Prospective longitudinal study: use of faecal gluten immunogenic peptides to monitor children diagnosed with coeliac disease during transition to a gluten-free diet

Social Adversities Associate with Worse Disease Control in Pediatric Celiac Disease

OBJECTIVE

To characterize how social adversities influence disease control in children with celiac disease (CeD).

STUDY DESIGN

We conducted a cross-sectional analysis of data from 325 eligible children ≤18 years old with CeD enrolled between 2015 through 2023 into iCureCeliac, a patient-centered US registry for CeD. We evaluated the associations between financial insecurity, social stigmatization, decreased health knowledge, and mental health comorbidity with 2 validated patient-reported outcomes on disease activity and gluten-free diet adherence: celiac symptom index and CeD adherence test, respectively. We used multivariable logistic and linear regression analysis to adjust for race, primary spoken language, and socioeconomic status.

RESULTS

Among 325 children with available financial insecurity data, the median age was 11 years (IQR 8, 15), 67% were female, and 88% were White. In multivariable logistic regression, the odds of elevated disease activity among children with financial insecurity, social stigmatization, decreased health knowledge, and mental health comorbidity were 2.6 (95% CI 0.9, 8.0; P = .09), 2.8 (95% CI 1.6, 5.1; P < .001), 4.8 (95% CI 2.4, 9.8; P < .001), and 1.9 (95% CI 1.1, 3.3; P = .03), respectively. For insufficient dietary adherence, the respective odds were 1.6 (95% CI 0.5, 4.7; P = .43), 3.3 (95% CI 1.7, 6.5; P < .001), 2.9 (95% CI 1.5, 5.7; P = .002), and 2.3 (95% CI 1.2, 4.2; P = .01). Statistically significant associations in logistic regression aligned with results of linear models.

CONCLUSIONS

Social stigmatization, decreased health knowledge, and mental health comorbidity were associated with worse disease control in pediatric CeD. Targeted interventions aimed at addressing these social adversities may improve disease activity and dietary adherence.

Gluten Unraveled: Latest Insights on Terminology, Diagnosis, Pathophysiology, Dietary Strategies, and Intestinal Microbiota Modulations-A Decade in Review

A decade of research on gluten-related disorders (GRDs) is reviewed in this study, with a particular emphasis on celiac disease (CD) and non-celiac gluten sensitivity (NCGS). GRDs are triggered by the ingestion of gluten and gluten-like proteins found in wheat, barley, and rye. These proteins lead to intestinal damage in celiac disease, an autoimmune condition characterized by villous atrophy and a variety of gastrointestinal and extraintestinal symptoms. More enigmatic and less understood, NCGS involves symptoms similar to CD but without the immunological reaction or intestinal damage. Recent years have seen advances in the understanding of GRDs, particularly in connection to how intestinal microbiota influences disease progression and patient outcomes. The gluten-free diet (GFD) is still the standard therapy recommended for GRDs despite significant challenges, as discussed in this article. Precise diagnostic methods, patient education and dietary counseling are critical for improving patients' quality of life. The purpose of this review is to provide a more clear and up-to-date understanding of GRDs, and to help further research on this important topic.

Transfer of celiac disease-associated immunogenic gluten peptides in breast milk: variability in kinetics of secretion

Background

Exposure to antigens is crucial for child immune system development, aiding disease prevention and promoting infant health. Some common food antigen proteins are found in human breast milk. However, it is unclear whether gluten antigens linked to celiac disease (CD) are transmitted through breast milk, potentially impacting the development of the infant's immune system.

Objective

This study aimed to analyze the passage of gluten immunogenic peptides (GIP) into human breast milk. We evaluated the dynamics of GIP secretion after lactating mothers adopted a controlled gluten-rich diet.

Methods

We prospectively enrolled 96 non-CD and 23 CD lactating mothers, assessing total proteins and casein in breast milk, and GIP levels in breast milk and urine. Subsequently, a longitudinal study was conducted in a subgroup of 12 non-CD lactating mothers who adopted a controlled gluten-rich diet. GIP levels in breast milk and urine samples were assayed by multiple sample collections over 96 hours.

