Gluten immunogenic peptide excretion detects dietary transgressions in treated celiac disease patients

Role of capsule endoscopy and double-balloon enteroscopy in the management of adult patients with coeliac disease and persisting symptoms

BACKGROUND

Small bowel capsule endoscopy (CE) and double-balloon enteroscopy (DBE) are recommended for the management of patients with nonresponsive or refractory coeliac disease (CD). However, there is a paucity of data regarding the clinical profiles and outcomes of patients undergoing these investigations.

METHODS

We conducted a retrospective analysis of two databases of adult patients with CD who underwent CE and/or DBE between 2017 and 2022 at the National Centre for Refractory CD in England. Patient demographic, clinical and endoscopic data were collected, and clinically relevant outcomes were reported.

RESULTS

A total of 132 patients (median age 53 years, 64.4 % female) underwent 146 CEs and 25 DBEs. The most common symptoms were diarrhoea (51.5 %), abdominal pain (37.8 %), bloating (34.8 %), and weight loss (29.5 %). The overall detection rate of CE and DBE was 87.6 % and 92 %, respectively. Following CE and DBE, 14 patients (10.6 %) were diagnosed with CD-related complications such as ulcerative jejunitis, strictures and malignancy. Seven patients (5.3 %) died during follow-up, with five of these deaths directly attributed to CD. Older age, weight loss and anaemia were associated with poor outcomes.

CONCLUSIONS

The sequential approach of CE and DBE identified CD-related complications in almost 1 in 10 patients with nonresponsive or refractory CD. Older patients with persistent villous atrophy, weight loss and anaemia require close monitoring to help with the early diagnosis and management of complications.

Evolution in coeliac disease diagnosis and management

The traditional gut-centric view of coeliac disease is evolving as immune and genetic insights underscore the central importance of a systemic, T cell immune response to gluten in disease pathogenesis. As the field increasingly recognize the limitations of small intestinal histology as the diagnostic standard, data supporting the accuracy of an immune (serologic) diagnosis of coeliac disease - well demonstrated in children - are growing for adults. Novel biomarkers such as interleukin-2 that identify the gluten-specific T cell demonstrate high sensitivity and specificity for coeliac disease and offer the potential for a diagnostic approach that avoids the need for gluten challenge. Asymptomatic disease and manifestations outside the gut pose considerable challenges for diagnosis using a case-finding strategy and enthusiasm for population screening is growing. The gluten-free diet remains a highly restrictive treatment and there is a paucity of controlled data to inform a safe gluten intake threshold. Ongoing symptoms and enteropathy are common and require systematic evaluation. Slowly-responsive disease is prevalent in the older patient diagnosed with coeliac disease, and super-sensitivity to gluten is an emerging concept that may explain many cases of nonresponsive disease. While there is great interest in developing novel therapies for coeliac disease, no drug has yet been registered. Efficacy studies are generally assessing drugs in patients with treated coeliac disease who undergo gluten challenge or in patients with nonresponsive disease; however, substantial questions remain around specific endpoints relevant for patients, clinicians and regulatory agencies and optimal trial design. Novel immune tools are providing informative readouts for clinical trials and are now shaping their design.

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.

Risk of Gluten Cross-Contamination Due to Food Handling Practices: A Mini-Review

Celiac disease (CD) is an autoimmune disease triggered by the ingestion of gluten in genetically predisposed individuals, affecting 1.4% of the world population. CD induces an inflammatory reaction that compromises small intestine villi, leading to nutrient malabsorption, and gastro and extraintestinal manifestations. Although other treatment approaches are being studied, adherence to a gluten-free diet (GFD) is the only effective intervention to date. Despite this, about 50% of patients experience persistent inflammation, often associated with unintentional gluten ingestion through contaminated food. There are regulations for labeling gluten-free foods which specify a limit of 20 mg/kg (20 ppm). The risks of gluten cross-contamination above that level are present throughout the whole food production chain, emphasizing the need for caution. This review explores studies that tested different procedures regarding the shared production of gluten-containing and gluten-free food, including the use of shared equipment and utensils. A literature review covering PubMed, Scielo, Web of Science, VHL and Scopus identified five relevant studies. The results indicate that shared environments and equipment may not significantly increase gluten cross-contamination if appropriate protocols are followed. Simultaneous cooking of gluten-containing and gluten-free pizzas in shared ovens has demonstrated a low risk of contamination. In general, shared kitchen utensils and equipment (spoon, ladle, colander, knife, fryer, toaster) in controlled experiments did not lead to significant contamination of samples. On the other hand, cooking gluten-free and gluten-containing pasta in shared water resulted in gluten levels above the established limit of 20 ppm. However, rinsing the pasta under running water for a few seconds was enough to reduce the gluten content of the samples to less than 20 ppm.

Barriers at various levels of human ecosystem for maintaining adherence to gluten free diet in adult patients with celiac disease

INTRODUCTION

While lifelong and strict adherence to gluten-free diet (GFD) is essential for the successful treatment of celiac disease (CeD), only 30-50% of patients are able to maintain a good adherence to GFD. We determined factors influencing the adherence to GFD at various ecological levels including intra-personal, inter-personal, organizational, community and system-based levels in adult patients with CeD.

METHODS

A questionnaire to assess the adherence was developed and it was administered in the CeD clinic to patients with CeD on GFD for >1 year. Adherence to GFD was assessed in a subset of patients (n = 320) using Celiac Disease Adherence Test (CDAT).

RESULTS

Overall, 978 patients [median age: 29 years; females: 592] with CeD on GFD were recruited. They reported many barriers to adherence to GFD including intra-personal barriers such as lack of knowledge about GFD (19%), inadequate financial resources (27.2%) and lack of self-motivation/confidence (55.3%); inter-personal barriers such as intake of gluten-containing food upon forceful insistence of friends/family (23.4%); organizational barriers such as high cost (70.8%) and non-availability of GF-food products (48.6%); community-based barriers like consumption of gluten-containing food at religious occasions/festivals (11.1%) and social occasions (27.2%); and system-based barriers such as non-referral to dietitian for counseling (21.9%). As per CDAT, 204 (63.7%), 73(22.8%) and 43(13.4%) patients had good, average, and poor adherence to GFD, respectively. On multivariable analysis, occasional consumption of gluten, non-availability of GF-food while dining out and coercing by family and friends for consumption of GC-food were found to have highest odds for poor adherence to GFD.

