Coeliac disease and gluten sensitivity

High-resolution analysis of the treated coeliac disease microbiome reveals strain-level variation

BACKGROUND

Coeliac disease (CeD) is an immune-mediated disorder primarily affecting the small intestine, characterized by an inflammatory immune reaction to dietary gluten. CeD onset results from a multifaceted interplay of genetic and environmental factors. While recent data show that alterations in gut microbiome composition could play an important role, many current studies are constrained by small sample sizes and limited resolution.

METHODS

To address these limitations, we analyzed fecal gut microbiota from two Dutch cohorts, CeDNN (128 treated CeD patients (tCeD), 106 controls) and the Lifelines Dutch Microbiome Project (24 self-reported tCeD, 654 controls), using shotgun metagenomic sequencing. Self-reported IBS (570 cases, 1710 controls) and IBD (93 cases, 465 controls) were used as comparative conditions of the gastrointestinal tract. Interindividual variation within the case and control groups was calculated at whole microbiome and strain level. Finally, species-specific gene repertoires were analyzed in tCeD patients and controls.

RESULTS

Within-individual microbiome diversity was decreased in patients with self-reported IBS and IBD but not in tCeD patients. Each condition displayed a unique microbial pattern and, in addition to confirming previously reported microbiome associations, we identify an increase in the levels of Clostridium sp. CAG:253, Roseburia hominis, and Eggerthella lenta, amongst others. We further show that the observed changes can partially be explained by gluten-free diet adherence. We also observe increased interindividual variation of gut microbiome composition among tCeD patients and a higher bacterial mutation frequency in tCeD that contributes to higher interindividual variation at strain level. In addition, the immotile European subspecies of Eubacterium rectale, which has a distinct carbohydrate metabolism potential, was nearly absent in tCeD patients.

CONCLUSION

Our study sheds light on the complex interplay between the gut microbiome and CeD, revealing increased interindividual variation and strain-level variation in tCeD patients. These findings expand our understanding of the microbiome's role in intestinal health and disease.

Potential coeliac disease in children: a single-center experience

OBJECTIVES

Potential coeliac disease (PCD) is defined by the presence of positive CD-specific autoantibodies with a normal/extremely mildly damaged intestinal mucosa. This study sought to examine the progression of PCD in children maintaining a gluten-containing diet and to identify risk factors associated with the onset of CD. A comparative literature review was conducted to assess the results in the context of existing evidence.

METHODS

A retrospective cohort study was performed on 67 children diagnosed with PCD between January 2005 and January 2022, with a maximum follow up of 53 months. The associations between baseline clinical characteristics and the development of CD were assessed using hazard ratios (HR).

RESULTS

Nineteen percent (19 %) (12/67, cumulative incidence) of PCD children, with a median age of 4.3 years, progressed to CD during a median follow up period of 30 months. A fluctuating trend in tissue transglutaminase IgA (tTG-IgA) levels was observed in 35.8 % (24/67) of the children, while 46.2 % (31/67) showed tTG-IgA negativization. In univariable analysis, the presence of autoimmune disease and one-year increase in age at diagnosis were significantly associated with CD progression [HR=17.7 (95%CI: 3.0-106.8; p=0.0017) and HR=1.3 (95%CI: 1.1-1.5; p=0.0125), respectively].

CONCLUSIONS

Our study confirms that only a small proportion of PCD children progress to CD. It also highlights that advancing age and the presence of autoimmune disease are the main risk factors for the development of villous atrophy. A better understanding of tTG-IgA trend during follow up could help in the management of PCD children.

Differential immune responses behind different celiac disease manifestations

In celiac disease (CeD), dietary gluten serves as the driver for a comparatively well characterized small bowel mucosal immune response that generally results in small bowel mucosal villous atrophy and crypt hyperplasia along with a disease-specific transglutaminase 2 (TG2) targeting autoantibody response. Individuals with positive TG2 autoantibodies but normal small intestinal mucosal morphology are regarded at increased risk of developing CeD and represent patients with potential CeD. The removal of gluten from the diet leads to disappearance of the autoantibodies and normalization of the mucosal architecture in most cases. However, refractory CeD patients deviate from this dogma as they present with abnormal T cell compartment, persistent symptoms and villous atrophy despite a strict gluten-free diet. The heterogeneity of CeD presentation is further diversified by varying symptomatology. Gastrointestinal symptoms are the most canonical signs of CeD, and they include for instance diarrhea, vomiting, constipation and abdominal pain. Yet, a great portion of the patients manifest the disease at extraintestinal sites such as skin, musculoskeletal system or neuronal tissues. Beyond the involvement of various transglutaminase autoantibodies, the detailed immune mechanisms contributing to the development of these manifestations remains elusive, though. This review highlights the current understanding of the immunological differences in various manifestations of CeD. As the immunological basis of the different CeD phenotypes is at present insufficiently understood, more research on the subject is warranted before such data could be maximally applied to clinical practice.

