Infectious associations of Celiac disease

Strain-specific differences in reovirus infection of murine macrophages segregate with polymorphisms in viral outer-capsid protein σ3

Mammalian orthoreovirus (reovirus) strains type 1 Lang (T1L) and type 3 Dearing-RV (T3D-RV) infect the intestine in mice but differ in the induction of inflammatory responses. T1L infection is associated with the blockade of oral immunological tolerance to newly introduced dietary antigens, whereas T3D-RV is not. T1L infection leads to an increase in infiltrating phagocytes, including macrophages, in gut-associated lymphoid tissues that are not observed in T3D-RV infection. However, the function of macrophages in reovirus intestinal infection is unknown. Using cells sorted from infected intestinal tissue and primary cultures of bone-marrow-derived macrophages (BMDMs), we discovered that T1L infects macrophages more efficiently than T3D-RV. Analysis of T1L × T3D-RV reassortant viruses revealed that the viral S4 gene segment, which encodes outer-capsid protein σ3, is responsible for strain-specific differences in infection of BMDMs. Differences in the binding of T1L and T3D-RV to BMDMs also segregated with the σ3-encoding S4 gene. Paired immunoglobulin-like receptor B (PirB), which serves as a receptor for reovirus, is expressed on macrophages and engages σ3. We found that PirB-specific antibody blocks T1L binding to BMDMs and that T1L binding to PirB-/- BMDMs is significantly diminished. Collectively, our data suggest that reovirus T1L infection of macrophages is dependent on engagement of PirB by viral outer-capsid protein σ3. These findings raise the possibility that macrophages function in the innate immune response to reovirus infection that blocks immunological tolerance to new food antigens.IMPORTANCEMammalian orthoreovirus (reovirus) infects humans throughout their lifespan and has been linked to celiac disease (CeD). CeD is caused by a loss of oral immunological tolerance (LOT) to dietary gluten and leads to intestinal inflammation following gluten ingestion, which worsens with prolonged exposure and can cause malnutrition. There are limited treatment options for CeD. While there are genetic risk factors associated with the illness, triggers for disease onset are not completely understood. Enteric viruses, including reovirus, have been linked to CeD induction. We found that a reovirus strain associated with oral immunological tolerance blockade infects macrophages by virtue of its capacity to bind macrophage receptor PirB. These data contribute to an understanding of the innate immune response elicited by reovirus, which may shed light on how viruses trigger LOT and inform the development of CeD vaccines and therapeutic agents.

The immune and microbial homeostasis determines the Candida-mast cells cross-talk in celiac disease

Celiac disease (CD) is an autoimmune enteropathy resulting from an interaction between diet, genome, and immunity. Although many patients respond to a gluten-free diet, in a substantive number of individuals, the intestinal injury persists. Thus, other factors might amplify the ongoing inflammation. Candida albicans is a commensal fungus that is well adapted to the intestinal life. However, specific conditions increase Candida pathogenicity. The hypothesis that Candida may be a trigger in CD has been proposed after the observation of similarity between a fungal wall component and two CD-related gliadin T-cell epitopes. However, despite being implicated in intestinal disorders, Candida may also protect against immune pathologies highlighting a more intriguing role in the gut. Herein, we postulated that a state of chronic inflammation associated with microbial dysbiosis and leaky gut are favorable conditions that promote C. albicans pathogenicity eventually contributing to CD pathology via a mast cells (MC)-IL-9 axis. However, the restoration of immune and microbial homeostasis promotes a beneficial C. albicans-MC cross-talk favoring the attenuation of CD pathology to alleviate CD pathology and symptoms.

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.

The gut protist Tritrichomonas arnold restrains virus-mediated loss of oral tolerance by modulating dietary antigen-presenting dendritic cells

Loss of oral tolerance (LOT) to gluten, driven by dendritic cell (DC) priming of gluten-specific T helper 1 (Th1) cell immune responses, is a hallmark of celiac disease (CeD) and can be triggered by enteric viral infections. Whether certain commensals can moderate virus-mediated LOT remains elusive. Here, using a mouse model of virus-mediated LOT, we discovered that the gut-colonizing protist Tritrichomonas (T.) arnold promotes oral tolerance and protects against reovirus- and murine norovirus-mediated LOT, independent of the microbiota. Protection was not attributable to antiviral host responses or T. arnold-mediated innate type 2 immunity. Mechanistically, T. arnold directly restrained the proinflammatory program in dietary antigen-presenting DCs, subsequently limiting Th1 and promoting regulatory T cell responses. Finally, analysis of fecal microbiomes showed that T. arnold-related Parabasalid strains are underrepresented in human CeD patients. Altogether, these findings will motivate further exploration of oral-tolerance-promoting protists in CeD and other immune-mediated food sensitivities.

The Influence of SARS-CoV-2 Pandemic on the Diagnosis of Celiac Disease and Clinical Practice in Pediatric Gastroenterology

Celiac disease (CD) has a high prevalence but remains largely underdiagnosed. Although extensive studies have confirmed that children with CD do not have an increased risk of severe COVID-19, public health regulations associated with the SARS-CoV-2 pandemic may have exacerbated this problem. The aim of this study was to assess the effect of SARS-CoV-2 on the number of new-onset CD cases. Additionally, the role of SARS-CoV-2 in autoimmune diseases and its influence on clinical practice in pediatric gastroenterology were briefly reviewed. We described the data from the hospital electronic registry of new-onset CD, during the COVID-19 pandemic and 2 years before. A total of 423 children were diagnosed with CD between March 2018 and February 2022: 228 in the 2-year pre-COVID-19 period and 195 during the pandemic. The number of patients during the COVID-19 pandemic was 14.5% lower than in the previous years. The quarterly comparison of CD diagnoses showed a reduction in all quarters. A reduction in diagnoses during the lockdown and in the following months was evident and not compensated thereafter. This is the first study to evaluate the impact of SARS-CoV-2 on the diagnosis of CD in children. Further studies are necessary to improve the system of biopsy-sparing diagnosis and to evaluate the effect of the diagnostic delay. Special attention should be given to the implementation of telemedicine services.

The gut microbiota and celiac disease: Pathophysiology, current perspective and new therapeutic approaches

Celiac disease (CD) as a chronic gluten-sensitive intestinal condition, mainly affects genetically susceptible hosts. The primary determinants of CD have been identified as environmental and genetic variables. The development of CD is significantly influenced by environmental factors, including the gut microbiome. Therefore, gut microbiome re-programming-based therapies using probiotics, prebiotics, postbiotics, gluten-free diet, and fecal microbiota transplantation have shown promising results in the modification of the gut microbiome. Due to the importance and paucity of information regarding the CD pathophysiology, in this review, we have covered the association between CD development and gut microbiota, the effects of infectious agents, particularly the recent Covid-19 infection in CD patients, and the efficacy of potential therapeutic approaches in the CD have been discussed. Hence, scientific literature indicates that the diverse biological functions of the gut microbiota against immunomodulatory responses have made microbiome-based therapy an alternative therapeutic paradigm to ameliorate the symptoms of CD and quality of life. However, the exact potential of microbiota-based techniques that aims to quantitatively and qualitatively alter the gut microbiota to be used in the treatment and ameliorate the symptoms of CD will be determined with further research in the future.

