Detection of gluten immunogenic peptides in the urine of patients with coeliac disease reveals transgressions in the gluten-free diet and incomplete mucosal healing

Development of the Dietitian Integrated Evaluation Tool for Gluten-free Diets (DIET-GFD)

OBJECTIVES

Celiac disease (CD) treatment involves a gluten-free diet (GFD). There is no standardized tool for dietitians to objectively grade GFD adherence. This study aimed to develop a standardized tool for dietitians to evaluate and communicate GFD adherence.

METHODS

Participants were recruited from the Manitoba Celiac Disease Cohort. Using a consensus process, an expert panel of gastroenterologists, dietitians, clinical health psychologists, and persons with CD developed the Dietitian Integrated Evaluation Tool for Gluten-free Diets (DIET-GFD). Two dietitians performed duplicate assessments of 27 newly diagnosed participants who had been advised to follow a GFD. The global adherence scale was further revised after panel discussions of the cases where there was uncertainty or discordance on dietitian ratings. Subsequently, the scoring system was evaluated using duplicate assessments of an additional 37 participants with CD. Interrater agreement was assessed using square-weight Cohen's kappa.

RESULTS

The DIET-GFD includes features related to frequency and quantity of gluten ingestion based on self-reporting and food frequency evaluation, shopping and dining habits, how and where food is prepared and consumed, eating behaviors, and label reading skills. The DIET-GFD global assessment is reported using a 10-point ordinal descriptive scale, ranging from 1 (takes few precautions and regularly eats gluten) to 10 (no gluten in kitchen and rarely eats food prepared outside the home). The kappa of DIET-GFD global assessment was 0.845, which indicates excellent agreement.

CONCLUSIONS

DIET-GFD is a useful tool for dietitians to evaluate GFD adherence. Further studies are needed to confirm that the score from the DIET-GFD is reliable across various settings.

New celiac disease biomarkers

Advances in the knowledge regarding celiac disease have enabled the development of diagnostic markers, such as anti-tissue transglutaminase and anti-deaminated gliadin antibodies. The wide availability of these antibodies, genetic studies of HLA-DQ and duodenal biopsies constitute the pillars necessary for a definitive diagnosis. However, difficulties sometimes arise in both the diagnosis and follow-up of celiac patients, which cannot be resolved using these tools. This article reviews the scientific evidence and possible clinical utility of different biomarkers. This review is structured according to biomarkers that have been evaluated pathophysiologically in relation to intestinal damage or immune response and their potential clinical utility in the diagnosis and follow-up of celiac disease patients.

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.

In vitro validation of the tear matrix metalloproteinase 9 in-situ immunoassay

We aimed to validate a tear MMP-9 in-situ immunoassay (InflammaDry) and to identify factors that could affect results or interpretation. Three factors were examined: sample concentration, volume, and time. Recombinant human (rh) MMP-9 (10 or 20 μl; 0, 12.5, 25, 50, 100, 200, 500, and 1,000 ng/ml) was applied to the kit and the detection limit and assay reproducibility were examined. At a rhMMP-9 volume of 10 μl (≥ 50 ng/ml), all positive results were identified by densitometry at 10 and 20 min; however, after 20 min, more than half of the nine ophthalmologists interpreted a positive result. At a rhMMP-9 volume of 20 μl (≥ 25 ng/ml), ophthalmologists and densitometry identified almost all test lines at 10 and 20 min. At 10 μl, densitometry showed a linear dose–response pattern. At 20 μl, densitometry showed a linear dose–response pattern at concentrations up to 500 ng/ml; however, full saturation was achieved at concentrations ≥ 500 ng/ml. When the same amount of rhMMP-9 was applied, the density result increased significantly upon doubling of the solvent volume (i.e., by adding the same volume of PBS to a sample). InflammaDry showed a high inter- and intra-assay coefficient of variation at 10 min (28.4% and 24.7%, respectively). The results of the MMP-9 in-situ immunoassay varied significantly depending on sample volume. Therefore, when interpreting the results, careful attention must be paid to tear volume.

Influence of Compliance to Diet and Self-Efficacy Expectation on Quality of Life in Patients with Celiac Disease in Spain

The purpose of this study is to understand the health-related quality of life (HRQoL) in patients with celiac disease (CD) and analyze its main determinants. A transversal descriptive study of 738 patients with celiac disease was carried out. A series of questionnaires were answered related to their HRQoL, adherence to a gluten-free diet (GFD), and self-efficacy beliefs among other relevant variables. Regression analyses were carried out in order to explore the predictive variables in adherence to the GFD and HRQoL. A total of 61.2% showed a good HRQoL, and the main predictors of HRQoL were specific self-efficacy, adherence to the diet, risk perception, time since diagnosis, and age. While 68.7% of participants showed good or excellent adherence to the GFD, and the main predictors of adherence were specific self-efficacy, perceived adoption of recommended behaviors, HRQoL and gender. The HRQoL of patients with CD, and adherence to the GFD in Spain, are good. It is the self-efficacy expectation, measured specifically and not generally, which is the best predictor of both adherence and HRQoL. It is necessary to develop programs to improve the HRQoL of patients with CD that focus on improving specific self-efficacy.

Comparative Characterization of Gluten and Hydrolyzed Wheat Proteins

Hydrolyzed wheat proteins (HWPs) are widely used as functional ingredients in foods and cosmetics, because of their emulsifying and foaming properties. However, in individuals suffering from celiac disease or wheat allergy, HWPs may have a modified immunoreactivity compared to native gluten due to changes in molecular structures. Although a variety of HWPs are commercially available, there are no in-depth comparative studies that characterize the relative molecular mass (M_r) distribution, solubility, and hydrophilicity/hydrophobicity of HWPs compared to native gluten. Therefore, we aimed to fill this gap by studying the above characteristics of different commercial HWP and gluten samples. Up to 100% of the peptides/proteins in the HWP were soluble in aqueous solution, compared to about 3% in native gluten. Analysis of the M_r distribution indicated that HWPs contained high percentages of low-molecular-weight peptides/proteins and also deamidated glutamine residues. We also found considerable differences between the seven HWPs studied, so that each HWP needs to be studied in detail to help explain its potential immunoreactivity.

[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.

Predictive Factors and Clinical Impact of Deep Remission in Celiac Disease

INTRODUCTION

The ultimate indicator of adherence to a gluten-free diet is the demonstration of mucosal healing. However, the need for histological reassessment is subject to controversy among "experts". The aim of this study was to evaluate celiac patients who underwent histological reevaluation after starting a gluten-free diet in order to identify those with histological remission and associated factors.

METHODS

This retrospective study included patients who agreed to a histological reassessment after apparent clinical and serological remission and reported at least 12 months of diet adherence. In all cases, informed consent was signed for upper endoscopy.