CONCLUSIONS

Non-referral to a dietitian for counseling, irregular follow-up visits, unavailability of flour mill, non-supportive family/friends, high cost and limited availability of GF-food are the most common barriers to adherence to GFD. There is a need to create infrastructure and develop strategies to overcome these diverse barriers at various levels of ecosystem and thereby facilitate better adherence to GFD.

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.

Guidelines for best practices in monitoring established coeliac disease in adult patients

Coeliac disease (CeD) is an immunological disease triggered by the consumption of gluten contained in food in individuals with a genetic predisposition. Diagnosis is based on the presence of small bowel mucosal atrophy and circulating autoantibodies (anti-type 2 transglutaminase antibodies). After diagnosis, patients follow a strict, life-long gluten-free diet. Although the criteria for diagnosis of this disease are well defined, the monitoring phase has been studied less and there is a lack of specific guidelines for this phase. To develop a set of clinical guidelines for CeD monitoring, we followed the Grading of Recommendations Assessment, Development and Evaluation methodology. Statements and recommendations with the level of evidence were developed and approved by the working group, which comprised gastroenterologists, pathologists, dieticians and biostatisticians. The proposed guidelines, endorsed by the North American and European coeliac disease scientific societies, make recommendations for best practices in monitoring patients with CeD based on the available evidence. The evidence level is low for many topics, suggesting that further research in specific aspects of CeD would be valuable. In conclusion, the present guidelines support clinicians in improving CeD treatment and follow-up and highlight novel issues that should be considered in future studies.

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.

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.

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.

Low Levels of Detectable Urine and Stool GIPs in Children with Celiac Disease on a Gluten-Free Diet

Objectives

This study examines the prevalence of detectable gluten immunogenic peptides (GIPs) as a proxy for gluten exposure in children with celiac disease on a gluten-free diet in the United States, as estimated by gluten breakdown products excreted in urine and stool.

Methods

Urine and stool samples were collected in 3 settings (home, gastroenterology clinic, and endoscopy) for pediatric participants (ages 6-21 years old) across 2 medical centers. Commercial ELISA assays were used to quantify the GIPs in each sample.

Results

GIPs were detected in 4 out of 44 (9.1%) of stool samples and 6 out of 125 (4.8%) of urine samples provided by 84 children. These samples were collected across all settings, and most participants (70%) were asymptomatic at the time of sample collection. For the urine samples collected at the time of endoscopy, all subjects found to have persistent enteropathy had no detectable GIPs (0/12).

Discussion

GIPs provide an additional method for screening for gluten exposures in individuals with celiac disease on a gluten-free diet, and may be used across multiple settings. We found a low detection rate of GIPs in children. Our finding of undetectable GIPs in individuals with persistent enteropathy may be expected of a single determination under close observation or represent a lack of gluten exposure within the detection window. More research is needed to understand the dynamics of gluten absorption and excretion in the US pediatric population.

The use of urine peptidomics to define dietary gluten peptides from patients with celiac disease and the clinical relevance

INTRODUCTION

Determination of urinary gluten immunogenic peptides (GIP) has emerged as one of the most attractive test to monitor the adherence to the gluten-free diet (GFD) of patients with celiac disease (CD), being a simple, noninvasive and direct method to detect gluten contamination of the GFD.

AREAS COVERED

We conducted a scoping review in Medline (PubMed) of articles published up to April 2023 that analyzed any aspect of the clinical relevance of the use of urinary GIP measurement in patients with CD. A total of 17 articles reporting the clinical use of urinary peptidomics for the follow-up of CD patients were finally included.

EXPERT OPINION

Available data suggest that a negative urinary GIP result is a reliable noninvasive predictor of intestinal mucosa healing in CD patients treated with the GFD, especially if testing three urine samples on different days including the weekend. Due to conflicting results about the sensitivity and the specificity of the urinary GIP determination, additional in-depth information is needed, particularly related to (1) the relationship between the amount of ingested gluten and the quantity of urinary GIP excreted in treated CD patients, (2) the GIP kinetics and best timing for sample collection.

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.

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.

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.

Current Applications of Telemedicine in Gastroenterology

Telemedicine generally refers to the use of technology to communicate with patients and provide health care from a distance. Advances in technology, specifically computers, cellphones, and other mobile devices, have facilitated healthcare providers' growing ability to virtually monitor and mentor patients. There has been a progressive expansion in the use of telemedicine in the field of gastroenterology (GI), which has been accelerated by the COVID-19 pandemic. In this review, we discuss telemedicine-its history, various forms, and limitations-and its current applications in GI. Specifically, we focus on telemedicine in GI practice in general and specific applications, including the management of inflammatory bowel disease, celiac disease, and colorectal cancer surveillance and its use as an aid in endoscopic procedures.

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.

Biomarkers to Monitor Adherence to Gluten-Free Diet by Celiac Disease Patients: Gluten Immunogenic Peptides and Urinary miRNAs

Celiac disease (CD) is a multifactorial autoimmune enteropathy with a prevalence greater than 1% in the pediatric population. The only therapy for CD patients is a strict gluten-free diet (GFD). Gluten-free food contamination by other cereals during packaging and cooking or accidental ingestion of gluten may cause several intestinal and extraintestinal symptoms in CD patients. Therefore, the monitoring of gluten contamination in food and assessing the level of ingested gluten by analytical biomarkers has been of great interest in recent years. To this aim, small gluten immunogenic peptides (GIPs) obtained by the hydrolysis of gluten and present in urine and feces have been studied as biomarkers of gluten intake and to monitor adherence to GFD by CD patients. More recently, the use of circulating, fecal and urinary miRNAs has emerged as a novel diagnostic tool that can be potentially applied to assess adherence to GFD. Moreover, the presence of GIPs and miRNAs in both feces and urine suggests a similar excretion modality and the possibility of using urinary miRNAs, similarly to GIPs, as potential biomarkers of GFD in CD patients.

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.

Association in Clinical Practice Between Gluten Intake and Gluten Immunogenic Peptides in Celiac Children

Background and Aims

The dietary compliance and its assessment in celiac disease (CD) patients on a strict gluten-free diet (GFD) remain a challenge. Two relatively new, validated methods have been proposed to detect occasional gluten ingestion: standardized dietary questionnaire and determination of urinary gluten immunogenic peptides (GIPs). Our aim was to prospectively assess dietary compliance via these methods and compare their results with those of tissue transglutaminase antibodies (tTGA).