Results

Analysis of a single sample revealed that 24% of non-CD lactating mothers on a regular unrestricted diet tested positive for GIP in breast milk, and 90% tested positive in urine, with significantly lower concentrations in breast milk. Nevertheless, on a controlled gluten-rich diet and the collection of multiple samples, GIP were detected in 75% and 100% of non-CD participants in breast milk and urine, respectively. The transfer dynamics in breast milk samples were long-enduring and GIP secretion persisted from 0 to 72 h. In contrast, GIP secretion in urine samples was limited to the first 24 h, with inter-individual variations. In the cohort of CD mothers, 82.6% and 87% tested negative for GIP in breast milk and urine, respectively.

Conclusions

This study definitively established the presence of GIP in breast milk, with substantial inter-individual variations in secretion dynamics. Our findings provide insights into distinct GIP kinetics observed in sequentially collected breast milk and urine samples, suggesting differential gluten metabolism patterns depending on the organ or system involved. Future research is essential to understand whether GIP functions as sensitizing or tolerogenic agents in the immune system of breastfed infants.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The Gluten-Free Diet for Celiac Disease and Beyond

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

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.

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.

Adherence to gluten-free diet and follow-up of pediatric celiac disease patients, during childhood and after transition to adult care

Long-term data on pediatric celiac disease (CD) patients after transition to adult care is scarce. We aimed to evaluate patients' adherence to a gluten-free diet (GFD), the normalization of celiac serology and the frequency of follow-up before age 18, and to study changes in adherence and follow-up frequency after transition to adult care. Presenting symptoms, serology and biopsy results, patients' reported GFD adherence, frequency of follow-up visits, and complications before and after 18 years were collected for CD patients diagnosed between 1998 and 2017. Of 441 CD patients diagnosed and followed in childhood, a quarter (108/441) were over 18 y (years) at data collection. Median age at diagnosis 7.1 y (9 months-18 y), at data collection 23 y (18-38 y), disease duration 11.3 y (2-36 y). Below the age of 18 y, most patients 386/436 (88.5%) reported adherence to GFD, and most 372/425 (85.7%) normalized serology. Of the 441 patients, only 3 failed to attend any follow-up visit, and 338/441 (76.6%) attended yearly visits. Over the age 18 y, serology testing was done in 78/108 (72.2%), every 1-3 y in 46/78 (59%). Serology normalized in 61/78 (78.2%). Most adult patients 77/108 (71.5%) never attended a gastroenterology clinic. CD-related complications were rare. Younger age at diagnosis, regular follow-up visits in childhood, resolution of symptoms, and normalization of serology before age 18 were identified as predictors of negative serology after the age of 18 y.Conclusions: Children who have regular follow-up and normalize serology before age 18 years are likely to maintain a GFD and have negative serology as adults. What is Known: • The rate of adherence to gluten-free diet (GFD) is higher among children compared to adults. • Data on long-term follow-up after transition to adult care is scarce. What is New: • Patients diagnosed with CD at a younger age (<12 y), who have yearly follow-up visits, resolution of symptoms, and negative serology in childhood are very likely to maintain GFD and have negative serology as adults. • Even though most patients do not attend GI clinics after transition to adulthood, most adhere to GFD, and complications are rare.

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.

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.

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.

Exposure sources, amounts and time course of gluten ingestion and excretion in patients with coeliac disease on a gluten-free diet

BACKGROUND

A major deficit in understanding and improving treatment in coeliac disease (CD) is the lack of empiric data on real world gluten exposure.

AIMS

To estimate gluten exposure on a gluten-free diet (GFD) using immunoassays for gluten immunogenic peptides (GIP) and to examine relationships among GIP detection, symptoms and suspected gluten exposures METHODS: Adults with biopsy-confirmed CD on a GFD for 24 months were recruited from a population-based inception cohort. Participants kept a diary and collected urine samples for 10 days and stools on days 4-10. 'Doggie bags' containing ¼ portions of foods consumed were saved during the first 7 days. Gluten in food, stool and urine was quantified using A1/G12 ELISA.