RESULTS

A total of 69 patients were included. In 67.9% of cases, the diagnosis was made in the context of "classic" symptomatology, 17% had "nonclassical" presentation, and 15.1% were in latent phase. 69.2% of the diagnoses were initially suspected by serology. Endoscopically, 11.8% of the patients did not present suggestive features macroscopically, and a histological grade of Marsh IIIa-c was observed in 75.5% of all cases. The histological findings were normalized in 37.7%, which was associated with the presence of lower Marsh score values at diagnosis (p = 0.014) and lower DEXA T-score values (p = 0.038). A histological improvement was observed in 55 patients (≥2 grades in 37 cases), which was related to the initial transferrin saturation (p = 0.027) and with higher Marsh scores at diagnosis (p = 0.007).

CONCLUSION

Even under a gluten-free diet, celiac histology normalization is difficult to obtain and appears to be independent of most clinical and serological findings at diagnosis. Patients with less severe histological levels at diagnosis reach remission more easily, but only represent the -minority of the population.

Nutrition Assessment, Interventions, and Monitoring for Patients with Celiac Disease: An Evidence Analysis Center Scoping Review

The objectives of this scoping review were to identify and characterize studies examining nutrition assessment, interventions, and measures to monitor gluten-free diet (GFD) adherence/compliance in patients with celiac disease (CD). An electronic literature search of four databases (Cochrane Database for systematic reviews, CINAHL, Embase, and Ovid MEDLINE) was conducted to identify articles examining nutrition care in CD individuals. Except for narrative review, grey literature, and case study/report, all types of peer-reviewed articles published between January 2007 and August 2018 were eligible. There were a total of 10,823 records; 10,368 were excluded during the first round of screening due to irrelevancy and/or duplication. Of the 455 full-text articles that were assessed, 292 met the criteria and were included. Most of the studies were observational studies (n=212), followed by experimental trials (n=50), evidence-based practice guideline (EBPG)/report/statement (n=16), and systematic review (SR) (n=14). Nine original studies examined assessment, focusing mainly on different tools/ways to assess GFD adherence. The majority of the included original articles (n=235) were in the nutrition intervention category with GFD, oats, and prebiotics/probiotics as the top-three most studied interventions. There were eight SRs on GFD and five on oats. One SR and 21 original studies investigated the effectiveness of different measures to monitor GFD adherence/compliance. Although recent CD EBPGs were identified, different methods with varying levels of rigor, in terms of literature search and assessment of evidence strength, were used. Based on this scoping review, interventions focused on gluten-free diet and oats have been significantly covered by either SRs or EBPGs. Studies related to prebiotics/probiotics and education program/counseling focused interventions, as well as assessment, in CD patients have increased in recent years. Thus, it might be beneficial to conduct SRs/EBPGs focused on these topics to guide practitioners.

Interplay between Type 2 Transglutaminase (TG2), Gliadin Peptide 31-43 and Anti-TG2 Antibodies in Celiac Disease

Celiac disease (CD) is a common intestinal inflammatory disease involving both a genetic background and environmental triggers. The ingestion of gluten, a proteic component of several cereals, represents the main hexogen factor implied in CD onset that involves concomitant innate and adaptive immune responses to gluten. Immunogenicity of some gluten sequences are strongly enhanced as the consequence of the deamidation of specific glutamine residues by type 2 transglutaminase (TG2), a ubiquitous enzyme whose expression is up-regulated in the intestine of CD patients. A short gluten sequence resistant to intestinal proteases, the α-gliadin peptide 31-43, seems to modulate TG2 function in the gut; on the other hand, the enzyme can affect the biological activity of this peptide. In addition, an intense auto-immune response towards TG2 is a hallmark of CD. Auto-antibodies exert a range of biological effects on several cells, effects that in part overlap with those induced by peptide 31-43. In this review, we delineate a scenario in which TG2, anti-TG2 antibodies and peptide 31-43 closely relate to each other, thus synergistically participating in CD starting and progression.

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.

A compact SPR biosensor device for the rapid and efficient monitoring of gluten-free diet directly in human urine

Celiac disease (CD) is a chronic autoimmune disorder induced in genetically susceptible individuals by the ingestion of gluten from wheat, rye, barley, or certain varieties of oats. A careful diet follow-up is necessary to avoid health complications associated with long-term gluten intake by the celiac patients. Small peptides (GIP, gluten immunogenic peptides) derived from gluten digestion, which are excreted in the urine and feces, have emerged as promising biomarkers to monitor gluten intake. We have implemented a simple and sensitive label-free point-of-care (POC) device based on surface plasmon resonance for the direct detection of these biomarkers in urine. The assay employs specific monoclonal antibodies and has been optimized for the detection of the 33-mer α2-gliadin, known as the main immunogenic peptide of wheat gluten, and for the detection of GIP. Direct detection in undiluted urine has been accomplished by using biosensing chips containing a robust and stable biorecognition layer, obtained after carefully optimizing the biofunctionalization protocol. Excellent limits of detection have been reached (1.6-4.0 ng mL^-1 using mAb G12 and A1, respectively), which ensures the detection of gluten peptides even when the gluten intake is around the maximum tolerable amount in the digestive tract (< 50 mg) for celiac individuals. No sample pretreatment, extraction, or dilution is required, and the analysis takes less than 15 min. The assays have excellent reproducibility' as demonstrated by measuring spiked urine samples containing the same target concentration using different biofunctionalized chips prepared and stored at different periods of time (i.e., CV% of 3.58% and 11.30%, for G12- and A1-based assays, respectively). The assay has been validated with real samples. These features pave the way towards an end-user easy-to-handle biosensor device for the rapid monitoring of gluten-free diet (GFD) and follow-up of the health status in celiac patients.

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.

Refractory Celiac Disease

PURPOSE OF REVIEW

To review the epidemiology, pathophysiology, diagnosis, management, and prognosis of refractory celiac disease, with a specific emphasis on recent literature.

RECENT FINDINGS

While the pathophysiology of type I refractory celiac disease remains unclear, there have been advances in the understanding of the pathophysiology of type II refractory celiac disease. This has included recognition of the significant role of interleukin-15 and somatic mutations in JAK1 or STAT3 in the proliferation of aberrant T cells. This in turn has led to potential novel therapies targeting these factors, one of which has reached the clinical trial stage. The morbidity and mortality associated with type II refractory celiac disease remain significant; however, recent advances in the understanding of the pathophysiology of this condition have led to potential therapeutic options that should be investigated.

