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

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

Standardizing Randomized Controlled Trials in Celiac Disease: An International Multidisciplinary Appropriateness Study.

BACKGROUND & AIMS: There is a need to develop safe and effective pharmacologic options for the treatment of celiac disease (CeD); however, consensus on the appropriate design and configuration of randomized controlled trials (RCTs) in this population is lacking. METHODS: A 2-round modified Research and Development/University of California Los Angeles Appropriateness Method study was conducted. Eighteen gastroenterologists (adult and pediatric) and gastrointestinal pathologists voted on statements pertaining to the configuration of CeD RCTs, inclusion and exclusion criteria, gluten challenge, and trial outcomes. Two RCT designs were considered, representing the following distinct clinical scenarios for which pharmacotherapy may be used: trials incorporating a gluten challenge to simulate exposure; and trials evaluating reversal of histologic changes, despite attempted adherence to a gluten-free diet. Each statement was rated as appropriate, uncertain, or inappropriate, using a 9-point Likert scale. RESULTS: For trials evaluating prevention of relapse after gluten challenge, participants adherent to a gluten-free diet for 12 months or more with normal or near-normal-sized villi should be enrolled. Gluten challenge should be FODMAPS (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) free, and efficacy evaluated using histology with a secondary patient-reported outcome measure. For trials evaluating reversal of villus atrophy, the panel voted it appropriate to enroll participants with a baseline villus height to crypt depth ratio ≤2 and measure efficacy using a primary histologic end point. Guidance for measuring histologic, endoscopic, and patient-reported outcomes in adult and pediatric patients with CeD are provided, along with recommendations regarding the merits and limitations of different end points. CONCLUSIONS: We developed standardized recommendations for clinical trial design, eligibility criteria, outcome measures, gluten challenge, and disease evaluations for RCTs in patients with CeD.

Anti-infliximab antibodies and low infliximab levels correlate with drug discontinuation in pediatric inflammatory bowel disease.

BACKGROUND: Infliximab (IFX) use is limited by loss of response often due to the development of anti-IFX antibodies and low drug levels. METHODS: We performed a single center prospective observational cohort study of pediatric and young adult subjects with inflammatory bowel disease (IBD) on IFX with over 3 years of follow-up. Infliximab levels (IFXL) and antibodies to infliximab (ATI) were measured throughout the study. Subjects were followed until IFX was discontinued. RESULTS: We enrolled 219 subjects with IBD (184: Crohn's disease; 33: Ulcerative colitis; and 2 Indeterminant colitis; 84 female, median age 14.4 years, 37% on concomitant immunomodulator). Nine hundred and nineteen serum samples (mean 4.2 ± 2.1 per patient) were tested for IFXL and ATI. During the study, 31 (14%) subjects discontinued IFX. Sixty patients had ATI. Twenty-two of those 60 patients with ATI discontinued IFX; 14 of 31 patients who discontinued IFX had detectable ATI at study onset. The combination of ATI and IFXL < 5 µg/mL at study entry was associated with the highest risk of drug discontinuation (hazard ratios [HR] ATI 4.27 [p < 0.001] and IFXL < 5 µg/mL [HR]: 3.2 p = 0.001). Patients with IFXL 5-10 µg/mL had the lowest rate of discontinuation (6%). IFX dose escalation eliminated ATI in 21 of 60 subjects. CONCLUSIONS: ATI is a strong predictor of needing to stop IFX use and inversely correlates with IFXL. Detection of ATI during therapeutic drug monitoring postinduction but also periodically during maintenance therapy identifies individuals who may benefit from IFX dose escalation and/or the addition of an immunomodulator, as these interventions may reduce or eliminate ATI.

A Composite Morphometric Duodenal Biopsy Mucosal Scale for Celiac Disease Encompassing Both Morphology and Inflammation.