RESULTS

Eighteen participants with CD (12 female; age 21-70 years) and three participants on a gluten-containing diet enrolled and completed the study. Twelve out of 18 CD participants had a median 2.1 mg gluten per exposure (range 0.2 to >80 mg). Most exposures were asymptomatic and unsuspected. There was high intra-individual variability in the interval between gluten ingestion and excretion. Participants were generally unable to identify the food.

CONCLUSIONS

Gluten exposure on a GFD is common, intermittent, and usually silent. Excretion kinetics are highly variable among individuals. The amount of gluten varied widely, but was typically in the milligram range, which was 10-100 times less than consumed by those on an unrestricted diet. These findings suggest that a strict GFD is difficult to attain, and specific exposures are difficult to detect due to variable time course of excretion.

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.

Update on celiac disease

PURPOSE OF REVIEW

The purpose of this review is to describe current updates in celiac disease.

RECENT FINDINGS

Recent developments in the understanding of the pathogenesis of celiac disease continue to emerge that may implicate the role of gluten exposure. Several studies have shown that the amount of gluten consumed by the infant may affect the age of onset of celiac disease in genetically predisposed individuals. New guidelines from the European Society of Paediatric Gastroenterology, Hepatology and Nutrition allow serology-based celiac diagnosis, omitting endoscopic biopsies, in children. Recent data and updated guidelines in adults no longer support biopsies in all patients who are genetically susceptible with celiac disease who have been identified by serology with clinical signs and symptoms of celiac disease. A new assay was identified in the immune response to epitopes of the tissue transglutaminase-deamidated gliadin peptide complex. In addition, a recent study shows that serum IL-2 elevations correlate with timing and severity of symptoms after gluten ingested in celiac disease patients. Measuring gluten immunogenic peptides (GIPs) in the stool of celiac patients may help monitor adherence to a gluten-free diet (GFD). Of importance, we should be aware that the quality of life is affected in celiac disease patients. During adolescence, the education on the importance of long-term follow-up with an adult gastroenterologist is associated with more successful rates of medical care transition for young adults with celiac disease. Latiglutenase, an orally administered mixture of two gluten-specific recombinant proteases that degrades gluten proteins into small physiologically irrelevant fragments, is currently in a phase 2 trial. Latiglutenase has shown to be safe and effective in reducing symptoms of celiac disease patients upon a GFD with improvement of quality of life. Lastly, a recent study describes a mouse model that is characteristic of celiac disease.

SUMMARY

Our knowledge of celiac disease continues to grow with increasing evidence of contributory factors to its pathogenesis. There is some evidence that the quantity ingested of gluten by the infant effects the age of onset of celiac disease in genetically susceptible patients. Changes have been made to the guidelines in the diagnosis of celiac disease proposed by new studies. Recent studies have shown the significant effects on quality of life for celiac patients. As improved laboratory methods continue to be developed, these tests can have utility in both diagnosis of celiac disease and monitoring adherence to the GFD. Current therapeutic trials offer promising nondietary treatment for celiac patients. The development of an animal model can provide a better understanding of the pathogenesis of celiac disease.

Testing for fecal gluten immunogenic peptides: a useful tool to evaluate compliance with gluten-free diet by celiacs

Background

Although experts agree that strict dietary compliance is fundamental for the health of celiac patients, there are no evidence-based recommendations on the best way to assess dietary compliance. Detection of gluten immunogenic peptides (GIPs) in feces was recently proposed as an effective method of assessing the dietary compliance of celiac patients.

Methods

Fifty-five consecutive celiac patients (27 adults and 28 children, age 6-72 years), who had been on a gluten-free diet for at least 2 years, were enrolled. All patients were evaluated clinically for symptoms, physical parameters and laboratory parameters. Dietary compliance was assessed with the Biagi questionnaire and serum anti-tissue transglutaminase (tTG) IgA antibodies were measured. GIPs were determined by immunoenzymatic assay on an automated Chorus analyzer (DIESSE Diagnostica Senese), after extraction of fecal samples by the method developed by DIESSE.

