urine (urinary gluten immunogenic peptides-uGIP) is a novel technique that directly evaluates the ingestion of gluten. The aim of this study was to evaluate the clinical efficacy of uGIP in the follow-up of celiac disease (CD).

METHODS

From April 2019 to February 2020, CD patients reporting complete adherence to the GFD were prospectively enrolled but were unaware of the reason for the tests. Urinary GIP, the celiac dietary adherence test (CDAT), symptomatic visual analog scales (VAS), and tissue transglutaminase antibodies (tTGA) titres were evaluated. Duodenal histology and capsule endoscopy (CE) were performed when indicated.

RESULTS

A total of 280 patients were enrolled. Thirty-two (11.4%) had a positive uGIP test (uGIP+). uGIP+ patients did not show significant differences in demographic parameters, CDAT, or VAS scores. The tTGA+ titre was not related to the positivity of uGIP (14.4% vs. 10.9% in patients with tTGA+ and tTGA-). Regarding histology, 66.7% of the GIP+ patients had atrophy compared to 32.7% of the GIP patients (p-value 0.01). However, the presence of atrophy did not correlate with tTGA. Mucosal atrophy was detected in 29 (47.5%) out of 61 patients by CE. With this method, no noticeable dependence on uGIP results (24 GIP- vs. 5 GIP+) was observed.

CONCLUSIONS

The single uGIP test was positive in 11% of CD cases referring a correct GFD adherence. Furthermore, uGIP results significantly correlated with the duodenal biopsy, formerly considered the gold standard for assessing CD activity.

Role of Serology, Dietary Assessment, and Fecal Gluten Immunogenic Peptides for Predicting Histologic Recovery in Children with Celiac Disease

BACKGROUND

A strict lifelong gluten-free diet (GFD) remains the only treatment of celiac disease (CD). Adherence to gluten-free diet is best reflected by mucosal healing. Noninvasive tools capable of predicting mucosal recovery in CD patients need to be identified.

AIMS

To compare the ability of various modalities used to assess compliance to GFD, for predicting persistent mucosal damage in children with CD.

METHODS

A prospective, single-center, observational study on children with CD on a GFD was conducted between January 2020 and April 2021. Children with CD on GFD were consecutively enrolled and various modalities used to assess adherence to GFD were compared.

RESULTS

One hundred and fifty children (Mean age 12.2 ± 3.6 years, 58% Boys) on GFD (Mean duration 6 ± 3.1 years) were enrolled in the study. Persistent mucosal damage was seen in 88% of the enrolled. Fecal gluten immunogenic peptide (GIP) was positive in 87.8% (129/147). Antibodies to tissue transglutaminase (TGA-IgA) and/or deamidated gliadin peptide (DGP) were positive in 32% (48/150) whereas antibody to synthetic neoepitopes of TGA-IgA was positive in 24.8% (37/149). Non-compliance as assessed by local questionnaire, Biagi score, and dietitian detailed interview were 62.7%, 60%, and 75.3%, respectively. Serology had the highest specificity (83%) and fecal GIP had the highest sensitivity (89%). On logistic regression analysis, only non-compliance by Biagi score predicted poor mucosal recovery.

CONCLUSION

Fecal GIP may be sensitive to detect only "one-point dietary transgression." None of the existing modalities used to assess compliance to GFD accurately predict persistent mucosal damage. A subset of patients may develop gluten tolerance.

Changes in the gut bacteriome upon gluten-free diet intervention do not mediate beta cell preservation

AIMS/HYPOTHESIS

We previously detected indications that beta cell function is protected by gluten-free diet (GFD) introduced shortly after the onset of childhood type 1 diabetes. The present aim was to assess whether GFD was associated with changes in the gut bacteriome composition and in its functional capacity, and whether such changes mediated the observed effects of GFD on beta cell function.

METHODS

Forty-five children (aged 10.2 ± 3.3 years) were recruited into a self-selected intervention trial primarily focused on determining the role of GFD on beta cell preservation ( ClinicalTrials.gov NCT02867436). Stool samples were collected prior to the dietary intervention and then at 3-month intervals. A total of 128 samples from the GFD group and 112 from the control group were analysed for bacteriome 16S rDNA community profiles, the bacteriome functional capacity was predicted using PICRUSt2 and actual gut metabolome profiles measured using NMR. Intestinal permeability was assessed using serum zonulin concentrations at 1, 6 and 12 months and lactulose/mannitol tests at the end of intervention. Dietary questionnaires were used to ensure that the dietary intervention did not result in differences in energy or nutrient intake.