Utilizing Telemedicine Applications in Celiac Disease and Other Gluten-Free-Diet-Dependent Conditions: Insights from the COVID-19 Pandemic

BACKGROUND

Globally, approximately 1.4% of people have celiac disease (CD), induced by gluten sensitivity. If left untreated, it causes small intestinal inflammation and villous atrophy, which can result in failure to thrive, anemia, osteoporosis, malabsorption, and even malignancy. The only treatment option available is a gluten-free diet (GFD). Few studies have looked at the role and perception of telehealth in relation to CD and selective nutrition both before and after the COVID-19 pandemic.

AIM

Our goal was to screen and investigate the research conducted both before and after the COVID-19 pandemic concerning the utilization of telehealth applications and solutions in CD and other GFD-dependent circumstances.

METHODS

We employed a narrative review approach to explore articles that were published in scholarly journals or organizations between the years 2000 and 2024. Only English-language publications were included. PubMed and Google Scholar searches were mainly conducted using the following keywords: telemedicine, telehealth, telecare, eHealth, m-health, COVID-19, SARS-CoV-2, celiac disease, and gluten-free diet (GFD). Manual searches of the references in the acquired literature were also carried out, along with the authors' own personal contributions of their knowledge and proficiency in this field.

RESULTS

Only a few studies conducted prior to the COVID-19 outbreak examined the viewpoints and experiences of adult patients with CD with relation to in-person clinic visits, as well as other options such as telehealth. The majority of patients believed that phone consultations were appropriate and beneficial. Video conferencing and telemedicine became more popular during the COVID-19 pandemic, demonstrating the effectiveness of using these technologies for CD on a global basis. In recent years, urine assays for gluten identification have become accessible for use at home. These tests could be helpful for CD monitoring with telemedicine assistance.

CONCLUSIONS

The extended knowledge gathered from the COVID-19 pandemic is expected to complement pre-COVID-19 data supporting the usefulness of telemedicine even after the emergent pandemic, encouraging its wider adoption in standard clinical practice. The monitoring and follow-up of CD patients and other GFD-dependent conditions can greatly benefit from telemedicine.

Psoriasis, bone and bowel: a comprehensive review and new insights

Psoriasis is a chronic immune-mediated disorder affecting about 2% of the population worldwide which is associated with significant morbidity. The disease usually presents as raised, well-demarcated erythematous plaques with adherent silvery scales. Psoriasis can appear at any age but it has two peaks occurring at 15–20 and 55–60 years of age. It affects males and females equally. Despite the multitude of investigations about psoriasis and even development of drugs with satisfactory results, its pathogenesis is not fully understood yet and its course is unpredictable. Various environmental triggers, e.g., obesity, stress and drugs may induce disease in genetically susceptible patients. Although psoriasis was considered primarily as a disease of the skin, more investigations have been revealed its systemic nature. Psoriatic arthritis (PsA) may complicate up to one-third of cases of psoriasis vulgaris (PV). Also, the association between psoriasis and a variety of other immune-mediated disorders such as inflammatory bowel disease (IBD) and celiac disease (CD) has been confirmed in various studies. Moreover, a growing body of evidences indicates that psoriasis shares some common histological and phenotypical properties with the spectrum of osteoimmunological diseases such as Paget’s disease of bone (PDB). Thus, exploring the common molecular and genetic mechanisms underlying psoriasis and related disorders is of paramount importance for better elucidating disease pathogenesis and designing more targeted treatments.

Role of Human Leukocyte Antigen Class II in Antibody-Mediated Skin Disorders

HLA class II molecules are key factors determining susceptibility to autoimmune disorders, and their role in immune-mediated skin conditions such as psoriasis has been extensively investigated. However, there is currently little understanding of their role in antibody-mediated skin diseases such as autoimmune blistering disorders. We researched the available literature using PubMed to narratively review the current knowledge on HLA associations in antibody-mediated blistering skin pathologies. Our results summarized the risk alleles that are identified in the literature, together with certain known protective alleles: in the pemphigus group, alleles HLA-DQB1*0503 and HLA-DRB1*0402 are most commonly associated with disease; in the pemphigoid group, the most studied allele is HLA-DQB1*0301; in epidermolysis bullosa acquisita, few genetic studies are available; in dermatitis herpetiformis, the association with haplotypes HLA-DQ2 and HLA-DQ8 is strongly established; finally, in linear IgA bullous disease, specific HLA alleles may be responsible for pediatric presentations. Our current pathogenic understanding of this group of disorders assigns a key role to predisposing HLA class II alleles that are able to bind disease autoantigens and therefore stimulate antigen-specific autoreactive T cells. The latter engage B lymphocytes that will produce pathogenic autoantibodies. The distribution of HLA alleles and their disease associations are variable across demographics, and an in-depth pathogenetic understanding is needed to support associations between HLA alleles and disease phenotypes. Additionally, in a personalized medicine approach, the identification of HLA alleles associated with the risk of disease may become clinically relevant in identifying susceptible subjects that should avoid exposure to known triggers, such as medication, when possible.