Seroprevalence of Anti-tTg-IgA among Symptomized Celiac Disease Patients and Their Correlation with Rotavirus Infection

Celiac disease (CD) is a chronic inflammatory disorder in the intestinal tract as a response to the use of gluten in genetically predisposed individuals. It is a worldwide problem, with a high prevalence rate in North America. This is a descriptive cross-sectional study involving 1090 samples collected from different hospitals of Rawalpindi and Islamabad, Pakistan, from January 2019 to December 2019. In this study, 1090 blood samples screened for seroprevalence of anti-tTG antibodies in CD symptomatic patients via ELISA (enzyme-linked immunosorbent assay). 1090 fecal samples from the same CD patients were collected and tested for the presence of rotavirus (RV) via ELISA and RT-PCR. Of the 1090 patients tested for seroprevalence of anti-tTG antibodies, 112/1090 (10.3%) were found to be positive. Of the 112 anti-tTG-positive patients, 78/112 (70%) were positive for RV via ELISA and 74/112 (66.1%) were RV positive via RT-PCR. A statistically significant association was reported between rotavirus infection and celiac disease (p˂0.05). Anti-tTG antibodies were higher in age group 6 (12-18 years) patients (18.4%) and at minimum in age group 3 (1-3 years) patients (4.8%). However, there was a statistically insignificant relationship between group age and CD prevalence (p > 0.05). The highest CD prevalence was noted during winter season (19.6%) and the lowest (3.0%) during fall/autumn. Our study findings demonstrate that Pakistan has a high prevalence of CD compared to other studies. Further studies in the fields of environmental risk factors and treatment with more advanced serological and histopathological studies are needed in the future.

NK cells contribute to reovirus-induced IFN responses and loss of tolerance to dietary antigen

Celiac disease is an immune-mediated intestinal disorder that results from loss of oral tolerance (LOT) to dietary gluten. Reovirus elicits inflammatory Th1 cells and suppresses Treg responses to dietary antigen in a strain-dependent manner. Strain type 1 Lang (T1L) breaks oral tolerance, while strain type 3 Dearing reassortant virus (T3D-RV) does not. We discovered that intestinal infection by T1L in mice leads to the recruitment and activation of NK cells in mesenteric lymph nodes (MLNs) in a type I IFN-dependent manner. Once activated following infection, NK cells produce type II IFN and contribute to IFN-stimulated gene expression in the MLNs, which in turn induces inflammatory DC and T cell responses. Immune depletion of NK cells impairs T1L-induced LOT to newly introduced food antigen. These studies indicate that NK cells modulate the response to dietary antigen in the presence of a viral infection.

Latitude and Celiac Disease Prevalence: A Meta-Analysis and Meta-Regression

BACKGROUND & AIMS

The latitudinal gradient effect is described for several autoimmune diseases including celiac disease in the United States. However, the association between latitude and global celiac disease prevalence is unknown. We aimed to explore the association between latitude and serology-based celiac disease prevalence through meta-analysis.

METHODS

We searched MEDLINE, Embase, Cochrane, and Scopus databases from their beginning through June 29, 2018, to identify screening studies that targeted a general population sample, used serology-based screening tests, and provided a clear location from which we could assign a latitude. Studies were excluded if sampling was based on symptoms, risk factors, or referral. Study selection and data extraction were performed by independent reviewers. The association measures between latitude and prevalence of serology-based celiac disease were evaluated with random-effects meta-analyses and meta-regression.

RESULTS

Of the identified 4667 unique citations, 128 studies were included, with 155 prevalence estimates representing 40 countries. Celiac disease was more prevalent at the higher latitudes of 51° to 60° (relative risk [RR], 1.62; 95% CI, 1.09-2.38) and 61° to 70° (RR, 2.30; 95% CI, 1.36-3.89) compared with the 41° to 50° reference level. No statistically significant difference was observed at lower latitudes. When latitude was treated as continuous, we found a statistically significant association between CD prevalence and latitude overall in the world (RR, 1.03, 95% CI, 1.01-1.05) and a subregional analysis of Europe (RR, 1.05; 95% CI, 1.02-1.07) and North America (RR, 1.1; 95% CI, 1.0-1.2).

CONCLUSIONS

In this comprehensive review of screening studies, we found that a higher latitude was associated with greater serology-based celiac disease prevalence.

Association between idiopathic pulmonary hemosiderosis and celiac disease in pediatric patients: A scoping review of the literature over the past 50 years

INTRODUCTION

Idiopathic pulmonary hemosiderosis (IPH) is a rare cause of diffuse alveolar hemorrhage, the mechanism of which is currently unknown. Nearly one-third of pediatric patients with IPH test positive for Celiac disease (CD) serology. Several hypothetical mechanisms have been proposed to unify the coexistence of these two entities, also referred to as Lane-Hamilton syndrome (LHS).

METHOD

This manuscript is a scoping review of the medical literature. Medline, Embase, and PubMed Central databases were searched between 1971 and 2021 with appropriate search words to identify all cases of pediatric LHS.

RESULTS

A total of 20 manuscripts with 23 pediatric patients with LHS were identified. The mean age was 11 years, and 13/23 (56.5%) of the children were boys. Hemoptysis was present in 57% of patients during diagnosis. Bronchoscopy with bronchoalveolar lavage demonstrating hemosiderin laden macrophages was the primary mode of diagnostic confirmation. Only three patients underwent lung biopsy. Any significant GI symptom was reported in a minority of patients (22%). Iron deficiency anemia on presentation was described in 83% of children. The majority of patients were malnourished. Serology for CD was positive in all patients, as was the histopathologic analysis of the small bowel biopsy. No patients had any other autoantibody positivity. The introduction of gluten free diet (GFD) was associated with a positive response in 20/23 patients.

CONCLUSION

All pediatric patients with IPH should undergo screening for CD. Low serum ferritin in patients with IPH could be suggestive of coexisting CD. Strict GFD should be tried as the initial therapy.

Comparative Analysis of Adult Patients With Idiopathic Pulmonary Hemosiderosis and Lane-Hamilton Syndrome: A Systematic Review of the Literature in the Period 1971-2022

Idiopathic pulmonary hemosiderosis (IPH) causes diffuse alveolar hemorrhage (DAH) by a yet unknown mechanism. The coexistence of IPH and celiac disease (CD), also known as Lane-Hamilton syndrome (LHS), has been reported in both pediatric and adult patients. The objective of this study was to compare demographics, clinical and radiologic findings, treatment, and outcomes between adult patients with IPH and LHS.