Methods

This was a prospective single-center study. Consecutive CD patients (aged 1-18 years) on a GFD scheduled for regular consultation between March and August 2019 were invited. In addition to standard care, a completed dietary questionnaire and urine sample for GIP were collected. Pearson's chi-square test, Fisher's exact test, and Mann-Whitney U test were performed.

Results

Of the 156 eligible children, 110 provided informed consent. Completed dietary questionnaire, GIP, and tTGA results were available from 86 children (median age 12.8 years, median GFD duration 30 months, 65% female). Adherence to the GFD evaluated by GIP, dietary questionnaire, and anti-tTGA was 94.2%, 75.6% and 94.2%, respectively. No association was found between the tTGA results and the detection of GIP, as well as between the tTGA results and the dietary questionnaires scores (P = .5 and .312, respectively). The participants perceived both the questionnaire and the measurement of GIP as reassuring with regard to correct implementation of the GFD.

Conclusion

All the 3 methods have limitations to monitor dietary compliance. The comparison of their performance shows that the best single method is the use of the validated dietary questionnaire, which should therefore be implemented in the regular care for children with CD. The most effective combination of dietary questionnaire and urinary GIP determination should be used in specific clinical situations.

An efficient urine peptidomics workflow identifies chemically defined dietary gluten peptides from patients with celiac disease

Celiac disease (CeD) is an autoimmune disorder induced by consuming gluten proteins from wheat, barley, and rye. Glutens resist gastrointestinal proteolysis, resulting in peptides that elicit inflammation in patients with CeD. Despite well-established connections between glutens and CeD, chemically defined, bioavailable peptides produced from dietary proteins have never been identified from humans in an unbiased manner. This is largely attributable to technical challenges, impeding our knowledge of potentially diverse peptide species that encounter the immune system. Here, we develop a liquid chromatographic-mass spectrometric workflow for untargeted sequence analysis of the urinary peptidome. We detect over 600 distinct dietary peptides, of which ~35% have a CeD-relevant T cell epitope and ~5% are known to stimulate innate immune responses. Remarkably, gluten peptides from patients with CeD qualitatively and quantitatively differ from controls. Our results provide a new foundation for understanding gluten immunogenicity, improving CeD management, and characterizing the dietary and urinary peptidomes.

Gluten peptides from wheat enter the bloodstream and are excreted in urine but are yet to be chemically characterised. Here, the authors show by mass spectrometry that quantitative and qualitative differences in urinary peptides can be detected between healthy people and patients with celiac disease.

Maintaining, Managing, and Tele-Monitoring a Nutritionally Adequate Mediterranean Gluten-Free Diet and Proper Lifestyle in Adult Patients

The gluten-free diet (GFD) is a restrictive diet. In many cases, it must be permanent and strict, and it may be associated with both nutritional deficiencies and excesses, which can be prevented by following a healthy, natural Mediterranean GFD (Med-GFD). In this paper, we describe the importance of the Mediterranean diet, the correct intake of vitamins and minerals, and how they may play an important protective role against chronic or degenerative conditions. Herewith, we analyze different aspects that influence the ability to maintain a correct and balanced Med-GFD, which may contribute to the health status of patients, including a conscious use of gluten-free products to maintain a healthy lifestyle. Monitoring the Med-GFD remains a pivotal issue: to evaluate the presence of gluten peptides in urine, it could be important to introduce point-of-care testing, an efficient method for GFD self-monitoring (immunochromatographic technique), together with online nutritional questionnaires. Indeed, medical care via telemedicine can provide practical indications aimed at supporting patients and doctors. A natural Med-GFD can ensure the correct intake of nutrients and could be important for patients affected by gluten-related disorders, helping them to maintain a correct and healthy lifestyle.

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.

Nutrition in Patients with Lactose Malabsorption, Celiac Disease, and Related Disorders

Lactose malabsorption (LM), celiac disease (CD), non-celiac gluten sensitivity (NCGS), and irritable bowel syndrome (IBS) are conditions associated with food triggers, improvement after withdrawal, treatment with dietary restriction, and subsequent nutritional detriments. LM occurs when there is incomplete hydrolysis of lactose due to lactase deficiency and frequently produces abdominal symptoms; therefore, it can cause lactose intolerance (LI). A lactose-restricted diet is frequently recommended, although it can potentially lead to nutrient deficiencies. Furthermore, lactose is an essential component of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) and is subsequently associated with intolerance to these compounds, especially in IBS. LM commonly presents in CD. Nutritional deficits are common in CD and can continue even on a gluten-free diet (GFD). Conditions triggered by gluten are known as gluten-related disorders (GRDs), including CD, wheat allergy, and NCGS. IBS can also be associated with a gluten sensitivity. A GFD is the treatment for CD, GRDs, and gluten sensitive IBS, although compliance with this restricted diet can be difficult. Strict dietary therapies can have a negative effect on quality of life. This review aims to provide an overview of the difficult nutritional elements of these disorders, which are critical for medical providers to recognize when managing these patients.

Gluten Immunogenic Peptides (GIP) Point-of-Care Urine Test in Coeliac Disease Follow-up before and during the COVID-19 Lockdown in Italy

Introduction

Celiac disease (CeD) diagnosis has worldwide shared protocols. Conversely, follow-up of patients is still an object of study. Gluten immunogenic peptide detection in the urine (GIP) appears to be a new and efficient method for dietary gluten control of patients. The present study aims to assess the clinical usefulness of the GIP point-of-care urine test in the follow-up of symptomatic and asymptomatic patients with CeD before and during the COVID-19 lockdown in Italy.

Methods

Thirty adult CeD patients on a gluten-free diet (GFD) were enrolled before and during the COVID-19 lockdown through follow-up visits or remote consultation. Patients underwent anthropometrical evaluation, dietetic interview, and State-Trait Anxiety Inventory (STAI). Then, two groups were formed: symptomatic and worried about gluten contamination. Each patient received 5 GIP point-of-care tests to perform a maximum of 5 times in the following 5 weeks in case of symptoms or anxiety state due to hypothesized gluten contamination.