Positivity of celiac disease-specific antibodies and non-celiac hypersensitivity in psoriasis

INTRODUCTION

Plaque psoriasis and celiac disease are multisystemic diseases. The association of psoriasis and enteropathy with histological changes similar to celiac disease has already been described, and it has also been found that a gluten-free diet improves psoriatic changes. This study assesses the relationship between celiac disease antibodies and psoriasis.

METHODS

The study included 112 participants: 60 with psoriasis in a test group and 52 healthy subjects in a control group. Within the psoriasis group, participants were further divided into two subgroups: one consisting of patients with both psoriasis and psoriatic arthritis (n = 17) and another comprising patients with psoriasis alone (n = 43). After informed consent was obtained, the Dermatology Life Quality Index (DLQI) score and Psoriasis Area and Severity Index (PASI) score were evaluated. Laboratory tests included assessment of anti-deaminated gliadin peptide antibodies (DGP), anti-gliadin antibodies (AGA), and anti-tissue transglutaminase antibodies (tTG).

RESULTS

Immunoglobulin G (IgG) and immunoglobulin A (IgA) DGP antibodies were detected more frequently and at higher serum concentrations in patients with psoriasis compared to healthy controls (p = 0.03, p = 0.04, respectively). Similarly, elevated levels of IgG-tTG antibodies (p = 0.003) and IgA-DGP antibodies (p = 0.02) were observed in the same test group.

CONCLUSIONS

A relationship between positivity to celiac disease antibodies and psoriasis, particularly with regard to AGA, has been identified. Further studies are required to elucidate the nature, pathophysiology, and significance of these findings.

Co-occurrence of celiac disease and glycogen storage disease in a five-year-old patient with diabetes mellitus; a case report

A patient presented with edema, ascites and jaundice. Histologic report was consistent with Celiac Disease. Liver biopsy commensurate with Glycogen storage disease III, which was confirmed by genetic testing. A gluten-free diet was initiated. After 2 months, ascites was relieved, hepatic function was improved, and hepatic size reduced.

Gluten proteins: Enzymatic modification, functional and therapeutic properties

Glutens are potential proteins with multifunctional therapeutic effects. Their covalence network structures with and without protease inhibitors are expected to enhance or to serve further properties and further technological points such as increased bioactive surfaces, gelatinization, gelation and pasting properties. The depletion of the allergic peptide sequences of gluten proteins comprising sometimes protease inhibitors are valid via the enzymatic ingestion using proteolytic enzymes that might enhance these functional and technological processes by producing active peptides having osmoregulation and regular glass transitions, surface activity for coating and encapsulation properties. In addition to further therapeutic functions such as immunoregulatory, antithrombin and opioidal activities, particularly in eradicating most of the free radicals, suppressing diabetes Mellitus II complications and inhibiting angiotensin converting enzyme cardiovascular growth diseases.

Intestinal Cellular Biomarkers of Mucosal Lesion Progression in Pediatric Celiac Disease

Celiac disease (CD) is a chronic intestinal inflammation caused by gluten ingestion in genetically predisposed individuals. Overt-CD and potential-CD are the two main forms of gluten intolerance in pediatric patients with different grades of intestinal mucosa lesion and clinical management. For overt-CD patients the gluten-free diet is mandatory, while for potential-CD the dietary therapy is recommended only for those subjects becoming clinically symptomatic overtime. To date, specific early biomarkers of evolution to villous atrophy in potential-CD are lacking. We recently observed an expansion of TCRγδ+ T cells and a concomitant disappearance of IL4-producing T cells in the intestinal mucosa of overt-CD patients compared to potential-CD children, suggesting the involvement of these two cells subsets in the transition from potential-CD to overt-CD. In this study, we demonstrated that the intestinal densities of IL4+ T cells inversely correlated with TCRγδ+ T cell expansion (p < 0.005) and with the serum levels of anti-tissue transglutaminase antibodies (p < 0.01). The changes of these two cell subsets strongly correlated with mucosal lesions, according to the histological Marsh classification, as the transition from M0 to M3 lesions was associated with a significant reduction of IL4+ T cells (M0 vs. M1 p < 0.04, M0 vs. M3 p < 0.007) and an increase of TCRγδ+ T cells (M0 vs. M1 p < 0.05, M0 vs. M3 p < 0.0006). These findings strongly suggest that the detection of TCRγδ+ and IL4+ T cells could serve as cellular biomarkers of mucosal lesion and targets of novel immunomodulatory therapies for CD.

