The prevalence and rate of undiagnosed celiac disease in an adult general population, the Trøndelag Health Study, Norway.

BACKGROUND & AIMS: This study aimed to determine the total prevalence of celiac disease (CeD), including undiagnosed cases, in a population-based study of adults screened for CeD. METHODS: The study utilized the fourth Trøndelag Health Study (HUNT4), conducted in 2017-2019, where 56,042 adult (aged >20 years) residents of Nord-Trøndelag County, Norway, participated. Serum samples from 54,505 participants were analysed for anti-transglutaminase 2 immunoglobulin A and G. Seropositive individuals were invited for a clinical assessment, including upper endoscopy with duodenal biopsies. Previously diagnosed and seronegative CeD cases were identified through linkage to hospital records and the Norwegian Patient Registry. RESULTS: The rate of CeD seropositivity was 2.0% (1107/54,505). Out of these, 724 individuals attended the clinical assessment. Additionally, the hospital records and registry identified individuals with a known CeD diagnosis, that were seronegative or without serology in HUNT4 or seropositive in HUNT4 but did not participate in the clinical assessment. In total, the study confirmed a new CeD diagnosis after participation in HUNT4 in 470 individuals and a known CeD diagnosis before participation in HUNT4 in 383 individuals. The total biopsy-confirmed prevalence of CeD was 1.5% (853/56,042), and the ratio of new, previously undiagnosed CeD cases (after HUNT4) to known, previously diagnosed CeD cases (before HUNT4) was 1.2:1 (470/383). CONCLUSION: The total prevalence of CeD in this population-based study of adults in Norway was high and many individuals were previously undiagnosed. Detection of CeD should be improved, as early diagnosis is crucial for effective management and prevention of complications.

Generation of circulating autoreactive pre-plasma cells fueled by naive B cells in celiac disease.

Autoantibodies against the enzyme transglutaminase 2 (TG2) are characteristic of celiac disease (CeD), and TG2-specific immunoglobulin (Ig) A plasma cells are abundant in gut biopsies of patients. Here, we describe the corresponding population of autoreactive B cells in blood. Circulating TG2-specific IgA cells are present in untreated patients on a gluten-containing diet but not in controls. They are clonally related to TG2-specific small intestinal plasma cells, and they express gut-homing molecules, indicating that they are plasma cell precursors. Unlike other IgA-switched cells, the TG2-specific cells are negative for CD27, placing them in the double-negative (IgD-CD27-) category. They have a plasmablast or activated memory B cell phenotype, and they harbor fewer variable region mutations than other IgA cells. Based on their similarity to naive B cells, we propose that autoreactive IgA cells in CeD are generated mainly through chronic recruitment of naive B cells via an extrafollicular response involving gluten-specific CD4+ T cells.

Biopsy Proteome Scoring to Determine Mucosal Remodeling in Celiac Disease.

BACKGROUND & AIMS: Histologic evaluation of gut biopsies is a cornerstone for diagnosis and management of celiac disease (CeD). Despite its wide use, the method depends on proper biopsy orientation, and it suffers from interobserver variability. Biopsy proteome measurement reporting on the tissue state can be obtained by mass spectrometry analysis of formalin-fixed paraffin-embedded tissue. Here we aimed to transform biopsy proteome data into numerical scores that give observer-independent measures of mucosal remodeling in CeD. METHODS: A pipeline using glass-mounted formalin-fixed paraffin-embedded sections for mass spectrometry-based proteome analysis was established. Proteome data were converted to numerical scores using 2 complementary approaches: a rank-based enrichment score and a score based on machine learning using logistic regression. The 2 scoring approaches were compared with each other and with histology analyzing 18 patients with CeD with biopsies collected before and after treatment with a gluten-free diet as well as biopsies from patients with CeD with varying degree of remission (n = 22). Biopsies from individuals without CeD (n = 32) were also analyzed. RESULTS: The method yielded reliable proteome scoring of both unstained and H&E-stained glass-mounted sections. The scores of the 2 approaches were highly correlated, reflecting that both approaches pick up proteome changes in the same biological pathways. The proteome scores correlated with villus height-to-crypt depth ratio. Thus, the method is able to score biopsies with poor orientation. CONCLUSIONS: Biopsy proteome scores give reliable observer and orientation-independent measures of mucosal remodeling in CeD. The proteomic method can readily be implemented by nonexpert laboratories in parallel to histology assessment and easily scaled for clinical trial settings.