Results

Eight patients tested positive for GIPs (GIPs+); 71.4% of GIP-positive patients were asymptomatic; tTG antibodies were detected in 3/8 GIP+ patients. The Biagi score was significantly associated with fecal positivity for GIPs (P=0.02). However, according to the Biagi score, 57.1% of GIP+ patients followed the diet strictly and 5.4% of GIP- subjects did not comply with the diet or made substantial mistakes.

Conclusions

Assay of fecal GIPs identified more patients who did not comply with the diet than did the Biagi questionnaire, evaluation of symptoms or anti-tTG antibodies. Detection of fecal GIPs offers a direct, objective, quantitative assessment of even occasional exposure to gluten and is confirmed as a practical way to check dietary compliance.

[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.

Non-invasive prediction of persistent villous atrophy in celiac disease

BACKGROUND

Celiac disease (CD) is an immune-mediated enteropathy that is primarily treated with a gluten-free diet (GFD). Mucosal healing is the main target of the therapy. Currently, duodenal biopsy is the only way to evaluate mucosal healing, and non-invasive markers are challenging. Persistent elevation of anti-tissue transglutaminase antibodies (aTTG) is not an ideal predictor of persistent villous atrophy (VA). Data regarding prediction of atrophy using anti-deamidated gliadin peptide antibodies (aDGP) and abdominal ultrasonography are lacking.

AIM

To evaluate the ability of aTTG, aDGP, small bowel ultrasonography, and clinical and laboratory parameters in predicting persistent VA determined using histology.

METHODS

Patients with CD at least 1 year on a GFD and available follow-up duodenal biopsy, levels of aTTG and aDGP, and underwent small bowel ultrasonography were included in this retrospective cohort study. We evaluated the sensitivity, specificity, and positive and negative predictive values of aTTG, aDGP, small bowel ultrasonography, laboratory and clinical parameters to predict persistent VA. A receiver operating characteristic (ROC) curve analysis of antibody levels was used to calculate cut off values with the highest accuracy for atrophy prediction.

RESULTS

Complete data were available for 82 patients who were followed up over a period of four years (2014-2018). Among patients included in the analysis, women (67, 81.7%) were predominant and the mean age at diagnosis was 33.8 years. Follow-up biopsy revealed persistent VA in 19 patients (23.2%). The sensitivity and specificity of aTTG using the manufacturer’s diagnostic cutoff value to predict atrophy was 50% and 85.7%, respectively, while the sensitivity and specificity of aDGP (using the diagnostic cutoff value) was 77.8% and 75%, respectively. Calculation of an optimal cutoff value using ROC analysis (13.4 U/mL for aTTG IgA and 22.6 U/mL for aDGP IgA) increased the accuracy and reached 72.2% [95% confidence interval (CI): 46.5-90.3] sensitivity and 90% (95%CI: 79.5-96.2) specificity for aDGP IgA and 66.7% (95%CI: 41.0-86.7) sensitivity and 93.7% (95%CI: 84.5-98.2) specificity for aTTG IgA. The sensitivity and specificity of small bowel ultrasonography was 64.7% and 73.5%, respectively. A combination of serology with ultrasound imaging to predict persistent atrophy increased the positive predictive value and specificity to 88.9% and 98% for aTTG IgA and to 90.0% and 97.8% for aDGP IgA. Laboratory and clinical parameters had poor predictive values.

CONCLUSION

The sensitivity, specificity, and negative predictive value of aTTG and aDGP for predicting persistent VA improved by calculating the best cutoff values. The combination of serology and experienced bowel ultrasound examination may achieve better accuracy for the detection of atrophy.