This is a systematic review of the literature. Multiple databases were searched using appropriate formulas to identify relevant articles. A total of 60 studies reporting 65 patients were included in the review. Forty-nine of these patients had IPH and 16 had LHS. The prevalence of anti-CD antibodies among tested patients was 13/22 (59%). The symptom onset and diagnosis of IPH occurred earlier in patients with LHS. The median delay in diagnosis was the same between the two groups (52 weeks). The classic triad was more likely to be present in patients with LHS. Only 20% of patients in the LHS cohort had any significant gastrointestinal (GI) symptoms at the time of IPH diagnosis. A gluten-free diet alone was effective in the majority of patients. Fewer patients in the LHS cohort received systemic corticosteroid than the IPH cohort. The recurrence and mortality in patients with LHS appear to be less than in the IPH cohort. The prevalence of CD is 25% in adult patients with IPH. Patients with LHS may have a milder course than patients without CD. Serologic testing for CD should be performed in all patients diagnosed with IPH.

Frontiers in Celiac Disease: Where Autoimmunity and Environment Meet

Celiac disease is a chronic, immune-mediated enteropathy driven by dietary gluten found in genetically susceptible hosts. It has a worldwide distribution, is one of the most common autoimmune disorders globally, and is the only autoimmune condition for which the trigger is known. Despite advances in characterizing mechanisms of disease, gaps in understanding of celiac disease pathogenesis remain. A "frontier" concept is considering what moves an HLA-DQ2 or DQ8-positive individual from asymptomatic gluten tolerance to celiac disease manifestation. In this arena, environmental triggers, including age at the time of initial gluten exposure, the occurrence of usual childhood viral infections, and microbiome alterations have emerged as key events in triggering the symptomatic disease. Pathologists play a major role in frontier aspects of celiac disease. This includes the discovery that duodenal mucosal histology in follow-up biopsies does not correlate with ongoing patient symptoms, antitissue transglutaminase antibody titers and diet adherence in celiac disease patients. Further, in light of recent evidence that the detection of monoclonal T-cell populations in formalin-fixed biopsies is not specific for type II refractory celiac disease, pathologists should resist performing such analyses until common causes of "apparent" refractoriness are excluded. The promise of therapies in celiac disease has led to clinical trials targeting many steps in the inflammatory cascade, which depend upon a pathologist's confirmation of the initial diagnosis and evaluation of responses to therapies. As pathologists continue to be active participants in celiac disease research, partnering with other stakeholders, we will continue to impact this important autoimmune disease.

Interplay Between Gluten, HLA, Innate and Adaptive Immunity Orchestrates the Development of Coeliac Disease

Several environmental, genetic, and immune factors create a "perfect storm" for the development of coeliac disease: the antigen gluten, the strong association of coeliac disease with HLA, the deamidation of gluten peptides by the enzyme transglutaminase 2 (TG2) generating peptides that bind strongly to the predisposing HLA-DQ2 or HLA-DQ8 molecules, and the ensuing unrestrained T cell response. T cell immunity is at the center of the disease contributing to the inflammatory process through the loss of tolerance to gluten and the differentiation of HLA-DQ2 or HLA-DQ8-restricted anti-gluten inflammatory CD4⁺ T cells secreting pro-inflammatory cytokines and to the killing of intestinal epithelial cells by cytotoxic intraepithelial CD8⁺ lymphocytes. However, recent studies emphasize that the individual contribution of each of these cell subsets is not sufficient and that interactions between these different populations of T cells and the simultaneous activation of innate and adaptive immune pathways in distinct gut compartments are required to promote disease immunopathology. In this review, we will discuss how tissue destruction in the context of coeliac disease results from the complex interactions between gluten, HLA molecules, TG2, and multiple innate and adaptive immune components.

The microbiota-mediated dietary and nutritional interventions for COVID-19

Worldwide, scientists are looking for specific treatment for COVID-19. Apart from the antiviral approach, the interventions to support healthy immune responses to the virus are feasible through diet, nutrition, and lifestyle approaches. This narrative review explores the recent studies on dietary, nutritional, and lifestyle interventions that influence the microbiota-mediated immunomodulatory effects against viral infections. Cumulative studies reported that the airway microbiota and SARS-CoV-2 leverage each other and determine the pathogen-microbiota-host responses. Cigarette smoking can disrupt microbiota abundance. The composition and diversification of intestinal microbiota influence the airway microbiota and the innate and adaptive immunity, which require supports from the balance of macro- and micronutrients from the diet. Colorful vegetables supplied fermentable prebiotics and anti-inflammatory, antioxidant phytonutrients. Fermented foods and beverages support intestinal microbiota. In sensitive individuals, the avoidance of the high immunoreactive food antigens contributes to antiviral immunity. This review suggests associations between airway and intestinal microbiota, antiviral host immunity, and the influences of dietary, nutritional, and lifestyle interventions to prevent the clinical course toward severe COVID-19.

Role of the gut microbiota in the pathogenesis of coeliac disease and potential therapeutic implications

PURPOSE

Although genetic predisposition and exposure to dietary gluten are considered necessary triggers for the development of coeliac disease, alterations in the gut microbial composition may also contribute towards the pathogenesis of coeliac disease. This review aims to provide an overview of the available data on the potential mechanisms through which the gut microbiota plays a role in the causation of coeliac disease and to discuss the potential therapeutic strategies that could diminish the consequences of microbial dysbiosis.

METHOD

A search of the literature was performed using the PubMed, Embase, and JSTOR databases; relevant articles were included.

RESULTS

Recent studies in patients with coeliac disease have reported an increase in the relative amounts of gram negative bacterial genera such as Bacteroides, Prevotella, and Escherichia, and reduced amounts of protective anti-inflammatory bacteria such as Bifidobacteria and Lactobacilli. Dysbiotic microbiota may lead to a dysregulated immune response that may contribute to the pathogenesis of coeliac disease. In infancy, antibiotic use and certain infant feeding practices may lead to alterations in the developing gut microbiota to influence the immune maturation process and predispose to coeliac disease.

CONCLUSION

The induction of the intestinal immune system and gluten intolerance may be influenced by the relative abundance of certain microbiota. Factors such as infant feeding practices, diet, antibiotics, and infections, may be involved in the development of coeliac disease due to their influence on gut microbial composition. The efficacy of potential modulators of the gut microbiota such as probiotics, prebiotics, and fecal microbial transplant as adjunctive treatments to gluten-free diet in coeliac disease is unproven and requires further investigation.

Molecular Biomarkers for Celiac Disease: Past, Present and Future

Celiac disease (CeD) is a complex immune-mediated disorder that is triggered by dietary gluten in genetically predisposed individuals. CeD is characterized by inflammation and villous atrophy of the small intestine, which can lead to gastrointestinal complaints, malnutrition, and malignancies. Currently, diagnosis of CeD relies on serology (antibodies against transglutaminase and endomysium) and small-intestinal biopsies. Since small-intestinal biopsies require invasive upper-endoscopy, and serology cannot predict CeD in an early stage or be used for monitoring disease after initiation of a gluten-free diet, the search for non-invasive biomarkers is ongoing. Here, we summarize current and up-and-coming non-invasive biomarkers that may be able to predict, diagnose, and monitor the progression of CeD. We further discuss how current and emerging techniques, such as (single-cell) transcriptomics and genomics, can be used to uncover the pathophysiology of CeD and identify non-invasive biomarkers.