Gluten-Free Diet Induces Rapid Changes in Phenotype and Survival Properties of Gluten-Specific T Cells in Celiac Disease.

BACKGROUND & AIMS: The treatment of celiac disease (CeD) with gluten-free diet (GFD) normalizes gut inflammation and disease-specific antibodies. CeD patients have HLA-restricted, gluten-specific T cells persisting in the blood and gut even after decades of GFD, which are reactivated and disease driving upon gluten exposure. Our aim was to examine the transition of activated gluten-specific T cells into a pool of persisting memory T cells concurrent with normalization of clinically relevant biomarkers during the first year of treatment. METHODS: We followed 17 CeD patients during their initial GFD year, leading to disease remission. We assessed activation and frequency of gluten-specific CD4+ blood and gut T cells with HLA-DQ2.5:gluten tetramers and flow cytometry, disease-specific serology, histology, and symptom scores. We assessed gluten-specific blood T cells within the first 3 weeks of GFD in 6 patients and serology in an additional 9 patients. RESULTS: Gluten-specific CD4+ T cells peaked in blood at day 14 while up-regulating Bcl-2 and down-regulating Ki-67 and then decreased in frequency within 10 weeks of GFD. CD38, ICOS, HLA-DR, and Ki-67 decreased in gluten-specific cells within 3 days. PD-1, CD39, and OX40 expression persisted even after 12 months. IgA-transglutaminase 2 decreased significantly within 4 weeks. CONCLUSIONS: GFD induces rapid changes in the phenotype and number of gluten-specific CD4+ blood T cells, including a peak of nonproliferating, nonapoptotic cells at day 14. Subsequent alterations in T-cell phenotype associate with the quiescent but chronic nature of treated CeD. The rapid changes affecting gluten-specific T cells and disease-specific antibodies offer opportunities for clinical trials aiming at developing nondietary treatments for patients with newly diagnosed CeD.

Diagnosis of Seronegative and Ultrashort Celiac Disease.

In its conventional form, celiac disease (CeD) is characterized by both positive serology and flat villi in the duodenum, and is well known by gastroenterologists and general practitioners. The aim of this review was to shed light on 2 neglected and not yet well-defined celiac phenotypes, that is, seronegative and ultrashort CeD. Seronegative CeD can be suspected in the presence of flat villi, positive HLA-DQ2 and/or HLA-DQ8, and the absence of CeD antibodies. After ruling out other seronegative enteropathies, the diagnosis can be confirmed by both clinical and histologic improvements after 1 year of a gluten-free diet. Ultrashort CeD is characterized by the finding of flat villi in the duodenal bulb in the absence of mucosal damage in the distal duodenum and with serologic positivity. Data on the prevalence, clinical manifestations, histologic lesions, genetic features, and outcome of seronegative and ultrashort CeD are inconclusive due to the few studies available and the small number of patients diagnosed. Some additional diagnostic tools have been developed recently, such as assessing intestinal transglutaminase 2 deposits, flow cytometry technique, microRNA detection, or proteomic analysis, and they seem to be useful in the identification of complex cases. Further cooperative studies are highly desirable to improve the knowledge of these 2 still-obscure variants of CeD.

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.

Expression of transglutaminase 2 in human gut epithelial cells: Implications for coeliac disease.