Results

Sixteen symptomatic patients and 14 patients with concerns related to gluten contamination were included. There were no differences in age, BMI, compliance to GFD and GIP positive tests between the two groups. Worried group showed a borderline higher level of anxiety than symptomatic group (p = 0.06), with a significant minor percentage of patients reporting “no or low anxiety” (14.3% vs 50% p = 0.03). The symptomatic patients showed a higher rate of diarrhea than worried group (25% vs 0%, p = 0.04). Gluten in urine samples was globally found in 8 out of 30 cases (26.6%).

Conclusion

The GIP test is a tool that can be used as a point of care test to assess adequate compliance with GFD and reassure symptomatic CeD patients from the feeling of anxiety for gluten contamination, especially during the COVID-19 pandemic.

Determination of gluten immunogenic peptides for the management of the treatment adherence of celiac disease: A systematic review

BACKGROUND

Gluten is a complex mixture of proteins with immunogenic peptide sequences triggering the autoimmune activity in patients with celiac disease (CeD). Gluten immunogenic peptides (GIP) are resistant to gastrointestinal digestion and are then excreted via the stool and urine. Most common detection methods applied in the follow-up visits for CeD patients such as serology tests, dietetic interviews, questionnaires, and duodenal biopsy have been proved to be inefficient, invasive, or inaccurate for evaluating gluten-free diet (GFD) compliance. Determination of excreted GIP in stool and urine has been developed as a non-invasive, direct, and specific test for GFD monitoring.

AIM

To summarize published literature about the clinical utility of GIP determination in comparison to the tools employed for GFD monitoring.

METHODS

PubMed and Web of Science searches were performed using the keywords “gluten immunogenic peptides” or “gluten immunogenic peptide” and a combination of the previous terms with “feces”, “stools”, “urine”, “celiac disease”, “gluten-free diet”, and “adherence” to identify relevant clinical studies published in English and Spanish between 2012 to January 2021. Reference lists from the articles were reviewed to identify additional pertinent articles. Published articles and abstracts reporting the clinical use of GIP determination in stool and/or urine for the follow-up of patients with CeD in comparison with other tools in use were included. Case reports, commentaries, reviews, conference papers, letters, and publications that did not focus on the aims of this review were excluded.

RESULTS

Total of 15 publications were found that involved the use of GIP determination in stool and/or urine to monitor the adherence to the GFD in comparison to other tools. Studies included both children and adults diagnosed with CeD and healthy volunteers. Overall, these preliminary studies indicated that this novel technique was highly sensitive for the detection of GFD transgressions and therefore could facilitate the follow-up of patients with CeD. Tools identified in this work included the CeD-specific serology, dietetic questionnaires, symptomatology, and the duodenal biopsy. Review of the literature revealed that the rates of GFD adherence may vary between 30%-93% using either stool or urine GIP determination, 49%-96% by the serology, 59%-94% using the dietetic questionnaires, 56%-95% by the reported symptoms and 44%-76% with the duodenal biopsy. In addition, the association between the different methods and histological abnormalities (Marsh II-III) was found to be 33%-100% for GIP determination (stool and urine), 25%-39% for CeD-specific serology, 3%-50% for dietetic questionnaires, and 22%-28% for the symptomatology.

CONCLUSION

Excreted GIP detection is the precise approach for determining voluntary or involuntary gluten consumption in CeD patients preventing future complications arising from gluten exposure.

Determination of Urinary Gluten Immunogenic Peptides to Assess Adherence to the Gluten-Free Diet: A Randomized, Double-Blind, Controlled Study

INTRODUCTION

The adherence to a gluten-free diet (GFD) is a trending topic in the management of celiac disease. The aim of our study was to evaluate the diagnostic performance of urinary gluten immunogenic peptides (GIP) determination to detect gluten contamination of the GFD.

METHODS

In study A, 25 healthy adults on a standard GFD performed 6 gluten challenges (0, 10, 50, 100, 500, and 1,000 mg) with quantification of urinary GIP before (T0) and during the following 24 hours. In study B, 12 participants on a gluten contamination elimination diet underwent urinary GIP determination at T0 and after challenge with 5 or 10 mg gluten. Urine GIP concentration was determined by an immunochromatographic assay.

RESULTS

In study A, 51 of 150 baseline urine samples were GIP+ on GFD and 7 of 17 were GIP+ after the zero-gluten challenge, whereas only 55 of 81 were GIP+ after the 10-1,000 mg gluten challenges. There was no significant change in the 24-hour urinary GIP when increasing gluten from 10 to 1,000 mg. In study B, 24 of 24 baseline urine samples were GIP-, whereas 8 of 24 were GIP+ after 5 or 10 mg of gluten.

DISCUSSION

Traces of gluten in the standard GFD may cause positivity of urinary GIP determination, whereas a false negativity is common after a gluten intake of 10-1,000 mg. Owing to the impossibility of standardizing the test in normal conditions, it seems unlikely that urinary GIP determination may represent a reliable tool to assess the compliance to the GFD of patients with celiac disease or other gluten-related disorders.

Gluten-free diet can ameliorate the symptoms of non-celiac autoimmune diseases

CONTEXT

A gluten-free diet (GFD) is the recommended treatment for gluten-dependent disease. In addition, gluten withdrawal is popular and occasionally is suggested as a treatment for other autoimmune diseases (ADs).

OBJECTIVE

The current systematic review summarizes those entities and discusses the logic behind using a GFD in classical non-gluten-dependentADs.

DATA SOURCES

A search for medical articles in PubMed/MEDLINE, Web of Sciences, LILACS, and Scielo published between 1960 and 2020 was conducted, using the key words for various ADs and GFDs.

DATA EXXTRACTION

Eight-three articles were included in the systematic review (using PRISMA guidelines).

DATA ANALYSIS

Reduction in symptoms of ADs after observance of a GFD was observed in 911 out of 1408 patients (64.7%) and in 66 out of the 83 selected studies (79.5%). The age of the patients ranged from 9 months to 69 years. The duration of the GFD varied from 1 month to 9 years. A GFD can suppress several harmful intraluminal intestinal events. Potential mechanisms and pathways for the action of GFD in the gut - remote organs' axis have been suggested.

CONCLUSION

A GFD might represent a novel nutritional therapeutic strategy for classical non-gluten-dependent autoimmune conditions.