Coeliac Disease Pathogenesis: The Uncertainties of a Well-Known Immune Mediated Disorder

Coeliac disease is a common small bowel enteropathy arising in genetically predisposed individuals and caused by ingestion of gluten in the diet. Great advances have been made in understanding the role of the adaptive immune system in response to gluten peptides. Despite detailed knowledge of these adaptive immune mechanisms, the complete series of pathogenic events responsible for development of the tissue lesion remains less certain. This review contributes to the field by discussing additional mechanisms which may also contribute to pathogenesis. These include the production of cytokines such as interleukin-15 by intestinal epithelial cells and local antigen presenting cells as a pivotal event in the disease process. A subset of unconventional T cells called gamma/delta T cells are also persistently expanded in the coeliac disease (CD) small intestinal epithelium and recent analysis has shown that these cells contribute to pathogenic inflammation. Other unconventional T cell subsets may play a local immunoregulatory role and require further study. It has also been suggested that, in addition to activation of pathogenic T helper cells by gluten peptides, other peptides may directly interact with the intestinal mucosa, further contributing to the disease process. We also discuss how myofibroblasts, a major source of tissue transglutaminase and metalloproteases, may play a key role in intestinal tissue remodeling. Contribution of each of these factors to pathogenesis is discussed to enhance our view of this complex disorder and to contribute to a wider understanding of chronic immune-mediated disease.

MAGI2 Gene Region and Celiac Disease

Celiac disease (CD) patients present a loss of intestinal barrier function due to structural alterations in the tight junction (TJ) network, the most apical unions between epithelial cells. The association of TJ-related gene variants points to an implication of this network in disease susceptibility. This work aims to characterize the functional implication of TJ-related, disease-associated loci in CD pathogenesis. We performed an association study of 8 TJ-related gene variants in a cohort of 270 CD and 91 non-CD controls. The expression level of transcripts located in the associated SNP region was analyzed by RT-PCR in several human tissues and in duodenal biopsies of celiac patients and non-CD controls. (si)RNA-driven silencing combined with gliadin in the Caco2 intestinal cell line was used to analyze the implication of transcripts from the associated region in the regulation of TJ genes. We replicated the association of rs6962966^*A variant [p = 0.0029; OR = 1.88 (95%1.24–2.87)], located in an intron of TJ-related MAGI2 coding gene and upstream of RP4-587D13.2 transcript, bioinformatically classified as a long non-coding RNA (lncRNA). The expression of both genes is correlated and constitutively downregulated in CD intestine. Silencing of lncRNA decreases the levels of MAGI2 protein. At the same time, silencing of MAGI2 affects the expression of several TJ-related genes. The associated region is functionally altered in disease, probably affecting CD-related TJ genes.

Autoimmune and Allergic Disorders are More Common in People With Celiac Disease or on a Gluten-free Diet in the United States

GOALS

We analyzed demographics, lifestyle patterns, and clinical characteristics of people with celiac disease (CD) and people without CD avoiding gluten (PWAG) to better understand associations with medical conditions and consumer behavior.

BACKGROUND

Clinical significance of CD and gluten avoidance in the general population is incompletely understood. Recently, a high incidence of CD in adolescents with susceptibility genotypes, similar to other autoimmune or allergic disorders, and regional differences in consumer practices of gluten avoidance were reported.

METHODS

Among 22,277 participants in the National Health and Nutrition Examination Survey 2009-2014, we identified persons with CD by testing CD serology or by both a health care provider diagnosis and adherence to a gluten-free diet. Similarly, PWAG were defined as adherent to a gluten-free diet without a CD diagnosis. Consumer behavior and characteristics of both groups, CD and PWAG were compared with those without these conditions, using survey-weighted generalized logistic regression.

RESULTS

Participants with CD considered nutrition very important when grocery shopping and tended to have more constipation and thyroid disease. PWAG tended to spend more money on groceries, purchase organic foods, and check food labels more frequently during grocery shopping. They also reported having more food allergies, asthma, and thyroid disease.

CONCLUSIONS

Our study confirms that CD and PWAG share comorbidities of autoimmune nature. PWAG had more autoimmune/allergy-related disorders that may be associated with non-celiac gluten sensitivity a self-justifiable reason to be on the diet.

Early Probiotic Supplementation and the Risk of Celiac Disease in Children at Genetic Risk

Probiotics are linked to positive regulatory effects on the immune system. The aim of the study was to examine the association between the exposure of probiotics via dietary supplements or via infant formula by the age of 1 year and the development of celiac disease autoimmunity (CDA) and celiac disease among a cohort of 6520 genetically susceptible children. Use of probiotics during the first year of life was reported by 1460 children. Time-to-event analysis was used to examine the associations. Overall exposure of probiotics during the first year of life was not associated with either CDA (n = 1212) (HR 1.15; 95%CI 0.99, 1.35; p = 0.07) or celiac disease (n = 455) (HR 1.11; 95%CI 0.86, 1.43; p = 0.43) when adjusting for known risk factors. Intake of probiotic dietary supplements, however, was associated with a slightly increased risk of CDA (HR 1.18; 95%CI 1.00, 1.40; p = 0.043) compared to children who did not get probiotics. It was concluded that the overall exposure of probiotics during the first year of life was not associated with CDA or celiac disease in children at genetic risk.

Reovirus: Friend and Foe

Purpose of Review

Mammalian orthoreovirus (reovirus) is a powerful tool for studying viral replication and pathogenesis. Most reovirus infections are subclinical, however recent work has catapulted reovirus into the clinical spotlight.

Recent Findings

Owing to its capacity to kill cancer cells more efficiently than normal cells, reovirus is under development as a therapeutic for a variety of cancers. New efforts have focused on genetically engineering reovirus to increase its oncolytic capacity, and determining how reovirus potentiates immunotherapy. Other recent studies highlight a potential role for reovirus in celiac disease (CeD). Using mouse models of CeD, reovirus caused loss of oral tolerance to dietary antigens, opening the possibility that reovirus could trigger CeD in humans.

Summary

We will focus on new developments in reovirus oncolysis and studies suggesting a role for reovirus as a trigger for celiac disease (CeD) that make reovirus a potential friend and foe to human health.

The Revival of the Battle between David and Goliath in the Enteric Viruses and Microbiota Struggle: Potential Implication for Celiac Disease

The human gut is inhabited by overcrowded prokaryotic communities, a major component of which is the virome, comprised of viruses, bacteriophages, archaea, eukaryotes and bacteria. The virome is required for luminal homeostasis and, by their lytic or synergic capacities, they can regulate the microbial community structure and activity. Dysbiosis is associated with numerous chronic human diseases. Since the virome can impact microbial genetics and behavior, understanding its biology, composition, cellular cycle, regulation, mode of action and potential beneficial or hostile activities can change the present paradigm of the cross-talks in the luminal gut compartment. Celiac disease is a frequent autoimmune disease in which viruses can play a role in disease development. Based on the current knowledge on the enteric virome, in relation to celiac disease pathophysiological evolvement, the current review summarizes the potential interphases between the two. Exploring and understanding the role of the enteric virome in gluten-dependent enteropathy might bring new therapeutic strategies to change the luminal eco-event for the patient's benefit.