Optimising the follow-up of adult coeliac disease with a clinical-based score to identify patients in need of a histological reassessment: a retrospective single centre study

Follow-up modalities for adult coeliac patients remain controversial. Non-invasive markers to identify coeliac patients on a gluten-free diet (GFD) with persistence of villous atrophy (VA) are still lacking. We aim to develop a score to stratify coeliac patients on a GFD according to their risk of having persistent VA and to tailor follow-up modalities accordingly. The clinical notes of over 700 coeliac patients attending our unit (September 1999-November 2018) were retrospectively examined. A total of 273 patients on a GFD with a histological follow-up performed 12-24 months after diagnosis were selected. We developed a bivariable model based on diet adherence and clinical response evaluated by previously validated methods. A four-level score (0·5, 1·5, 3, 4) was obtained. Patients on a strict GFD and with good clinical conditions (score 4) have a very low risk of persistence of VA (2 (95 % CI 1, 5) %). Conversely, the risk is very high (46 (95 % CI 25, 68) %) in patients with poor adherence to a GFD and unsatisfactory clinical response (score 0·5). A score of 1·5 (poor GFD adherence and persistent well-being) is linked with a high risk (23 (95 % CI 14, 36) %). Risk is intermediate (6 (95 % CI 3, 10) %) in patients scoring 3 (strict GFD and no/partial clinical improvement). Three patients who developed complications belonged to this scenario. Patients at low risk of persistent VA can be followed-up non-invasively, whereas a biopsy should be repeated in those at high/very high risk. Case-by-case evaluation is needed in patients at intermediate risk. Studies on a larger sample size are required to confirm these data.

Non-Responsive Coeliac Disease: A Comprehensive Review from the NHS England National Centre for Refractory Coeliac Disease

Coeliac disease is a common small intestinal enteropathy which manifests following ingestion of gluten in genetically susceptible individuals. Since gluten was identified as the driving factor in coeliac disease, the gluten-free diet (GFD) has remained the mainstay of treatment. While most individuals will display improvement in symptoms and signs of coeliac disease following institution of the GFD, up to 30% will continue to experience symptoms and/or have persisting intestinal inflammation. These individuals can be classified as having non-responsive coeliac disease (NRCD), which may be associated with dietary indiscretion, slow healing, refractory coeliac disease, and/or an alternative condition. The purpose of this review is to provide an overview of the causes of NRCD in adults, highlight a systematic approach to investigate these patients, and appraise the latest management aspects of this subset of coeliac disease.

Masked bolus gluten challenge low in FODMAPs implicates nausea and vomiting as key symptoms associated with immune activation in treated coeliac disease

BACKGROUND

In patients with coeliac disease, FODMAPs in gluten-containing foods, and participant anticipation of a harmful ('nocebo') effect, may contribute to acute symptoms after gluten challenge.

AIM

To establish acute gluten-specific symptoms linked to immune activation in coeliac disease METHODS: We included 36 coeliac disease patients on a gluten-free diet receiving placebo in the RESET CeD trial. Double-blind, bolus vital wheat gluten (~6-g gluten protein) and sham challenges low in FODMAPs were consumed 2 weeks apart. Assessments included daily Coeliac Disease Patient Reported Outcome (CeD PRO) symptom scores (0-10), adverse events and serum interleukin-2 (baseline and 4 hours).

RESULTS

Median CeD PRO score for nausea increased most (sham: 0 vs gluten: 5.5; P < .001). Apart from tiredness (1 vs 4, P = .005) and headache (0 vs 2, P = .002), changes in other symptoms were small or absent. Only nausea increased significantly in occurrence with gluten (11% vs 69%, P < .001). Without nausea, only tiredness and flatulence were common after gluten. Nausea (6% vs 61%, P < .001; median onset: 1:34 hours) and vomiting (0% vs 44%, P < .001; 1:51 hours) were the only adverse events more common with gluten than sham. Interleukin-2 was always below the level of quantitation (0.5 pg/mL) at baseline, and after sham. Interleukin-2 was elevated after gluten in 97% of patients (median fold-change: 20), and correlated with severity of nausea (r_s  = .49, P = .0025) and occurrence of vomiting (P = .0005).

CONCLUSIONS

Nausea and vomiting are relatively specific indicators of acute gluten ingestion, and correlate with immune activation. IBS-like symptoms without nausea are unlikely to indicate recent gluten exposure.

Current and emerging trends in point-of-care urinalysis tests

Introduction: The development of point-of-care testing (POCT) has made clinical diagnostics available, affordable, rapid, and easy to use since the 1990s.The significance of this platform rests on its potential to empower patients to monitor their own health status more frequently, in the convenience of their home, so that diseases can be diagnosed at the earliest possible time-point. Recent advances have expanded traditional formats such as qualitative or semi-quantitative dipsticks and lateral flow immunoassays to newer platforms such as microfluidics and paper-based assays where signals can be measured quantitatively using handheld devices.Areas covered: This review discusses: (1) working principles and operating mechanisms of both existing and emerging POCT platforms, (2) urine analytes measured using POCT in comparison to the laboratory or clinical 'gold standard,' and (3) limitations of existing POCT and expectations of emerging POCT in urinalysis.Expert opinion: Currently, a variety of biological samples such as urine, saliva, serum, plasma, and other fluids can be applied to POCT for quick diagnosis, especially in resource-limited settings. Emerging platforms will increasingly empower individuals to monitor their health status through frequent urine analysis even from their homes. The impact of these emerging technologies on healthcare is likely to be transformative.

The effect of self-efficacy expectations in the adherence to a gluten free diet in celiac disease

Objective: To analyse the effect of general and specific self-efficacy on the adherence to a gluten free diet (GFD) in patients with celiac disease along with the effect of other relevant variables.Design: 271 patients with celiac disease participated in this transversal descriptive study and completed a series of questionnaires regarding adherence (CDAT), general self-efficacy (GSES) and specific self-efficacy (Celiac-SE) and quality of life (CD-Qol), among others.Main Outcome Measures: Dependent variable was adherence to the Gluten Free Diet (GFD). Main independent variables were general self-efficacy, specific self-efficacy and quality of life. Model tests were conducted using regression analysis.Results: 71.9% of patients show an excellent or good adherence to the diet. Higher levels of adherence are positively associated to a high expectancy of specific self-efficacy, to the perceived adoption of recommended behaviours, risk perception and better quality of life (these variables accounted for 36.4% of the variance in the adherence to a GFD, p < .001).Conclusions: Specific self-efficacy rather than general has a predictive value in adherence to a GFD. Therefore, we need to develop and transculturally adapt new instruments to assess specific self-efficacy. Celiac-SE has proved to be a useful scale for this objective.