RESULTS

The bacteriome community composition changed during the intervention with GFD: of abundant genera, a 3.3-fold decrease was noted for Bifidobacterium genus (adjusted p=1.4 × 10^-4 in a DESeq2 model, p=0.026 in generalised estimating equations model), whereas a 2.4-fold increase was observed in Roseburia (adjusted p=0.02 in DESeq2 model, p=0.002 in generalised estimating equations model). The within-sample (alpha) diversity did not change, and there was no statistically significant clustering of GFD samples in the ordination graphs of beta diversity. Neither of the genera changes upon GFD intervention showed any association with the pace of beta cell loss (p>0.50), but of the remaining taxa, several genera of Bacteroidaceae family yielded suggestive signals. The faecal metabolome profile ordination correlated with that of bacteriomes but did not associate with GFD or categories of beta cell preservation. There was no indication of changes in gut permeability.

CONCLUSIONS/INTERPRETATION

The bacteriome reacted to GFD, but the changes were unrelated to the pace of beta cell capacity loss. The previously observed moderately protective effect of GFD is therefore mediated through other pathways.

American College of Gastroenterology Guidelines Update: Diagnosis and Management of Celiac Disease

This guideline presents an update to the 2013 American College of Gastroenterology Guideline on the Diagnosis and Management of Celiac Disease with updated recommendations for the evaluation and management of patients with celiac disease (CD). CD is defined as a permanent immune-mediated response to gluten present in wheat, barley, and rye. CD has a wide spectrum of clinical manifestations that resemble a multisystemic disorder rather than an isolated intestinal disease, and is characterized by small bowel injury and the presence of specific antibodies. Detection of CD-specific antibodies (e.g., tissue transglutaminase) in the serum is very helpful for the initial screening of patients with suspicion of CD. Intestinal biopsy is required in most patients to confirm the diagnosis. A nonbiopsy strategy for the diagnosis of CD in selected children is suggested and discussed in detail. Current treatment for CD requires strict adherence to a gluten-free diet (GFD) and lifelong medical follow-up. Most patients have excellent clinical response to a GFD. Nonresponsive CD is defined by persistent or recurrent symptoms despite being on a GFD. These patients require a systematic workup to rule out specific conditions that may cause persistent or recurrent symptoms, especially unintentional gluten contamination. Refractory CD is a rare cause of nonresponsive CD often associated with poor prognosis.

Patient Perspectives on the Long-term Management of Celiac Disease

GOAL

The aim of this study was to survey adults with celiac disease (CD) on the utility of specific aspects of follow-up and on information needs.

BACKGROUND

Currently, the treatment for CD is strict gluten avoidance. Although this places the onus on the patient for disease management, patient perspectives on CD care have not been formally assessed.

STUDY

The Manitoba Celiac Disease Cohort prospectively enrolled adults newly diagnosed with CD using serology and histology. At the 24-month study visits, participants rated the utility of aspects of CD care on a 5-point scale anchored by "not at all useful" and "very useful" and the helpfulness of information on CD-related topics on a 6-point scale anchored by "not at all helpful" and "very helpful."

RESULTS

The online survey was completed by 149 of 211 cohort members [median age 40 (interquartile range 30 to 56) y; 68% female]. Adherence to a gluten-free diet was good. Most participants (87%) responded that they should be seen regularly for medical follow-up of CD, preferably every 6 (26%) or 12 months (48%). Blood tests were the most highly rated care component (rated scored ≥4/5 by 78% of respondents), followed by the opportunity to ask about vitamins and supplements (50%), symptom review (47%), and information on CD research (44%). Diet review was not considered helpful.

CONCLUSIONS

Two years after diagnosis, most individuals with CD find regular specialist follow-up helpful, particularly for biochemical assessment of disease activity and its complications. Furthermore, information on research and long-term complications of CD is also valued.