Dynamics and Considerations in the Determination of the Excretion of Gluten Immunogenic Peptides in Urine: Individual Variability at Low Gluten Intake

BACKGROUND

A lifelong strict gluten-free diet is the only available treatment for celiac disease, but total exclusion of gluten is difficult to achieve. The aim of this study was to determine the range of time and the amount of gluten immunogenic peptides (GIP) excreted in urine after specific gluten ingestions.

METHODS

20 healthy participants followed the same diet for 12 days in which 50 mg and 2 g of gluten were ingested and all the urinations were collected. GIP were analyzed by lateral flow immunoassay (LFIA) tests and quantified using an LFIA reader.

RESULTS

GIP were detected in 15% and 95% of participants after 50 mg and 2 g gluten intakes, respectively. The higher frequency and concentration of GIP was found between 6 and 9 h after both gluten ingestions. The ranges of detection were 3-12 h (50 mg) and 0-15 h (2 g).

CONCLUSIONS

An increase in the frequency of urine tests may be a suitable approach to avoid false negative results. The use of the LFIA test in three urine samples collected at different times may show a sensitivity of 19.6% for a gluten ingestion like 50 mg, increasing to 93% after 2 g consumption.

Whether a Gluten-Free Diet Should Be Recommended in Chronic Autoimmune Thyroiditis or Not?-A 12-Month Follow-Up

Elimination diets have recently become extremely popular among people with autoimmune diseases. A gluten-free diet is indicated in celiac disease (CD), but some studies show its effectiveness in cases of autoimmunity. The aim of this study was to assess whether the use of a gluten-free diet is also effective in patients with chronic autoimmune thyroid disease (cAITD), which is the most common thyroid autoimmune pathology associated with chronic inflammation, over-reactivity of the immune system, auto-destruction of thyrocytes and hypothyroidism. The final analysis of the study included 62 Caucasian women randomized into a control group (CG: n = 31) and an experimental group on a gluten-free diet (GFDG: n = 31), were subject to a 12-month follow-up, during which the concentrations of thyrotropin (TSH), free triiodothyronine (fT3), free thyroxine (fT4), anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies were assessed at baseline and after 3, 6 and 12 months. During the 12-month follow-up between the CG and the GFDG, no differences were found in anti-TPO and anti-TG antibodies, fT3 or fT4 levels, except a significant reduction in TSH levels in the GFDG. Additionally, performed analysis between individual appointments presented no significant differences in changes in the median concentrations of anti-TPO, anti-TG or fT3, but confirmed a significant decrease in TSH and showed accessory an increase in fT4 after 12 months in GFDG. Statistical analyses performed separately for both groups indicated a constant reduction of anti-TG concentrations in the GFDG. In conclusion, a GFD may be administered in cAITD after ruling out celiac disease, but it is necessary to perform more studies to assess if cAITD patients achieve the benefits of following a GFD. Patients with cAITD should be offered proper nutrition education combined with a healthy lifestyle promotion.

Challenges of Monitoring the Gluten-Free Diet Adherence in the Management and Follow-Up of Patients with Celiac Disease

Celiac disease (CD) is a chronic gluten-responsive immune mediated enteropathy and is treated with a gluten-free diet (GFD). However, a strict diet for life is not easy due to the ubiquitous nature of gluten. This review aims at examining available evidence on the degree of adherence to a GFD, the methods to assess it, and the barriers to its implementation. The methods for monitoring the adherence to a GFD are comprised of a dietary questionnaire, celiac serology, or clinical symptoms; however, none of these methods generate either a direct or an accurate measure of dietary adherence. A promising advancement is the development of tests that measure gluten immunogenic peptides in stools and urine. Causes of adherence/non-adherence to a GFD are numerous and multifactorial. Inadvertent dietary non-adherence is more frequent than intentional non-adherence. Cross-contamination of gluten-free products with gluten is a major cause of inadvertent non-adherence, while the limited availability, high costs, and poor quality of certified gluten-free products are responsible for intentionally breaking a GFD. Therefore, several studies in the last decade have indicated that many patients with CD who follow a GFD still have difficulty controlling their diet and, therefore, regularly consume enough gluten to trigger symptoms and damage the small intestine.

New Insights into Non-Dietary Treatment in Celiac Disease: Emerging Therapeutic Options

To date, the only treatment for celiac disease (CD) consists of a strict lifelong gluten-free diet (GFD), which has numerous limitations in patients with CD. For this reason, dietary transgressions are frequent, implying intestinal damage and possible long-term complications. There is an unquestionable need for non-dietary alternatives to avoid damage by involuntary contamination or voluntary dietary transgressions. In recent years, different therapies and treatments for CD have been developed and studied based on the degradation of gluten in the intestinal lumen, regulation of the immune response, modulation of intestinal permeability, and induction of immunological tolerance. In this review, therapeutic lines for CD are evaluated with special emphasis on phase III and II clinical trials, some of which have promising results.

Study of adherence to the gluten-free diet in coeliac patients

INTRODUCTION

The following of a strict gluten-free diet (GFD) is essential in the control of coeliac disease. The aim of this study was to determine the adherence to a GFD in coeliac patients and to evaluate the factors that could influence this adherence.

MATERIAL AND METHODS

A descriptive observational study was carried out, in which gluten immunogenic peptides (GIP) were determined in faeces using a semi-quantitative method, and the Coeliac Dietary Adherence Test was completed. Sociodemographic and clinical details were collected, and an ad hoc questionnaire was prepared.

RESULTS

Of the 80 patients included, 92.5% were adherent according to the GIP and 86.3% according to Coeliac Dietary Adherence Test (acceptable agreement; Kappa: 0.31, P = .004). The large majority (83.3%) of patients with positive GIP gave negative anti-transglutaminase antibodies in the latest determination. Current age and time of onset were significantly associated with adherence. Those with a positive GIP had a mean age of 5 years more (P = .0001) and were 52 months more on a GFD (P = .025). One quarter of those surveyed considered the diet difficult to follow. Just under two-thirds (60%) considered that the variability in the eating site was an important factor in leading to infringements, with children's parties being the main area where they occurred (66.7%). The lack of variety (61.4%) and the increased cost (98.6%) of gluten-free foods is highlighted.

CONCLUSIONS

The adherence to the GFD is generally good. The analysis of GIP helps to detect non-adherent patients that would pass unnoticed in other circumstances. Measures must be established in order to maintain good long-term adherence, taking into account the risk factors and difficulties detected.