Toward New Paradigms in the Follow Up of Adult Patients With Celiac Disease on a Gluten-Free Diet

Gluten free diet is the only available treatment for celiac disease (CeD). Patients with CeD who do not adhere to a strict gluten-free diet (GFD) have been found to have complications involving nutritional deficiencies, increased risk of bone fractures, increased risk of mortality, and certain types of cancers. Complete removal of gluten from the diet in a patient with CeD often results in symptomatic, serologic, and histologic remission. However, strict compliance with the diet is challenging. Long-term follow-up care is needed to assure treatment compliance and positive health outcomes. Monitoring celiac specific serology, nutrient deficiencies, bone mineral density, and assessment of GFD compliance have been recommended in clinical practice. However, there is no consensus on which specific tests and how often they should be performed during the follow up. Here, we have performed a review of the literature on current strategies to follow up patients with CeD. There are new tools for monitoring adherence to the GFD which could change some paradigms in following up treated patients.

Safety and efficacy of AMG 714 in adults with coeliac disease exposed to gluten challenge: a phase 2a, randomised, double-blind, placebo-controlled study

BACKGROUND

Interleukin 15 (IL-15) is implicated in the pathophysiology of coeliac disease. AMG 714 is the first anti-IL-15 monoclonal antibody to be investigated for the treatment of coeliac disease. We aimed to investigate the effects of AMG 714 in patients with coeliac disease who underwent gluten challenge.

METHODS

This randomised, double-blind, placebo-controlled, parallel-group, phase 2a trial was done at three clinical sites in Finland. Inclusion criteria included age 18-80 years, a confirmed diagnosis of coeliac disease, and adherence to a gluten-free diet for at least 12 months before screening. Patients were randomly assigned (1:1:1) to 150 mg AMG 714, 300 mg AMG 714, or placebo using permuted blocks and stratified by study site and sex. Patients and study staff were masked to treatment assignment. Treatments were administered by two subcutaneous injections every 2 weeks for 10 weeks (total six doses). Patients without severe villous atrophy at baseline received a gluten challenge (2-4 g daily) during weeks 2-12. Small bowel biopsy samples were obtained for histological assessments at baseline and week 12. The primary efficacy endpoint was the percentage change from baseline to week 12 in villous height-to-crypt depth (VHCD) ratio. Secondary endpoints were CD3-positive intraepithelial lymphocyte density; clinical symptoms measured by gastrointestinal symptom rating scale (GSRS), coeliac disease GSRS, and Bristol stool form scale (BSFS); and changes in anti-tTG and anti-DGP antibodies from baseline. The primary analysis was done in the per-protocol 1 population of patients who received at least one dose of study drug and who underwent the gluten challenge. Safety analyses were done in all patients who received at least one dose of study drug. This trial is registered at ClinicalTrials.gov, NCT02637141 and EudraCT, 2015-003647-19.

FINDINGS

Between April 13, 2016, and Nov 22, 2016, 64 patients were enrolled and randomly assigned to either the 150 mg AMG 714 group (n=22), the 300 mg AMG 714 group (n=22), or the placebo group (n=20). Two patients did not start treatment and two did not provide post-treatment biopsy samples. 49 patients underwent the gluten challenge (per-protocol 1 population) and 11 patients did not because of baseline villous atrophy. AMG 714 did not prevent mucosal injury due to gluten challenge. The least square mean difference in the relative change from baseline in VHCD ratio was -2·49% (95% CI -16·82 to 11·83; p=0·73) between 150 mg AMG 714 and placebo and 6·39% (-7·07 to 19·85; p=0·34) between 300 mg AMG 714 and placebo. Neither comparison was statistically significant. The density of CD3-positive intraepithelial lymphocytes increased in all groups, with smaller increases in the 300 mg group (-41·24% [95% CI -79·28 to -3·20] vs placebo, nominal p=0·03) but not the 150 mg group (-14·32% [-54·39 to 25·74], nominal p=0·47). Clinical symptoms were ameliorated with AMG 714 treatment between baseline and week 12, particularly diarrhoea as measured by the BSFS (nominal p=0·01 for 150 mg vs placebo, and nominal p=0·0002 for 300 mg vs placebo). Serum antibody titres for anti-tTG and anti-DGP antibodies increased in all three treatment groups, with no significant difference between AMG 714 and placebo. Treatment-emergent adverse events occurred in 21 (95%) patients in the 150 mg AMG 714 group, 0 (95%) in the 300 mg AMG 714 group, and 19 (100%) in the placebo group. The most common treatment-emergent adverse events were gastrointestinal disorders (17 [77%] participants in the 150 mg AMG 714 group, 16 [76%] in the 300 mg AMG 714 group, and 13 [68%] in the placebo group). Injection site reactions were the most common individual adverse event, reported in eight (36%) patients in the 150 mg AMG 714 group, 11 (52%) in the 300 mg group, and five (26%) in the placebo group. No serious adverse events occurred.

INTERPRETATION

The primary endpoint, change in VHCD ratio from baseline after 12 weeks of treatment in patients with coeliac disease undergoing gluten challenge, was not significantly different between placebo and AMG 714 at either 150 mg or 300 mg. Effects on intraepithelial lymphocyte density and symptoms suggest that further research of AMG 714 may be warranted in patients with non-responsive coeliac disease.

FUNDING

Celimmune and Amgen.

How to manage adult coeliac disease: perspective from the NHS England Rare Diseases Collaborative Network for Non-Responsive and Refractory Coeliac Disease

Adult coeliac disease (CD) affects approximately 1% of the population. Most patients diagnosed will respond to a gluten-free diet; however, up to 30% may have persisting symptoms. Such patients may have ongoing issues associated with adherence, non-responsive CD or refractory CD. This article provides a clinical overview of how to manage this group of patients with persisting symptoms, including an investigational algorithm and details of how to contact the National Health Service England Rare Diseases Collaborative Network for Non-Responsive and Refractory Coeliac Disease. We hope this will be a valuable source of contemporary information for all UK gastroenterologists and internationally.

Diagnosis and Treatment Patterns in Celiac Disease

Celiac disease (CD) is an immune-mediated gastrointestinal (GI) disorder driven by innate and adaptive immune responses to gluten. Presentation of CD has changed over time, with non-GI symptoms, such as anemia and osteoporosis, presenting more commonly. With improved screening and diagnostic methods, the reported prevalence of CD has increased globally, and there is considerable global variation in diagnostic and treatment practices. The objective of this study was to describe the current state of CD diagnosis and treatment patterns. A targeted review of literature from MEDLINE, Embase, the Cochrane Library, and screening of relevant conference abstracts was performed. The generally recommended diagnostic approach is GI endoscopy with small bowel biopsy; however, in selected patients, biopsy may be avoided and diagnosis based on positive serology and clinical symptoms. Diagnosis often is delayed; the average diagnostic delay after symptom onset is highly variable and can last up to 12 years. Barriers to accurate and timely diagnosis include atypical presentation, lack of physician awareness about current diagnostic criteria, misdiagnosis, and limited access to specialists. Currently, strict adherence to a gluten-free diet (GFD) is the only recommended treatment, which is not successful in all patients. Only one-third of patients are monitored regularly following diagnosis. Unmet needs for CD include improvements in the accuracy and timeliness of diagnosis, and the development of treatments for both refractory CD and GFD nonresponsive CD. Further research should investigate the impact of education about gluten-free eating and the availability of gluten-free foods support adherence and improve outcomes in patients with CD.