Assessment of activated gut-homing CD8+ T cells in blood by flow cytometry during a 3-day gluten challenge

Accurate celiac disease (CD) diagnosis must be performed in individuals following a gluten containing diet. Diagnostic procedures for individuals already on a gluten-free diet (GFD) avoiding long gluten reintroductions are still challenging. To deal with this issue, we developed an accurate but simple method that requires only a 3-day gluten challenge and circumvents the main limitations of previously suggested proposals such as requirement of specific peptides and unusual specialized lab facilities or high cost. In an attempt to standardize this methodology to be used in daily clinical practice, we describe here an optimized protocol for assessing activated gut-homing CD8+ T cells in blood combined with a short gluten challenge. Details about the amount and type of gluten antigen and the starting material are included, as well as the strategy to easily characterize and identify the cells of interest using flow cytometry. This methodology constitutes a diagnostic tool for CD diagnosis of high specificity and sensitivity for seropositive disease (>95%) as an alternative to long-term gluten challenge and open new possibilities to test the response to gluten in research and clinical trials.

Guidelines of the Italian societies of gastroenterology on the diagnosis and management of coeliac disease and dermatitis herpetiformis

INTRODUCTION

Coeliac disease and dermatitis herpetiformis are immune-mediated diseases triggered by the consumption of gluten in genetically predisposed individuals. These guidelines were developed to provide general practitioners, paediatricians, gastroenterologists, and other clinicians with an overview on the diagnosis, management and follow-up of coeliac patients and those with dermatitis herpetiformis.

METHODS

Guidelines were developed by the Italian Societies of Gastroenterology. Following a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the certainty of the evidence. Statements and recommendations were developed by working groups consisting of gastroenterologists and a paediatrician with expertise in this field.

RESULTS

These guidelines provide a practical guidance for the diagnosis, management and follow-up of coeliac patients and dermatitis herpetiformis in children and adults, both in primary care and in specialist settings. We developed four sections on diagnosis, gluten-free diet, follow-up and risk of complications in adults, one section focused on diagnosis and follow-up in children and one on the diagnosis and management of dermatitis herpetiformis.

CONCLUSIONS

These guidelines may support clinicians to improve the diagnosis and management of patients with coeliac disease.

ESPGHAN Position Paper on Management and Follow-up of Children and Adolescents With Celiac Disease

OBJECTIVES

To gather the current evidence and to offer recommendations for follow-up and management.

METHODS

The Special Interest Group on Celiac Diseases of the European Society of Paediatric Gastroenterology Hepatology and Nutrition formulated ten questions considered to be essential for follow-up care. A literature search (January 2010-March 2020) was performed in PubMed or Medline. Relevant publications were identified and potentially eligible studies were assessed. Statements and recommendations were developed and discussed by all coauthors. Recommendations were voted upon: joint agreement was set as at least 85%.

RESULTS

Publications (n = 2775) were identified and 164 were included. Using evidence or expert opinion, 37 recommendations were formulated on: The need to perform follow-up, its frequency and what should be assessed, how to assess adherence to the gluten-free diet, when to expect catch-up growth, how to treat anemia, how to approach persistent high serum levels of antibodies against tissue-transglutaminase, the indication to perform biopsies, assessment of quality of life, management of children with unclear diagnosis for which a gluten-challenge is indicated, children with associated type 1 diabetes or IgA deficiency, cases of potential celiac disease, which professionals should perform follow-up, how to improve the communication to patients and their parents/caregivers and transition from pediatric to adult health care.

CONCLUSIONS

We offer recommendations to improve follow-up of children and adolescents with celiac disease and highlight gaps that should be investigated to further improve management.

Non-Responsive and Refractory Coeliac Disease: Experience from the NHS England National Centre