The Revival of the Battle between David and Goliath in the Enteric Viruses and Microbiota Struggle: Potential Implication for Celiac Disease

The human gut is inhabited by overcrowded prokaryotic communities, a major component of which is the virome, comprised of viruses, bacteriophages, archaea, eukaryotes and bacteria. The virome is required for luminal homeostasis and, by their lytic or synergic capacities, they can regulate the microbial community structure and activity. Dysbiosis is associated with numerous chronic human diseases. Since the virome can impact microbial genetics and behavior, understanding its biology, composition, cellular cycle, regulation, mode of action and potential beneficial or hostile activities can change the present paradigm of the cross-talks in the luminal gut compartment. Celiac disease is a frequent autoimmune disease in which viruses can play a role in disease development. Based on the current knowledge on the enteric virome, in relation to celiac disease pathophysiological evolvement, the current review summarizes the potential interphases between the two. Exploring and understanding the role of the enteric virome in gluten-dependent enteropathy might bring new therapeutic strategies to change the luminal eco-event for the patient's benefit.

Celiac disease-on-chip: Modeling a multifactorial disease in vitro

Conventional model systems cannot fully recapitulate the multifactorial character of complex diseases like celiac disease (CeD), a common chronic intestinal disorder in which many different genetic risk factors interact with environmental factors such as dietary gluten. However, by combining recently developed human induced pluripotent stem cell (hiPSC) technology and organ-on-chip technology, in vitro intestine-on-chip systems can now be developed that integrate the genetic background of complex diseases, the different interacting cell types involved in disease pathology, and the modulating environmental factors such as gluten and the gut microbiome. The hiPSCs that are the basis of these systems can be generated from both diseased and healthy individuals, which means they can be stratified based on their load of genetic risk factors. A CeD-on-chip model system has great potential to improve our understanding of disease etiology and accelerate the development of novel treatments and preventive therapies in CeD and other complex diseases.

Coeliac disease: beyond genetic susceptibility and gluten. A narrative review

Coeliac disease (CD) is an immune-mediated disorder triggered by the ingestion of gluten in genetically susceptible individuals. However, only a small proportion of subjects harbouring CD-related genetic risk develop the disease. Among the environmental factors that may influence CD risk, pre- and perinatal factors, delivery methods, parental lifestyle, infant feeding practices, seasonality, dietary factors, drug use, childhood infections and variability in gut microbiota are those most widely studied regarding the risk to develop CD. Although for many of these external factors the exact mechanism of action is unknown, most of them are thought to act by disrupting the intestinal barrier, facilitating contact between potential antigens and the immune system effector cells. Management of CD is relatively easy in patients with a definite diagnosis and requires a strict, lifelong, gluten-free diet. Better knowledge of environmental exposures apart from gluten can facilitate understanding of the pathogenesis of the disorder and the wide heterogeneity of its clinical spectrum. The purpose of this review is to discuss current knowledge on environmental CD risk factors, as well as possible interaction between them, on the grounds of the reliable scientific evidence available. Key messages The risk of developing CD is influenced not only by gluten ingestion but also by a number of environmental factors including childhood infections and variability in gut microbiota, pre- and perinatal factors, infant feeding practices, delivery methods, parental lifestyle, seasonality, dietary factors and drug use, acting mainly by disrupting intestinal permeability. Better knowledge of exposure to these factors can facilitate their identification, and subsequent elimination, in the individual patient.

Mechanisms by which gut microorganisms influence food sensitivities

Finely tuned mechanisms enable the gastrointestinal tract to break down dietary components into nutrients without mounting, in the majority of cases, a dysregulated immune or functional host response. However, adverse reactions to food have been steadily increasing, and evidence suggests that this process is environmental. Adverse food reactions can be divided according to their underlying pathophysiology into food intolerances, when, for instance, there is deficiency of a host enzyme required to digest the food component, and food sensitivities, when immune mechanisms are involved. In this Review, we discuss the clinical and experimental evidence for enteric infections and/or alterations in the gut microbiota in inciting food sensitivity. We focus on mechanisms by which microorganisms might provide direct pro-inflammatory signals to the host promoting breakdown of oral tolerance to food antigens or indirect pathways that involve the metabolism of protein antigens and other dietary components by gut microorganisms. Better understanding of these mechanisms will help in the development of preventive and therapeutic strategies for food sensitivities.

Recent advances in biosensors for diagnosis of celiac disease: A review

Celiac disease (CD) is an intestinal issue activated by the inappropriate immune reaction towards gluten protein of wheat, rye, barley, oats, and autoantigen, tissue transglutaminase. Regardless of the accessibility of immunochemical conventions for research facility analysis of CD, there is as yet a need of speedier, less expensive, and simpler devices for diagnosing CD. This review concentrates on progresses in biosensors for diagnosing CD in perspective of the scaled down hardware, multianalyte discovery and low sample volume necessity. Various recently developed biosensors in this field are presented.

Murine Norovirus Infection Induces TH1 Inflammatory Responses to Dietary Antigens

Intestinal reovirus infection can trigger T helper 1 (TH1) immunity to dietary antigen, raising the question of whether other viruses can have a similar impact. Here we show that the acute CW3 strain of murine norovirus, but not the persistent CR6 strain, induces TH1 immunity to dietary antigen. This property of CW3 is dependent on its major capsid protein, a virulence determinant. Transcriptional profiling of mesenteric lymph nodes following infection reveals an immunopathological signature that does not segregate with protective immunity but with loss of oral tolerance, in which interferon regulatory factor 1 is critical. These data show that viral capacity to trigger specific inflammatory pathways at sites where T cell responses to dietary antigens take place interferes with the development of tolerance to an oral antigen. Collectively, these data provide a foundation for the development of therapeutic strategies to prevent TH1-mediated complex immune disorders triggered by viral infections.

Increased prevalence of pathogenic bacteria in the gut microbiota of infants at risk of developing celiac disease: The PROFICEL study

Celiac disease (CD) is an immune-mediated enteropathy involving genetic and environmental factors, whose interaction influences disease risk. The intestinal microbiota, including viruses and bacteria, could play a role in the pathological process leading to gluten intolerance. In this study, we investigated the prevalence of pathogens in the intestinal microbiota of infants at familial risk of developing CD. We included 127 full-term newborns with at least one first-degree relative with CD. Infants were classified according to milk-feeding practice (breastfeeding or formula feeding) and HLA-DQ genotype (low, intermediate or high genetic risk). The prevalence of pathogenic bacteria and viruses was assessed in the faeces of the infants at 7 days, 1 month and 4 months of age. The prevalence of Clostridium perfringens was higher in formula-fed infants than in breast-fed over the study period, and that of C. difficile at 4 months. Among breastfed infants, a higher prevalence of enterotoxigenic E. coli (ETEC) was found in infants with the highest genetic risk compared either to those with a low or intermediate risk. Among formula-fed infants, a higher prevalence of ETEC was also found in infants with a high genetic risk compared to those of intermediate risk. Our results show that specific factors, such as formula feeding and the HLA-DQ2 genotype, previously linked to a higher risk of developing CD, influence the presence of pathogenic bacteria differently in the intestinal microbiota in early life. Further studies are warranted to establish whether these associations are related to CD onset later in life.