Celiac disease: a comprehensive current review

BACKGROUND

Celiac disease remains a challenging condition because of a steady increase in knowledge tackling its pathophysiology, diagnosis, management, and possible therapeutic options.

MAIN BODY

A major milestone in the history of celiac disease was the identification of tissue transglutaminase as the autoantigen, thereby confirming the autoimmune nature of this disorder. A genetic background (HLA-DQ2/DQ8 positivity and non-HLA genes) is a mandatory determinant of the development of the disease, which occurs with the contribution of environmental factors (e.g., viral infections and dysbiosis of gut microbiota). Its prevalence in the general population is of approximately 1%, with female predominance. The disease can occur at any age, with a variety of symptoms/manifestations. This multifaceted clinical presentation leads to several phenotypes, i.e., gastrointestinal, extraintestinal, subclinical, potential, seronegative, non-responsive, and refractory. Although small intestinal biopsy remains the diagnostic 'gold standard', highly sensitive and specific serological tests, such as tissue transglutaminase, endomysial and deamidated gliadin peptide antibodies, have become gradually more important in the diagnostic work-up of celiac disease. Currently, the only treatment for celiac disease is a life-long, strict gluten-free diet leading to improvement in quality of life, ameliorating symptoms, and preventing the occurrence of refractory celiac disease, ulcerative jejunoileitis, and small intestinal adenocarcinoma and lymphoma.

CONCLUSIONS

The present review is timely and provides a thorough appraisal of various aspects characterizing celiac disease. Remaining challenges include obtaining a better understanding of still-unclear phenotypes such as slow-responsive, potential (minimal lesions) and seronegative celiac disease. The identification of alternative or complementary treatments to the gluten-free diet brings hope for patients unavoidably burdened by diet restrictions.

Nutritional Deficiencies in Children with Celiac Disease Resulting from a Gluten-Free Diet: A Systematic Review

BACKGROUND

A strictly gluten-free diet (GFD) is the basis for managing celiac disease (CD). Numerous studies have reported nutritional deficiencies/imbalances ascribable to a GFD. The aim of this review is to describe nutritional deficiencies observed in children with celiac disease on a GFD, to discuss the clinical consequences related to these nutritional imbalances, and to identify strategies that may be adopted to treat them.

METHODS

We reviewed the MEDLINE and EMBASE databases between January 1998 and January 2019.

RESULTS

Children are, regardless of whether they are on a gluten-free diet or not, at risk of consuming too much fat and insufficient fiber, iron, vitamin D, and calcium. These imbalances may be exacerbated when children are on a gluten-free diet. In particular, the intake of folate, magnesium, zinc, and foods with a high glycemic index in children with CD who are on a GFD is significantly altered.

CONCLUSIONS

Therapeutic protocols should include nutritional education to help teach subjects affected by disorders such as CD the importance of labels, the choice of foods, and the combination of macro- and micronutrients. Children with CD on a GFD should be encouraged to rotate pseudo-cereals, consume gluten-free commercial products that have been fortified or enriched, and use foods that are local and naturally gluten-free.

A new microbial gluten-degrading prolyl endopeptidase: Potential application in celiac disease to reduce gluten immunogenic peptides

Gluten is a complex of proteins present in barley, wheat, rye and several varieties of oats that triggers celiac disease in genetically predisposed subjects. Gluten is notoriously difficult to digest by mammalian proteolytic enzymes and therefore, proline-rich digestion-resistant peptides contain multiple immunogenic epitopes. Prolyl endopeptidases (PEP) hydrolyse internal proline residues on the carboxyl side of peptides and have been proposed for food gluten detoxification and as oral enzyme supplementation for celiacs. The aim of this study was to identify new gluten-degrading microbial enzymes with the potential to reduce gluten immunogenicity by neutralizing its antigenic epitopes. Using a gluten-degrading colony screening approach, a bacterial isolate (2RA3) displaying the highest glutenase activity was selected, characterized and its genome completely sequenced. The identification through 16S rDNA gene sequencing showed a 99,1% similarity to Chryseobacterium taeanense. Hydrolysis of gluten immunogenic peptides (GIP) was further monitored, over a 48-hour period, by colony encapsulation in gliadin-containing microspheres, followed by detection with the G12 anti-GIP monoclonal antibody. Glutenase activity was detected in the extracellular medium of 2RA3 cultures, where gel electrophoresis and gliadin zymography revealed the presence of a ~50 kDa gluten-degrading enzyme. Nano-ESI-Q-TOF of the excised active band identified 7 peptides contained in the protein product predicted for an open reading frame (ORF) in the 2RA3 genome. Based on sequence similarity to the PEP family, the new enzyme was named PEP 2RA3. The PEP 2RA3 coding sequence was PCR-amplified from C. taeanense 2RA3, cloned and expressed in Escherichia coli as a C-terminally His-tagged recombinant protein and purified by Ni-NTA affinity chromatography. The recombinant protein, with predicted molecular mass and isoelectric point of 78.95 kDa and 6.8, respectively, shows PEP activity with standard chromogenic substrates, works optimally at pH 8.0 and 30°C and remains stable at pH 6.0 and 50°C, indicating a potential use in gluten-containing food process applications. The ability of the recombinant enzyme to degrade GIP in beer into smaller peptides was confirmed.

Recent advances in celiac disease and refractory celiac disease

Celiac disease (CeD), defined as gluten-induced enteropathy, is a frequent and largely underdiagnosed disease. Diagnosis relies on the detection of highly specific serum IgA anti-transglutaminase auto-antibodies and on the demonstration of duodenal villous atrophy. Treatment necessitates a strict gluten-free diet, which resolves symptoms and enables histological recovery. However, regular follow-up is necessary to assess mucosal healing, which emerges as an important prognostic factor. Recent work on CeD pathogenesis has highlighted how the cross-talk between gluten-specific CD4 + T cells and interleukin-15 can activate cytotoxic intraepithelial lymphocytes and trigger epithelial lesions. Moreover, acquisition by a subset of intraepithelial lymphocytes of somatic gain-of-function mutations in the JAK-STAT pathway was shown to be a decisive step in the progression toward lymphomas complicating CeD, thus opening new therapeutic perspectives for these rare but life-threatening complications.