The utility of faecal and urine biomarkers for small bowel diseases

PURPOSE OF REVIEW

Small bowel diseases pose a unique diagnostic and management challenge and often requires tertiary specialist referral. The use of biomarkers may provide a cheap, noninvasive tool to assess the small bowel in terms of diagnosis, offering a better way to triage referrals and select patients for early management. This review looks at the most recent evidence behind the use of several faecal and urine biomarkers for small bowel diseases.

RECENT FINDINGS

Faecal calprotectin shows the most promise, with evidence to support its role in predicting relapse postsurgery and monitoring treatment response in patients with Crohn's disease. A faecal calprotectin less than 50 μg/g may also be used as a cut-off to triage further investigation. Faecal lactoferrin also appears promising as a marker of small bowel inflammation. A positive faecal immunohistochemistry test precapsule may help to prioritize referrals for obscure bleeding.

SUMMARY

The use of biomarkers in the diagnosis and management of small bowel disease is still controversial and remains unclear. More studies are required to further develop their potential and before societal guidelines can be developed to direct their appropriate use in clinical practice.

Persistent Villous Atrophy in De Novo Adult Patients With Celiac Disease and Strict Control of Gluten-Free Diet Adherence: A Multicenter Prospective Study (CADER Study)

INTRODUCTION

A substantial proportion of adult patients with celiac disease on a gluten-free diet exhibit persistent villous atrophy, and inadvertent gluten exposure may be one of the causes. The aim of the present study was to evaluate villous atrophy persistence after 2 years on a gluten-free diet in de novo adult patients with celiac disease with strict control of gluten exposure.

METHODS

Symptomatic de novo adult patients with celiac disease were prospectively included. Clinical visits and dietary surveillance were scheduled every 6 months during a 2-year follow-up period. At each visit, fecal samples were collected and stored at -20 °C until analysis for gluten immunogenic peptides (f-GIPs). A follow-up duodenal biopsy was performed at 2 years. We evaluated the variables associated with persistent villous atrophy.

RESULTS

Seventy-six patients completed the study (36.5 ± 1.6 years, 73% women); persistent villous atrophy was observed in 40 (53%), whereas 72.5% were asymptomatic and 75% had negative serology. Detectable f-GIP >0.08 μg/g in at least 1 fecal sample was seen in 69% of patients. There were no significant differences in the median f-GIP at each visit and median area under the curve over the serial measurements between patients with persistent villous atrophy and those who recovered. On multivariate analysis, only older age was associated with persistent villous atrophy (32% for 16-30 years; 67% for >30 years; P = 0.016).

DISCUSSION

The rate of persistent villous atrophy after 2 years was high in adult patients with celiac disease on an intentionally strict gluten-free diet. Low-level ongoing inadvertent gluten exposure could be a contributing factor to persistent villous atrophy.

Nutritional and Gastroenterological Monitoring of Patients With Celiac Disease During COVID-19 Pandemic: The Emerging Role of Telemedicine and Point-of-Care Gluten Detection Tests

Background and Aims: Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, telemedicine has been supporting many patients with chronic diseases worldwide. However, data on celiac disease (CeD) nutritional and gastroenterological remote monitoring are scanty. The aims of our study were to verify patients' trust in telemedicine and to evaluate the feasibility of telemedicine in nutritional monitoring. Material and Methods: We used telemedicine in place of the scheduled but not provided follow-up visits during the first lockdown of the COVID-19 pandemic. Patients received a phone call, and televisits were conducted for CeD patients with mild or moderate symptoms and/or with blood alterations. The patient's adherence to the gluten-free diet (GFD) was evaluated according to the Celiac Dietary Adherence Test (CDAT). When gluten contamination was suspected, a point-of-care gluten detection test was prescribed. The patient's trust in telemedicine was assessed, through an adapted version of the Patient Trust Assessment Tool (PATAT) questionnaire, as the percentage of patients giving a score of at least 4 out of 5 on a Likert scale for three selected key statements: "I can trust televisit," "I can trust that possible problems with the telemedicine service will be solved properly," and "I feel at ease when working with this website." Results: One hundred and twelve CeD patients were phone called; among symptomatic patients, 39 out of the 42 scheduled (92.9%) televisits were performed. Among the 39 visits, 34 (87.2%) questionnaires were compiled. The patients included in the study obtained a CDAT score from 7 to 13 (11 ± 2). Gluten detection tests were prescribed to 11 patients, resulting positive in 2. Trust in the telemedicine service was achieved in 94.1, 88.2, and 97.1% for the three selected key statements of the PATAT questionnaire. Conclusion: During the COVID-19 pandemic, telemedicine showed to be feasible and the majority of patients trusted the combined gastroenterological and nutritional televisits. Gluten detection tests demonstrated to be useful tools for the patient and for the caregiver to confirm adherence to the GFD remotely.

"Let Food Be Thy Medicine": Gluten and Potential Role in Neurodegeneration

Wheat is a most favored staple food worldwide and its major protein is gluten. It is involved in several gluten dependent diseases and lately was suggested to play a role in non-celiac autoimmune diseases. Its involvement in neurodegenerative conditions was recently suggested but no cause-and-effect relationship were established. The present narrative review expands on various aspects of the gluten-gut-brain axes events, mechanisms and pathways that connect wheat and gluten consumption to neurodegenerative disease. Gluten induced dysbiosis, increased intestinal permeabillity, enteric and systemic side effects, cross-reactive antibodies, and the sequence of homologies between brain antigens and gluten are highlighted. This combination may suggest molecular mimicry, alluding to some autoimmune aspects between gluten and neurodegenerative disease. The proverb of Hippocrates coined in 400 BC, "let food be thy medicine," is critically discussed in the frame of gluten and potential neurodegeneration evolvement.

Real-World Gluten Exposure in Patients With Celiac Disease on Gluten-Free Diets, Determined From Gliadin Immunogenic Peptides in Urine and Fecal Samples

BACKGROUND & AIMS

It is not clear how often patients who are on gluten-free diets (GFDs) for treatment of celiac disease still are exposed to gluten. We studied levels of gluten immunogenic peptides (GIP) in fecal and urine samples, collected over 4 weeks, from patients with celiac disease on a long-term GFD.