We characterised the aetiology of non-responsive coeliac disease (NRCD) and provided contemporary mortality data in refractory coeliac disease (RCD) from our centre. We also measured urine gluten immunogenic peptides (GIPs) in patients with established RCD1 to evaluate gluten exposure in these individuals. Methods: This was a longitudinal cohort study conducted in Sheffield, UK. Between 1998 and 2019, we evaluated 285 adult (≥16 years) patients with NRCD or RCD. Patients with established RCD1 and persisting mucosal inflammation and/or ongoing symptoms provided three urine samples for GIP analysis. Results: The most common cause of NRCD across the cohort was gluten exposure (72/285; 25.3%). RCD accounted for 65/285 patients (22.8%), 54/65 patients (83.1%) had RCD1 and 11/65 patients (16.9%) had RCD2. The estimated 5-year survival was 90% for RCD1 and 58% for RCD2 (p = 0.016). A total of 36/54 (66.7%) patients with RCD1 underwent urinary GIP testing and 17/36 (47.2%) had at least one positive urinary GIP test. Conclusion: The contemporary mortality data in RCD2 remains poor; patients with suspected RCD2 should be referred to a recognised national centre for consideration of novel therapies. The high frequency of urinary GIP positivity suggests that gluten exposure may be common in RCD1; further studies with matched controls are warranted to assess this further.

Review article: Follow-up of coeliac disease

Coeliac disease is a lifelong immune-mediated enteropathy with systemic features associated with increased morbidity and modestly increased mortality. Treatment with a strict gluten-free diet improves symptoms and mucosal damage but is not curative and low-level gluten intake is common despite strict attempts at adherence. Regular follow-up after diagnosis is considered best-practice however this is executed poorly in the community with the problem compounded by the paucity of data informing optimal approaches. The aim of dietary treatment is to resolve symptoms, reduce complication risk and improve quality of life. It follows that the goals of monitoring are to assess dietary adherence, monitor disease activity, assess symptoms and screen for complications. Mucosal disease remission is regarded a key measure of treatment success as healing is associated with positive health outcomes. However, persistent villous atrophy is common, even after many years of a gluten-free diet. As the clinical significance of asymptomatic enteropathy is uncertain the role for routine follow-up biopsies remains contentious. Symptomatic non-responsive coeliac disease is common and with systematic follow-up a cause is usually found. Effective models of care involving the gastroenterologist, dietitian and primary care doctor will improve the consistency of long-term management and likely translate into better patient outcomes. Identifying suitable treatment targets linked to long-term health is an important goal.

A hands-free stool sampling system for monitoring intestinal health and disease

Analysis of stool offers simple, non-invasive monitoring for many gastrointestinal (GI) diseases and access to the gut microbiome, however adherence to stool sampling protocols remains a major challenge because of the prevalent dislike of handling one's feces. We present a technology that enables individual stool specimen collection from toilet wastewater for fecal protein and molecular assay. Human stool specimens and a benchtop test platform integrated with a commercial toilet were used to demonstrate reliable specimen collection over a wide range of stool consistencies by solid/liquid separation followed by spray-erosion. The obtained fecal suspensions were used to perform occult blood tests for GI cancer screening and for microbiome 16S rRNA analysis. Using occult blood home test kits, we found overall 90% agreement with standard sampling, 96% sensitivity and 86% specificity. Microbiome analysis revealed no significant difference in within-sample species diversity compared to standard sampling and specimen cross-contamination was below the detection limit of the assay. Furthermore, we report on the use of an analogue turbidity sensor to assess in real time loose stools for tracking of diarrhea. Implementation of this technology in residential settings will improve the quality of GI healthcare by facilitating increased adherence to routine stool monitoring.

Coeliac disease

Coeliac disease is an autoimmune disorder that primarily affects the small intestine, and is caused by the ingestion of gluten in genetically susceptible individuals. Prevalence in the general population ranges from 0·5% to 2%, with an average of about 1%. The development of the coeliac enteropathy depends on a complex immune response to gluten proteins, including both adaptive and innate mechanisms. Clinical presentation of coeliac disease is highly variable and includes classical and non-classical gastrointestinal symptoms, extraintestinal manifestations, and subclinical cases. The disease is associated with a risk of complications, such as osteoporosis and intestinal lymphoma. Diagnosis of coeliac disease requires a positive serology (IgA anti-transglutaminase 2 and anti-endomysial antibodies) and villous atrophy on small-intestinal biopsy. Treatment involves a gluten-free diet; however, owing to the high psychosocial burden of such a diet, research into alternative pharmacological treatments is currently very active.

