Gluten, major histocompatibility complex, and the small intestine

A new algorithm for coeliac disease based on the 'long forgotten' TCRγδ+ intra-epithelial lymphocytes detected with an antibody working on FFPE sections

AIMS

Diagnosis of coeliac disease (CD) with mild mucosal changes is difficult for all parties involved. We aimed to determine the power of T cell receptor (TCR)γδ+ intra-epithelial lymphocytes (IELs) in discriminating CD from other causes of intra-epithelial lymphocytosis using a new monoclonal antibody.

METHODS

A total of 167 cases categorised as coeliac (117 untreated CD, classified according to Marsh, updated by Ensari, including 29 type 1, 29 type 2, 39 type 3 and 20 treated CD), and non-coeliac groups (24 controls and 26 non-coeliac IELosis) based on clinical, serological and histological data were studied for IEL counts enumerated per 100 enterocytes using haematoxylin and eosin, CD3, TCR δ-stains.

RESULTS

TCRγδ+ IELs were significantly higher in CD (24.83 ± 16.13) compared to non-CD (6.72 ± 6.32) and were correlated with the degree of mucosal damage. Both γδ+ IEL count and ratio showed higher performance in differentiating untreated coeliacs from controls, with a sensitivity of 83.76; 85.57 and specificity of 95.83; 79.17, respectively. TCRγδ+ IEL counts distinguished type 1 CD (20.41 ± 13.57) from non-coeliac IELosis (9.42 ± 7.28) (p = 0.025). Discriminant analysis revealed that villus/crypt ratio, γδ+ and CD3+ IEL counts, γδ+/CD3+IEL ratio, IEL distribution pattern were potent discriminants and correctly classified 82.3% of cases while the algorithm accurately diagnosed 93.4% of cases.

CONCLUSIONS

The new antibody detecting γδ+ IELs in FFPE sections revealed thresholds of 10.5 for γδ+ IELs and 14% for γδ+/CD3+IEL ratio which distinguished coeliacs from non-coeliacs with high sensitivity and specificity, particularly in cases with normal villus/crypt axis including type 1 CD, non-CD IELosis and controls. A 'coeliac algorithm' based on γδ+ IELs is proposed with the hope that it will be used in the histopathological diagnostic approach by the pathology community.

Cellular and molecular basis of proximal small intestine disorders

The proximal part of the small intestine, including duodenum and jejunum, is not only dedicated to nutrient digestion and absorption but is also a highly regulated immune site exposed to environmental factors. Host-protective responses against pathogens and tolerance to food antigens are essential functions in the small intestine. The cellular ecology and molecular pathways to maintain those functions are complex. Maladaptation is highlighted by common immune-mediated diseases such as coeliac disease, environmental enteric dysfunction or duodenal Crohn's disease. An expanding spectrum of more than 100 rare monogenic disorders inform on causative molecular mechanisms of nutrient absorption, epithelial homeostasis and barrier function, as well as inflammatory immune responses and immune regulation. Here, after summarizing the architectural and cellular traits that underlie the functions of the proximal intestine, we discuss how the integration of tissue immunopathology and molecular mechanisms can contribute towards our understanding of disease and guide diagnosis. We propose an integrated mechanism-based taxonomy and discuss the latest experimental approaches to gain new mechanistic insight into these disorders with large disease burden worldwide as well as implications for therapeutic interventions.

Undiagnosed Celiac Disease and Periodontal Bone Loss: A Cross-Sectional Radiological Assessment from the HUNT Study

Objective

The objective was to assess radiographic periodontal bone loss in a population with previously undiagnosed celiac disease, and to compare it to a reference group without celiac disease.

Background

Periodontitis and celiac disease are chronic inflammatory diseases with possible similar features related to immune reactions and microbial dysbiosis. The relationship between these two diseases is not clear.

Methods

Clinical variables, blood samples, and answers to questionnaires were collected from participants in the fourth Trøndelag Health Study (HUNT4). Celiac disease was determined based on transglutaminase 2 (TG2), immunoglobulin A (IgA), and G (IgG) in serum samples. Seropositive individuals were invited to endoscopic examination and tissue sampling. Radiographically assessed bone loss caused by periodontitis in two different levels of severity was applied as outcome, that is, ≥15% and >33% of root length. Bone loss was determined in panoramic images in participants that had attended radiographic examination in the HUNT4 Oral Health Study or in the HUNT4 Coeliac Disease Study. The association between previously undiagnosed celiac disease and radiographic bone loss was estimated by adjusted Poisson regression models.

Results

Radiographic assessment was completed in 485 individuals with celiac disease determined by positive serology and in 4,727 individuals with negative serology (without celiac disease). Compared to nonceliacs, seropositive participants were less likely to present with ≥15% radiographic bone loss (prevalence ratio (PR) 0.89 (95% CI 0.84-0.96). A similar association was also observed after histopathological confirmation of celiac disease (PR 0.89 (95% CI 0.82-0.98). No association between undiagnosed celiac disease and periodontal bone loss was observed when analyses were limited to individuals with severe bone loss (>33%).

Conclusion

In this study of previously undiagnosed celiac disease and periodontal bone loss, newly diagnosed celiac disease was associated with less likelihood of presenting with ≥15% radiographic bone loss compared to a nonceliac reference group.

Exploring the potential of human intestinal organoids: Applications, challenges, and future directions

The complex and dynamic environment of the gastrointestinal tract shapes one of the fastest renewing tissues in the human body, the intestinal epithelium. Considering the lack of human preclinical studies, reliable models that mimic the intestinal environment are increasingly explored. Patient-derived intestinal organoids are powerful tools that recapitulate in vitro many pathophysiological features of the human intestine. In this review, the possible applications of human intestinal organoids in different research fields are highlighted. From physiologically relevant to intestinal disease modeling, regenerative medicine, and toxicology studies, the potential of intestinal organoids will be here presented and discussed. Despite the remarkable opportunities offered, limitations related to ethical concerns, tissue collection, reproducibility, and methodologies may hinder the full exploitation of this cell-based model into high throughput studies and clinical practice. Currently, distinct approaches can be used to overcome the numerous challenges found along the way and to allow the full implementation of this ground-breaking technology.

Expression of MicroRNAs in Adults with Celiac Disease: A Narrative Review

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of proline- and glutamine-rich proteins, widely termed "gluten", in genetically susceptible individuals. CD induces an altered immune response that leads to chronic inflammation and duodenal mucosal damage. Currently, there are no specific tests for the accurate diagnosis of CD, and no drugs are available to treat this condition. The only available treatment strategy is lifelong adherence to a gluten-free diet. However, some studies have investigated the involvement of microRNAs (miRNAs) in CD pathogenesis. miRNAs are small noncoding ribonucleic acid molecules that regulate gene expression. Despite the growing number of studies on the role of miRNAs in autoimmune disorders, data on miRNAs and CD are scarce. Therefore, this study aimed to perform a literature review to summarize CD, miRNAs, and the potential interactions between miRNAs and CD in adults. This review shows that miRNA expression can suppress or stimulate pathways related to CD pathogenesis by regulating cell proliferation and differentiation, regulatory T-cell development, innate immune response, activation of the inflammatory cascade, focal adhesion, T-cell commitment, tissue transglutaminase synthesis, and cell cycle. Thus, identifying miRNAs and their related effects on CD could open new possibilities for diagnosis, prognosis, and follow-up of biomarkers.

Biopsy Proteome Score Performs Well as an Effect Measure in a Gluten Challenge Trial of Celiac Disease

BACKGROUND AND AIMS

Development of novel treatments for celiac disease is dependent on precise tools to monitor changes in gluten-induced mucosal damage. Current histology measures are subjective and difficult to standardize. Biopsy proteome scoring is an objective alternative to histology which is based on robust changes in biological pathways that directly reflect gluten-induced mucosal damage. In this study, we aimed to evaluate biopsy proteome scoring as an effect measure in a clinical trial setting by measuring intestinal remodeling in response to oral gluten challenge.