BACKGROUND: Formation of complexes between transglutaminase 2 (TG2) and gluten can mechanistically explain why TG2 serves both as B-cell autoantigen and as an enzyme that creates deamidated gluten epitopes in coeliac disease (CeD). A model has been proposed where TG2 released from shed epithelial cells encounters high concentrations of dietary gluten peptides to form these TG2:gluten complexes. In this work we have characterised TG2 protein expression in gut epithelial cells in humans. METHODS: Western blot analysis, immunofluorescence staining and mass spectrometry in combination with laser capture microdissection to gain spatial resolution were used to characterise TG2 expression in the epithelial cell layer of healthy and coeliac disease affected duodenum. FINDINGS: TG2 is expressed in human duodenal epithelial cells, including cells in the apical region that are shed into the gut lumen. In untreated CeD the apical expression of TG2 is doubled. Enzymatically active TG2 is readily released from isolated human intestinal epithelial cells. CONCLUSION: Shed epithelial cells are a plausible source of pathogenic TG2 enzyme in CeD. Increased epithelial TG2 expression and increased epithelial shedding in active CeD may reinforce action of luminal TG2 in this condition.

Nutritional assessment of women with celiac disease compared to the general population.

BACKGROUND & AIMS: The nutritional quality of a gluten-free diet is debated because of the elimination of grains that are important sources of nutrients. The aim of this cross-sectional study was to perform a nutritional assessment in treated women with celiac disease and ongoing symptoms, and compare dietary intake with a healthy reference group (Norkost 3). METHODS: Celiac disease patients with biopsy confirmed mucosal healing, but persistent gastrointestinal symptoms, were included from an ongoing clinical trial. Nutritional assessment included anthropometrics, blood samples and dietary intake obtained by two 24 h recalls. Dietary intake in celiac women was compared with dietary intake in healthy women (Norkost 3). Two sample t-test was used for comparison of CeD and Norkost 3 women. Adjustment for age, BMI, education and smoking, by use of multiple linear regression analysis, did not change the results. RESULTS: In total, 59 women with celiac disease and 925 women that participated in Norkost 3 were included, with a mean age of 45 years in both groups. Women with celiac disease had a higher proportion of energy (E%) from fat (39 vs 34%, P < 0.001) and saturated fat (15 vs 13%, P = 0.01), a lower E% from protein (16 vs 18%, P = 0.01) and a lower intake of dietary fiber (19 vs 22 g, P = 0.002) compared to Norkost 3 women. Women with celiac disease had a lower intake of bread, fruit and milk, and a higher intake of cereals and cheese compared to Norkost 3 women. The average requirement was not met for several micronutrients, but blood analysis revealed few nutritional deficiencies: two women with insufficient vitamin D status and one with insufficient folic acid status. CONCLUSION: The women with celiac disease had an unbalanced diet with a higher intake of total- and saturated fatty acids and a lower intake of fiber compared to the general population. These findings emphasizes the need for nutritional follow-up of celiac patients and development of nutrient dense gluten-free products.

Effects of faecal microbiota transplantation on the small intestinal mucosa in systemic sclerosis.

OBJECTIVES: In SSc, gastrointestinal tract (GIT) involvement is a major concern, with no disease-modifying and limited symptomatic therapies available. Faecal microbiota transplantation (FMT) represents a new therapeutic option for GIT-affliction in SSc, showing clinical promise in a recent controlled pilot trial. Here, we aim to investigate effects of FMT on duodenal biopsies collected from SSc patients by immunohistochemistry and transcriptome profiling. METHODS: We analysed duodenal biopsies obtained pre-intervention (week 0) and post-intervention (weeks 2 and 16) from nine SSc patients receiving an intestinal infusion of FMT (n = 5) or placebo (n = 4). The analysis included immunohistochemistry (IHC) with a selected immune function and fibrosis markers, and whole biopsy transcriptome profiling. RESULTS: In patients receiving FMT, the number of podoplanin- and CD64-expressing cells in the mucosa were lower at week 2 compared with baseline. This decline in podoplanin- (r = 0.94) and CD64-positive (r = 0.89) cells correlated with improved patient-reported lower GIT symptoms. Whole biopsy transcriptome profiling from week 2 showed significant enrichment of pathways critical for cellular and endoplasmic reticulum stress responses, microvillus and secretory vesicles, vascular and sodium-dependent transport, and circadian rhythm. At week 16, we found enrichment of pathways mandatory for binding activity of immunoglobulin receptors, T cell receptor complexes, and chemokine receptors, as well as response to zinc-ions. We found that 25 genes, including Matrix metalloproteinase-1 were upregulated at both week 2 and week 16. CONCLUSION: Combining selective IHC and unbiased gene expression analyses, this exploratory study highlights the potential for disease-relevant organ effects of FMT in SSc patients with GIT involvement. TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov, NCT03444220.