Oral Mucosa as a Potential Site for Diagnosis and Treatment of Allergic and Autoimmune Diseases

Most prevalent food allergies during early childhood are caused by foods with a high allergenic protein content, such as milk, egg, nuts, or fish. In older subjects, some respiratory allergies progressively lead to food-induced allergic reactions, which can be severe, such as urticaria or asthma. Oral mucosa remodeling has been recently proven to be a feature of severe allergic phenotypes and autoimmune diseases. This remodeling process includes epithelial barrier disruption and the release of inflammatory signals. Although little is known about the immune processes taking place in the oral mucosa, there are a few reports describing the oral mucosa-associated immune system. In this review, we will provide an overview of the recent knowledge about the role of the oral mucosa in food-induced allergic reactions, as well as in severe respiratory allergies or food-induced autoimmune diseases, such as celiac disease.

Iron Absorption in Celiac Disease and Nutraceutical Effect of 7-Hydroxymatairesinol. Mini-Review

Anemia is the main extra-gastrointestinal symptom in inflammatory bowel diseases (IBDs). Interleukin-6 (IL-6) and other cytokines are secreted and act in the microenvironment of the small intestine mucous membrane of IBD patients. Iron is essential for multiple cell functions and its homeostasis is regulated by the hepcidin–ferroportin axis. Hepcidin (HEPC) is mainly produced by the liver in response to iron needs but is also an acute phase protein. During inflammation, hepcidin is upregulated by IL-6 and is responsible for iron compartmentalization within cells, in turn causing anemia of inflammation. Tissues other than liver can produce hepcidin in response to inflammatory stimuli, in order to decrease iron efflux at a local level, then acting in an autocrine–paracrine manner. In IBDs and, in particular, in celiac disease (CeD), IL-6 might trigger the expression, upregulation and secretion of hepcidin in the small intestine, reducing iron efflux and exacerbating defective iron absorption. 7-Hydroxymatairesinol (7-HMR) belongs to the family of lignans, polyphenolic compounds produced by plants, and has nutraceutical antioxidant, anti-inflammatory and estrogenic properties. In this mini-review we revise the role of inflammation in IBDs and in particular in CeD, focusing our attention on the close link among inflammation, anemia and iron metabolism. We also briefly describe the anti-inflammatory and estrogenic activity of 7-HMR contained in foods that are often consumed by CeD patients. Finally, considering that HEPC expression is regulated by iron needs, inflammation and estrogens, we explored the hypothesis that 7-HMR consumption could ameliorate anemia in CeD using Caco-2 cells as bowel model. Further studies are needed to verify the regulation pathway through which 7-HMR may interfere with the local production of HEPC in bowel.

Non-celiac gluten sensitivity and chronic refractory low back pain with spondyloarthritis features

OBJECTIVE

To propose the hypothesis that non-celiac gluten sensitivity is associated with chronic low-back pain related to spondyloarthritis, and a gluten free diet has a therapeutic benefit in a subgroup of patients. Gut involvement is a well-known association of spondyloarthritis but limited to a few disorders such as inflammatory bowel disease. Currently the therapeutic implication of this association is pharmacologic treatment for inflammation with immunosupresive drugs for both diseases. Here is a case series of patients with chronic low-back pain, spondyloarthritis related features, and response to gluten free diet despite celiac disease being ruled out.

METHODS

Retrospective case report of 110 patients from a tertiary hospital rheumatology clinic specialized in chronic pain and gluten sensitivity. These are patients with refractory low-back pain and spondyloarthritis features who followed a gluten free diet despite celiac disease being ruled out. Demanding improvement was defined based on the achievement of at least one of the following objectives: asymptomatic status, remission of chronic low-back pain, returning to normal life, returning to work, changing from confinement to bed/wheelchair to being able to walk, returning to self-sufficiency for hygiene and personal care, discontinuation of opioids.

RESULTS

Average age at low-back onset pain was 30. Average disease duration was 15 years. 87 (79%) of the patients experienced improvement. 69 (62%) of the patients achieved demanding improvement. Average duration of gluten-free diet in patients with demanding improvement was 60 months. 56 out of 69 patients with demanding improvement ingested gluten. Of these 56 patients, 54 experienced clinical worsening and were considered as having non-celiac gluten sensitivity. Oral aphthae and having a relative with celiac disease were associated with demanding improvement. Out of 28 patients retrospectively classified as having axial spondyloarthritis, 23 had demanding improvement. Out of 16 patients with uveitis, 13 had demanding improvement. Out of 83 patients with fibromyalgia, 48 had demanding improvement.

CONCLUSION

These observational data support the proposed hypothesis and offer information regarding possible clinical predictors of response to diet.