BACKGROUND & AIMS: Villus height to crypt depth ratio (Vh:Cd) and intraepithelial lymphocytes (IEL) are key measures of histology of the small intestine in celiac disease. Although the field of celiac disease has advanced, there remains no broadly accepted measure of mucosal injury. We assessed whether a composite Vh:Cd and IEL scale (VCIEL) can improve accuracy and statistical precision for assessing histology, compared with individual measures. METHODS: The formulation of the VCIEL composite histologic scale was based on combining the Vh:Cd and IEL measurements for individual patients with equal weighting, by converting each scale to a fraction of their standard deviation and summing the results. The VCIEL formula was applied to several clinical trials and the results for Vh:Cd and IEL were compared with those for VCIEL with regards to clinical significance (effect size) and statistical significance. RESULTS: For the ALV003-1021 trial, we observed an effect size and P value (analysis of covariance) of 1.37 and 0.038 for ΔVh:Cd, 1.17 and 0.005 for ΔIEL, and 1.86 and 0.004 for ΔVCIEL. For the similar gluten-challenge IMGX003-NCCIH-1721 trial, the corresponding results were 0.76 and 0.057 for ΔVh:Cd, 0.98 and 0.018 for ΔIEL, and 1.14 and 0.007 for ΔVCIEL. Similar improvements with the use of VCIEL over individual Vh:Cd and IEL measures were observed for other studies, including a nontherapeutic gluten challenge study. CONCLUSIONS: The composite VCIEL scale combining Vh:Cd and IEL values seems to improve accuracy and statistical precision compared with either component alone.

A Clinician's Guide to Gluten Challenge.

Gluten challenge is an essential clinical tool that involves reintroducing or increasing the amount of gluten in the diet to facilitate diagnostic testing in celiac disease (CD). Nevertheless, there is no consensus regarding the applications of gluten timing, dosing, and duration in children. This review aims to summarize the current evidence, discuss practical considerations, and proposes a clinical algorithm to help guide testing in pediatric patients. Childhood development, social circumstances, and long-term health concerns must be considered when identifying a candidate for gluten challenge. Based on previous studies, the authors suggest baseline serology followed by a minimum of 3-6 grams of gluten per day for over 12 weeks to optimize diagnostic accuracy for evaluation of CD. A formal provider check-in at 4-6 weeks is essential so the provider and family can adjust dosing or duration as needed. Increasing the dose of gluten further may improve diagnostic yield if tolerated, although in select cases a lower dose and shorter course (6-12 weeks) may be sufficient. There is consensus that mild elevations in celiac serology (<10 times the upper limit of normal) or symptoms, while supportive are not diagnostic for CD. Current North American Society for Pediatric Gastroenterology, Hepatology and Nutrition guidelines recommend histologic findings of intraepithelial lymphocytosis, crypt hyperplasia, and villous atrophy as the accurate and most appropriate endpoint for gluten challenge.

Evaluating Responses to Gluten Challenge: A Randomized, Double-Blind, 2-Dose Gluten Challenge Trial.

BACKGROUND & AIMS: Gluten challenge is used to diagnose celiac disease (CeD) and for clinical research. Sustained gluten exposure reliably induces histologic changes but is burdensome. We investigated the relative abilities of multiple biomarkers to assess disease activity induced by 2 gluten doses, and aimed to identify biomarkers to supplement or replace histology. METHODS: In this randomized, double-blind, 2-dose gluten-challenge trial conducted in 2 US centers (Boston, MA), 14 adults with biopsy-proven CeD were randomized to 3 g or 10 g gluten/d for 14 days. The study was powered to detect changes in villous height to crypt depth, and stopped at planned interim analysis on reaching this end point. Additional end points included gluten-specific cluster of differentiation (CD)4 T-cell analysis with HLA-DQ2-gluten tetramers and enzyme-linked immune absorbent spot, gut-homing CD8 T cells, interleukin-2, symptoms, video capsule endoscopy, intraepithelial leukocytes, and tissue multiplex immunofluorescence. RESULTS: All assessments showed changes with gluten challenge. However, time to maximal change, change magnitude, and gluten dose-response relationship varied. Villous height to crypt depth, video capsule endoscopy enteropathy score, enzyme-linked immune absorbent spot, gut-homing CD8 T cells, intraepithelial leukocyte counts, and HLA-DQ2-restricted gluten-specific CD4 T cells showed significant changes from baseline at 10 g gluten only; symptoms were significant at 3 g. Symptoms and plasma interleukin-2 levels increased significantly or near significantly at both doses. Interleukin-2 appeared to be the earliest, most sensitive marker of acute gluten exposure. CONCLUSIONS: Modern biomarkers are sensitive and responsive to gluten exposure, potentially allowing less invasive, lower-dose, shorter-duration gluten ingestion. This work provides a preliminary framework for rational design of gluten challenge for CeD research. ClinicalTrials.gov number, NCT03409796.

Survey-Based Study on Food Insecurity During COVID-19 for Households With Children on a Prescribed Gluten-Free Diet.