Review on pediatric coeliac disease from a clinical perspective

Coeliac disease is an immune-mediated condition characterized by chronic inflammation of the small bowel with villous atrophy driven by gluten ingestion in genetically predisposed individuals. It occurs frequently in both children and adults, affecting 1-4% of the population. The disease is associated with both gastrointestinal and extra-intestinal symptoms related to malabsorption and/or immune activation, and autoantibodies to tissue transglutaminase. Removal of gluten from the diet results in resolution of symptoms and enteropathy in the majority of patients. A good diagnostic work-up is important to avoid unnecessary restrictive diets in children. In this review on pediatric coeliac disease, we address epidemiology including predisposing environmental factors and possible preventive strategies, as well as the clinical presentation, diagnosis and follow-up. What is Known: •Primary prevention of coeliac disease is not possible; however, secondary prevention by targeting high-risk groups is recommended. •The diagnosis is safe without duodenal biopsies if specific conditions are met, also in asymptomatic children. What is New: •HLA-DQ typing is not routinely required for the diagnosis, whereas it can rule out coeliac disease if HLA-DQ2 and HLA-DQ8 are absent. •Follow-up could be improved by a more rational use of (laboratory) tests, increased intention to dietary compliance and quality of life.

Biomarkers for the diagnosis and monitoring of celiac disease: can you count on me?

PURPOSE OF REVIEW

Different markers are available to diagnose and monitor celiac disease (CeD); however, the concordance among them and their efficacy are still controversial. We aim at defining the efficacy of CeD biomarkers, their advantages and limits.

RECENT FINDINGS

CeD diagnostic criteria are widely accepted, being a positive serology and duodenal atrophy (according to the Marsh-Oberhuber score) the main hallmarks. Flow cytometry and other molecular biomarkers support the diagnosis of refractory CeD. On the other side, CeD monitoring is less defined, as the biomarkers are not always reliable. To date, the reference standard to detect mucosal healing is represented by duodenal histology, but its timing and significance are debated. Novel scores may better define the trend of mucosal damage and MicroRNAs are among the innovative noninvasive biomarkers. The assessment of a correct gluten-free diet (GFD) is another aspect of CeD monitoring, based upon questionnaires and recently developed tools such as dosage of urinary or faecal gluten immunogenic peptides.

SUMMARY

Clinicians lack of a widely acknowledged tools to monitor CeD and GFD. Here, we present the efficacy of the most used markers.

Future challenges in gastroenterology and hepatology, between innovations and unmet needs: A SIGE Young Editorial Board's perspective

Gastroenterology, Digestive Endoscopy and Hepatology have faced significant improvements in terms of diagnosis and therapy in the last decades. However, many fields still remain poorly explored, and many questions unanswered. Moreover, basic-science, as well as translational and clinical discoveries, together with technology advancement will determine further steps toward a better, refined care for many gastroenterological disorders in the future. Therefore, the Young Investigators of the Italian Society of Gastroenterology (SIGE) joined together, offering a perspective on major future innovations in some hot clinical topics in Gastroenterology, Endoscopy, and Hepatology, as well as the current pitfalls and the grey zones.

The global burden of coeliac disease: opportunities and challenges

Coeliac disease is a systemic disorder characterized by immune-mediated enteropathy, which is caused by gluten ingestion in genetically susceptible individuals. The clinical presentation of coeliac disease is highly variable and ranges from malabsorption through solely extra-intestinal manifestations to asymptomatic. As a result, the majority of patients with coeliac disease remain undiagnosed, misdiagnosed or experience a substantial delay in diagnosis. Coeliac disease is diagnosed by a combination of serological findings of disease-related antibodies and histological evidence of villous abnormalities in duodenal biopsy samples. However, variability in histological grading and in the diagnostic performance of some commercially available serological tests remains unacceptably high and confirmatory assays are not readily available in many parts of the world. Currently, the only effective treatment for coeliac disease is a lifelong, strict, gluten-free diet. However, many barriers impede patients' adherence to this diet, including lack of widespread availability, high cost, cross-contamination and its overall restrictive nature. Routine follow-up is necessary to ensure adherence to a gluten-free diet but considerable variation is evident in follow-up protocols and the optimal disease management strategy is not clear. However, these challenges in the diagnosis and management of coeliac disease suggest opportunities for future research.