METHODS

We analyzed biopsies from a 14-day gluten challenge trial of treated celiac disease patients that consumed 3 g (n = 6) or 10 g (n = 7) gluten per day. Sections from individually embedded biopsies collected before and after challenge were processed for proteome scoring (n = 109) and measurement of villus height-to-crypt depth ratio (n = 58). Proteome scores were compared with histology, intraepithelial lymphocyte frequency and plasma interleukin-2.

RESULTS

Change in proteome scores were significant for the group of patients who consumed 10 g gluten, but not for the group who consumed 3 g gluten. Altogether, 8 of 13 patients had changes in delta proteome scores above the cutoff. Proteome scores correlated with villus height-to-crypt depth ratios both at run-in and at day 15. Proteome scores at day 15 correlated with intraepithelial lymphocyte frequency and with plasma interleukin-2 levels measured 4 hours post-gluten intake.

CONCLUSION

Biopsy proteome scoring is a simple and reliable measure of gluten-induced mucosal remodeling in response to 14-day oral gluten challenge.

CLINICALTRIALS

gov, Number: NCT03409796.

Association between celiac disease and fibromyalgia and their severity: a cross-sectional study

Background

Fibromyalgia (FMS) is a common musculoskeletal disorder with many causes. People with fibromyalgia often have the same symptoms as people with celiac disease (CD). Demonstration of the coordination and frequency of FMS and CD is important for effective treatment.

Methods

This is a single center cross-sectional clinical study. The study included 60 patients who were diagnosed with CD by the Gastroenterology Clinic based on American College of Gastroenterology (ACG) criteria. Patients were also asked to complete the Widespread Pain Index (WPI), Symptom Severity Scale (SSS), and Fibromyalgia Impact Questionnaire (FIQ) to diagnose fibromyalgia and assess its severity. The results were used to analyze the frequency of concomitance and relationship between the two diseases.

Results

The relationship between the clinical types of CD and the presence of fibromyalgia was insignificant. Analysis of the relationship between the pathologic typing of biopsy and fibromyalgia frequency was insignificant. Those with antibodies more frequently met criteria for fibromyalgia (P = 0.04, P = 0.04, respectively).

Conclusions

Presence of clinical extraintestinal manifestations in patients with CD should lead clinicians to consider FMS as a possible diagnosis. This points to the importance for clinicians in all subspecialties to be aware of the various symptoms and diseases associated with FMS.

The role of Killer immunoglobulin-like receptors (KIRs) in the genetic susceptibility to non-celiac wheat sensitivity (NCWS)

OBJECTIVES

Non-celiac wheat sensitivity (NCWS) is an emerging clinical condition characterized by gastrointestinal and extraintestinal symptoms following the ingestion of gluten-containing foods in patients without celiac disease (CD) or wheat allergy. Despite the great interest for NCWS, the genetic risk factors still need to be fully clarified. In this study, we first assessed the possible contribution of KIR genes and KIR haplotypes on the genetic predisposition to NCWS.

METHODS

Fifty patients with NCWS, 50 patients with CD, and 50 healthy controls (HC) were included in this study. KIR genes and KIR genotyping were investigated in all subjects by polymerase chain reaction with the sequence oligonucleotide probe (PCR-SSOP) method using Luminex technology.

RESULTS

We found a statistically different distribution of some KIR genes among NCWS, CD, and HC. Specifically, NCWS showed a decreased frequency of KIR2DL1, -2DL3, -2DL5, -2DS2, -2DS3, -2DS4, -2DS5, and -3DS1 genes, and an increased frequency of -3DL1 gene respect to both CD and HC. No difference was detected in the KIR haplotype expression. At the multivariate analysis, KIR2DL5, -2DS4, and -2DS5 were independent predictors of NCWS.

CONCLUSIONS

Our findings suggest a role of KIR genes in NCWS susceptibility, with KIR2DL5, -2DS4, and -2DS5 having a protective effect. Further large-scale multicentric studies are required to validate these preliminary findings.

Celiac Disease Deep Learning Image Classification Using Convolutional Neural Networks

Celiac disease (CD) is a gluten-sensitive immune-mediated enteropathy. This proof-of-concept study used a convolutional neural network (CNN) to classify hematoxylin and eosin (H&E) CD histological images, normal small intestine control, and non-specified duodenal inflammation (7294, 11,642, and 5966 images, respectively). The trained network classified CD with high performance (accuracy 99.7%, precision 99.6%, recall 99.3%, F1-score 99.5%, and specificity 99.8%). Interestingly, when the same network (already trained for the 3 class images), analyzed duodenal adenocarcinoma (3723 images), the new images were classified as duodenal inflammation in 63.65%, small intestine control in 34.73%, and CD in 1.61% of the cases; and when the network was retrained using the 4 histological subtypes, the performance was above 99% for CD and 97% for adenocarcinoma. Finally, the model added 13,043 images of Crohn's disease to include other inflammatory bowel diseases; a comparison between different CNN architectures was performed, and the gradient-weighted class activation mapping (Grad-CAM) technique was used to understand why the deep learning network made its classification decisions. In conclusion, the CNN-based deep neural system classified 5 diagnoses with high performance. Narrow artificial intelligence (AI) is designed to perform tasks that typically require human intelligence, but it operates within limited constraints and is task-specific.

The Humoral Immune Response against Human Endogenous Retroviruses in Celiac Disease: A Case-Control Study

BACKGROUND

Celiac disease (CD) is an immune-mediated disease characterized by disruptions of the small intestine. Factors such as viral and bacterial infections can trigger CD. Recently, the reactivation of Human Endogenous Retroviruses (HERVs) has also been implicated, but little is known about their specific role in patients with celiac disease.

METHODS

The purpose of this study is to explore the humoral immune response mounted against epitopes derived from the envelope portion of three families of HERVs (HERV-K, HERV-H, and HERV-W) in CD patients. Reactivity against the HERV-K, HERV-H, and HERV-W env-su peptides was tested by indirect ELISAs in plasma of 40 patients with celiac disease and 41 age-matched healthy subjects (HCs).

RESULTS

HERV-K, HERV-H, and HERV-W env-su peptides triggered different antibody responses in CD patients compared to HCs, with a stronger reactivity (p = 0.0001).

CONCLUSIONS

Present results show, for the first time, that epitopes of HERV-K, HERV-H, and HERV-W are more recognized in patients with CD. Taking into consideration their proinflammatory and autoimmune features, this might suggest that HERVs may contribute to the development of CD or its exacerbation in genetically predisposed subjects. Finally, to elucidate the interplay between gut inflammation and HERVs during the inflammatory process, further studies are required. Those investigations should focus on the expression levels of HERVs and their relationship with the immune response, specifically examining anti-transglutaminase 2 (TG2) antibody levels under both gluten-free and gluten-containing dietary conditions.

A human autoimmune organoid model reveals IL-7 function in coeliac disease

In vitro models of autoimmunity are constrained by an inability to culture affected epithelium alongside the complex tissue-resident immune microenvironment. Coeliac disease (CeD) is an autoimmune disease in which dietary gluten-derived peptides bind to the major histocompatibility complex (MHC) class II human leukocyte antigen molecules (HLA)-DQ2 or HLA-DQ8 to initiate immune-mediated duodenal mucosal injury1-4. Here, we generated air-liquid interface (ALI) duodenal organoids from intact fragments of endoscopic biopsies that preserve epithelium alongside native mesenchyme and tissue-resident immune cells as a unit without requiring reconstitution. The immune diversity of ALI organoids spanned T cells, B and plasma cells, natural killer (NK) cells and myeloid cells, with extensive T-cell and B-cell receptor repertoires. HLA-DQ2.5-restricted gluten peptides selectively instigated epithelial destruction in HLA-DQ2.5-expressing organoids derived from CeD patients, and this was antagonized by blocking MHC-II or NKG2C/D. Gluten epitopes stimulated a CeD organoid immune network response in lymphoid and myeloid subsets alongside anti-transglutaminase 2 (TG2) autoantibody production. Functional studies in CeD organoids revealed that interleukin-7 (IL-7) is a gluten-inducible pathogenic modulator that regulates CD8+ T-cell NKG2C/D expression and is necessary and sufficient for epithelial destruction. Furthermore, endogenous IL-7 was markedly upregulated in patient biopsies from active CeD compared with remission disease from gluten-free diets, predominantly in lamina propria mesenchyme. By preserving the epithelium alongside diverse immune populations, this human in vitro CeD model recapitulates gluten-dependent pathology, enables mechanistic investigation and establishes a proof of principle for the organoid modelling of autoimmunity.

