Leffler, Daniel A.

ABSTRACT Background Coeliac disease is due to an acquired, lifelong gluten‐specific immune response resulting in a gluten‐dependent chronic immune‐mediated enteropathy associated with gastrointestinal and extraintestinal morbidity. Strictly avoiding dietary gluten is the only available management but has never been subjected to rigorous efficacy assessment now required for a pharmaceutical agent. Gluten‐free diet (GFD) is partially and inconsistently effective, but it places a high burden on patients, families, the food industry, and regulators and is defined inconsistently around the world, highlighting the need for effective and convenient adjunctive pharmacological therapies. Aims To summarize key patient, scientific, and regulatory considerations for coeliac disease drug development based on a multi‐stakeholder meeting focused on accelerating clinical trials. Methods A pre‐competitive meeting convened by the Beyond Celiac Coalition (May 2024) included patients with coeliac disease, academic experts, pharmaceutical industry representatives, and participants from the US Food and Drug Administration. Moderated panel addressed patient priorities, symptom and histologic endpoints, biopsy and histology methods, gluten challenge design, clinical trial duration, and regulatory expectations. Themes were synthesized qualitatively with focus on trial design implications and unresolved questions. Results Participants described high symptom burden and psychosocial impact despite gluten‐free diet adherence underscoring unmet therapeutic need in coeliac disease. Regulatory perspectives emphasized the need for clinically meaningful improvement and evidence of intestinal benefit, framed as symptom and histology co‐primary endpoints in clinical trials. These expectations were discussed as most applicable to trial populations with both clinically meaningful symptoms and active histologic injury at baseline; for other phenotypes, it was emphasized that endpoint strategy, the role of gluten exposure, and trial duration should be tailored case by case to the population and mechanism of action. Practical challenges identified included endpoint selection and definition, discordance between symptoms and histology, selecting fit‐for‐purpose symptom measures; standardizing biopsy acquisition and central histology reads to address patchiness and variability, pre‐specifying definitions of meaningful histologic change given ongoing uncertainty about healing, and trial feasibility. Controlled gluten exposure was discussed as a tool to improve interpretability of efficacy outcomes, with careful consideration of dose, duration, patient burden and safety. Discussion addressed the ideal length of the double‐blind period, including a shorter 24‐week double‐blind study with an open‐label extension versus a 52‐week double‐blind design. Trial duration should balance scientific rigour, patient retention, and the need for longer‐term safety and durability data, with flexibility to tailor the approach to context. Conclusions Progress in coeliac disease drug development will require patient‐centred, scientifically robust but feasible trial designs with appropriate endpoints, justified use of gluten exposure, consideration of improved biomarkers to reduce patient burden and early regulatory engagement. Continued multi‐stakeholder collaboration, including dedicated consideration of paediatric drug development, is essential to advance effective therapies.

Validated nonbiopsy methods to assure duodenal mucosal healing in celiac disease are lacking, yet ongoing mucosal injury is associated with anemia, osteoporosis, and lymphoma. Most providers utilize clinical data as surrogates of mucosal status to avoid additional esophagogastroduodenoscopy. The reliability of such surrogates to predict mucosal recovery has been incompletely evaluated. The aim of this study was to rigorously assess patterns of histologic mucosal recovery at follow-up in celiac disease and to correlate findings with clinical data. Gastrointestinal pathologists from 13 centers evaluated initial and follow-up duodenal biopsies from 181 celiac disease patients. Marsh scores and intraepithelial lymphocytes (IELs)/100 enterocytes were assessed blindly. Histology at follow-up was correlated with symptoms, immunoglobulin A anti–tissue transglutaminase titers and gluten-free diet adherence. Fifty-six/181 (31%) patients had persistent villous blunting and 46/181 (25%) patients had just persistently elevated IELs at follow-up, with only 79/181 (44%) patients having complete histologic remission. IEL normalization (82/181; 45%) lagged villous recovery (125/181;69%). In a minority of patients, villous blunting was limited to proximal duodenal biopsies. No correlation was found between Marsh scores and symptoms, normalization of immunoglobulin A anti–tissue transglutaminase serology, or diet adherence. Children showed greater recovery of Marsh score (P<0.001) and IELs (P<0.01) than adults. Persistent mucosal injury is common in celiac disease, with discordant villous/IEL normalization. Pathologist awareness of expected findings in celiac disease follow-up biopsies, including their frequent lack of correlation with clinical data, is important for patient management, and has implications for eligibility criteria for therapeutics currently in development.