Pathogenesis of Celiac Disease and Other Gluten Related Disorders in Wheat and Strategies for Mitigating Them

Wheat is a major cereal crop providing energy and nutrients to the billions of people around the world. Gluten is a structural protein in wheat, that is necessary for its dough making properties, but it is responsible for imparting certain intolerances among some individuals, which are part of this review. Most important among these intolerances is celiac disease, that is gluten triggered T-cell mediated autoimmune enteropathy and results in villous atrophy, inflammation and damage to intestinal lining in genetically liable individuals containing human leukocyte antigen DQ2/DQ8 molecules on antigen presenting cells. Celiac disease occurs due to presence of celiac disease eliciting epitopes in gluten, particularly highly immunogenic alpha-gliadins. Another gluten related disorder is non-celiac gluten-sensitivity in which innate immune-response occurs in patients along with gastrointestinal and non-gastrointestinal symptoms, that disappear upon removal of gluten from the diet. In wheat allergy, either IgE or non-IgE mediated immune response occurs in individuals after inhalation or ingestion of wheat. Following a life-long gluten-free diet by celiac disease and non-celiac gluten-sensitivity patients is very challenging as none of wheat cultivar or related species stands safe for consumption. Hence, different molecular biology, genetic engineering, breeding, microbial, enzymatic, and chemical strategies have been worked upon to reduce the celiac disease epitopes and the gluten content in wheat. Currently, only 8.4% of total population is affected by wheat-related issues, while rest of population remains safe and should not remove wheat from the diet, based on false media coverage.

A Clinician's Guide to Celiac Disease HLA Genetics

Celiac disease is a common inflammatory disease triggered by dietary gluten in genetically susceptible individuals. The strongest and best-characterized genetic susceptibilities in celiac disease are class II human leukocyte antigen (HLA) genes known as HLA-DQ2 and DQ8. HLA genetic testing is available through a number of commercial and academic laboratories and is used in the evaluation of celiac disease and to identify at-risk family members. Importantly, HLA genetic testing has a high negative predictive value for celiac disease, but a low positive predictive value. Therefore, for a practicing clinician, it is important to understand when to order HLA genetic testing, what test to order, and how to interpret the result. This review provides a practical primer on HLA genetics in celiac disease.

The 5 Ws of a gluten challenge for gluten-related disorders

Gluten-related disorders (GRDs) are gradually emerging as epidemiologically relevant diseases, with a global prevalence estimated to be approximately 5% in the population. Conditions related to gluten ingestion include celiac disease (CD), wheat allergy (WA), and nonceliac gluten sensitivity (NCGS). Although mediated by different pathogenic pathways, these 3 conditions share similar clinical manifestations and can present a difficult differential diagnosis. The gluten challenge (GC) is an important diagnostic tool for GRDs, but there is great variability in regards to deciding which patients should be challenged, what amount of gluten should be used, what the GC duration should be, when and where the GC should occur, and, sometimes, why to conduct a GC. This review summarizes the current knowledge about the desirable characteristics of GCs in the 3 main GRDs following a 5 Ws approach-that is, the 5 main journalistic questions: who, what, when, where, why. The answers will help to determine the correct use of the GC in diagnosing GRDs.

Long-Term Outcome of Potential Celiac Disease in Genetically at-Risk Children: The Prospective CELIPREV Cohort Study

BACKGROUND

The long-term outcome of potential celiac disease (CD) is still a debated issue. We aimed to evaluate the progression of potential CD versus overt CD after 10-years of follow-up in a cohort of children genetically predisposed to CD.

METHODS

The CELIPREV study is prospectively following from birth 553 children with CD-predisposing HLA genes. Children with a diagnosis of potential CD continued to receive a normal diet and repeated the serological screening for CD every year. An intestinal biopsy was taken in presence of persistent positive serology.

RESULTS

Overall, 26 (4.7%) children received a diagnosis of potential CD (50% females, median age 24 months). All children were symptom-free. Twenty-three children continued a gluten-containing diet; at 10 years from the first biopsy, three children developed overt CD (13%), 19 (83%) became antibodies negative at 1 year from the first biopsy and remained negative up to 10 years of follow-up and one subject (4%) had fluctuating antibody course with transiently negative values and persistently negative biopsy.

CONCLUSIONS

In children genetically predisposed to CD with a diagnosis of potential CD the risk of progression to overt CD while on a gluten-containing diet is very low in the long-term.

Whole grain diet reduces systemic inflammation: A meta-analysis of 9 randomized trials

BACKGROUNDS

Observational studies had suggested an inverse association between whole grain consumption and concentration of inflammatory markers, but evidence from interventional studies was inconsistent. Therefore, we conducted a meta-analysis of randomized trials to have a better understanding of this issue.

METHODS

This study has been registered in PROSPERO (ID: CRD42018096533). We searched PubMed, Web of Science, Embase, Medline, and Cochrane Library for articles focusing on the topic from inception to 1 January, 2018. Summary standardized mean difference (SMD) and 95% confidence interval (CI) were calculated by using either random effect model or fixed effect model according to the heterogeneity of included studies. Subgroup analysis was also performed.