Contemporary Perspectives on the Role of Vitamin D in Enhancing Gut Health and Its Implications for Preventing and Managing Intestinal Diseases

Vitamin D, a crucial fat-soluble vitamin, is primarily synthesized in the skin upon exposure to ultraviolet radiation and is widely recognized as a bone-associated hormone. However, recent scientific advancements have unveiled its intricate association with gut health. The intestinal barrier serves as a vital component, safeguarding the intestinal milieu and maintaining overall homeostasis. Deficiencies in vitamin D have been implicated in altering the gut microbiome composition, compromising the integrity of the intestinal mucosal barrier, and predisposing individuals to various intestinal pathologies. Vitamin D exerts its regulatory function by binding to vitamin D receptors (VDR) present in immune cells, thereby modulating the production of pro-inflammatory cytokines and influencing the intestinal barrier function. Notably, numerous studies have reported lower serum vitamin D levels among patients suffering from intestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, and celiac disease, highlighting the growing significance of vitamin D in gut health maintenance. This comprehensive review delves into the latest advancements in understanding the mechanistic role of vitamin D in modulating the gut microbiome and intestinal barrier function, emphasizing its pivotal role in immune regulation. Furthermore, we consolidate and present relevant findings pertaining to the therapeutic potential of vitamin D in the management of intestinal diseases.

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.

Association of LPP and ZMIZ1 Gene Polymorphism with Celiac Disease in Subjects from Punjab, Pakistan

Celiac disease (CD) is a complicated autoimmune disease that is caused by gluten sensitivity. It was commonly believed that CD only affected white Europeans, but recent findings show that it is also prevailing in some other racial groups, like South Asians, Caucasians, Africans, and Arabs. Genetics plays a profound role in increasing the risk of developing CD. Genetic Variations in non-HLA genes such as LPP, ZMIZ1, CCR3, and many more influence the risk of CD in various populations. This study aimed to explore the association between LPP rs1464510 and ZMIZ1 rs1250552 and CD in the Punjabi Pakistani population. For this, a total of 70 human subjects were selected and divided into healthy controls and patients. Genotyping was performed using an in-house-developed tetra-amplification refractory mutation system polymerase chain reaction. Statistical analysis revealed a significant association between LPP rs1464510 (χ2 = 4.421, p = 0.035) and ZMIZ1 rs1250552 (χ2 = 3.867, p = 0.049) and CD. Multinomial regression analysis showed that LPP rs1464510 A allele reduces the risk of CD by ~52% (OR 0.48, CI: 0.24-0.96, 0.037), while C allele-carrying subjects are at ~2.6 fold increased risk of CD (OR 3.65, CI: 1.25-10.63, 0.017). Similarly, the ZMIZ1 rs1250552 AG genotype significantly reduces the risk of CD by 73% (OR 0.26, CI: 0.077-0.867, p = 0.028). In summary, Genetic Variations in the LPP and ZMIZ1 genes influence the risk of CD in Punjabi Pakistani subjects. LPP rs1464510 A allele and ZMIZ1 AG genotype play a protective role and reduce the risk of CD.

SKELETAL HEALTH ASSESSMENT IN BRAZILIAN MEN WITH CELIAC DISEASE AT DIAGNOSIS: HOW IMPORTANT IS IT?

BACKGROUND

Low bone mass density (BMD) is an extraintestinal finding in celiac disease (CD). This may result in bone fractures leading to loss in quality of life.

OBJECTIVE

To assess BMD in male CD patients at diagnosis according to the patient's age.

METHODS

Descriptive retrospective carried out during the period between 2013 and 2023 in a single office that studied dual-energy X-ray absorptiometry (DXA) results in 28 male patients with a recent diagnosis of CD, divided into three groups: group 1 (age up to 18 years); group 2 (from 19 to 49 years of age) and group 3 (over 50 years of age). Were studied demographic and anthropometric parameters, time delay between symptoms onset and CD diagnosis and fracture occurrence.

RESULTS

Celiac patients studied had median age 36.0 years (IQR=16.5-50.7). Among them, 39.3% had osteopenia and 14.3% had osteoporosis. Only 36% of the sample had normal DXA values (group 1 with 37.5%; group 2 with 46% and group 3 with 14.2%). No pathological fracture was observed in this sample. CD diagnosis delay observed had median 1.0 year (IQR=1.0-4.7). When the number of individuals with normal and abnormal DXA results were compared, there was no difference in body mass index, time of diagnosis delay or Marsh classification (P=0.18).

CONCLUSION

Male patients at the time of CD diagnosis showed a high prevalence of low BMD, which was particularly evident in individuals over 50 years of age.

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.

Opportunities for Improving Biopsy and Non-Biopsy-Based Diagnosis of Celiac Disease

The accumulating data regarding a non-biopsy diagnosis of celiac disease has led to its adoption in certain scenarios, although debate on whether and when to use non-biopsy criteria in clinical practice is ongoing. Despite the growing popularity and evidence basis for a biopsy-free approach to diagnosis in the context of highly elevated serologies, there will continue to be a role for a biopsy in some groups. This review summarizes the current evidence supporting a non-biopsy approach and arguments supporting continued reliance on biopsy, and focuses on opportunities to improve both approaches.

New Insights on Genes, Gluten, and Immunopathogenesis of Celiac Disease

Celiac disease (CeD) is a gluten-induced enteropathy that develops in genetically susceptible individuals upon consumption of cereal gluten proteins. It is a unique and complex immune disorder to study as the driving antigen is known and the tissue targeted by the immune reaction can be interrogated. This review integrates findings gained from genetic, biochemical, and immunologic studies, which together have revealed mechanisms of gluten peptide modification and HLA binding, thereby enabling a maladapted anti-gluten immune response. Observations in human samples combined with experimental mouse models have revealed that the gluten-induced immune response involves CD4+ T cells, cytotoxic CD8+ T cells, and B cells; their cross-talks are critical for the tissue-damaging response. The emergence of high-throughput technologies is increasing our understanding of the phenotype, location, and presumably function of the gluten-specific cells, which are all required to identify novel therapeutic targets and strategies for 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.

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.

Narrow-band imaging for optical diagnosis of duodenal villous atrophy in patients with suspected coeliac disease: A systematic review and meta-analysis

BACKGROUND

Narrow-band imaging (NBI) is a readily accessible imaging technique that enhances mucosal visualisation, allowing for a more accurate assessment of duodenal villi. However, its role in the diagnosis of coeliac disease (CD) in clinical practice remains limited.

METHODS

We systematically searched several databases in June 2023 for studies evaluating the diagnostic accuracy of NBI for detecting duodenal villous atrophy (VA) in patients with suspected CD. We calculated the summary sensitivity, specificity, and likelihood ratios using a bivariate random-effects model. The study followed PRISMA guidelines and was registered at PROSPERO (CRD42023428266).

RESULTS

A total of 6 studies with 540 participants were included in the meta-analysis. The summary sensitivity of NBI to detect VA was 93% (95% CI, 81% - 98%), and the summary specificity was 95% (95% CI, 92% - 98%). The area under the summary receiver operating characteristic curve was 0.98 (95% CI, 96 - 99). The positive and negative predictive values of NBI were 94% (95% CI, 92% - 97%) and 92% (95% CI, 90% - 94%), respectively.

CONCLUSION

NBI is an accurate non-invasive tool for identifying and excluding duodenal VA in patients with suspected CD. Further studies using a validated classification are needed to determine the optimal role of NBI in the diagnostic algorithm for CD.