Dose-Escalating (50–500 mg) Gluten Administration Leads to Detectable Gluten-Immunogenic-Peptides in Urine of Patients with Coeliac Disease Which Is Unrelated to Symptoms, a Placebo Controlled Trial

Background: To determine the applicability and sensitivity of a urine self-test to detect gluten-immunogenic-peptides (GIP) in daily-life for patients with coeliac disease and correlate the test results with reported symptoms. Methods: We performed a prospective double-blinded placebo-controlled study, including adults with coeliac disease adhering to a strictly gluten-free diet. Patients were administered gluten in test-cycles of ascending doses of 50, 100, 200, and 500 mg alternated with placebo. Urine portions from 2, 5–17 h after the ingestion were collected and analyzed for GIP using the iVYCHECK-GIP-Urine rapid lateral flow test. Patients completed a diary mapping symptoms (nausea, bloating, diarrhea, abdominal pain, and lower level of energy). Results: We enrolled 15 patients and 7 received all 4 cycles with increasing gluten dosing. GIP was detected from urine in 47% of the patients receiving 50 mg gluten and in 86% with 500 mg gluten. We detected GIP in 20–50% of urine samples after placebo. There was no correlation between symptoms, gluten administration and/or GIP in urine. Conclusions: Gluten intake, even with a dose as low as 50 mg, leads to detectable urinary GIP concentrations. There is no correlation of coeliac disease ascribed symptoms with detection of urinary GIP.

Dietary Behavior and Risk of Orthorexia in Women with Celiac Disease

Evidence points to a link between celiac disease and eating disorders. Although with the current limited knowledge, orthorexia cannot be formally recognized as an eating disorder, some features are similar. This study is the first to examine individuals with celiac disease in terms of the prevalence of risk of orthorexia. Participants were 123 females diagnosed with celiac disease. The standardized ORTO-15 questionnaire was used to assess the risk of orthorexia. In this study, eating habits and physical activity were assessed. The effect of celiac disease on diet was self-assessed on a 5-point scale. Taking a score of 40 on the ORTO-15 test as the cut-off point, a risk of orthorexia was found in 71% of individuals with celiac disease, but only in 32% when the cut-off point was set at 35. There was a positive correlation between age and ORTO-15 test scores (rho = 0.30). In the group with orthorexia risk, meals were more often self-prepared (94%) compared to those without risk of orthorexia (78%) (p = 0.006). Individuals at risk for orthorexia were less likely to pay attention to the caloric content of food (46%) relative to those without risk of orthorexia (69%) (p = 0.001). For 64% of those at risk for orthorexia vs. 8% without risk had the thought of food that worried them (p = 0.001). Given the survey instrument for assessing the prevalence of orthorexia and the overlap between eating behaviors in celiac disease and orthorexia, the prevalence of orthorexia in celiac disease cannot be clearly established. Therefore, future research should focus on using other research tools to confirm the presence of orthorexia in celiac disease.

Plasma IL-2 and Symptoms Response after Acute Gluten Exposure in Subjects With Celiac Disease or Nonceliac Gluten Sensitivity

INTRODUCTION

Treated patients with celiac disease (CeD) and nonceliac gluten sensitivity (NCGS) report acute, transient, incompletely understood symptoms after suspected gluten exposure. To determine whether (i) blinded gluten exposure induces symptoms, (ii) subjects accurately identify gluten exposure, and (iii) serum interleukin-2 (IL-2) levels distinguish CeD from NCGS subjects after gluten exposure.

METHODS

Sixty subjects (n = 20 treated, healed CeD; n = 20 treated NCGS; n = 20 controls) were block randomized to a single, double-blind sham (rice flour) or 3-g gluten challenge with 72-hours follow-up. Twelve serial questionnaires (100 mm visual analog scale; pain, bloating, nausea, and fatigue) and 10 serial plasma samples were collected. Mucosal permeability was assessed using both urinary lactulose-13C mannitol ratios and endoscopic mucosal impedance.

RESULTS

Thirty-five of 40 (83%) subjects with CeD and NCGS reported symptoms with gluten (8 CeD, 9 NCGS) and sham (9 CeD, 9 NCGS) compared with 9 of 20 (45%) controls after gluten (n = 6) and sham (n = 3). There was no significant difference in symptoms among groups. Only 2 of 10 subjects with CeD and 4 of 10 NCGS identified gluten, whereas 8 of 10 subjects with CeD and 5 of 10 NCGS identified sham. A significant plasma IL-2 increase occurred only in subjects with CeD after gluten, peaking at 3 hours and normalizing within 24 hours postchallenge despite no significant intestinal permeability change from baseline.