METHODS

We performed a prospective study of 53 adults with celiac disease who had been on a GFD for more than 2 years (median duration, 8 y; interquartile range, 5-12 y) in Argentina. At baseline, symptoms were assessed by the celiac symptom index questionnaire. Patients collected stool each Friday and Saturday and urine samples each Sunday for 4 weeks. We used a commercial enzyme-linked immunosorbent assay to measure GIP in stool and point-of-care tests to measure GIP in urine samples.

RESULTS

Overall, 159 of 420 stool and urine samples (37.9%) were positive for GIP; 88.7% of patients had at least 1 fecal or urine sample that was positive for GIP (median, 3 excretions). On weekends (urine samples), 69.8% of patients excreted GIP at least once, compared with 62.3% during weekdays (stool). The number of patients with a sample that was positive for GIP increased over the 4-week study period (urine samples in week 1 vs week 4: P < .05). Patients with symptoms had more weeks in which GIP was detected in stool than patients without symptoms (P < .05). The number of samples that were positive for GIP correlated with titers of deamidated gliadin peptide IgA in patients' blood samples, but not with levels of tissue transglutaminase.

CONCLUSIONS

Patients with celiac disease on a long-term GFD still frequently are exposed to gluten. Assays to detect GIP in stool and urine might be used to assist dietitians in assessment of GFD compliance.

Celiac Disease and Elevated Liver Enzymes: A Review

Aminotransferases are commonly found to be elevated in patients with celiac disease in association with two different types of liver dysfunction: cryptogenic liver disorders and autoimmune disorders. The purpose of this review is to discuss the mechanisms by which aminotransferases become elevated in celiac disease, clinical manifestations, and response to gluten-free diet. Many studies have shown that celiac patients with cryptogenic liver disease have normalization in aminotransferases, intestinal histologic improvement and serologic resolution after 6-12 months of strict gluten-free diet. In patients with an underlying autoimmune liver disease, simultaneous treatment for both conditions resulted in normalized elevated aminotransferases. The literature suggests that intestinal permeability may be at least one of the mechanisms by which liver damage occurs. Patients with celiac disease should have liver enzymes routinely checked and treated with a strict gluten-free diet if found to be abnormal. Lack of improvement in patients who have strictly adhered to gluten-free diet should prompt further workup for other causes of liver disease.

Dietary Compliance and Quality of Life in Celiac Disease: A Long-Term Follow-Up of Primary School Screening-Detected Patients

Background: Whether the diagnostic approach for celiac disease (CD) can really affect quality of life (QoL) and dietary compliance remains controversial. Aims: This study aimed to evaluate QoL and compliance to gluten-free diet (GFD) in adolescents/young adults diagnosed with CD through a screening strategy during childhood compared to age-matched CD patients diagnosed by case-finding and to assess whether follow-up at a referral center for CD influences compliance and QoL. Materials and Methods: Thirty-seven CD patients who were diagnosed by screening programs (SC-group) and 38 age-matched CD patients diagnosed due to symptoms (CF-group) were enrolled. Patients were asked to answer a questionnaire on QoL, dietary compliance, and follow-up care for CD. Results: Twenty-nine patients of the SC-group (median age 18.0 years, interquartile range [IQR] 16.0-19.0) and 31 patients of the CF-group (median age 17.0 years, IQR 15.5-18.0) completed the questionnaire. No significant difference relating adherence to the GFD and QoL was shown between the two groups. The majority (93.5%) of CF-group regularly had annual follow-up at a referral center compared to 37.9% of the SC-group (p < 0.001). Conclusion: The diagnostic strategy does not seem to impact QoL and dietary compliance. However, implementation of follow-up might still be necessary for patients identified through screening.

Negative predictive value of the repeated absence of gluten immunogenic peptides in the urine of treated celiac patients in predicting mucosal healing: new proposals for follow-up in celiac disease

BACKGROUND

The treatment of celiac disease (CD) is a lifelong gluten-free diet (GFD). The current methods for monitoring GFD conformance, such as a dietary questionnaire or serology tests, may be inaccurate in detecting dietary transgressions, and duodenal biopsies are invasive, expensive, and not a routine monitoring technique.

OBJECTIVES

Our aim was to determine the clinical usefulness of urine gluten immunogenic peptides (GIP) as a biomarker monitoring GFD adherence in celiac patients and to evaluate the concordance of the results with the degree of mucosal damage.

METHODS

A prospective observational study was conducted involving 22 de novo CD patients, 77 celiac patients consuming a GFD, and 13 nonceliac subjects. On 3 d of the week, urine samples were collected and the GIP concentrations were tested. Simultaneously, anti-tissue transglutaminase antibodies, questionnaire results, clinical manifestations, and histological findings were analyzed.

RESULTS

Approximately 24% (18 of 76) of the celiac patients consuming a GFD exhibited Marsh II-III mucosal damage. Among this population, 94% (17 of 18) had detectable urine GIP; however, between 60% and 80% were asymptomatic and exhibited negative serology and appropriate GFD adherence based on the questionnaire. In contrast, 97% (31 of 32) of the celiac patients without duodenal damage had no detectable GIP. These results demonstrated the high sensitivity (94%) and negative predictive value (97%) of GIP measurements in relation to duodenal biopsy findings. In the de novo CD-diagnosed cohort, 82% (18 of 22) of patients had measurable amounts of GIP in the urine.

CONCLUSIONS

Determining GIP concentrations in several urine samples may be an especially convenient approach to assess recent gluten exposure in celiac patients and appears to accurately predict the absence of histological lesions. The introduction of GIP testing as an assessment technique for GFD adherence may help in ascertaining dietary compliance and to target the most suitable intervention during follow-up.

Innate and adaptive immunity in celiac disease

PURPOSE OF REVIEW

The current review is prompted by recent studies indicating that adaptive immunity could be sufficient to explain rapid onset symptoms as well as many chronic effects of gluten in celiac disease.

RECENT FINDINGS

Gluten re-exposure in treated celiac disease drives a coordinated systemic cytokine release response implicating T-cell activation within 2 h. Instead of direct effects of gluten on innate immunity, long lasting memory CD4+ T cells activated within 2 h of ingesting gluten or injecting purified gluten peptides now appear to be responsible for acute digestive symptoms. In addition, memory B cells and plasma cells specific for gluten and transglutaminase 2, rather than innate immune cells, are the preferred antigen-presenting cells for gluten in the gut. A variety of innate immune stimuli such as transient infections and local intestinal microbiome, not necessarily gluten itself, may contribute to disease initiation and transition to overt intestinal mucosal injury. Gluten-specific adaptive immunity in the gut and blood are now shown to be closely linked, and systemic cytokine release after gluten provides an additional explanation for extraintestinal manifestations of celiac disease.