Tolerance-inducing therapies in coeliac disease - mechanisms, progress and future directions

Coeliac disease is an autoinflammatory condition caused by immune reactions to cereal gluten proteins. Currently, the only available treatment for the condition is a lifelong avoidance of gluten proteins in the diet. There is an unmet need for alternative therapies. Coeliac disease has a strong association with certain HLA-DQ allotypes (DQ2.5, DQ2.2 and DQ8), and these disease-associated HLA-DQ molecules present deamidated gluten peptides to gluten-specific CD4+ T cells. The gluten-specific CD4+ T cells are the drivers of the immune reactions leading to coeliac disease. Once established, the clonotypes of gluten-specific CD4+ T cells persist for decades, explaining why patients must adhere to a gluten-free diet for life. Given the key pathogenic role of gluten-specific CD4+ T cells, tolerance-inducing therapies that target these T cells are attractive for treatment of the disorder. Lessons learned from coeliac disease might provide clues for treatment of other HLA-associated diseases for which the disease-driving antigens are unknown. Thus, intensive efforts have been and are currently implemented to bring an effective tolerance-inducing therapy for coeliac disease. This Review discusses mechanisms of the various approaches taken, summarizing the progress made, and highlights future directions in this field.

Path Towards Biopsy-Free Diagnosis of Celiac Disease in Pediatric Patients

BACKGROUND

Laboratory testing for celiac disease in pediatric patients integrates serology, genetic susceptibility and duodenal biopsy examination. The 2023 American College of Gastroenterology guidelines recommend a biopsy-free approach in pediatric patients utilizing tissue transglutaminase antibody titers >10 times upper limit of normal and subsequent endomysial antibody seropositivity as sufficient for diagnosis. The objective of this study is to assess the diagnostic accuracy of biopsy-free approach at our pediatric hospital.

METHODS

We conducted a retrospective study involving pediatric patients who underwent biopsy for diagnostic confirmation of celiac disease between May 2019 and May 2023. For these patients, the tissue transglutaminase and endomysial antibody test results were retrieved and performance of biopsy-free approach was assessed using the duodenal histology as the gold standard for celiac disease diagnosis.

RESULTS

Tissue transglutaminase antibody titers >10 times upper limit of normal alone demonstrated a positive predictive value of 99% for identifying celiac disease in children. Although endomysial antibody testing is underutilized at our center, its inclusion further improved the predictability to 100 %.

CONCLUSION

Positive predictive value of tissue transglutaminase antibody titers >10 times upper limit of normal is sufficiently high for celiac disease diagnosis in children and may allow for deferral of duodenal biopsy at diagnosis.

Vascular dysfunction and arterial hypertension in experimental celiac disease are mediated by gut-derived inflammation and oxidative stress

AIMS

We examined the cardiovascular effects of celiac disease (CeD) in a humanized mouse model, with a focus on vascular inflammation, endothelial dysfunction, and oxidative stress.

METHODS AND RESULTS

NOD.DQ8 mice genetically predisposed to CeD were subjected to a diet regime and oral gavage to induce the disease (gluten group vs. control). We tested vascular function, confirmed disease indicators, and evaluated inflammation and oxidative stress in various tissues. Plasma proteome profiling was also performed. CeD markers were confirmed in the gluten group, indicating increased blood pressure and impaired vascular relaxation. Pro-inflammatory genes were upregulated in this group, with increased CD11b+ myeloid cell infiltration and oxidative stress parameters observed in aortic and heart tissue. However, heart function remained unaffected. Plasma proteomics suggested the cytokine interleukin-17A (IL-17A) as a link between gut and vascular inflammation. Cardiovascular complications were reversed by adopting a gluten-free diet.

CONCLUSION

Our study sheds light in the heightened cardiovascular risk associated with active CeD, revealing a gut-to-cardiovascular inflammatory axis potentially mediated by immune cell infiltration and IL-17A. These findings augment our understanding of the link between CeD and cardiovascular disease providing clinically relevant insight into the underlying mechanism. Furthermore, our discovery that cardiovascular complications can be reversed by a gluten-free diet underscores a critical role for dietary interventions in mitigating cardiovascular risks associated with CeD.

Gluten-related Disorders From Bench to Bedside

Celiac disease, non-celiac gluten sensitivity, and wheat allergy comprise 3 of the main conditions with wheat- and gluten-containing foods as the symptom trigger. Distinguishing between these entities can be daunting. In this review, we compare and contrast celiac disease, non-celiac gluten sensitivity, and wheat allergy to allow clinicians to determine which diagnosis fits their patient to facilitate high-quality management and longitudinal care.

The effect of adding wheat and corn gluten to the diet of rats on the autoimmune and histopathological parameters in the intestine and liver

This study investigated the histopathological and immunohistochemical effect on the intestine and liver tissues with addition of the soybean meal (SBM), wheat Gluten meal (WGM) and Corn gluten meal (CGM) to rat diet. A total of 24 average twenty–day–old male rats (Wistar albino) were used in the study. The rats were randomly divided into 3 groups with 8 animals in each group (Control, Wheat and Corn groups). The diet provided to all three groups contained proteins, which were SBM, WGM and CGM in the Control, Wheat and Corn groups, respectively. In the study, the group fed with SBM was used as the Control group. Rats were fed a diet containing 22% crude protein and 2,598 kcal·kg-1 metabolic energy throughout the experimental period. The feeding trial was continued for a period of 50 days. Degenerative changes of varying severity in intestinal epithelial cells and atrophy in villi were observed. Similarly, the degenerative changes, especially vacuolar or hydropic degeneration were determined in hepatocytes. It was determined that the CD4 level were statistically significantly increased in the Wheat and Corn groups compared to the Control group (P<0.01) on intestine tissue. Also, it was determined that the IgA level was statistically significantly increased of the Wheat and Corn groups in liver tissue. (P<0.05). As a result, it was observed that the histopathological and immunohistochemical parameters of the intestine and liver tissues of the rats fed with diets containing highly WGM and CGM were limitedly affected.

Guidelines for best practices in monitoring established coeliac disease in adult patients

Coeliac disease (CeD) is an immunological disease triggered by the consumption of gluten contained in food in individuals with a genetic predisposition. Diagnosis is based on the presence of small bowel mucosal atrophy and circulating autoantibodies (anti-type 2 transglutaminase antibodies). After diagnosis, patients follow a strict, life-long gluten-free diet. Although the criteria for diagnosis of this disease are well defined, the monitoring phase has been studied less and there is a lack of specific guidelines for this phase. To develop a set of clinical guidelines for CeD monitoring, we followed the Grading of Recommendations Assessment, Development and Evaluation methodology. Statements and recommendations with the level of evidence were developed and approved by the working group, which comprised gastroenterologists, pathologists, dieticians and biostatisticians. The proposed guidelines, endorsed by the North American and European coeliac disease scientific societies, make recommendations for best practices in monitoring patients with CeD based on the available evidence. The evidence level is low for many topics, suggesting that further research in specific aspects of CeD would be valuable. In conclusion, the present guidelines support clinicians in improving CeD treatment and follow-up and highlight novel issues that should be considered in future studies.

Concerns about the histological assessment in a mouse model of human celiac disease

Commentary on: Abadie V et al. IL‐15, gluten and HLA‐DQ8 drive tissue destruction in coeliac disease. Nature. 2020; 578: 600‐604

Prevalence of coeliac disease in patients with systemic lupus erythematosus: a systematic review and meta-analysis

BACKGROUND

There is some evidence of a higher prevalence of coeliac disease (CD) among patients with SLE than in the general population. However, the prevalence estimates vary substantially.

OBJECTIVE

To investigate the prevalence of CD among patients with SLE through systematic review and meta-analysis.

METHODS

We performed searches in the databases of Medline, Embase, Cochrane and Web of Science Core Collection between 1 January 1990 and 9 July 2023. A total of 2053 publications were rendered in the searches, of which 68 were reviewed in full text and 14 included in the analyses. Primary analysis estimated the pooled prevalence of biopsy-verified CD in patients with SLE. In the secondary analysis, the prevalence of serological markers indicative of CD was investigated. The quality of studies was appraised using the Joanna Briggs Institute Critical Appraisal Tool. We conducted meta-regression analyses to investigate associations between the prevalence of CD in individuals with SLE and publication year, study population size, CD prevalence in the general population, proportion of females and quality assessment score.

RESULTS

A total of 14 studies met the inclusion criteria, of which 11 were included in the primary analysis of biopsy-verified CD. Among 1238 patients with SLE, 14 had CD. The weighted pooled prevalence of CD was 0.7% (95% CI 0.0 to 1.8). The weighted pooled prevalence of CD serological markers in 1063 patients with SLE was 3.7% (95% CI 1.4 to 6.7). In meta-regression analyses, no associations between CD prevalence and study characteristics, demographics and quality assessment scores were found.