Intestinal Permeability in Children with Celiac Disease after the Administration of Oligofructose-Enriched Inulin into a Gluten-Free Diet-Results of a Randomized, Placebo-Controlled, Pilot Trial

Abnormalities in the intestinal barrier are a possible cause of celiac disease (CD) development. In animal studies, the positive effect of prebiotics on the improvement of gut barrier parameters has been observed, but the results of human studies to date remain inconsistent. Therefore, this study aimed to evaluate the effect of twelve-week supplementation of a gluten-free diet (GFD) with prebiotic oligofructose-enriched inulin (10 g per day) on the intestinal permeability in children with CD treated with a GFD. A pilot, randomized, placebo-controlled nutritional intervention was conducted in 34 children with CD, being on a strict GFD. Sugar absorption test (SAT) and the concentrations of intestinal permeability markers, such as zonulin, intestinal fatty acid-binding protein, claudin-3, calprotectin, and glucagon-like peptide-2, were measured. We found that the supplementation with prebiotic did not have a substantial effect on barrier integrity. Prebiotic intake increased excretion of mannitol, which may suggest an increase in the epithelial surface. Most children in our study seem to have normal values for intestinal permeability tests before the intervention. For individuals with elevated values, improvement in calprotectin and SAT was observed after the prebiotic intake. This preliminary study suggests that prebiotics may have an impact on the intestinal barrier, but it requires confirmation in studies with more subjects with ongoing leaky gut.

Refractory coeliac disease: what should we be doing different?

PURPOSE OF REVIEW

The aim of this review is to provide insight into the diagnosis and management of patients with refractory coeliac disease (RCD) and highlight recent advances in this field.

RECENT FINDINGS

The diagnosis of RCD can be more accurately confirmed with flow cytometry in addition to immunohistochemistry. Dietary input and excretion of gluten immunogenic peptides can help rule out gluten contamination, and therefore, substantiate a diagnosis of RCD type I. Small bowel capsule endoscopy (SBCE) is important at diagnosis and follow-up in addition to duodenal histology. Apart from ruling out complications, it can give information on extent of disease in the small bowel, and therefore, help assess response to therapy. Those patients with a poor response can have earlier intensification of therapy, which may result in an improved outcome. RCD also occurs in patients with serology negative coeliac disease but with an increased mortality compared with patients with serology-positive coeliac disease.

SUMMARY

Patients with RCD can present with persistent symptoms of malnutrition but can also be completely asymptomatic. Serology is not a reliable marker to detect refractory disease. Immunostaining and flow cytometry are necessary for a diagnosis of RCD. Small bowel endoscopy enables disease extent to be assessed and allows for small bowel biopsies to be taken in case of suspicious lesions. Small bowel radiology can be complementary to small bowel endoscopy.

Fecal gluten immunogenic peptides as indicators of dietary compliance in celiac patients

BACKGROUND

It is important to have methods for evaluating dietary compliance in patients with celiac disease (CD). Determination of fecal gluten immunogenic peptides (GIPs) was recently proposed as a method of detecting gluten intake. The aim of this study was to evaluate whether determination of GIPs can be used as an indicator of compliance with a gluten-free diet (GFD).

METHODS

Twenty-five persons with CD on a gluten-free diet for at least one year were enrolled in the study. Compliance with the diet was assessed by the Biagi questionnaire, evaluation of symptoms and assay of IgA anti-tissue transglutaminase antibodies (IgA anti-tTG). GIPs were determined by iVYLISA GIP-S test (Biomedal S.L., Seville, Spain) on an automated Chorus analyzer (DIESSE Diagnostica Senese, Siena, Italy), after extraction of fecal samples by the method developed by DIESSE.

RESULTS

Four patients tested positive for GIPs (GIP+), two of whom complied strictly with the gluten-free diet according to the Biagi questionnaire. None of the four GIP-positive patients manifested symptoms. IgA anti-tTG was significantly higher in GIP+ than in GIP- subjects.

CONCLUSIONS

Assay of fecal GIPs identified more patients who were not complying with the diet than the Biagi questionnaire or evaluation of symptoms. The anti-tTG and GIP results agreed perfectly; however, since anti-tTG antibodies remain high for longer and are not a completely reliable marker of GFD intake, detection of fecal GIPs offers a direct, objective, quantitative assessment of exposure, even occasional, to gluten and could be used to check dietary compliance.