Identification of gluten T cell epitopes driving celiac disease.

CD4+ T cells specific for cereal gluten proteins are key players in celiac disease (CeD) pathogenesis. While several CeD-relevant gluten T cell epitopes have been identified, epitopes recognized by a substantial proportion of gluten-reactive T cells remain unknown. The identification of such CeD-driving gluten epitopes is important for the food industry and in clinical settings. Here, we have combined the knowledge of a distinct phenotype of gluten-reactive T cells and key features of known gluten epitopes for the discovery of unknown epitopes. We tested 42 wheat gluten-reactive T cell clones, isolated on the basis of their distinct phenotype and with no reactivity to known epitopes, against a panel of synthetic peptides bioinformatically identified from a wheat gluten protein database. We were able to assign reactivity to 10 T cell clones and identified a 9-nucleotide oligomer core region of five previously uncharacterized gliadin/glutenin epitopes. This work represents an advance in the effort to identify CeD-driving gluten epitopes.

Duodenal inflammation in common variable immunodeficiency has altered transcriptional response to viruses.

BACKGROUND: A substantial proportion of common variable immunodeficiency (CVID) patients has duodenal inflammation of largely unknown etiology. However, because of its histologic similarities with celiac disease, gluten sensitivity has been proposed as a potential mechanism. OBJECTIVE: We aimed to elucidate the role of the duodenal microenvironment in the pathogenesis of duodenal inflammation in CVID by investigating the transcriptional, proteomic, and microbial signatures of duodenal biopsy samples in CVID. METHODS: DNA, total RNA, and protein were isolated from snap-frozen pieces of duodenal biopsy samples from CVID (with and without duodenal inflammation), healthy controls, and patients with celiac disease (untreated). RNA sequencing, mass spectrometry-based proteomics, and 16S ribosomal DNA sequencing (bacteria) were then performed. RESULTS: CVID separated from controls in regulation of transcriptional response to lipopolysaccharide and cellular immune responses. These differences were independent of mucosal inflammation. Instead, CVID patients with duodenal inflammation displayed alterations in transcription of genes involved in response to viral infections. Four proteins were differently regulated between CVID patients and healthy controls-DBNL, TRMT11, GCHFR, and IGHA2-independent of duodenal inflammation. Despite similar histology, there were major differences in CVID with duodenal inflammation and celiac disease both at the RNA and protein level. No significant difference was observed in the bacterial gut microbial signature between CVID, celiac, and healthy controls. CONCLUSION: Our findings suggest the existence of altered functions of the duodenal epithelium, particularly in response to lipopolysaccharide and viruses. The latter finding was related to duodenal inflammation, suggesting that viruses, not gluten sensitivity, could be related to duodenal inflammation in CVID.

Focused B cell response to recurring gluten motif with implications for epitope spreading in celiac disease.

Antibodies to deamidated gluten peptides are accurate diagnostic markers of celiac disease. However, binding of patient antibodies to all possible gluten epitopes has not previously been investigated. Here, we assess serum antibody specificity across the gluten proteome by use of high-density peptide arrays. We confirm the importance of deamidation for antibody binding, and we show that the response is remarkably focused on the known epitope QPEQPFP (where E results from deamidation of Q). In addition, we describe an epitope in native (non-deamidated) gluten, QQPEQII (where E is gene encoded), which is associated with both B cell and T cell reactivity. Antibodies to this native epitope are cross-reactive with the major deamidated epitope due to recognition of the shared PEQ motif. Since cross-reactive B cells can present peptides to different gluten-specific T cells, we propose that such B cells play a role in epitope spreading by engaging T cells with multiple specificities.