Gluten-free (GF) foods are generally costlier than their gluten-containing counterparts. We conducted an anonymous electronic survey to assess food insecurity in households with a child on a prescribed GF diet and how this relates to GF diet adherence during the COVID-19 pandemic. The proportion of households who screened positive using the Hunger Vital Sign was similar to national rates (19%-24%). Approximately 5% of families who screened food secure reported GF food insecurity. Parent-reported intentional gluten consumption due to limited GF food availability in the household increased during the pandemic (7.5%). Food insecurity should be considered in the management of celiac disease.

Patient Perspectives on the Long-term Management of Celiac Disease.

GOAL: The aim of this study was to survey adults with celiac disease (CD) on the utility of specific aspects of follow-up and on information needs. BACKGROUND: Currently, the treatment for CD is strict gluten avoidance. Although this places the onus on the patient for disease management, patient perspectives on CD care have not been formally assessed. STUDY: The Manitoba Celiac Disease Cohort prospectively enrolled adults newly diagnosed with CD using serology and histology. At the 24-month study visits, participants rated the utility of aspects of CD care on a 5-point scale anchored by "not at all useful" and "very useful" and the helpfulness of information on CD-related topics on a 6-point scale anchored by "not at all helpful" and "very helpful." RESULTS: The online survey was completed by 149 of 211 cohort members [median age 40 (interquartile range 30 to 56) y; 68% female]. Adherence to a gluten-free diet was good. Most participants (87%) responded that they should be seen regularly for medical follow-up of CD, preferably every 6 (26%) or 12 months (48%). Blood tests were the most highly rated care component (rated scored ≥4/5 by 78% of respondents), followed by the opportunity to ask about vitamins and supplements (50%), symptom review (47%), and information on CD research (44%). Diet review was not considered helpful. CONCLUSIONS: Two years after diagnosis, most individuals with CD find regular specialist follow-up helpful, particularly for biochemical assessment of disease activity and its complications. Furthermore, information on research and long-term complications of CD is also valued.

Celiac Disease: Fallacies and Facts.

Our understanding of the pathophysiology of celiac disease has progressed greatly over the past 25 years; however, some fallacies about the clinical characteristics and management persist. Worldwide epidemiologic data are now available showing that celiac disease is ubiquitous. An elevated body mass index is common at the time of the diagnosis. The gluten-free diet (GFD) is an imperfect treatment for celiac disease; not all individuals show a response. This diet is widely used by people without celiac disease, and symptomatic improvement on a GFD is not sufficient for diagnosis. Finally, the GFD is burdensome, difficult to achieve, and thus has an incomplete efficacy, opening exciting opportunities for novel, nondietary treatments.

Enteric-Release Budesonide May Be Useful in the Management of Non-Responsive Celiac Disease.

BACKGROUND: Non-responsive celiac disease (NRCD) has many aetiologies, including gluten exposure. Budesonide may be used for refractory celiac disease (RCD) and celiac crisis. AIMS: We reviewed the effectiveness of budesonide to induce clinical and histologic response in NRCD with villous atrophy (VA). METHODS: Case series of adult cases with NRCD and VA prescribed budesonide at two celiac centers. Clinical variables and mucosal recovery (i.e., normal villous architecture within 1 year of treatment) were evaluated. RESULTS: Forty-two cases [77% female, median age 45.0 (IQR 28.3-60.0) years] were included. Most common symptoms were diarrhea (64%) and abdominal pain (62%). Budesonide was initiated at 9 mg (83%) for a median duration of 16.0 weeks (IQR 6.8-25.0 weeks). In total, 57% exhibited a clinical response, positively associated with diarrhea (adjusted OR 6.08 95% CI 1.04-35.47) and negatively with fatigue (adjusted OR 0.18 95% CI 0.03-0.98). Clinical response was higher among those with dietitian counseling prior to budesonide (n = 29, 70 vs. 23%, p < 0.01). Mucosal recovery was observed in 11/24 with follow-up duodenal biopsies. There was no association between clinical response and mucosal recovery, and 79% of clinical responders had a symptomatic relapse. RCD (48%) and chronic gluten exposure (24%) were the main suspected aetiologies of NRCD. Most individuals without a clinical response subsequently received an IBS-related diagnosis. CONCLUSIONS: Budesonide may be effective to induce clinical response in NRCD presenting with diarrhea and VA, but clinical recurrence and lack of mucosal recovery are frequent after tapering. Other diagnoses, including coexisting IBS, may be considered in non-responders to budesonide therapy.

Efficacy of Enteric-Release Oral Budesonide in Treatment of Acute Reactions to Gluten in Patients With Celiac Disease.

Celiac disease (CeD) is a common gluten-responsive T cell-mediated enteropathy. The only current treatment is gluten avoidance; however, even when attempting to adhere to a gluten-free diet (GFD), symptomatic gluten exposures are frequent.1.