Celiac Disease: What Do We Know in 2017?

Celiac disease is one of the most prevalent digestive conditions. Diagnosis requires that strict criteria are used so that a life-long gluten-free diet may be correctly prescribed. Although genetic susceptibility has been known for a long time, there have been elusive environmental factors that lead to the occurrence of clinical disease. Many studies have addressed the identification of environmental modifiers, and different lines of research have been tried with variable success and even contradictory results. Infections and age of gluten introduction into the diet in the first few months of life have been evaluated, but a firm relationship could not be established. A recent paper addresses a fascinating hypothesis that could explain how some infectious agents might modulate the immune system and modify response to dietary antigens. Subsequently, animal models with genetic susceptibility were tested, and, indeed, there was abnormal response to gluten. These observations still do not provide final answers about the pathophysiology of celiac disease but certainly lead to progress in the knowledge of gluten sensitization and the role of some environmental factors.

Borrelia infection and risk of celiac disease

BACKGROUND

Environmental factors, including infectious agents, are speculated to play a role in the rising prevalence and the geographic distribution of celiac disease, an autoimmune disorder. In the USA and Sweden where the regional variation in the frequency of celiac disease has been studied, a similarity with the geographic distribution of Lyme disease, an emerging multisystemic infection caused by Borrelia burgdorferi spirochetes, has been found, thus raising the possibility of a link. We aimed to determine if infection with Borrelia contributes to an increased risk of celiac disease.

METHODS

Biopsy reports from all of Sweden's pathology departments were used to identify 15,769 individuals with celiac disease. Through linkage to the nationwide Patient Register, we compared the rate of earlier occurrence of Lyme disease in the patients with celiac disease to that in 78,331 matched controls. To further assess the temporal relationship between Borrelia infection and celiac disease, we also examined the risk of subsequent Lyme disease in patients with a diagnosis of celiac disease.

RESULTS

Twenty-five individuals (0.16%) with celiac disease had a prior diagnosis of Lyme disease, whereas 79 (0.5%) had a subsequent diagnosis of Lyme disease. A modest association between Lyme disease and celiac disease was seen both before (odds ratio, 1.61; 95% confidence interval (CI), 1.06-2.47) and after the diagnosis of celiac disease (hazard ratio, 1.82; 95% CI, 1.40-2.35), with the risk of disease being highest in the first year of follow-up.

CONCLUSIONS

Only a minor fraction of the celiac disease patient population had a prior diagnosis of Lyme disease. The similar association between Lyme disease and celiac disease both before and after the diagnosis of celiac disease is strongly suggestive of surveillance bias as a likely contributor. Taken together, the data indicate that Borrelia infection is not a substantive risk factor in the development of celiac disease.

Microbes and Viruses Are Bugging the Gut in Celiac Disease. Are They Friends or Foes?

The links between microorganisms/viruses and autoimmunity are complex and multidirectional. A huge number of studies demonstrated the triggering impact of microbes and viruses as the major environmental factors on the autoimmune and inflammatory diseases. However, growing evidences suggest that infectious agents can also play a protective role or even abrogate these processes. This protective crosstalk between microbes/viruses and us might represent a mutual beneficial equilibrium relationship between two cohabiting ecosystems. The protective pathways might involve post-translational modification of proteins, decreased intestinal permeability, Th1 to Th2 immune shift, induction of apoptosis, auto-aggressive cells relocation from the target organ, immunosuppressive extracellular vesicles and down regulation of auto-reactive cells by the microbial derived proteins. Our analysis demonstrates that the interaction of the microorganisms/viruses and celiac disease (CD) is always a set of multidirectional processes. A deeper inquiry into the CD interplay with Herpes viruses and Helicobacter pylori demonstrates that the role of these infections, suggested to be potential CD protectors, is not as controversial as for the other infectious agents. The outcome of these interactions might be due to a balance between these multidirectional processes.

The progression of coeliac disease: its neurological and psychiatric implications

The aim of the paper is to show the various neurological and psychiatric symptoms in coeliac disease (CD). CD is a T cell-mediated, tissue-specific autoimmune disease which affects genetically susceptible individuals after dietary exposure to proline- and glutamine-rich proteins contained in certain cereal grains. Genetics, environmental factors and different immune systems, together with the presence of auto-antigens, are taken into account when identifying the pathogenesis of CD. CD pathogenesis is related to immune dysregulation, which involves the gastrointestinal system, and the extra-intestinal systems such as the nervous system, whose neurological symptoms are evidenced in CD patients. A gluten-free diet (GFD) could avoid cerebellar ataxia, epilepsy, neuropathies, migraine and mild cognitive impairment. Furthermore, untreated CD patients have more symptoms and psychiatric co-morbidities than those treated with a GFD. Common psychiatric symptoms in untreated CD adult patients include depression, apathy, anxiety, and irritability and schizophrenia is also common in untreated CD. Several studies show improvement in psychiatric symptoms after the start of a GFD. The present review discusses the state of the art regarding neurological and psychiatric complications in CD and highlights the evidence supporting a role for GFD in reducing neurological and psychiatric complications.

Ethnic differences in coeliac disease autoimmunity in childhood: the Generation R Study

OBJECTIVE

The aim was to identify whether ethnic differences in coeliac disease autoimmunity (CDA) in children at 6 years of age exist, and when present, to evaluate how these differences may be explained by sociodemographic and environmental factors.

DESIGN

This study was embedded within a multi-ethnic population-based prospective cohort study.

SETTING AND PATIENTS

4442 six-year-old children born between 2002 and 2006 were included. Information on ethnicity, environmental and lifestyle characteristics was assessed by questionnaires. Ethnicity was categorised into Western (Dutch, European, Indonesian, American, Oceanian) and non-Western (Turkish, Moroccan, Cape Verdean, Antillean, Surinamese). Serum transglutaminase type 2 antibody (TG2A) levels were measured with fluorescence enzyme immunoassay. Serum IgG levels against cytomegalovirus (CMV) were measured by ELISA.

MAIN OUTCOME MEASURES

TG2A positivity was defined as TG2A ≥7 U/mL, strong TG2A positivity as TG2A ≥10 upper limit normal (70 U/mL).

RESULTS

Of 4442 children, 60 (1.4%) children were TG2A positive, of whom 31 were strong positive. 66% of children were Western, 33% non-Western. Western ethnicity, high socioeconomic position and daycare attendance were positively associated with strong TG2A positivity (odds ratio (OR) 6.85 (1.62 to 28.8) p<0.01, OR 3.70 (1.40 to 9.82) p<0.01, OR 3.90 (1.38 to 11.0) p=0.01 resp.), whereas CMV seropositivity was inversely related to strong TG2A positivity (OR 0.32 (0.12 to 0.84) p=0.02). Together, these factors explained up to 47% (-67 to -17; p=0.02) of the ethnic differences in TG2A positivity between Western and non-Western children.