SUMMARY

Clinical studies utilizing cytokines as new biomarkers for gluten immunity promise to improve understanding of clinical effects of gluten, accelerate therapeutics development, and augment diagnosis.

Coeliac disease and noncoeliac wheat or gluten sensitivity

Coeliac disease (CD) and noncoeliac wheat or gluten sensitivity (NCWS/NCGS) are common gluten-related disorders. Both conditions can present with gastrointestinal and extraintestinal manifestations, which can be a challenge for physicians to discern between. Whilst coeliac serology and histological assessment are required for the diagnosis of CD, there are no clear biomarkers for the diagnosis of NCGS. The management of both conditions is with a gluten-free diet (GFD), although the duration, as well as strictness of adherence to a GFD in NCGS, is unclear. Adherence to a GFD in CD can also be challenging, with recent developments of noninvasive assessments, although histological assessment via duodenal biopsies remains the gold standard. The management of refractory coeliac disease remains particularly challenging, often requiring specialist input. Whilst wheat is noted to be a trigger for symptom generation in NCGS, it is unclear which components of wheat are responsible for symptom generation in this group, with further research required to elucidate the pathophysiology.

Analysis of gluten immunogenic peptides in feces to assess adherence to the gluten-free diet in pediatric celiac patients

PURPOSE

In celiac disease (CD) there is a need for precise and non-invasive tools to assess dietary compliance to the gluten-free diet (GFD). Our aim is to evaluate the efficacy of the detection of gluten immunogenic peptides (GIP) in feces, to monitor in real life, the adherence to GFD in pediatric patients with CD.

METHODS

A cross-sectional, prospective study was conducted. Fecal samples from CD children were analyzed by a rapid immunochromatographic (IC) test and by an ELISA method, both based on the antigliadin 33-mer monoclonal antibody.

RESULTS

Group 1 comprises 43 children on a GFD. According to the food records (FR), 39/43 patients were compliant with the GFD and gluten consumption was recorded in 4. GIP were detected in 15/43 individuals by the ELISA method and also in 7 by IC strips. Group 2: comprise 18 children at CD diagnosis; GIP levels decreased over time (p < 0.001) in a non-linear way (p = 0.028) after starting a GFD and were below the detection limit on the third day in most individuals.

CONCLUSION

GIP were detected, both by ELISA and by IC strips, in CD patients on a GFD, in which no consumption of gluten had been registered on the FR, confirming GIP detection to be superior to FR discovering involuntary transgressions. Despite a positive correlation between the amount of gluten intake and the concentration of GIP in feces, the interindividual variations observed suggest gastrointestinal factors influencing GIP recovery need to be further investigated.

Effect of Bifidobacterium infantis NLS super strain in symptomatic coeliac disease patients on long-term gluten-free diet - an exploratory study

Bifidobacterium infantis NLS super strain (B. infantis NLS-SS) was previously shown to alleviate gastrointestinal symptoms in newly diagnosed coeliac disease (CD) patients consuming gluten. A high proportion of patients following a gluten-free diet experiences symptoms despite dietary compliance. The role of B. infantis in persistently symptomatic CD patients has not been explored. The aim of the study was to evaluate the effect of B. infantis NLS-SS on persistent gastrointestinal symptoms in patients with CD following a long-term GFD. We conducted a randomised, cross-over, double-blind, placebo-controlled trial in symptomatic adult CD patients on a GFD for at least two years. After one-week run-in, patients were randomised to B. infantis NLS-SS or placebo for 3 weeks with cross-over after a 2-week wash-out period. We estimated changes (Δ) in celiac symptom index (CSI) before and after treatment. Stool samples were collected for faecal microbiota analysis (16S rRNA sequencing). Gluten immunogenic peptide (GIP) excretion in stool and urine samples was measured at each study period. Eighteen patients were enrolled; six patients were excluded due violations in protocol. For patients with the highest clinical burden, CD symptoms were lower in probiotic than in placebo treatment (P=0.046). B. infantis and placebo treated groups had different microbiota profiles as assessed by beta diversity clustering. In probiotic treated groups, we observed an increase in abundance of B. infantis. Treatment with B. infantis was associated with decreased abundance of Ruminococcus sp. and Bifidobacterium adolescentis. GIP excretion in stools and urine was similar at each treatment period. There were no differences in adverse effects between the two groups. B. infantis NLS-SS improves specific CD symptoms in a subset of highly symptomatic treated patients (GFD). This is associated with a shift in stool microbiota profile. Larger studies are needed to confirm these findings. ClinicalTrials.gov: NCT03271138.

[Study of adherence to the gluten-free diet in coeliac patients]

INTRODUCTION

The following of a strict gluten-free diet (GFD) is essential in the control of coeliac disease. The aim of this study was to determine the adherence to a GFD in coeliac patients and to evaluate the factors that could influence this adherence.

MATERIAL AND METHODS

A descriptive observational study was carried out, in which gluten immunogenic peptides (GIP) were determined in faeces using a semi-quantitative method, and the Coeliac Dietary Adherence Test was completed. Sociodemographic and clinical details were collected, and an ad hoc questionnaire was prepared.

RESULTS

Of the 80 patients included, 92.5% were adherent according to the GIP and 86.3% according to Coeliac Dietary Adherence Test (acceptable agreement; Kappa: 0.31, P=.004). The large majority (83.3%) of patients with positive GIP gave negative anti-transglutaminase antibodies in the latest determination. Current age and time of onset were significantly associated with adherence. Those with a positive GIP had a mean age of 5 years more (P=.0001) and were 52 months more on a GFD (P=.025). One quarter of those surveyed considered the diet difficult to follow. Just under two-thirds (60%) considered that the variability in the eating site was an important factor in leading to infringements, with children's parties being the main area where they occurred (66.7%). The lack of variety (61.4%) and the increased cost (98.6%) of gluten-free foods is highlighted.

CONCLUSIONS

The adherence to the GFD is generally good. The analysis of GIP helps to detect non-adherent patients that would pass unnoticed in other circumstances. Measures must be established in order to maintain good long-term adherence, taking into account the risk factors and difficulties detected.