CONCLUSIONS

In this meta-analysis, we found a weighted pooled prevalence of biopsy-verified CD in patients with SLE comparable with the prevalence in the general population. Our findings do not support routine screening for CD in patients with SLE. However, individual screening could be considered in cases of clinical suspicion and additional risk factors for CD.

PROSPERO REGISTRATION NUMBER

CRD42022339594.

Clinical and Pathological Correlation in Concomitant Celiac Disease and Eosinophilic Esophagitis Suggests Separate Etiologies

Introduction. Recently, an increased risk of celiac disease or eosinophilic esophagitis has been postulated among patients with either of these disorders, prompting some to suggest a common underlying mechanism, whereas others maintain that their co-existence is coincidental. Methods. We compared clinical and pathological features of 29 patients meeting criteria for both celiac disease and eosinophilic esophagitis to 26 celiac disease and 26 eosinophilic esophagitis controls to determine whether any distinguished study patients from controls. Results. Eight (28%) study patients presented with symptoms of both celiac disease and eosinophilic esophagitis, whereas 14 (48%) had celiac disease symptoms only and 5 had (17%) esophageal symptoms only. Study patients had similar autoimmune and atopic conditions seen in both control groups. Histological severity of disease, including Marsh II-III duodenal histology (study specimens: 87%; controls: 89%), mean peak esophageal eosinophil counts (study specimens: 55/400x field; controls: 80/400X field, P = .1), and presence of eosinophil microabscesses, scale crust, and subepithelial fibrosis were also similar to controls. Gluten-free diet resolved celiac disease-related symptoms (19 of 20, 95%) and histology (10 of 12, 83%), but not esophageal symptoms or eosinophilia in most study patients. Conclusion. Patients with concomitant celiac disease and eosinophilic esophagitis lack distinguishing features compared to controls with celiac disease or eosinophilic esophagitis alone. The occurrence of both disorders is likely coincidental in most cases.

A tip-predominant distribution of villous intraepithelial lymphocytes is not specific to celiac disease in children with Marsh I lesions

OBJECTIVES

To assess if the distribution of villous intraepithelial lymphocytes (IELs) in a pediatric cohort with Marsh I histopathology is specific to celiac disease (CeD).

METHODS

Multicenter, retrospective case-control study between January 2001 and December 2019 in children (<18 years) with and without CeD with intraepithelial lymphocytosis and normal villous architecture. Pathology specimens were reviewed by 2 study pathologists who were blinded to the final diagnosis. Morphologic features (villous height to crypt depth ratio [Vh:Cd]) and IELs in the villous tip, top, or bottom half of the villus were quantified.

RESULTS

Of the 97 children with Marsh I histopathology identified during the study period, 63 were excluded due to an insufficient number of well-oriented villous-crypt complexes or a Vh:Cd less than 2. Villous IELs were measured in 34 cases (14 CeD, 20 non-CeD controls). There was no difference between the non-CeD and CeD groups in the mean IELs at the villous tip (14.0 ± 7.1 vs 11.7 ± 6.0, P = .31), top (46.4 ± 18.4 vs 38.3 ± 10.8, P = .11), or bottom (29.8 ± 16.8 vs 28.5 ± 12.8, P = .80) half of each villus, respectively.

CONCLUSIONS

The distribution of IELs in Marsh I lesions is not specific for CeD.

Predicting wheat gluten concentrations in potato starch using GPR and SVM models built by terahertz time-domain spectroscopy

The purpose of this study was for the first time to explore the feasibility of terahertz (THz) spectral imaging for the detection of gluten contents in food samples. Based on the obtained 80 THz spectrum data, Gaussian process regression (GPR) and support vector machine (SVM) models were established to predict wheat gluten concentrations in 40 potato starch mixture samples. The prediction performances of GPR and SVM obtained were R2 = 0.859 and RMSE = 0.070, and R2 = 0.715 and RMSE = 0.101 in the gluten concentration range of 1.3%-100%, respectively, showing that the linear SVM algorithm had better prediction performance. The results indicated that THz spectral imaging combined with GPR could be used to predict the gluten content in food samples. It is thus hoped that this research should provide a novel technique for gluten content detection to ensure gluten-free food samples.

Diagnosis, Clinical Presentation and Management of Celiac Disease in Children and Adolescents in Poland

Celiac disease (CD) is a chronic immune-mediated disorder triggered by the ingestion of gluten in genetically predisposed individuals, affecting about 1% of the general population in the developed world. In 2012, the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) recommendations for CD diagnoses in children and adolescents were introduced, allowing the "no-biopsy" approach if certain criteria were met. This approach was also confirmed in the revised guidelines published in 2020. Thus, the aim of this study was to assess-over a one-year period-the clinical presentations and current status of the management of children and adolescents diagnosed with CD in Poland. Medical records of children and adolescents, newly diagnosed with CD in 2022/2023 in three medical centers in Poland, were involved. Gastroenterologists completed the specific anonymous web-based forms developed in the CD SKILLS project, including data routinely assessed at individual visits about the diagnostic approach and clinical presentation of the disease. Our study assessed 100 patients (56% girls) with an age range 1.6-18.0 years. We found that 98% of patients were serologically tested prior to a CD diagnosis and 58% of patients were diagnosed using the "no-biopsy" approach. In the analyzed group, 40% belonged to a known risk group, only 22% had annual screening before the CD diagnosis (the longest for 9 years), and 19% showed no symptoms at the time of the CD diagnosis. Our research confirmed the applicability of the "no-biopsy" approach for the diagnosis of CD in children and adolescents in Poland, and also showed changes in the clinical picture of CD. Moreover, we highlight the need to introduce broad CD serological screening in risk groups of the Polish population.

Expression of Elafin and CD200 as Immune Checkpoint Molecules Involved in Celiac Disease

We comprehensively evaluated the expression of therapeutically targetable immune checkpoint molecules involved in celiac disease (CD). We have focused on the alteration of the CD200/CD200R pathway and Elafin expression in celiac disease and discussed their roles in regulating the immune response. There are limited data related to the expression or function of these molecules in celiac disease. This finding could significantly contribute to the understanding of the clinical manifestation of CD. CD200, CD200R and Elafin distributions were determined by ELISA and immunohistochemistry analyses in serum and biopsies of CD patients. Analyses of Th1 and Th17 cytokines were determined. PCR amplification of a fragment of the PI3 gene was carried out using genomic DNA isolated from whole blood samples of the study subjects. Different aliquots of the PCR reaction product were subjected to RFLP analysis for SNP genotyping and detection. We characterized the expression and function of the CD200-CD200R axis and PI3 in celiac disease. A significantly higher level of soluble CD200 and CD200R and lower expression of PI3 in serum of CD patients was observed compared to healthy controls. Consistent with our results, CD200 expression is regulated by IFN-gamma. Interaction of CD200/CD200R leads to production of type-Th1 and -Th17 cytokines. Regarding the PI3 genotype, the CT genotype proportion SNP rs1733103 and the GG genotype SNP rs41282752 were predominant in CD patients. SNP rs1733103 showed a significant association between the SNP variables and CD. In celiac disease the immune checkpoint is compromised or dysregulated, which can contribute to inflammation and the autoimmunity process. The study of these checkpoint points will lead to the development of targeted therapies aimed at restoring immunological balance in CD. Specific coding regions of the PI3 gene-splice variants predispose the Elafin protein, both at the transcriptional and post-translational levels, to modify its expression and function, resulting in reduced differential functional protein levels in patients with active celiac disease.

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.