The development and validation of a high-capacity serological assay for celiac disease.

BACKGROUND: The aim of the present study was to develop and clinically validate a high-throughput assay for serum IgA and IgG antibodies against transglutaminase-2 (TG2) and to determine appropriate assay cut-offs for large-scale population screening for celiac disease. METHOD: An automated method was developed using dual label time-resolved fluorometry on the AutoDELFIA platform. Individuals (n = 1920) from the general population were screened. Subjects with serum anti-TG2 concentrations above a preliminary cut-off (>0.3 mg*/L anti-TG2 IgA or >0.5 mg*/L anti-TG2 IgG) were offered endoscopic examination and biopsy. A diagnosis of celiac disease was given if villous atrophy (Marsh grade 3) was found. RESULTS: The assay had a limit of quantification of 0.25 mg*/L (anti-TG2 IgA) and 0.60 mg*/L (anti-TG2 IgG) with imprecision (CV) < 16% and <18% respectively. A total of 66 individuals were above the preliminary cut-off, and 56 underwent endoscopy. Of these, 26 were diagnosed with celiac disease. Sixty-eight percent of subjects with anti-TG2 IgA ≥ 0.7 mg*/L or anti-TG2 IgG ≥ 1.0 mg*/L had biopsy-proven celiac disease, and utilization of these higher cut-offs identified 96% of biopsy-positive patients. At the time of endoscopy, all individuals with anti-TG2 IgA > 2.0 mg*/L had celiac disease, and this cut-off identified 88% of newly diagnosed celiac patients. Eight percent (2/26) of the newly diagnosed patients had primarily anti-TG2 IgG. CONCLUSIONS: In this study we developed and clinically validated a robust and automated assay suitable for celiac disease screening in the general population.

A Low FODMAP Diet Reduces Symptoms in Treated Celiac Patients With Ongoing Symptoms-A Randomized Controlled Trial.

BACKGROUND & AIMS: A gluten-free diet usually leads to mucosal remission in celiac disease, but persistent symptoms are common. A low fermentable oligo-, di-, monosaccharides and polyols (FODMAP) diet is an established treatment for irritable bowel syndrome (IBS). We have assessed the efficacy of a moderately low FODMAP diet on persistent symptoms in treated celiac patients. METHODS: A randomized controlled trial was performed from 2018 to 2019 in 70 adults with biopsy-proven celiac disease. Inclusion criteria were as follows: persistent gastrointestinal symptoms defined by a Gastrointestinal Symptom Rating Scale (GSRS)-IBS version score of 30 or higher, gluten-free diet adherence for 12 months or longer, and serologic and mucosal remission. Participants were randomized to a low FODMAP-gluten-free diet (intervention) or usual gluten-free diet (control). The GSRS-IBS score was recorded at baseline and at weeks 1 to 4, and the Celiac Symptom Index at baseline and at week 4. Statistics included marginal models for repeated data and analyses of covariance. RESULTS: We included 34 participants in the intervention group and 36 in the control group. Time development of GSRS-IBS total scores differed significantly between the groups (Pinteraction < .001), evident after 1 week (mean difference in intervention vs control, -8.2; 95% CI, -11.5 to -5.0) and persisting through week 4 (mean difference in intervention vs control, -10.8; 95% CI, -14.8 to -6.8). Moreover, significantly lower scores were found for the dimensions of pain, bloating, diarrhea, and satiety (Pinteraction ≤ .04), but not constipation (Pinteraction = .43). FODMAP intake during the intervention was moderately low (mean, 8.1 g/d; 95% CI, 6.7-9.3 g/d). The Celiac Symptom Index was significantly lower in the intervention group at week 4 (mean difference, -5.8; 95% CI, -9.6 to -2.0). CONCLUSIONS: A short-term moderately low FODMAP diet significantly reduced gastrointestinal symptoms and increased celiac disease-specific health, and should be considered for the management of persistent symptoms in celiac disease. CLINICALTRIALS: gov: NCT03678935.

Pathogenic T Cells in Celiac Disease Change Phenotype on Gluten Challenge: Implications for T-Cell-Directed Therapies.