RESULTS

Totally 9 randomized trials included 838 participants were identified. In a pooled analysis of all studies, consumption of whole grains had an inverse association with inflammatory markers (SMD 0.16, 95% CI, 0.02-0.30), including C-reactive protein (CRP), Interleukin-6 (IL-6), Tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β). Specific analyses for CRP and IL-6 yielded that whole grain diet was related with a significant decrease in the concentration of CRP (SMD 0.29, 95% CI, 0.08-0.50) and IL-6 (SMD 0.19, 95% CI, 0.03-0.36).

CONCLUSIONS

The evidence suggested that citizens could benefit from increased whole grain intake for reducing systemic inflammation. Further well-designed studies are required to investigate the mechanism under the appearance.

Autoantibodies in the Extraintestinal Manifestations of Celiac Disease

Increased antibody reactivity towards self-antigens is often indicative of a disruption of homeostatic immune pathways in the body. In celiac disease, an autoimmune enteropathy triggered by the ingestion of gluten from wheat and related cereals in genetically predisposed individuals, autoantibody reactivity to transglutaminase 2 is reflective of the pathogenic role of the enzyme in driving the associated inflammatory immune response. Autoantibody reactivity to transglutaminase 2 closely corresponds with the gluten intake and clinical presentation in affected patients, serving as a highly useful biomarker in the diagnosis of celiac disease. In addition to gastrointestinal symptoms, celiac disease is associated with a number of extraintestinal manifestations, including those affecting skin, bones, and the nervous system. Investigations of these manifestations in celiac disease have identified a number of associated immune abnormalities, including B cell reactivity towards various autoantigens, such as transglutaminase 3, transglutaminase 6, synapsin I, gangliosides, and collagen. Clinical relevance, pathogenic potential, mechanism of development, and diagnostic and prognostic value of the various identified autoantibody reactivities continue to be subjects of investigation and will be reviewed here.

Non-celiac gluten or wheat sensitivity: It's complicated!

In the last 30 years, non-celiac gluten sensitivity (NCGS) has emerged as an intriguing and controversial topic in gastroenterology. The diagnosis of NCGS/NCWS requires a symptomatic reaction to gluten, or wheat-containing food, and remission of symptoms with gluten or wheat challenge, in patients in whom celiac disease and wheat allergy have been excluded. There have been several randomized clinical trials (RCT) addressing this issue which have produced controversial results. In this issue of Neurogastroenterology and Motility, a double-blind placebo-controlled randomized trial in patients with suspected NCGS on GFD, did not reproduce symptoms after gluten intake compared to placebo. This mini-review addresses outstanding issues related to the diagnosis of NCGS/NCWS as well as areas of interest for future studies that could explain, in part, the controversy in this area.

The incidence of HLA-DQ2/DQ8 in Turkish children with celiac disease and a comparison of the geographical distribution of HLA-DQ

Introduction

Celiac disease (CD) is an auto-immune enteropathy that occurs in genetically pre-disposed people as a result of the consumption of gluten-containing foods.

Aim

To identify the incidence of HLA-DQ2 and HLA-DQ8 observed in children with CD.

Material and methods

In this study, we focused on children ranging in age from 2 to 18 years and diagnosed with celiac disease. In our patients diagnosed with CD, in addition to tissue transglutaminase antibodies (anti-tTG), we also evaluated HLA-DQ2 B1 and HLA-DQ8 B1 alleles using the method of polymerase chain reaction (PCR)/sequence-specific oligonucleotide probes (Luminex^®). The detection of 0201/0202 for HLA-DQ2 allele and 0302 for HLA-DQ8 allele was accepted as a positive result.

Results

The mean age of our patients with celiac disease was 7.42 ±3.18 years, and the female/male ratio was 1.5/1. Seventy-six percent of our patients were HLA-DQ2 and/or HLA-DQ8 positive, 67% were HLA-DQ2 positive, and 25% were HLA-DQ8 positive. Nevertheless, 24% of them were HLA-DQ2 and HLA-DQ8 negative. The incidence of HLA-DQ2 in the control group was 18.8% with a significant difference compared to the HLA-DQ2 incidence in the patient group (67%) (p < 0.05). Similarly the HLA-DQ8 incidence in the control group (5.7%) was significantly lower than the incidence in the patient group (25%) (p < 0.05).

Conclusions

The incidence of the patients diagnosed with CD, who are HLA-DQ2 and HLA-DQ8 negative, varies among different populations.