A Population-Based Cross-Sectional Study of Paediatric Coeliac Disease in Catalonia Showed a Downward Trend in Prevalence Compared to the Previous Decade

(1) Background: Previous studies showed an increased prevalence and incidence of coeliac disease (CD) over time. The objective is to ascertain whether the CD prevalence in Catalonia (a region of Southern Europe) among children aged 1-5 is as high as previously found in 2004-2009; (2) Methods: From 2013 to 2019, 3659 subjects aged 1-5 years were recruited following the previously used methodology. Factors with a potential impact on CD prevalence were investigated; (3) Results: In 2013-2019, 43/3659 subjects had positive serology, giving a standardised seroprevalence of 12.55/1000 (95% CI: 8.92; 17.40), compared to 23.62 (13.21; 39.40) in 2004-2007. The biopsy-proven crude prevalence was 7.92/1000 (95% CI: 5.50; 11.30), and the crude prevalence based on ESPGHAN criteria was 8.74/1000 (95% CI: 6.20-12.30). In contrast to 2004-2009, we did not find differences in the seroprevalence rates between 1 and 2 years vs. 3 and 4 years of age (age percentage of change -7.0 (-29.5; 22.8) vs. -45.3 (-67.5; -8.0)). Rotavirus vaccination was the most remarkable potential protective factor (48% vs. 9% in 2004-2009; p < 0.0001), but not the time of gluten introduction. (4) Conclusion: The present study did not confirm a worldwide CD prevalence increase and emphasizes the need to perform prevalence studies over time using the same methodology in the same geographical areas.

Clinical and demographic comparison of celiac disease diagnosed during adulthood versus childhood and adolescence: A single-center experience

Background and Aim

Celiac disease (CeD) is mainly reported from the northern and western parts of India. In central India, it is believed to be a disease of children, with limited data among adults diagnosed for the first time after the age of 18 years. Hence, we aimed to describe CeD's clinical and demographic features among adults and children/adolescents in central India.

Methods

This is a retrospective analysis of a prospectively maintained database of all patients diagnosed for CeD from 2010 to 2019. The disease in adults was confirmed when symptoms developed for the first time after 18 years and had positive anti-transglutaminase antibodies with villous atrophy on duodenal biopsy. It was compared with pediatric patients with CeD diagnosed during the same time period.

Results

Of the 170 patients diagnosed with CeD, 118 were adults and 52 were children or adolescents. The mean age of presentation of adult CeD was 37.3 ± 11.93 years, while in the pediatric and adolescent group it was 9.19 ± 5.4 years. Classical presentation with chronic, painless, small-bowel-type diarrhea was seen in 44.1% of adults compared to 57.7% in the pediatric age group. Among the adult patients, 55.9% presented with nonclassical symptoms, which included abdominal pain (40.7%) and weight loss (36.4%). The common presenting symptom in children other than diarrhea was weight loss (50%) and abdominal pain (34.6%).

Conclusion

CeD is common in central India, with an increasing number of patients being diagnosed for the first time after 18 years of age and presenting more often with nonclassical symptoms.

Celiac Disease in Moroccan Children: Diagnostic Characteristics and Determinants of Diagnosis Delay

Advances in the field of celiac disease have led to a better understanding of the disease, but it remains underdiagnosed and poses a daily challenge to clinicians to make a timely diagnosis. This study aims to analyze and describe diagnosis characteristics, diagnosis delay, and the factors influencing this delay in Moroccan children. Our study included 324 children diagnosed during the study period from January 01, 2010, to December 30, 2019, at the Department of Pediatrics, Hassan II University Hospital in Fez, Morocco. Data were collected using a collection grid and then analyzed using SPSS 26 software (IBM Corp., Armonk, NY). The results showed a female predominance (n=197, 60.8%), with a diagnosis age of 73.8±46.8 months. The mean age onset of symptoms was 51.3±41.2 months, and the diagnosis delay was 22.2±22.6 months, with only 32.7% (n=106) diagnosed less than 12 months after symptom onset. The most common consultation reason was diarrhea (n=149, 46%) and growth delay (n=105, 32.4%) and 50.5% (n=98) of parents consulted a pediatrician first. The three clinical, serologic, and histologic criteria made it possible to agree on the diagnosis, with the clinical profile dominated by the digestive form at 84.9% (n=279), serologic with the presence of IgA transglutaminase antibodies (95.7%; n=310), and histologic with villous atrophy at 91.7% (n=297). Unfortunately, 14.8% (n=48) of the children were diagnosed with a celiac crisis. The multivariate logistic regression analysis showed that as symptoms onset age increased, so did the risk of late diagnosis (OR=0.96, 95% CI: 0.94 to 0.97, p<0.001). Age of diagnosis was also associated with delayed diagnosis (OR=19.68, 95% CI: 8.77 to 44.15, p<0.001). The combination of these variables and the diagnosis delay argues in favor of adopting a diagnosis strategy that includes raising awareness among healthcare professionals of the need to identify typical and atypical cases early in order to reduce the adverse effects of late diagnosis and the complications that can result. This methodology for improving diagnoses may also unearth previously unknown aspects of celiac disease in Moroccan children.

Celiac disease: mechanisms and emerging therapeutics

Celiac disease (CeD) is a widespread, gluten-induced, autoimmune disorder that lacks any medicinal therapy. Towards the goal of developing non-dietary treatments for CeD, research has focused on elucidating its molecular and cellular etiology. A model of pathogenesis has emerged centered on interactions between three molecular families: specific class II MHC proteins on antigen-presenting cells (APCs), deamidated gluten-derived peptides, and T cell receptors (TCRs) on inflammatory CD4+ T cells. Growing evidence suggests that this pathogenic axis can be pharmacologically targeted to protect patients from some of the adverse effects of dietary gluten. Further studies have revealed the existence of additional host and environmental contributors to disease initiation and tissue damage. This review summarizes our current understanding of CeD pathogenesis and how it is being harnessed for therapeutic design and development.

Specific T-cell receptor beta-rearrangements of gluten-triggered CD8+ T-cells are enriched in celiac disease patients' duodenal mucosa

Celiac disease (CeD) is an autoimmune disorder affecting the small intestine with gluten as disease trigger. Infections including Influenza A, increase the CeD risk. While gluten-specific CD4+ T-cells, recognizing HLA-DQ2/DQ8 presented gluten-peptides, initiate and sustain the celiac immune response, CD8+ α/β intraepithelial T-cells elicit mucosal damage. Here, we subjected TCRs from a cohort of 56 CeD patients and 22 controls to an analysis employing 749 published CeD-related TCRβ-rearrangements derived from gluten-specific CD4+ T-cells and gluten-triggered peripheral blood CD8+ T-cells. We show, that in addition to TCRs from gluten-specific CD4+ T-cells, TCRs of gluten-triggered CD8+ T-cells are significantly enriched in CeD duodenal tissue samples. TCRβ-rearrangements of gluten-triggered CD8+ T-cells were even more expanded in patients than TCRs from gluten-specific CD4+ T-cells (p < 0.0002) and highest in refractory CeD. Sequence alignments with TCR-antigen databases suggest that a subgroup of these most likely indirectly gluten-triggered TCRs recognize microbial, viral, and autoantigens.

Serum anti-tissue transglutaminase IgA and prediction of duodenal villous atrophy in adults with suspected coeliac disease without IgA deficiency (Bi.A.CeD): a multicentre, prospective cohort study

BACKGROUND

Whether coeliac disease in adults can be diagnosed with serology alone remains controversial. We aimed to evaluate the accuracy of serum anti-tissue transglutaminase IgA (tTG-IgA) in the diagnosis of coeliac disease.

METHODS

In this multicentre, prospective cohort study, adult participants (aged ≥18 years) with suspected coeliac disease without IgA deficiency who were not on a gluten-free diet and who had a local serum tTG-IgA measurement, were enrolled from Feb 27, 2018, to Dec 24, 2020, by 14 tertiary referral centres (ten from Europe, two from Asia, one from Oceania, and one from South America) to undergo local endoscopic duodenal biopsy. Local serum tTG-IgA was measured with 14 different test brands and concentration expressed as a multiple of each test's upper limit of normal (ULN), and defined as positive when greater than 1 times the ULN. The main study outcome was the reliability of serum tests for the diagnosis of coeliac disease, as defined by duodenal villous atrophy (Marsh type 3 or Corazza-Villanacci grade B). Histology was evaluated by the local pathologist, with discordant cases (positive tTG-IgA without duodenal villous atrophy or negative tTG-IgA with duodenal villous atrophy) re-evaluated by a central pathologist. The reliability of serum tests for the prediction of duodenal villous atrophy was evaluated according to sensitivity, specificity, positive predictive value, negative predictive value, and the area under the receiver operating characteristic curve (AUC) for categorical and continuous data.