Gluten-specific CD4+ T cells being drivers of celiac disease (CeD) are obvious targets for immunotherapy. Little is known about how cell markers harnessed for T-cell-directed therapy can change with time and upon activation in CeD and other autoimmune conditions. In-depth characterization of gluten-specific CD4+ T cells and CeD-associated (CD38+ and CD103+ ) CD8+ and γδ+ T cells in blood of treated CeD patients undergoing a 3 day gluten challenge is reported. The phenotypic profile of gluten-specific cells changes profoundly with gluten exposure and the cells adopt the profile of gluten-specific cells in untreated disease (CD147+ , CD70+ , programmed cell death protein 1 (PD-1)+ , inducible T-cell costimulator (ICOS)+ , CD28+ , CD95+ , CD38+ , and CD161+ ), yet with some markers being unique for day 6 cells (C-X-C chemokine receptor type 6 (CXCR6), CD132, and CD147) and with integrin α4ß7, C-C motif chemokine receptor 9 (CCR9), and CXCR3 being expressed stably at baseline and day 6. Among gluten-specific CD4+ T cells, 52% are CXCR5+ at baseline, perhaps indicative of germinal-center reactions, while on day 6 all are CXCR5- . Strikingly, the phenotypic profile of gluten-specific CD4+ T cells on day 6 largely overlaps with that of CeD-associated (CD38+ and CD103+ ) CD8+ and γδ+ T cells. The antigen-induced shift in phenotype of CD4+ T cells being shared with other disease-associated T cells is relevant for development of T-cell-directed therapies.

A high-affinity human TCR-like antibody detects celiac disease gluten peptide-MHC complexes and inhibits T cell activation.

Antibodies specific for peptides bound to human leukocyte antigen (HLA) molecules are valuable tools for studies of antigen presentation and may have therapeutic potential. Here, we generated human T cell receptor (TCR)-like antibodies toward the immunodominant signature gluten epitope DQ2.5-glia-α2 in celiac disease (CeD). Phage display selection combined with secondary targeted engineering was used to obtain highly specific antibodies with picomolar affinity. The crystal structure of a Fab fragment of the lead antibody 3.C11 in complex with HLA-DQ2.5:DQ2.5-glia-α2 revealed a binding geometry and interaction mode highly similar to prototypic TCRs specific for the same complex. Assessment of CeD biopsy material confirmed disease specificity and reinforced the notion that abundant plasma cells present antigen in the inflamed CeD gut. Furthermore, 3.C11 specifically inhibited activation and proliferation of gluten-specific CD4+ T cells in vitro and in HLA-DQ2.5 humanized mice, suggesting a potential for targeted intervention without compromising systemic immunity.

Mortality and microbial diversity after allogeneic hematopoietic stem cell transplantation: secondary analysis of a randomized nutritional intervention trial.

Gut mucosal barrier injury is common following allogeneic hematopoietic stem cell transplantation (allo-HSCT) and associated with poor clinical outcomes. Diet is critical for microbial diversity, but whether nutritional support affects microbiota and outcome after allo-HSCT is unknown. We present a secondary analysis of a randomized controlled nutritional intervention trial during allo-HSCT. We investigated if the intervention influenced gut microbiota, short-chain fatty acids (SCFAs), and markers of gut barrier functions, and if these parameters were associated with clinical outcomes. Fecal specimens were available from 47 recipients, and subjected to 16S rRNA gene sequencing. We found no significant differences between the intervention group and controls in investigated parameters. We observed a major depletion of microbiota, SCFAs, and altered markers of gut barrier function from baseline to 3 weeks post-transplant. One-year mortality was significantly higher in patients with lower diversity at 3 weeks post-HSCT, but not related to diversity at baseline. The relative abundance of Blautia genus at 3 weeks was higher in survivors. Fecal propionic acid was associated with survival. Markers of gut barrier functions were less strongly associated with clinical outcomes. Possibly, other strategies than dietary intervention are needed to prevent negative effects of gut microbiota and clinical outcomes after allo-HSCT.ClinicalTrials.gov (NCT01181076).