Intestinal Production of Anti-Tissue Transglutaminase 2 Antibodies in Patients with Diagnosis Other Than Celiac Disease

It has been hypothesized that gluten-dependent production of anti-tissue-transglutaminase 2 (anti-TG2) antibodies may occur only at an intestinal level. We have investigated intestinal production of anti-TG2 antibodies in 136 patients with normal serum levels of anti-TG2 antibodies and normal duodenal mucosa. Intestinal deposits of anti-TG2 antibodies were evaluated by immunofluorescence and anti-TG2 antibodies released in organ culture supernatants measured by ELISA. Intestinal antibody libraries were obtained from 10 subjects. Immunohistochemistry for CD25⁺, CD3⁺, and TCR-γδ⁺ was assessed in subjects with positive (n = 32) and negative (n = 31) intestinal anti-TG2 antibodies. Globally 33/136 (24%) seronegative patients produced anti-TG2 autoantibodies at an intestinal level. Antibody libraries analysis confirmed the anti-TG2 antibodies mucosal production in all (n = 8) positive subjects. Lamina propria CD25⁺ cell count was significantly (p < 0.05) higher in patients with intestinal anti-TG2. Moreover, 13/32 (41%) of them showed high TCR-γδ⁺/CD3⁺ ratios. Intestinal anti-TG2 antibody production does not show absolute specificity for CD. It is seen more often in association with inflamed mucosa. Further investigations are necessary to prove the possible role of dietary gluten.

Celiac disease: From pathophysiology to treatment

Celiac disease, also known as "celiac sprue", is a chronic inflammatory disorder of the small intestine, produced by the ingestion of dietary gluten products in susceptible people. It is a multifactorial disease, including genetic and environmental factors. Environmental trigger is represented by gluten while the genetic predisposition has been identified in the major histocompatibility complex region. Celiac disease is not a rare disorder like previously thought, with a global prevalence around 1%. The reason of its under-recognition is mainly referable to the fact that about half of affected people do not have the classic gastrointestinal symptoms, but they present nonspecific manifestations of nutritional deficiency or have no symptoms at all. Here we review the most recent data concerning epidemiology, pathogenesis, clinical presentation, available diagnostic tests and therapeutic management of celiac disease.

Intestinal, Systemic, and Oral Gluten-related Alterations in Patients With Nonceliac Gluten Sensitivity

BACKGROUND

Nonceliac gluten sensitivity (NCGS) is an emergent condition, the framework of which is yet unclear, whereas the diagnosis is suggested only by gluten-dependent symptoms after excluding wheat allergy and celiac disease (CD). Our goal was to highlight intestinal, systemic, and oral alterations to clarify the NCGS pathogenesis and identify new diagnostic tools.

STUDY

A total of 60 NCGS patients, 20 untreated CD, 20 treated CD, and 20 healthy volunteers were recruited. The differential diagnosis among gluten-related disorders was performed by serological, allergy, and histologic tools. NCGS patients were also subjected to antigliadin antibody (AGA) detection and HLA typing. All participants underwent an oral mucosa patch test for gluten (GOMPT), whereas an oral provocation test (OPT) for gluten was performed in 26 NCGS patients.

RESULTS

About 6/60 (10%) NCGS patients showed IgG AGA-positive results, whereas 45/60 (75%) patients carried HLA-DQ2 and/or HLA-DQ8 genes. GOMPT showed positive results in 45/60 (75%) NCGS patients, 3/20 (15%) untreated CD patients, 5/20 (25%) treated CD patients, and in no healthy volunteers. No significant difference was found between the severity of symptoms reported by NCGS patients subjected to OPT with gluten-containing croissants and those who underwent OPT with gluten-free croissants.

CONCLUSIONS

GOMPT seems to be a specific tool for NCGS diagnosis, although further investigations are needed to overcome limits due to the small population studied and to contextualize GOMPT false-positive results.

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.

The opioid effects of gluten exorphins: asymptomatic celiac disease

Gluten-containing cereals are a main food staple present in the daily human diet, including wheat, barley, and rye. Gluten intake is associated with the development of celiac disease (CD) and related disorders such as diabetes mellitus type I, depression, and schizophrenia. However, until now, there is no consent about the possible deleterious effects of gluten intake because of often failing symptoms even in persons with proven CD. Asymptomatic CD (ACD) is present in the majority of affected patients and is characterized by the absence of classical gluten-intolerance signs, such as diarrhea, bloating, and abdominal pain. Nevertheless, these individuals very often develop diseases that can be related with gluten intake. Gluten can be degraded into several morphine-like substances, named gluten exorphins. These compounds have proven opioid effects and could mask the deleterious effects of gluten protein on gastrointestinal lining and function. Here we describe a putative mechanism, explaining how gluten could "mask" its own toxicity by exorphins that are produced through gluten protein digestion.

Measuring Biomarkers for an Innovative Personal Food Profile

Measuring the level of inflammation with an innovative approach (with blood analyses to evaluate the action of cytokines such as B-cell activating factor [BAFF], platelet activating factor [PAF], interleukin-6 [IL-6], sirtuin) allows you to better understand the body's language. The body recognizes foods and food antigens through a mapping performed by means of immunoglobulin G (IgG). Recent studies have shown that high levels of IgG in a nutrient express the personal excess of that food in the daily nutrition. Food is the most important source of hidden inflammation but is also the main tool for regaining wellness. Europeans have reactions to milk, yeast, and gluten, whereas the Japanese have reactions to rice and soybeans. Scientific knowledge of inflammatory mediators allows the discovery of new drugs, new supplements, and new plant compounds (Resveratrol, Maqui, oil of Perilla) that are able to reduce inflammation and support well-being. The interaction between the environment, nutrition, and knowledge of inflammation is an evolution and at the same time a revolution to gain and maintain health.