DISCUSSION

Symptoms do not reliably indicate gluten exposure in either subjects with CeD or NCGS. IL-2 production indicates a rapid-onset gluten-induced T-cell activation in CeD despite long-standing treatment. The effector site is unknown, given no increased intestinal permeability after gluten.

Detection of gluten immunogenic peptides and the Celiac Disease Adherence Test to monitor gluten-free diet: a pilot study

Gluten immunogenic peptides (GIP) in feces and/or urine have recently been proposed as a sensitive and specific marker to detect ongoing gluten intake. Here, we compared GIP with the Celiac Disease Adherence Test (CDAT), a simple validated self-administered questionnaire that measures adherence to gluten-free diet (GFD). Of 70 subjects (59 women), six were classified as non-adherent by fecal GIP (mean 0.23 µg/g, standard deviation 0.08, range 0.082-0.319), including five classified as non-adherent by CDAT. GFD adherence was significantly higher by GIP than CDAT (p < 0.001). Fecal GIP may be useful as a biomarker for ongoing gluten intake that is not possible to detect with current clinical methods to assess GFD adherence, and may play a role in the management of persistent gastrointestinal symptoms in celiac disease.

Individual variability in patterns and dynamics of fecal gluten immunogenic peptides excretion after low gluten intake

Purpose

Determination of Gluten Immunogenic Peptides (GIP) in feces is a direct tool for gluten exposure detection. The sensitivity of GIP detection methods for cases of unintentional low gluten intakes is unknown. We studied the interindividual variability in the kinetic of excretion under homogeneously controlled dietary conditions, and the sensitivity of fecal GIP tests after low amounts of punctual gluten ingestions.

Methods

Participants (n = 20) followed the same gluten-free menu for 12 days in which two separated doses of gluten (50 mg and 2 g) were ingested and all the depositions were collected. GIP from stool samples were analyzed by ELISA and lateral flow immunoassay (LFIA) tests.

Results

Most participants had detectable GIP after 50 mg and 2 g gluten ingestions using ELISA test (72.2% and 95%, respectively), whereas the LFIA test showed less sensitivity (22.2% and 80%, respectively). GIP were detected at higher either frequency or concentration in the range of 12–36 h after 50 mg intake, and 12–84 h after 2 g consumption. Considering this period, diagnostic sensitivity of GIP detection after a single 50 mg ingestion may be significatively increased analyzing three stool samples per individual. High variability among participants was found in the time and amount of GIP excretion; however, some individuals showed common patterns for both gluten intakes.

Conclusion

Sporadic gluten exposure detection may require several fecal samples to achieve level of sensitivity above 90%. Interindividual variability in the dynamic of GIP excretion may suggest patterns of gluten metabolism.

Extracellular vesicle microRNAs in celiac disease patients under a gluten-free diet, and in lactose intolerant individuals

BACKGROUND

Celiac disease (CD) is an autoimmune disorder triggered by an abnormal immunological response to gluten ingestion and is associated with deregulated expression of cellular microRNAs (miRNAs) of the gut mucosa. It is frequently misdiagnosed as lactose intolerance (LI) due to symptom resemblance. Microvilli loss may be counteracted by a rigorous gluten-free diet (GFD).

AIMS

To identify altered extracellular vesicle miRNAs from plasma among CD patients on GFD (n=34), lactose intolerant individuals on restrictive diet (n=14) and controls (n=23), and to predict biological pathways in which these altered miRNAs may play a part.

METHODS

Five different small RNA samples of each group were pooled twice and then screened by new-generation sequencing. Four miRNAs were selected to be quantified by RT-qPCR in the entire sample.

RESULTS

The levels of four miRNAs - miR-99b-3p, miR-197-3p, miR-223-3p, and miR-374b-5p - differed between CD patients and controls (P<0.05). Apart from miR-223-3p, all these miRNAs tended to have altered levels also between LI and controls (P<0.10). The results for miR-99b-3p and miR-197-3p between CD and controls were confirmed by RT-qPCR, which also indicated different levels of miR-99b-3p and miR-374b-5p between CD-associated LI and LI (P<0.05).