FINDINGS

We enrolled 436 participants with complete local data on serum tTG-IgA and duodenal histology (296 [68%] women and 140 [32%] men; mean age 40 years [SD 15]). Positive serum tTG-IgA was detected in 363 (83%) participants and negative serum tTG-IgA in 73 (17%). Of the 363 participants with positive serum tTG-IgA, 341 had positive histology (true positives) and 22 had negative histology (false positives) after local review. Of the 73 participants with negative serum tTG-IgA, seven had positive histology (false negatives) and 66 had negative histology (true negatives) after local review. The positive predictive value was 93·9% (95% CI 89·2-98·6), the negative predictive value was 90·4% (85·5-95·3), sensitivity was 98·0% (95·3-100·0), and specificity was 75·0% (66·6-83·4). After central re-evaluation of duodenal histology in 29 discordant cases, there were 348 true positive cases, 15 false positive cases, 66 true negative cases, and seven false negative cases, resulting in a positive predictive value of 95·9% (92·0-99·8), a negative predictive value of 90·4% (85·5-95·3), a sensitivity of 98·0% (95·3-100·0), and a specificity of 81·5% (73·9-89·1). Either using the local or central definition of duodenal histology, the positive predictive value of local serum tTG-IgA increased when the serological threshold was defined at increasing multiples of the ULN (p<0·0001). The AUC for serum tTG-IgA for the prediction of duodenal villous atrophy was 0·87 (95% CI 0·81-0·92) when applying the categorical definition of serum tTG-IgA (positive [>1 × ULN] vs negative [≤1 × ULN]), and 0·93 (0·89-0·96) when applying the numerical definition of serum tTG-IgA (multiples of the ULN). Additional endoscopic findings included peptic gastritis (nine patients), autoimmune atrophic gastritis (three), reflux oesophagitis (31), gastric or duodenal ulcer (three), and Barrett's oesophagus (one). In the 1-year follow-up, a midgut ileum lymphoma was diagnosed in a woman on a gluten-free diet.

INTERPRETATION

Our data showed that biopsy could be reasonably avoided in the diagnosis of coeliac disease in adults with reliable suspicion of coeliac disease and high serum tTG-IgA.

FUNDING

None.

Relationship between gluten availability and celiac disease prevalence: A geo-epidemiologic systematic review

Celiac disease is a global disease requiring genetic susceptibility and gluten exposure to trigger immune-mediated enteropathy. The effect of the degree of gluten-containing grain availability on celiac disease prevalence is unknown. Our objective was to compare country-based gluten availability to celiac prevalence using a systematic literature review. We searched MEDLINE, Embase, Cochrane, and Scopus until May 2021. We included population-based serum screening with confirmatory testing (second serological study or small intestine biopsy) and excluded specific, high-risk, or referral populations. We determined country-specific gluten availability using the United Nations food balance for wheat, barley, and rye. Human leukocyte antigen (HLA) frequencies were obtained from allelefrequencies.net. The primary outcome was association between gluten-containing grain availability and celiac disease prevalence. Generalized linear mixed models method with Poisson's link was used for analysis. We identified 5641 articles and included 120 studies on 427 146 subjects from 41 countries. Celiac disease prevalence was 0-3.1%, median 0.75% (interquartile range 0.35, 1.22). Median wheat supply was 246 g/capita/day (interquartile range 214.8, 360.7). The risk ratio (RR) for wheat availability on celiac disease was 1.002 (95% confidence interval [CI]: 1.0001, 1.004, P = 0.036). A protective association was seen with barley, RR 0.973 (95% CI: 0.956, 0.99, P = 0.003), and rye, RR 0.989 (95% CI: 0.982, 0.997, P = 0.006). The RR for gross domestic product on celiac disease prevalence was 1.009 (95% CI: 1.005, 1.014, P < 0.001). The RR for HLA-DQ2 was 0.982 (95% CI: 0.979, 0.986, P < 0.001), and that for HLA-DQ8 was 0.957 (95% CI: 0.950, 0.964, P < 0.001). In this geo-epidemiologic study, gluten-containing grain availability showed mixed associations with celiac disease prevalence.

Study of the immune response in celiac patients with selective IgA deficiency who start a gluten-free diet

Studies are scarce regarding IgG anti-tissue transglutaminase 2 (tTG) normalization in selective IgA deficient (SIgAD) celiac disease (CD) patients after beginning a gluten free diet (GFD). The aim of this study is to analyse the decreasing dynamics of IgG anti-tTG in patients diagnosed with CD who start a GFD. To achieve this objective, IgG and IgA anti-tTG levels at diagnosis and during follow-up in 11 SIgAD CD patients and in 20 IgA competent CD patients were retrospectively evaluated. At diagnosis, statistical differences were not found when comparing IgA anti-tTG levels of IgA competent subjects with IgG anti-tTG levels of SIgAD subjects. Regarding the decreasing dynamics, even though no statistical differences were found (p = 0.06), normalization rates were slower for SIgAD CD patients. After 1 and 2 years on GFD, respectively, only 18.2% and 36.3% of the SIgAD CD patients normalized IgG anti-tTG levels; otherwise, IgA anti-tTG reached values under the reference values in 30% and 80% of the IgA competent patients in the same time-points. Although IgG anti-tTG has demonstrated a high diagnostic efficiency in SIgAD CD pediatric patients, this test does not appear to be as precise for long-term GFD response monitoring as IgA anti-tTG levels in IgA sufficient patients.

Pathological Manifestations of Gluten-Related Neuro-Psychiatric Disorders and the Impact of Gluten-Free Diet in a Pediatric Age Group: A Systematic Review

Gluten, as a term, causes unease among a vast majority of the population. The reason is the body's inability to process gluten, causing various pathological manifestations. While celiac disease is predominantly a gastrointestinal disease, it also has various extra-intestinal manifestations. Many children receive diagnoses of idiopathic neuropsychiatric symptoms such as epilepsy, attention-deficit hyperactivity disorder (ADHD), restless leg syndrome (RLS), and peripheral neuropathy without ever finding the root cause. A majority of these cases may be associated with celiac disease if only their antibody titers and other appropriate investigations were conducted. The treatment of these manifestations may be eliminated or at least controllable with dietary modification to a gluten-free diet (GFD). In this paper, we will discuss the pathology of celiac disease and the impact of GFD on the neuropsychiatric aspects of this disease, which is of higher prevalence in the pediatric population. A comprehensive literature search was conducted in prominent databases, namely PubMed and Google Scholar, to include studies that provided individual-level data on the neuropathological manifestations and the impact of a GFD on extra-intestinal manifestations of celiac disease. The research protocol was registered in the PROSPERO database (International Prospective Register of Systematic Reviews) with the registration ID: CRD42023415100. Based on the inclusion and exclusion criteria, we included prospective studies, observational studies, and case reports on pediatric patients with biopsy-proven celiac disease, serologically positive celiac disease, celiac disease with neuropsychiatric manifestations, and studies reporting the impact of GFD. After a rigorous quality assessment to remove the risk of bias, we finally included 20 studies to be discussed.  In 6 (30%) studies, patients with neuropsychiatric manifestations had positive serology findings and a relatively higher grade of biopsy results. Seven studies discussed the positive impact of GFD. Five of these seven studies reported statistically significant results (p ≤ 0.001). Our study suggests that gluten plays a role in the severity of neuropsychiatric manifestations of celiac disease. Considering the results of our study, we can see that GFD does impact the prognosis of the disease. Neuropsychiatric findings without gastrointestinal manifestations are more common in the pediatric age group. We have clear evidence that several neurological conditions (neuropathy, ADHD, epilepsy, and RLS) have not only a significant association with gluten but can also potentially benefit from GFD. Thus, screening, with a combination of serological, biopsy, and imaging techniques, must be adapted into the guidelines for early detection and induction of GFD. Furthermore, studies should aim at introducing GFD in the pediatric population as a mode of primary prevention. In conclusion, our review underscores the importance of gluten while dealing with idiopathic neurological conditions in children and hopes to shed light on this commonly misdiagnosed and easily manageable disease.