Non-Invasive Biomarkers for Celiac Disease

Once thought to be uncommon, celiac disease has now become a common disease globally. While avoidance of the gluten-containing diet is the only effective treatment so far, many new targets are being explored for the development of new drugs for its treatment. The endpoints of therapy include not only reversal of symptoms, normalization of immunological abnormalities and healing of mucosa, but also maintenance of remission of the disease by strict adherence of the gluten-free diet (GFD). There is no single gold standard test for the diagnosis of celiac disease and the diagnosis is based on the presence of a combination of characteristics including the presence of a celiac-specific antibody (anti-tissue transglutaminase antibody, anti-endomysial antibody or anti-deamidated gliadin peptide antibody) and demonstration of villous abnormalities. While the demonstration of enteropathy is an important criterion for a definite diagnosis of celiac disease, it requires endoscopic examination which is perceived as an invasive procedure. The capability of prediction of enteropathy by the presence of the high titer of anti-tissue transglutaminase antibody led to an option of making a diagnosis even without obtaining mucosal biopsies. While present day diagnostic tests are great, they, however, have certain limitations. Therefore, there is a need for biomarkers for screening of patients, prediction of enteropathy, and monitoring of patients for adherence of the gluten-free diet. Efforts are now being made to explore various biomarkers which reflect different changes that occur in the intestinal mucosa using modern day tools including transcriptomics, proteomics, and metabolomics. In the present review, we have discussed comprehensively the pros and cons of available biomarkers and also summarized the current status of emerging biomarkers for the screening, diagnosis, and monitoring of celiac disease.

Gold-platinum nanoflowers as a label and as an enzyme mimic for use in highly sensitive lateral flow immunoassays: application to detection of rabbit IgG

The authors describe the preparation of gold-platinum nanoflower (AuPt NFs) and show that they can be simultaneously used as a label and as an enzyme mimic in lateral flow immunoassays (LFIs). The AuPt NFs were prepared by growing Pt nanowires on the surface of gold nanoparticle. The assay involves the capture of target proteins (here: rabbit IgG as a model analyte) by the immobilized capture antibody, and by using AuPt NF-labeled secondary antibody. The AuPt NFs are thus captured by the test zone and produce a characteristic black band for visual detection of the antigen (IgG). The coloration of the test line can be further enhanced by addition of the chromogenic substrate 3-amino-9-ethyl-carbazole which is catalytically oxidized by the captured Pt nanowires on the AuPt NF and produce a red coloration. Quantitative results were obtained by reading the test line intensities with a portable strip reader. The LFI has a 5 pg mL-1 detection limit for IgG under optimized experimental conditions. This is 100 times lower than that of the conventional AuNP-based LFI. Conceivably, this assay has a wide scope in that it may be applied to numerous other targets for which appropriate antibodies are available. Graphical abstract Gold-platinum nanoflowers are used as a label and as an enzyme mimic in a highly sensitive lateral flow immunoassay for IgG. The detection limit of gold-platinum nanoflower-based lateral flow assay is 100 times lower than that of the conventional gold nanopaticle-based lateral flow assay.

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

BACKGROUND

Life-long removal of gluten from the diet is currently the only way to manage celiac disease (CeD). Until now, no objective test has proven useful to objectively detect ingested gluten in clinical practice. Recently, tests that determine consumption of gluten by assessing excretion of gluten immunogenic peptides (GIP) in stool and urine have been developed. Their utility, in comparison with conventional dietary and analytical follow-up strategies, has not been fully established.

AIM

To assess the performance of enzyme-linked immunosorbent assay (ELISA) and point-of-care tests (PoCTs) for GIP excretion in CeD patients on gluten-free diet (GFD).

METHODS

We conducted an observational, prospective, cross-sectional study in patients following a GFD for at least two years. Using the Gastrointestinal Symptom Rating Scale questionnaire, patients were classified at enrollment as asymptomatic or symptomatic. Gluten consumption was assessed twice by 3-d dietary recall and GIP excretion (by ELISA in stool and PoCTs (commercial kits for stool and urine) in two consecutive samples. These samples and dietary reports were obtained 10 day apart one from the other. Patients were encouraged to follow their usual GFD during the study period.

RESULTS

Forty-four patients were enrolled, of which 19 (43.2%) were symptomatic despite being on a GFD. Overall, 83 sets of stool and/or urine samples were collected. Eleven out of 44 patients (25.0%) had at least one positive GIP test. The occurrence of at least one positive test was 32% in asymptomatic patients compared with 15.8% in symptomatic patients. GIP was concordant with dietary reports in 65.9% of cases (Cohen´s kappa: 0.317). PoCT detected dietary indiscretions. Both ELISA and PoCT in stool were concordant (concomitantly positive or negative) in 67 out of 74 (90.5%) samples. Excretion of GIP was detected in 7 (8.4%) stool and/or urine samples from patients considered to be strictly compliant with the GFD by dietary reports.

CONCLUSION

GIP detects dietary transgressions in patients on long-term GFD, irrespective of the presence of symptoms. PoCT for GIP detection constitutes a simple home-based method for self-assessment of dietary indiscretions.

(Outcome) Measure for (Intervention) Measures: A Guide to Choosing the Appropriate Noninvasive Clinical Outcome Measure for Intervention Studies in Celiac Disease

There is an unmet need for diagnostic and treatment interventions for celiac disease. Both clinical trials and real-world studies require careful selection of clinical outcome measures. Often, neither serology nor histology is an appropriate primary outcome. This article reviews various measures of intestinal function and nutrition, patient-reported outcome measures for symptoms and for health-related quality of life, and measures of sickness burden as they apply to intervention studies for celiac disease. A series of case studies is presented to illustrate key considerations in selecting outcome measures for dietary interventions, pharmacologic interventions, and real-world studies.

Refractory Celiac Disease

Refractory celiac disease (RCD) refers to persistence of malnutrition and intestinal villous atrophy for more than 1 to 2 years despite strict gluten-free diet in patients with celiac disease. Diagnosis remains difficult and impacts treatment and follow-up. RCD has been subdivided into 2 subgroups according to the normal (RCDI) or abnormal phenotype of intraepithelial lymphocytes (IELs) (RCDII). RCDII is considered as a low-grade intraepithelial lymphoma and has a poor prognosis due to gastrointestinal and extraintestinal dissemination of the abnormal IELs, and high risk of overt lymphoma.