CONCLUSIONS

Ethnic differences in children with CDA are present in childhood. Socioeconomic position, daycare attendance and CMV seropositivity partly explained these differences, which may serve as targets for prevention strategies for CDA.

Reovirus infection triggers inflammatory responses to dietary antigens and development of celiac disease

Viral infections have been proposed to elicit pathological processes leading to the initiation of T helper 1 (TH1) immunity against dietary gluten and celiac disease (CeD). To test this hypothesis and gain insights into mechanisms underlying virus-induced loss of tolerance to dietary antigens, we developed a viral infection model that makes use of two reovirus strains that infect the intestine but differ in their immunopathological outcomes. Reovirus is an avirulent pathogen that elicits protective immunity, but we discovered that it can nonetheless disrupt intestinal immune homeostasis at inductive and effector sites of oral tolerance by suppressing peripheral regulatory T cell (pTreg) conversion and promoting TH1 immunity to dietary antigen. Initiation of TH1 immunity to dietary antigen was dependent on interferon regulatory factor 1 and dissociated from suppression of pTreg conversion, which was mediated by type-1 interferon. Last, our study in humans supports a role for infection with reovirus, a seemingly innocuous virus, in triggering the development of CeD.

HLA specificities are associated with prognosis in IGHV-mutated CLL-like high-count monoclonal B cell lymphocytosis

Introduction

Molecular alterations leading progression of asymptomatic CLL-like high-count monoclonal B lymphocytosis (hiMBL) to chronic lymphocytic leukemia (CLL) remain poorly understood. Recently, genome-wide association studies have found 6p21.3, where the human leukocyte antigen (HLA) system is coded, to be a susceptibility risk region for CLL. Previous studies have produced discrepant results regarding the association between HLA and CLL development and outcome, but no studies have been performed on hiMBL.

Aims

We evaluated the role of HLA class I (-A, -B and -C) and class II (-DRB1 and -DQB1) in hiMBL/CLL susceptibility, hiMBL progression to CLL, and treatment requirement in a large series of 263 patients diagnosed in our center with hiMBL (n = 156) or Binet A CLL (n = 107).

Results

No consistent association between HLA specificities and hiMBL or CLL susceptibility was found. With a median follow-up of 7.7 years, 48/156 hiMBLs (33%) evolved to asymptomatic CLLs, while 16 hiMBLs (10%) and 44 CLLs (41%) required treatment. No HLA specificities were found to be significantly associated with hiMBL progression or treatment in the whole cohort. However, within antigen-experienced immunoglobulin heavy-chain (IGHV)-mutated hiMBLs, which represents the highest proportion of hiMBL cases (81%), the presence of HLA-DQB1*03 showed a trend to a higher risk of progression to CLL (60% vs. 26%, P = 0.062). Moreover, HLA-DQB1*02 specificity was associated with a lesser requirement for 15-year treatment (10% vs. 36%, P = 0.012).

Conclusion

In conclusion, our results suggest a role for HLA in IGHV-mutated hiMBL prognosis, and are consistent with the growing evidence of the influence of 6p21 on predisposition to CLL. Larger non-biased series are required to enable definitive conclusions to be drawn.

Herpesvirus Infections and Transglutaminase Type 2 Antibody Positivity in Childhood: The Generation R Study

OBJECTIVES

Persistent viral infections have been implicated in the etiology of autoimmune diseases in adulthood, but it is not known whether herpesviruses are associated with the development of celiac disease autoimmunity in childhood. We assessed whether herpesvirus infections are associated with transglutaminase type 2 antibody (TG2A) concentrations in children at 6 years of age.

METHODS

The present study was embedded within a population-based prospective cohort study. Serum immunoglobulin G levels against Epstein-Barr virus, cytomegalovirus (CMV), and herpes simplex virus type 1 were measured by enzyme-linked immunosorbent assay , and TG2A concentrations with fluorescence enzyme immunoassay in 4420 children at 6 years of age. Children were categorized based on TG2A concentrations into negative (<7 U/mL), positive (≥7-70 U/mL), and strongly positive (≥70 U/mL), that is, 10 times upper limit normal.

RESULTS

Fifty-nine children (1.3%) were TG2A positive, and of these 31 (53%) had concentrations 70 U/mL or more. Children with TG2A concentrations 70 U/mL or more were less often infected with CMV (adjusted odds ratio (aOR) 0.38, 95% CI 0.14-0.98, P = 0.04) and with any of the 3 viruses (aOR 0.38, 95% CI 0.18-0.78, P < 0.01) than children with TG2A negative concentrations. In addition, children with TG2A concentrations 70 U/mL or more were less often infected with 2 or more viruses than children with TG2A negative concentrations (aOR 0.15, 95% CI 0.03-0.65, P = 0.01).

CONCLUSIONS

Both CMV single infection and combined CMV, Epstein-Barr virus and/or herpes simplex virus type 1 infections are inversely associated with strongly TG2A positivity. This may indicate a protective effect of herpesvirus infections in the pathogenesis of celiac disease autoimmunity.

Immunopathogenesis and therapeutic approaches in pediatric celiac disease

Celiac Disease is an autoimmune enteropathy with increasing incidence worldwide in both adults and children. It occurs as an inflammatory condition with destruction of the normal architecture of villi on consumption of gluten and related protein products found in wheat, barley and rye. However, the exact pathogenesis is not yet fully understood. A gluten-free diet remains the main modality of therapy to date. While some patients continue to have symptoms even on a gluten-free diet, adherence to this diet is also difficult, especially for the children. Hence, there is continued interest in novel methods of therapy and the current research focus is on the promising novel non-dietary modalities of treatment. Here, we critically reviewed the existing literature regarding the pathogenesis of celiac disease in children including the role of in-utero exposure leading to neonatal and infant sensitization and its application for the development of new therapeutic approaches for these patients.

All disease begins in the gut: Celiac disease co-existence with SLE

BACKGROUND

Case reports and case series have indicated a possible association between celiac disease (CD) and systemic lupus erythematosus (SLE), but additional population-based studies are required. The true prevalence of CD in SLE patients is still unknown, but is indeed an important factor when considering the clinical implications, notably the necessity of screening strategies in SLE patients. Our objective was to investigate the association between CD and SLE using a community-based approach in a real-life population database.

METHODS

Patients with SLE were compared with age- and sex-matched controls regarding the prevalence of CD in a case-control study. Chi-square and t-tests were used for univariate analysis and a logistic regression model was used for multivariate analysis. The study was performed utilizing the medical database of Clalit Health Services.

RESULTS

The study included 5018 patients with SLE and 25,090 age- and sex-matched controls. The prevalence of CD was significantly higher in patients with SLE than in controls in univariate analysis (0.8% and 0.2%, respectively, p<0.001). Also, SLE was associated with CD (OR 3.92, 95% CI 2.55-6.03, p<0.001) in a multivariate logistic regression model.

CONCLUSIONS

Patients with SLE had a greater prevalence of CD than matched controls in a large case-control study. A complex combination of genetic, immunological and novel environmental factors may explain this positive association. Physicians should keep in mind that CD can be a tricky diagnosis in SLE patients, yet a treatable condition, probably more common in this population than we used to think.