Inter- and Intra-assay Variation in the Diagnostic Performance of Assays for Anti-tissue Transglutaminase in 2 Populations.

Tissue transglutaminse-2 (TG2)-based immunoassays are the cornerstone of diagnosis in celiac disease (CeD), with a reported pooled sensitivity as high as 98%.1 However, a few small, single-center studies have questioned their sensitivity in clinical practice.2-5 Moreover, commercial kits use variable TG2 antigens,6 with cutoffs determined by using small, poorly defined populations. Variation in diagnostic performance of anti-TG2 assays in different racial and geographic populations has not yet been studied. We compared the interassay and intra-assay variations in diagnostic performance of 4 immunoglobulin (Ig)A-anti-TG2 assays in Canadian and Indian populations.

The Utility of IgA-Based Serologic Markers in Diagnosing Celiac Disease in Children 24 Months of Age or Younger.

Current screening guidelines in North America for celiac disease recommend additional IgG based testing for younger children. Our multicenter retrospective study showed that the anti-tissue transglutaminase IgA antibody test should be the recommended initial test in all children, including those ≤24 months of age.

Celiac Disease: Extraintestinal Manifestations and Associated Conditions.

Celiac disease is a common form of enteropathy with frequent extraintestinal manifestations (EIM). Misrecognition of these presentations may lead to significant delays in diagnosis. Any organ may be involved, either through an immune/inflammatory phenomenon, or nutritional deficiencies. Some EIM, such as gluten ataxia, may be irreversible if left untreated, but most will improve with a gluten-free diet. Knowledge of the various EIM, as well as the associated conditions which do not improve on a gluten-free diet, will avoid delays in the diagnosis and management of celiac disease and associated manifestations.

A Quantitative Assessment of Gluten Cross-contact in the School Environment for Children With Celiac Disease.

OBJECTIVES: A gluten-free (GF) diet is the primary treatment for celiac disease (CD). Gluten is used in schools, particularly in early childhood, art, and home-economics classrooms. This study aimed to measure gluten transfer from school supplies to GF foods that a child with CD may eat. Also, to measure efficacy of washing techniques to remove gluten from hands and tables. METHODS: Five experiments measured potential gluten cross-contact in classrooms: Play-Doh (n = 30); baking project (n = 30); paper mâché (n = 10); dry pasta in sensory table (n = 10); cooked pasta in sensory table (n = 10). Thirty participants ages 2 to 18 were enrolled. Following activities, gluten levels were measured on separate slices of GF bread rubbed on participant's hands and table surfaces. Participants were assigned 1 of 3 handwashing methods (soap and water, water alone, or wet wipe). Repeat gluten transfer measurements were taken from hands and tables. Gluten measurements made using R-Biopharm R7001 R5-ELISA Sandwich assay. RESULTS: Paper mâché, cooked pasta in sensory tables, and baking project resulted in rates of gluten transfer far greater than the 20 ppm threshold set by Codex Alimentarius Commission. Play-Doh and dry pasta, however, resulted in few gluten transfers to GF bread >20 ppm. Soap and water was consistently the most effective method for removing gluten, although other methods proved as effective in certain scenarios. CONCLUSIONS: The potential for gluten exposure at school is high for some materials and low for others. For high-risk materials, schools should provide GF supplies and have a robust strategy to prevent gluten cross-contact with food.

Lack of Follow-up of Pediatric Patients With Celiac Disease.

Celiac disease (CD) is often diagnosed in childhood, and the treatment is a lifelong gluten-free diet (GFD).1,2 It may take several years to gain competence in the skills required to follow a GFD successfully. Inadequately treated CD is associated with bone fractures, nutritional deficiencies, and lymphoma.3,4 Healthcare providers are key resources for patients with CD. Consultation with a dietitian with GFD expertise at diagnosis and annual disease-specific follow-up care are recommended.2,5 The primary objective of this study was to evaluate adherence to guidelines for dietitian consultation and follow-up for children with CD. A secondary objective was to identify factors associated with loss to follow-up.

Red Spot Lesions in the Duodenal Bulb Are a Highly Specific Endoscopic Sign of Celiac Disease: A Prospective Study.