Follow-up of Celiac Disease

Currently, the only effective treatment for celiac disease is complete removal of gluten from the diet. However, patients need to follow a strict gluten-free diet that results in symptomatic, serologic, and histologic remission in most patients. Histologic remission is usually complete in children, but recovery is slower and more frequently incomplete in adults. When remission has been achieved, yearly follow-up is recommended for adults, children, and adolescents. This article deals with conventional strategies used in order to follow-up patients on treatment and aiming to obtain the best clinical outcome.

Influence of infant feeding on the excretion of gluten immunopeptides in feces

INTRODUCTION

the secretion of antigens from the diet into breast milk has been extensively documented. The transfer of gliadin could be critical for the development of an immune response.

OBJECTIVES

to investigate the presence of immunogenic gluten peptides in the feces of infants fed with different diets.

MATERIAL AND METHODS

a blind, prospective, controlled, collaborative study was performed in three hospitals, between September 2016 and January 2017. The study protocol was approved by the Ethics Committee of the hospitals in Seville prior to starting the study.

RESULTS

the cohort was divided into three groups of 30 infants: an experimental group (average age 9.2 ± 2.8 weeks) with exclusive breastfeeding, a control group 1 (average age 10.3 ± 3.3 weeks) exclusively fed with onset formula and a control group 2 (average age 56 ± 3.7 weeks) with infants that consumed gluten on a regular basis. The peptide 33-mer of gliadin was negative in all feces samples from both the experimental and control group 1. With regard to control group 2, the peptide 33-mer of gliadin was negative in 23% of cases (seven children). There was no difference in the amount of gluten ingested by these children compared to those who excreted the 33-mer peptide.

CONCLUSIONS

the failure to detect gluten in the feces of infants that were exclusively breastfed indicates that it is probably below the limits of detection. Healthy children who consume gluten may not excrete it in feces.

Detection and quantification of gluten immunogenic peptides in feces of infants and their relationship with diet

BACKGROUND

there are no effective methods to easily control the correct adherence to a gluten-free diet (GFD) in celiac disease (CD) patients.

AIM

to assess the sensitivity and specificity of a rapid immunochromatographic (IC) test that detects gluten immunogenic peptides (GIP) in feces, compared to an enzyme-linked immunosorbent assay (ELISA) method.

METHODS

fecal samples from healthy infants were analyzed by a rapid IC test and ELISA, both methods are based on the anti-gliadin 33-mer monoclonal antibody. Group 1 included infants aged from 6 to 24 months, with an unrestricted consumption of gluten containing cereals. Group 2 (negative controls) was comprised of infants aged from 0 to 6 months, either breastfed or formula fed who had never ingested gluten.

RESULTS

in group 1 (n = 34), all infants had positive values by ELISA, the mean was 13.13 μgGIP/g (range 0.56-46.79). The IC test was negative in 5/20 cases and there was a significant correlation (p=0.006) between the mean daily gluten intake and GIP in feces. In group 2 (n = 20), all the samples were negative by both methods. Moreover, the Kappa Fleiss concordance index (Kappa = 0.79 CI95% [0.616, 0.965]) indicated a moderate concordance between both methods.

CONCLUSIONS

according to our results, both methods are highly specific. However, the ELISA test had a higher sensitivity. Although we found a significant correlation between the amount of gluten consumed and GIP recovery in feces, further studies are needed to clarify the impact of individual confounding factors in GIP recovery.

Identifying and improving adherence to the gluten-free diet in people with coeliac disease

Coeliac disease (CD) is an autoimmune gastrointestinal disorder whereby the ingestion of gluten, a storage protein found in wheat, barley and rye, causes damage to intestinal mucosa with resultant malabsorption, increased risk of anaemia and osteoporosis. Worldwide estimates suggest 1% of the population have CD. With no cure, the only treatment is a gluten-free diet (GFD). Adhering to a GFD can be very challenging; it requires knowledge, motivation and modified behaviours. Assessing adherence to a GFD is methodologically challenging. This review aims to provide an overview of the literature reporting adherence to a GFD in people with CD and the methodological challenges encountered. From six studies it has been reported that rates of adherence to a GFD range between 45 and 90% in patients of different ethnicities with CD. GF dietary adherence can be influenced by age at diagnosis, coexisting depression, symptoms on ingestion of gluten, nutrition counselling, knowledge of GF foods, understanding of food labels, cost and availability of GF foods, receiving GF foods on prescription and membership of a coeliac society. To date only five intervention studies in adults with CD have been undertaken to improve GF dietary adherence. These have included dietary and psychological counselling, and the use of online training programmes, apps, text messages and telephonic clinics. Future interventions should include people of all ethnicities, consider patient convenience and the cost-effectiveness for the healthcare environment.

Coeliac disease

Coeliac disease is an immune-mediated enteropathy against dietary gluten present in wheat, rye and barley and is one of the most common lifelong food-related disorders worldwide. Coeliac disease is also considered to be a systemic disorder characterized by a variable combination of gluten-related signs and symptoms and disease-specific antibodies in addition to enteropathy. The ingestion of gluten leads to the generation of harmful gluten peptides, which, in predisposed individuals, can induce adaptive and innate immune responses. The clinical presentation is extremely variable; patients may have severe gastrointestinal symptoms and malabsorption, extraintestinal symptoms or have no symptoms at all. Owing to the multifaceted clinical presentation, diagnosis remains a challenge and coeliac disease is heavily underdiagnosed. The diagnosis of coeliac disease is achieved by combining coeliac disease serology and small intestinal mucosal histology during a gluten-containing diet. Currently, the only effective treatment for coeliac disease is a lifelong strict gluten-free diet; however, the diet is restrictive and gluten is difficult to avoid. Optimizing diagnosis and care in coeliac disease requires continuous research and education of both patients and health-care professionals.

Molecular mechanisms of 33-mer gliadin peptide oligomerisation

The 33-mer gliadin peptide oligomerizes driven by its non-ionic polar character, flexible PPII secondary structure and stable glutamine H-bonds.

Gluten Immunogenic Peptides as Standard for the Evaluation of Potential Harmful Prolamin Content in Food and Human Specimen

Gluten is a complex mixture of storage proteins in cereals like wheat, barley, and rye. Prolamins are the main components of gluten. Their high content in proline and glutamine makes them water-insoluble and difficult to digest in the gastrointestinal tract. Partial digestion generates peptide sequences which trigger immune responses in celiac and gluten-sensitive patients. Gluten detection in food is challenging because of the diversity, in various food matrices, of protein proportions or modifications and the huge number of immunogenic sequences with differential potential immunoactivity. Attempts to develop standard reference materials have been unsuccessful. Recent studies have reported the detection of a limited number of dominant Gluten Immunogenic Peptides (GIP) that share similarities to epitopes presented in the α-gliadin 33-mer, which showed to be highly proteolytic resistant and is considered to be the most immunodominant peptide within gluten in celiac disease (CD). GIP were detectable and quantifiable in very different kind of difficult to analyze food, revealing the potential immunogenicity by detecting T-cell activity of celiac patients. But GIP were also found in stool and urine of celiac patients on a supposedly gluten-free diet (GFD), showing the capacity to resist and be absorbed and excreted from the body, providing the first simple and objective means to assess adherence to the GFD. Methods to specifically and sensitively detect the most active GIP in food and biological fluids are rational candidates may use similar analytical standard references for determination of the immunopathological risk of gluten exposure in gluten-related diseases.