INTRODUCTION: Anemia and micronutrient deficiencies are common in newly diagnosed patients with celiac disease (CeD). We aim to determine the prevalence and etiology of anemia in a cohort of patients with CeD in the United States and examine the effect of a gluten-free diet (GFD) on the laboratory parameters related to anemia in CeD. METHODS: We analyzed a prospectively collected cohort of adults with biopsy-proven CeD followed in a specialized CeD center between January 2000 and June 2016. We used the level of hemoglobin (Hb) and micronutrients suggested by the World Health Organization to establish the diagnosis of anemia or deficiencies. Demographic data and laboratory parameters related to anemia and micronutrients were recorded at the time of diagnosis and on a GFD. A celiac expert nutritionist or gastroenterologist evaluated all patients. RESULTS: In 572 patients with laboratory evaluation before starting a GFD, approximately 25% presented with anemia at the time of diagnosis of CeD. Iron deficiency was present in 50.8% of the cohort and in 78.8% of the patients with anemia. Within the anemic population, 84.4% of female patients as compared with 58.3% of male patients ( P = 0.02) showed iron deficiency. Folate deficiency (23.2%), vitamin B12 deficiency (11%), and anemia of chronic diseases (7.8%) were also part of both sexes' anemia etiology. Of the initially anemic patients, 81% and 89% normalized their Hb levels within 1 year and 2 years of beginning a GFD, respectively. All patients received appropriate supplementation when needed. DISCUSSION: Approximately 25% of individuals have anemia at CeD diagnosis. The anemia etiology included iron deficiency, vitamin deficiencies, and anemia of chronic diseases. Most of the patients will normalize their Hb levels and the anemia laboratory parameters 1 year after starting a strict GFD.

Objective Differential diagnosis of villous atrophy (VA) without coeliac antibodies in adults includes seronegative coeliac disease (CD) and chronic enteropathies unrelated to gluten, ie. non-coeliac enteropathies (NCEs). There is currently no international consensus on the nomenclature and diagnostic criteria for these enteropathies. In this work, a Delphi process was conducted to address this diagnostic and clinical uncertainty. Design An international task force of 13 gastroenterologists from six countries was recruited at the 16th International Coeliac Disease Symposium, Paris, 2019. Between September 2019 and July 2021, a Delphi process was conducted through mail surveys to reach a consensus on which conditions to consider in the differential diagnosis of VA with negative coeliac serology and the clinical diagnostic approaches required for these conditions. A 70% agreement threshold was adopted. Results Chronic enteropathies characterised by VA and negative coeliac serology can be attributed to two main clinical scenarios: forms of CD presenting with negative serology, which also include seronegative CD and CD associated with IgA deficiency, and NCEs, with the latter recognising different underlying aetiologies. A consensus was reached on the diagnostic criteria for NCEs assisting clinicians in differentiating NCEs from seronegative CD. Although in adults seronegative CD is the most common aetiology in patients with VA and negative serology, discriminating between seronegative CD and NCEs is key to avoid unnecessary lifelong gluten-free diet, treat disease-specific morbidity and contrast poor long-term outcomes. Conclusion This paper describes the Paris consensus on the definitions and diagnostic criteria for seronegative CD and chronic NCEs in adults.

Objective A gluten-free diet is the only treatment option of coeliac disease, but recently an increasing number of trials have begun to explore alternative treatment strategies. We aimed to review the literature on coeliac disease therapeutic trials and issue recommendations for outcome measures. Design Based on a literature review of 10 062 references, we (17 researchers and 2 patient representatives from 10 countries) reviewed the use and suitability of both clinical and non-clinical outcome measures. We then made expert-based recommendations for use of these outcomes in coeliac disease trials and identified areas where research is needed. Results We comment on the use of histology, serology, clinical outcome assessment (including patient-reported outcomes), quality of life and immunological tools including gluten immunogenic peptides for trials in coeliac disease. Conclusion Careful evaluation and reporting of outcome measures will increase transparency and comparability of coeliac disease therapeutic trials, and will benefit patients, healthcare and the pharmaceutical industry.

SummaryBackgroundRefractory coeliac disease is a severe complication of coeliac disease with heterogeneous outcome.AimTo create a prognostic model to estimate survival of patients with refractory coeliac disease.MethodsWe evaluated predictors of 5‐year mortality using Cox proportional hazards regression on subjects from a multinational registry. Bootstrap resampling was used to internally validate the individual factors and overall model performance. The mean of the estimated regression coefficients from 400 bootstrap models was used to derive a risk score for 5‐year mortality.ResultsThe multinational cohort was composed of 232 patients diagnosed with refractory coeliac disease across seven centres (range of 11–63 cases per centre). The median age was 53 years and 150 (64%) were women. A total of 51 subjects died during a 5‐year follow‐up (cumulative 5‐year all‐cause mortality = 30%). From a multiple variable Cox proportional hazards model, the following variables were significantly associated with 5‐year mortality: age at refractory coeliac disease diagnosis (per 20 year increase, hazard ratio = 2.21; 95% confidence interval, CI: 1.38–3.55), abnormal intraepithelial lymphocytes (hazard ratio = 2.85; 95% CI: 1.22–6.62), and albumin (per 0.5 unit increase, hazard ratio = 0.72; 95% CI: 0.61–0.85). A simple weighted three‐factor risk score was created to estimate 5‐year survival.ConclusionsUsing data from a multinational registry and previously reported risk factors, we create a prognostic model to predict 5‐year mortality among patients with refractory coeliac disease. This new model may help clinicians to guide treatment and follow‐up.