A Randomized Trial of a Transglutaminase 2 Inhibitor for Celiac Disease.

BACKGROUND: In celiac disease, small intestinal transglutaminase 2 causes deamidation of glutamine residues in gluten peptides, which enhances stimulation of T cells and leads to mucosal injury. Inhibition of transglutaminase 2 is a potential treatment for celiac disease. METHODS: In a proof-of-concept trial, we assessed the efficacy and safety of a 6-week treatment with ZED1227, a selective oral transglutaminase 2 inhibitor, at three dose levels as compared with placebo, in adults with well-controlled celiac disease who underwent a daily gluten challenge. The primary end point was the attenuation of gluten-induced mucosal damage, as measured by the ratio of villus height to crypt depth. Secondary end points included intraepithelial lymphocyte density, the Celiac Symptom Index score, and the Celiac Disease Questionnaire score (for assessment of health-related quality of life). RESULTS: Of the 41 patients assigned to the 10-mg ZED1227 group, the 41 assigned to the 50-mg group, the 41 assigned to the 100-mg group, and the 40 assigned to the placebo group, 35, 39, 38, and 30 patients, respectively, had adequate duodenal-biopsy samples for the assessment of the primary end point. Treatment with ZED1227 at all three dose levels attenuated gluten-induced duodenal mucosal injury. The estimated difference from placebo in the change in the mean ratio of villus height to crypt depth from baseline to week 6 was 0.44 (95% confidence interval [CI], 0.15 to 0.73) in the 10-mg group (P = 0.001), 0.49 (95% CI, 0.20 to 0.77) in the 50-mg group (P<0.001), and 0.48 (95% CI, 0.20 to 0.77) in the 100-mg group (P<0.001). The estimated differences from placebo in the change in intraepithelial lymphocyte density were -2.7 cells per 100 epithelial cells (95% CI, -7.6 to 2.2) in the 10-mg group, -4.2 cells per 100 epithelial cells (95% CI, -8.9 to 0.6) in the 50-mg group, and -9.6 cells per 100 epithelial cells (95% CI, -14.4 to -4.8) in the 100-mg group. Use of the 100-mg dose may have improved symptom and quality-of-life scores. The most common adverse events, the incidences of which were similar across all groups, were headache, nausea, diarrhea, vomiting, and abdominal pain. Rash developed in 3 of 40 patients (8%) in the 100-mg group. CONCLUSIONS: In this preliminary trial, treatment with ZED1227 attenuated gluten-induced duodenal mucosal damage in patients with celiac disease. (Funded by Dr. Falk Pharma; CEC-3 EudraCT number, 2017-002241-30.).

Circulating CD103+ γδ and CD8+ T cells are clonally shared with tissue-resident intraepithelial lymphocytes in celiac disease.

Gut intraepithelial γδ and CD8+ αß T lymphocytes have been connected to celiac disease (CeD) pathogenesis. Based on the previous observation that activated (CD38+), gut-homing (CD103+) γδ and CD8+ αß T cells increase in blood upon oral gluten challenge, we wanted to shed light on the pathogenic involvement of these T cells by examining the clonal relationship between cells of blood and gut during gluten exposure. Of 20 gluten-challenged CeD patients, 8 and 10 had increase in (CD38+CD103+) γδ and CD8+ αß T cells, respectively, while 16 had increase in gluten-specific CD4+ T cells. We obtained γδ and αß TCR sequences of >2500 single cells from blood and gut of 5 patients, before and during challenge. We observed extensive sharing between blood and gut γδ and CD8+ αß T-cell clonotypes even prior to gluten challenge. In subjects with challenge-induced surge of γδ and/or CD8+ αß T cells, as larger populations of cells analyzed, we observed more expanded clonotypes and clonal sharing, yet no discernible TCR similarities between expanded and/or shared clonotypes. Thus, CD4+ T cells appear to drive expansion of clonally diverse γδ or CD8+ αß T-cell clonotypes that may not be specific for the gluten antigen.