Gluten-Free Diet in Celiac Disease-Forever and for All?

The gluten-free diet is the only effective treatment available for celiac disease. However, it is difficult to adhere to and a closer look on the diet’s implementation and indications reveals several ambiguities: Not only is there controversy on the threshold of gluten that can be tolerated in the frame of a strict gluten-free diet, but it is also unclear whether the gluten-free diet is an appropriate treatment in patient subgroups with asymptomatic or potential celiac disease. Reports from a number of research groups suggest that a certain proportion of patients may effectively develop tolerance to gluten and thus become suitable for gluten reintroduction over time. In this review, we set out to create an overview about the current state of research as regards the definition of a strict gluten-free diet in terms of the gluten thresholds considered tolerable and the indication for a gluten-free diet in the absence of histological abnormalities or symptoms. Furthermore, we discuss the concept that a gluten-free diet must be followed for life by all patients.

Descriptive Study of the Different Tools Used to Evaluate the Adherence to a Gluten-Free Diet in Celiac Disease Patients

Celiac disease (CD) is a genetically conditioned autoimmune process that appears in susceptible people. It can affect people of any age, and slightly predominates in females. It has a fairly homogenous global distribution, with an average prevalence of 1⁻2%, the frequency having increased in recent decades. The only effective treatment is a strict and permanent gluten-free diet (GFD), although the level of compliance is poor, at about 50% of cases. To monitor the effectiveness of the GFD, several procedures involving various approaches are employed: (a) Periodic visits by expert Nutritionists; (b) Clinical follow-up; (c) Serological time controls of specific antibodies; (d) Serial endoscopies with collection of duodenal biopsies; (e) Use of structured questionnaires; and (f) Determination of gluten peptides derived from gluten in faeces and/or urine. All of these procedures are useful when applied, alone or in combination, depending on the cases. Some patients will only need to consult to their doctors, while others will require a multidisciplinary approach to assess their compliance with the GFD. In children, normalization of duodenal mucosa was achieved in 95% of cases within two years, while it is more delayed in adults, whose mucosa take longer time (3⁻5 years) to heal completely.

Rapid Multiplexed Detection on Lateral-Flow Devices Using a Laser Direct-Write Technique

Paper-based lateral flow devices (LFDs) are regarded as ideal low-cost diagnostic solutions for point-of-care (POC) scenarios that allow rapid detection of a single analyte within a fluidic sample, and have been in common use for a decade. In recent years, there has been an increasing need for rapid and simultaneous detection of multiple analytes present within a single sample and to facilitate this, we report here a novel solution—detection using a multi-path LFD created via the precise partitioning of the single flow-path of a standard LFD using our previously reported laser direct-write (LDW) technique. The multiple flow-paths allow the simultaneous detection of the different analytes individually within each of the parallel channels without any cross-reactivity. The appearance of coloured test lines in individual channels indicates the presence of the different analytes within a sample. We successfully present the use of a LDW-patterned multi-path LFD for multiplexed detection of a biomarker panel comprising C-reactive protein (CRP) and Serum amyloid A-1 (SAA1), used for the diagnosis of bacterial infections. Overall, we demonstrate the use of our LDW technique in the creation of a novel LFD that enables multiplexed detection of two inflammation markers within a single LFD providing a detection protocol that is comparatively more efficient than the standard sequential multiplexing procedure.

Adherence to Gluten-Free Diet in Children with Celiac Disease

Celiac disease (CD) can only be treated by rigorous life-long gluten-free diet (GFD). The study included 102 mothers and their CD children treated with GFD for at least two years. Frequency and cause of diet failure in children treated at present (54 children) and 10 years ago (48 children) were compared. Dietary adherence was evaluated serologically (tTG), while diet management difficulties were examined by means of a questionnaire. The study shows that one-third of patients fail to follow GFD, more often 10 years ago than now (40% vs. 26%; p < 0.05), mainly children aged 13⁻18 (54% vs. 40% now; p < 0.05). Younger children (up to 12) are less likely to abandon the diet (27% vs. 8%; p < 0.05). In this age group non-intentional diet failure prevails, while teenagers interrupt their diet intentionally (45% vs. 33%; p = ns (small population of children in this groups)). Currently, the most common causes of teenage diet failure are the absence of symptoms after consuming a small amount of gluten and, even more often, troublesome diet administration. Previously, the absence of peer acceptance prevailed. With this study we found that: 1. In West Pomerania, every fourth CD child does not follow GFD. 2. For years, teenagers have failed to follow GFD due to the absence of symptoms after consuming small amounts of gluten. 3. The incidence of non-intentional failure to follow GFD has significantly decreased over years, which indicates better dietary care.

Preparation of a Defined Gluten Hydrolysate for Diagnosis and Clinical Investigations of Wheat Hypersensitivities

Gluten is the trigger for celiac disease (CD), non-celiac gluten/wheat sensitivity (NCGS), and wheat allergy. An oral food challenge is often needed for diagnosis, but there are no standardized gluten challenge materials with known composition available. To fill this gap, two materials, commercially available gluten and a food-grade gluten hydrolysate (pepgluten), were extensively characterized. Pepgluten was prepared from gluten by incubation with a pepsin dietary supplement and acetic acid at 37 °C for 120 min. The components of pepgluten were crude protein (707 mg/g), starch (104 mg/g), water (59 mg/g), fat (47 mg/g), dietary fiber (41 mg/g) and ash (11 mg/g). The protein/peptide fraction of pepgluten (1 g) contained equivalents derived from 369 mg gliadins and 196 mg glutenins, resulting in 565 mg total gluten equivalents, 25 mg albumins/globulins, 22 mg α-amylase/trypsin inhibitors and 48 mg pepsin capsule proteins. The slightly acidic, dough-like smell and bitter taste of pepgluten could be completely camouflaged in multivitamin juice with bitter lemon, grapefruit juice, or vegetable and fruit smoothies. Thus, pepgluten met the criteria for placebo-controlled challenges (active and placebo materials are identical regarding appearance, taste, smell, and texture) and is appropriate as a standard preparation for the oral food challenge and clinical investigations to study wheat hypersensitivities.