We have recognized red spot lesions (RSLs) in the duodenal bulb in children with celiac disease (CD) and believe they may represent an underappreciated and distinct endoscopic sign of CD. A total of 171 pediatric patients undergoing esophagogastroduodenoscopy with duodenal biopsy for symptoms consistent with CD were prospectively recruited. There were 75 patients who met criteria for CD and the remaining 96 patients served as symptomatic controls. As compared to endoscopic markers frequently mentioned in literature, RSLs had comparable sensitivity, specificity, positive predictive value, and negative predictive value of 31%, 94%, 80%, and 64%, respectively. If RSLs are noted during endoscopy in a patient with gastrointestinal symptoms that might be the result of CD, then sufficient duodenal biopsies to make the diagnosis of CD should be obtained.

Tests for Serum Transglutaminase and Endomysial Antibodies Do Not Detect Most Patients With Celiac Disease and Persistent Villous Atrophy on Gluten-free Diets: a Meta-analysis.

BACKGROUND & AIMS: Tests to measure serum endomysial antibodies (EMA) and antibodies to tissue transglutaminase (tTG) were developed to screen for celiac disease in patients consuming gluten. However, they are commonly used to monitor patients on a gluten-free diet (GFD). We conducted a meta-analysis to assess the sensitivity and specificity of tTG IgA and EMA IgA assays in identifying patients with celiac disease who have persistent villous atrophy despite a GFD. METHODS: We searched PUBMED, EMBASE, BIOSIS, SCOPUS, clinicaltrials.gov, Science Citation Index, and Cochrane Library databases through November 2016. Inclusion criteria were studies of subjects with biopsy-confirmed celiac disease, follow-up biopsies, and measurement of serum antibodies on a GFD, biopsy performed on subjects regardless of symptoms, or antibody test results. Our analysis excluded subjects with refractory celiac disease, undergoing gluten challenge, or consuming a prescribed oats-containing GFD. Tests were considered to have positive or negative findings based on manufacturer cut-off values. Villous atrophy was defined as a Marsh 3 lesion or villous height:crypt depth ratio below 3.0. We constructed forest plots to determine the sensitivity and specificity of detection for individual studies. For the meta-analysis, a bivariate random effects model was used to jointly model sensitivity and specificity. RESULTS: Our search identified 5408 unique citations. Following review of abstracts, 442 articles were reviewed in detail. Only 26 studies (6 of tTG assays, 15 of EMA assays, and 5 of tTG and EMA assays) met our inclusion criteria. The most common reason studies were excluded from our analysis was inability to cross-tabulate histologic and serologic findings. The serum assays identified patients with persistent villous atrophy with high levels of specificity: 0.83 for the tTG IgA assay (95% CI, 0.79-0.87) and 0.91 for the EMA IgA assay (95% CI, 0.87-0.94). However, they detected villous atrophy with low levels of sensitivity: 0.50 for the tTG IgA assay (95% CI, 0.41-0.60) and 0.45 for the EMA IgA assay (95% CI, 0.34-0.57). The tests had similar levels of performance in pediatric and adult patients. CONCLUSIONS: In a meta-analysis of patients with biopsy-confirmed celiac disease undergoing follow-up biopsy on a GFD, we found that tests for serum tTG IgA and EMA IgA levels had low sensitivity (below 50%) in detection of persistent villous atrophy. We need more-accurate non-invasive markers of mucosal damage in children and adults with celiac disease who are following a GFD.

Value of IgA tTG in Predicting Mucosal Recovery in Children With Celiac Disease on a Gluten-Free Diet.

OBJECTIVES: Our objective was to determine the rate of mucosal recovery in pediatric patients with celiac disease on a gluten-free diet. We also sought to determine whether immunoglobulin A tissue transglutaminase (tTG) correlates with mucosal damage at the time of a repeat endoscopy with duodenal biopsy in these patients. METHODS: We performed a retrospective chart review of 103 pediatric patients, younger than 21 years, with a diagnosis of celiac disease defined as Marsh 3 histology, and who underwent a repeat endoscopy with duodenal biopsy at least 12 months after initiating a gluten-free diet. RESULTS: We found that 19% of pediatric patients treated with a gluten-free diet had persistent enteropathy. At the time of the repeat biopsy, tTG was elevated in 43% of cases with persistent enteropathy and 32% of cases in which there was mucosal recovery. Overall the positive predictive value of the autoantibody tTG was 25% and the negative predictive value was 83% in patients on a gluten-free diet for a median of 2.4 years. CONCLUSIONS: Nearly 1 in 5 children with celiac disease in our population had persistent enteropathy despite maintaining a gluten-free diet and immunoglobulin A tTG was not an accurate marker of mucosal recovery. Neither the presence of symptoms nor positive serology were predictive of a patient's histology at the time of repeat biopsy. These findings suggest a revisitation of monitring and management criteria of celiac disease in childhood.