Celiac disease (CD) is an inflammatory disorder triggered by ingested gluten, causing immune-mediated damage to the small-intestinal mucosa. Gluten proteins are strikingly similar in amino acid composition and sequence to proline-rich proteins (PRPs) in human saliva. On the basis of this feature and their shared destination in the gastrointestinal tract, we hypothesized that salivary PRPs may modulate gluten-mediated immune responses in CD. Parotid salivary secretions were collected from CD patients, refractory CD patients, non-CD patients with functional gastrointestinal complaints, and healthy controls. Structural similarities of PRPs with gluten were probed with anti-gliadin antibodies. Immune responses to PRPs were investigated toward CD patient-derived peripheral blood mononuclear cells and in a humanized transgenic HLA-DQ2/DQ8 mouse model for CD. Anti-gliadin antibodies weakly cross-reacted with the abundant salivary amylase but not with PRPs. Likewise, the R5 antibody, recognizing potential antigenic gluten epitopes, showed negligible reactivity to salivary proteins from all groups. Inflammatory responses in peripheral blood mononuclear cells were provoked by gliadins whereas responses to PRPs were similar to control levels, and PRPs did not compete with gliadins in immune stimulation. In vivo, PRP peptides were well tolerated and nonimmunogenic in the transgenic HLA-DQ2/DQ8 mouse model. Collectively, although structurally similar to dietary gluten, salivary PRPs were nonimmunogenic in CD patients and in a transgenic HLA-DQ2/DQ8 mouse model for CD. It is possible that salivary PRPs play a role in tolerance induction to gluten early in life. Deciphering the structural basis for the lack of immunogenicity of salivary PRPs may further our understanding of the toxicity of gluten.

A multidisciplinary panel of 18 physicians and 3 non-physicians from eight countries (Sweden, UK, Argentina, Australia, Italy, Finland, Norway and the USA) reviewed the literature on diagnosis and management of adult coeliac disease (CD). This paper presents the recommendations of the British Society of Gastroenterology. Areas of controversies were explored through phone meetings and web surveys. Nine working groups examined the following areas of CD diagnosis and management: classification of CD; genetics and immunology; diagnostics; serology and endoscopy; follow-up; gluten-free diet; refractory CD and malignancies; quality of life; novel treatments; patient support; and screening for CD.

Summary Background Coeliac disease, an autoimmune disorder triggered by gluten ingestion, is managed by a gluten‐free diet ( GFD ), which is difficult for many patients. Larazotide acetate is a first‐in‐class oral peptide that prevents tight junction opening, and may reduce gluten uptake and associated sequelae. Aim To evaluate the efficacy and tolerability of larazotide acetate during gluten challenge. Methods This exploratory, double‐blind, randomised, placebo‐controlled study included 184 patients maintaining a GFD before and during the study. After a GFD run‐in, patients were randomised to larazotide acetate (1, 4, or 8 mg three times daily) or placebo and received 2.7 grams of gluten daily for 6 weeks. Outcomes included an experimental biomarker of intestinal permeability, the lactulose‐to‐mannitol ( LAMA ) ratio and clinical symptoms assessed by Gastrointestinal Symptom Rating Scale ( GSRS ) and anti‐transglutaminase antibody levels. Results No significant differences in LAMA ratios were observed between larazotide acetate and placebo groups. Larazotide acetate 1‐mg limited gluten‐induced symptoms measured by GSRS ( P = 0.002 vs. placebo). Mean ratio of anti‐tissue transglutaminase IgA levels over baseline was 19.0 in the placebo group compared with 5.78 ( P = 0.010), 3.88 ( P = 0.005) and 7.72 ( P = 0.025) in the larazotide acetate 1‐, 4‐, and 8‐mg groups, respectively. Adverse event rates were similar between larazotide acetate and placebo groups. Conclusions Larazotide acetate reduced gluten‐induced immune reactivity and symptoms in patients with coeliac disease undergoing gluten challenge and was generally well tolerated; however, no significant difference in LAMA ratios between larazotide acetate and placebo was observed. Results and design of this exploratory study can inform the design of future studies of pharmacological interventions in patients with coeliac disease.