More Than Three Years for Normalisation of Routine Laboratory Values after Gluten Withdrawal in Paediatric Coeliac Patients

The assessment of the nutritional and inflammatory status of paediatric patients with coeliac disease is an interesting approach to early diagnosis and functional follow-up. Most authors agree that the normalisation of symptoms takes about one year. The aim of the study was to evaluate the clinical manifestation and normalisation of routine analytics in Spanish children diagnosed with celiac disease.

METHODS

We performed a retrospective case-control study in Spanish paediatric patients, including 21 celiac patients and 20 healthy controls. The 21 patients selected in the case-control study were followed for 5 years after starting a gluten-free diet (GFD). All patients had type 3 villous atrophy according to the Marsh-Oberhuber classification. A total of 39 blood samples were taken before the start of the GFD, and 109 were taken after. Twenty control sera from healthy donors were used for comparison.

RESULTS

We found that patients had a subclinical but statistically significant increase in blood calcium, transaminases, and white blood cells, and a decrease in serum iron, at the time of diagnosis. Our study also shows that analytical values normalise within five years on a gluten-free diet.

CONCLUSIONS

The use of a combination of subclinical changes, including low iron, high calcium, elevated leukocytes, lymphocytes, and ALT levels in blood samples, together with a low growth percentile, is pertinent in detecting coeliac disease. This set of parameters could help in the diagnosis of patients without clinical symptoms. We can also show that the levels of Fe, Ca, transaminases, and leucocytes remain subclinically altered after 3 years, despite the gluten-free diet.

Is There a Time and a Place for the Gluten-Free Diet in Potential Celiac Disease?

Potential celiac disease (PCD) is characterized by the absence of villous atrophy on duodenal biopsies (Marsh 0 or 1) despite positive celiac serology and HLA DQ2 or DQ8 heterodimers. Recent epidemiological studies report that PCD represents one fifth of the total CD diagnoses. Compared to patients with CD, the majority of adult patients with PCD show lower rates of nutrient deficiencies and extraintestinal symptoms at diagnosis. Recommending a gluten-free diet (GFD) to PCD patients depends on whether they have symptoms or not. A significant clinical improvement is reported by symptomatic patients, but for asymptomatic PCD, diet implementation is still a matter of debate. Some questions remain to be answered: does PCD serve as an intermediary phase leading to the progression of true CD? Is it reasonable to hypothesize that PCD and active CD represent different manifestations of the same condition? Is there a potential for both underdiagnosis and overdiagnosis of CD in those who may have the condition? Additional research is required to address these inquiries and ascertain the specific subset of people with potential progression to overt CD, as well as to determine the potential advantages of early implementation of a GFD for these individuals. The investigation of risk factors in CD warrants examination of variables such as the timing of diagnosis, the genetic profile, the extent of gluten exposure, and the composition of the microbiome.

Frequency and predictive factors for spontaneous normalization of anti-tissue transglutaminase-IgA serology among Saudi children with type 1 diabetes mellitus: A cohort study

Background

Celiac serology can be transiently elevated in patients with type 1 diabetes mellitus (T1DM) and normalized despite gluten consumption. This study aimed to identify the frequency and predictive factors of spontaneous normalization of anti-tissue transglutaminase (anti-TTG-IgA) antibodies in these patients.

Methods

The charts of all patients (≤18 years) with T1DM were retrospectively reviewed from 2012 to 2021 at a tertiary care center in Riyadh, Saudi Arabia. The following data were collected: clinical characteristics of the participants, anti-TTG-IgA-immunoglobulin (Ig) A antibody, and histological findings. The outcome of positive anti-TTG-IgA-IgA in patients with T1DM and the predictive factors for spontaneous normalization were investigated.

Results

Of the 1,006 patients with T1DM, 138 (13.7%) had elevated anti-TTG-IgA antibodies, celiac disease was diagnosed in 58/138 (42%) patients, spontaneous normalization of anti-TTG-IgA was observed in 65 (47.1%) patients, and fluctuating anti-TTG-IgA antibodies were seen in 15 (10.9%) patients. The patients with anti-TTG-IgA levels at 3-10 times the upper normal limits (UNL), and those with levels ≥10 times UNL were less likely to have spontaneous normalization of anti-TTG-IgA compared to patients with levels at 1-3 times UNL (hazard ratio [HR] = 0.28, 95% confidence interval [Cl] = 0.13-0.61, P = 0.001, and HR = 0.03, 95% Cl = 0.00-0.19, P < 0.001, respectively).

Conclusion

Asymptomatic patients with T1DM with mild elevation of anti-TTG-IgA need not be rushed for invasive endoscopy or exposed to an un-needed gluten-free diet but should rather have a regular follow-up of their celiac serology.

Modelling digital health data: The ExaMode ontology for computational pathology

Computational pathology can significantly benefit from ontologies to standardize the employed nomenclature and help with knowledge extraction processes for high-quality annotated image datasets. The end goal is to reach a shared model for digital pathology to overcome data variability and integration problems. Indeed, data annotation in such a specific domain is still an unsolved challenge and datasets cannot be steadily reused in diverse contexts due to heterogeneity issues of the adopted labels, multilingualism, and different clinical practices.

Material and methods

This paper presents the ExaMode ontology, modeling the histopathology process by considering 3 key cancer diseases (colon, cervical, and lung tumors) and celiac disease. The ExaMode ontology has been designed bottom-up in an iterative fashion with continuous feedback and validation from pathologists and clinicians. The ontology is organized into 5 semantic areas that defines an ontological template to model any disease of interest in histopathology.

Results

The ExaMode ontology is currently being used as a common semantic layer in: (i) an entity linking tool for the automatic annotation of medical records; (ii) a web-based collaborative annotation tool for histopathology text reports; and (iii) a software platform for building holistic solutions integrating multimodal histopathology data.

Discussion

The ontology ExaMode is a key means to store data in a graph database according to the RDF data model. The creation of an RDF dataset can help develop more accurate algorithms for image analysis, especially in the field of digital pathology. This approach allows for seamless data integration and a unified query access point, from which we can extract relevant clinical insights about the considered diseases using SPARQL queries.

High frequency of gastrointestinal complaints, but insignificant prevalence of gluten-sensitive enteropathies in Brazilian fibromyalgia patients

INTRODUCTION/OBJECTIVES

Coeliac disease (CD) and non-coeliac gluten sensitivity (NCGS) cause symptoms like those seen in patients with fibromyalgia (FM) and functional gastrointestinal disorders. There is no consistent data on frequency of these symptoms and no study performed duodenal biopsies to investigate CD/NCGS in Brazilian FM patients. Therefore, we sought to verify the prevalence of CD/NCGS in FM patients and the association between gastrointestinal manifestations and FM symptoms.

MATERIAL AND METHODS

Sixty-two individuals with FM (ACR2010) were recruited from FM outpatient clinics of a tertiary hospital. Clinical evaluation included the Widespread Pain Index (WPI), Severity Symptom Scale (SS), Polysymptomatic Distress Scale (PDS), and Fibromyalgia Impact Questionnaire (FIQ). Subjects were screened for the presence of coeliac antibodies and upper gastrointestinal endoscopy (duodenal biopsies) was performed for diagnosis of CD/NCGS.

RESULTS

46 (74.2%) women reported at least one digestive symptom: constipation, abdominal distension, loss of weight/inappetence, and nausea/vomiting. Fourteen (31.8%) presented macroscopic duodenitis and 2(4.5%) had duodenal lymphocytic infiltrates, but none met CD criteria. In 1(1.6%) patient NCGS was confirmed. There was association between presence of any digestive symptom and WPI and SS (fatigue, waking up tired, cognition), but no difference on FIQ between patients with and without gastrointestinal symptoms.

CONCLUSION

Gastrointestinal complaints were frequent and associated with increased degree of polysymptomatic distress in FM patients, but presence of these symptoms was not related to overall impact of FM over different dimensions of the patient's life. Moreover, the prevalence of CD/NCGS was very low. This suggests that screening for CD in Brazilian FM patients might not be cost-effective, since the frequency of CD/NCGS was very low.