Prevalence and Natural History of Celiac Disease in a Cohort of At-risk Children

OBJECTIVES

To assess the prevalence and clinical presentation of celiac disease (CD) in a cohort of children with HLA-DQ2 positive and evaluate the risk factors in the development of CD.

METHODS

Between July 2004 and July 2005, parents of all healthy full-term newborns in our hospital were invited to participate. HLA-DQ2 was tested in blood sample of the umbilical cord. A point of contact serological test was performed on children between 2 and 3 years of age. Positive results were confirmed by serum anti-transglutaminase 2 and endomysial antibodies. Children with high autoantibody titers underwent an intestinal biopsy. Children of the cohort diagnosed with CD before the screening study were included. Sex, mode of delivery, breast-feeding duration, and age of gluten introduction were studied.

RESULTS

Of 1291 children, 362 were HLA-DQ2 positive and 262 participated in the study. CD was diagnosed in 4.1% (95% confidence interval (CI) 1.9-6.3). In the whole cohort, 60% had gastrointestinal symptoms, 7% poor weight gain, and 33% were asymptomatic. Five children with potential CD and 6 with CD autoimmunity became negative (42.3%) and are still negative after 5 to 7 years. Female sex was at-risk factor odds ratio 5.7 (95% CI 1.5-20.9), whereas breast-feeding during gluten introduction had a protective effect odds ratio 0.1 (95% CI 0.01-0.8).

CONCLUSIONS

Prevalence of CD in this cohort was 4%, half of whom had digestive symptoms. Because a high proportion of children showed a spontaneous disappearance of antibodies, prevalence studies of CD in young children should be based on intestinal damage so as not to overestimate results.

Study of duodenal bacterial communities by 16S rRNA gene analysis in adults with active celiac disease vs non-celiac disease controls

AIMS

Several studies have suggested that abnormalities in the small-intestinal microbiota might be involved in the development or the pathogenesis of celiac disease (CD). The objective of this study was to characterize and compare the composition of the duodenal microbiota between CD patients and non-CD controls.

METHOD AND RESULTS

Bacterial communities were identified by pyrosequencing of 16S rRNA extracted from duodenal biopsies. The sequences analysis showed that the majority of the reads were classified within two phyla: Firmicutes and Proteobacteria. Bacterial richness and diversity were higher in non-CD controls than in untreated CD patients, but the differences were not statistically significant. The principal coordinates analysis revealed that bacterial communities of non-CD controls and untreated CD patients were dispersed without forming a clear group according to diagnosis of CD.

CONCLUSIONS

There are no statistically significant differences in the upper small intestinal composition of bacterial communities between untreated CD patients and non-CD controls.

SIGNIFICANCE AND IMPACT OF THE STUDY

This pyrosequencing analysis reveals a global picture of the duodenal microbiota that could be useful in future trials investigating the role of the microbiota in CD.

The virus-induced HSPs regulate the apoptosis of operatus APCs that result in autoimmunity, not in homeostasis

The viruses stand salient as environmental factors that trigger autoimmunity. The virus realizes its effects through induction of heat-shock proteins (HSPs) as well as by the viral IE-axis-mediated conversion of organ epithelial cells into virgin de novo professional antigen-presenting cells (APCs). The HSP is the accomplished operator in homeostasis by the logic of it being the regulator of apoptosis. By virtue of its regulation of apoptosis, the HSP is also involved in autoimmunity: (1) adornment of viral IE-axis-generated virgin de novo professional APCs with HSP-induced co-stimulatory molecules which transform these otherwise epithelial cells to competent antigen presenters, the operatus APCs, liable to apoptosis that becomes the initiator of organ damages; (2) molecular mimicry mechanism: epitopes on the HSP may be mistaken for viral peptides and be presented by operatus APCs to autoreactive TCRs resulting in the apoptosis of the operatus APCs; (3) regulation of MHC class II DR-mediated apoptosis of operatus APCS which can result in organ-specific autoimmune syndromes. We should remember, however, that Nature's intended purpose for apoptosis of the professional APCs is benevolence: as a principal regulator of immune homeostasis. But the apoptosis of our postulated operatus APCs can result in autoimmunity. The transformation of virgin de novo professional APCs to operatus APCs mirrors the maturation of DCs through their acquisition of HSP-induced costimulatory molecules. What happens to mature DCs as antigen presenters that end in homeostasis is replicated by what happens to operatus APCs that ends instead in autoimmunity.

The Interaction among Microbiota, Immunity, and Genetic and Dietary Factors Is the Condicio Sine Qua Non Celiac Disease Can Develop

Celiac disease (CD) is an immune-mediated enteropathy, triggered by dietary wheat gluten and similar proteins of barley and rye in genetically susceptible individuals. This is a complex disorder involving both environmental and immune-genetic factors. The major genetic risk factor for CD is determined by HLA-DQ genes. Dysfunction of the innate and adaptive immune systems can conceivably cause impairment of mucosal barrier function and development of localized or systemic inflammatory and autoimmune processes. Exposure to gluten is the main environmental trigger responsible for the signs and symptoms of the disease, but exposure to gluten does not fully explain the manifestation of CD. Thus, both genetic determination and environmental exposure to gluten are necessary for the full manifestation of CD; neither of them is sufficient alone. Epidemiological and clinical data suggest that other environmental factors, including infections, alterations in the intestinal microbiota composition, and early feeding practices, might also play a role in disease development. Thus, this interaction is the condicio sine qua non celiac disease can develop. The breakdown of the interaction among microbiota, innate immunity, and genetic and dietary factors leads to disruption of homeostasis and inflammation; and tissue damage occurs. Focusing attention on this interaction and its breakdown may allow a better understanding of the CD pathogenesis and lead to novel translational avenues for preventing and treating this widespread disease.

Sourdough fermentation of wheat flour does not prevent the interaction of transglutaminase 2 with α2-gliadin or gluten

The enzyme transglutaminase 2 (TG2) plays a crucial role in the initiation of celiac disease by catalyzing the deamidation of gluten peptides. In susceptible individuals, the deamidated peptides initiate an immune response leading to celiac disease. Several studies have addressed lactic fermentation plus addition of enzymes as a means to degrade gluten in order to prevent adverse response in celiacs. Processing for complete gluten degradation is often harsh and is not likely to yield products that are of comparable characteristics as their gluten-containing counterparts. We are concerned that incomplete degradation of gluten may have adverse effects because it leads to more available TG2-binding sites on gluten peptides. Therefore, we have investigated how lactic acid fermentation affects the potential binding of TG2 to gluten protein in wheat flour by means of estimating TG2-mediated transamidation in addition to measuring the available TG2-binding motif QLP, in α₂-gliadin. We show that lactic fermentation of wheat flour, as slurry or as part of sourdough bread, did not decrease the TG2-mediated transamidation, in the presence of a primary amine, to an efficient level (73%–102% of unfermented flour). Nor did the lactic fermentation decrease the available TG2 binding motif QLP in α₂-gliadin to a sufficient extent in sourdough bread (73%–122% of unfermented control) to be useful for celiac safe food.