CONCLUSIONS

These miRNAs may have targets that affect cell death, cell communication, adhesion, and inflammation modulation pathways. Hence, altered miRNA levels could be associated with CD-related aspects and gut mucosa recovery.

Oral Consumption of Bread from an RNAi Wheat Line with Strongly Silenced Gliadins Elicits No Immunogenic Response in a Pilot Study with Celiac Disease Patients

Celiac disease (CD) is a genetically predisposed, T cell-mediated and autoimmune-like disorder caused by dietary exposure to the storage proteins of wheat and related cereals. A gluten-free diet (GFD) is the only treatment available for CD. The celiac immune response mediated by CD4+ T-cells can be assessed with a short-term oral gluten challenge. This study aimed to determine whether the consumption of bread made using flour from a low-gluten RNAi wheat line (named E82) can activate the immune response in DQ2.5-positive patients with CD after a blind crossover challenge. The experimental protocol included assessing IFN-γ production by peripheral blood mononuclear cells (PBMCs), evaluating gastrointestinal symptoms, and measuring gluten immunogenic peptides (GIP) in stool samples. The response of PBMCs was not significant to gliadin and the 33-mer peptide after E82 bread consumption. In contrast, PBMCs reacted significantly to Standard bread. This lack of immune response is correlated with the fact that, after E82 bread consumption, stool samples from patients with CD showed very low levels of GIP, and the symptoms were comparable to those of the GFD. This pilot study provides evidence that bread from RNAi E82 flour does not elicit an immune response after a short-term oral challenge and could help manage GFD in patients with CD.

Compliance to a Gluten-Free Diet in Swedish Children with Type 1 Diabetes and Celiac Disease

Children with type 1 diabetes (T1D) are at increased risk of celiac disease (CD). The replacement of insulin in T1D, and the exclusion of gluten in CD, are lifelong, burdensome treatments. Compliance to a gluten-free diet (GFD) in children with CD is reported to be high, while compliance in children with both diseases has scarcely been studied. To examine compliance to a GFD in children with both T1D and CD, we analyzed tissue transglutaminase IgA-antibodies (tTGA). Moreover, associations between compliance and age, sex, glycemic control, ketoacidosis (DKA), body mass index (BMI), and time of CD diagnosis were investigated. Of the 743 children diagnosed with T1D in southern Sweden between 2005 and 2012, 9% were also diagnosed with CD. Of these, 68% showed good compliance to a GFD, 18% showed intermediate compliance, and 14% were classified as non-compliant. Higher age, poorer HbA1c, and more DKAs were significantly (p < 0.05) associated with poorer compliance. In conclusion, we found that compliance to a GFD in children with T1D and CD is likely be lower than in children with CD only. Our results indicate that children with both T1D and CD could need intensified dietary support and that older children and children with poor metabolic control are especially vulnerable subgroups.

A Bioinformatic Workflow for InDel Analysis in the Wheat Multi-Copy α-Gliadin Gene Family Engineered with CRISPR/Cas9

The α-gliadins of wheat, along with other gluten components, are responsible for bread viscoelastic properties. However, they are also related to human pathologies as celiac disease or non-celiac wheat sensitivity. CRISPR/Cas was successfully used to knockout α-gliadin genes in bread and durum wheat, therefore, obtaining low gluten wheat lines. Nevertheless, the mutation analysis of these genes is complex as they present multiple and high homology copies arranged in tandem in A, B, and D subgenomes. In this work, we present a bioinformatic pipeline based on NGS amplicon sequencing for the analysis of insertions and deletions (InDels) in α-gliadin genes targeted with two single guides RNA (sgRNA). This approach allows the identification of mutated amplicons and the analysis of InDels through comparison to the most similar wild type parental sequence. TMM normalization was performed for inter-sample comparisons; being able to study the abundance of each InDel throughout generations and observe the effects of the segregation of Cas9 coding sequence in different lines. The usefulness of the workflow is relevant to identify possible genomic rearrangements such as large deletions due to Cas9 cleavage activity. This pipeline enables a fast characterization of mutations in multiple samples for a multi-copy gene family.