Immune response to Hepatitis B vaccine in patients with celiac disease: A systematic review and meta-analysis

It is debated whether patients with celiac disease (CD) have non-protective antibody responses to HBV vaccination more frequently than non-affected subjects. To perform a literature review and meta-analysis on protective response to HBV vaccination in CD patients. RCTs and observational controlled studies were eligible. Outcome of interest was an anti-HBs (HBsAb) titer ≥ 10 IU/L after last vaccine dose. Comparative index was rate ratio (RR). Heterogeneity between studies was addressed and funnel plots were analyzed. Meta-regression models were applied to investigate effect size due to study-specific variables. Twelve retrospective studies on a total of 1,447 participants and 4 prospective studies on 184 subjects were selected. The RR was 0.732 (95% C.I.: 0.664-0.808) and 0.777 (95% C.I.: 0.629-0.960) in the prospective and retrospective studies, respectively. The I(2), indicating heterogeneity, was 51.1% in retrospective, 39.8% in prospective studies. Non-protective antibody responses occurred more frequently in patients than controls. Due to limitations in the available studies, additional trials to evaluate post-vaccination HBsAb titer in CD patients are needed.

Distinct and Synergistic Contributions of Epithelial Stress and Adaptive Immunity to Functions of Intraepithelial Killer Cells and Active Celiac Disease

BACKGROUND & AIMS

The mechanisms of tissue destruction during progression of celiac disease are poorly defined. It is not clear how tissue stress and adaptive immunity contribute to the activation of intraepithelial cytotoxic T cells and the development of villous atrophy. We analyzed epithelial cells and intraepithelial cytotoxic T cells in family members of patients with celiac disease, who were without any signs of adaptive antigluten immunity, and in potential celiac disease patients, who have antibodies against tissue transglutaminase 2 in the absence of villous atrophy.

METHODS

We collected blood and intestinal biopsy specimens from 268 patients at tertiary medical centers in the United States and Italy from 2004 to 2012. All subjects had normal small intestinal histology. Study groups included healthy individuals with no family history of celiac disease or antibodies against tissue transglutaminase 2 (controls), healthy family members of patients with celiac disease, and potential celiac disease patients. Intraepithelial cytotoxic T cells were isolated and levels of inhibitory and activating natural killer (NK) cells were measured by flow cytometry. Levels of heat shock protein (HSP) and interleukin 15 were measured by immunohistochemistry, and ultrastructural alterations in intestinal epithelial cells (IECs) were assessed by electron microscopy.

RESULTS

IECs from subjects with a family history of celiac disease, but not from subjects who already had immunity to gluten, expressed higher levels of HS27, HSP70, and interleukin-15 than controls; their IECs also had ultrastructural alterations. Intraepithelial cytotoxic T cells from relatives of patients with celiac disease expressed higher levels of activating NK receptors than cells from controls, although at lower levels than patients with active celiac disease, and without loss of inhibitory receptors for NK cells. Intraepithelial cytotoxic T cells from potential celiac disease patients failed to up-regulate activating NK receptors.

CONCLUSIONS

A significant subset of healthy family members of patients with celiac disease with normal intestinal architecture had epithelial alterations, detectable by immunohistochemistry and electron microscopy. The adaptive immune response to gluten appears to act in synergy with epithelial stress to allow intraepithelial cytotoxic T cells to kill epithelial cells and induce villous atrophy in patients with active celiac disease.

Celiac disease

This review will focus on the pathogenesis, clinical manifestations, diagnosis, and management of celiac disease (CD). Given an increasing awareness of gluten-related disorders, medical professionals of all varieties are encountering patients with a diagnosis of CD or who are thought to have food intolerance to gluten. The prevalence of CD among the general population is estimated to be 1% in Western nations, and there is growing evidence for underdiagnosis of the disease, especially in non-Western nations that were traditionally believed to be unaffected. The development of serologic markers specific to CD has revolutionized the ability both to diagnose and monitor patients with the disease. Additionally, understanding of the clinical presentations of CD has undergone a major shift over the past half century. Although it is well understood that CD develops in genetically predisposed subjects exposed to gluten, the extent of other environmental factors in the pathogenesis of the disease is an area of continued research. Currently, the main therapeutic intervention for CD is a gluten-free diet; however, novel nondietary agents are under active investigation. Future areas of research should also help us understand the relationship of CD to other gluten-related disorders.

Non-Celiac Gluten Sensitivity Has Narrowed the Spectrum of Irritable Bowel Syndrome: A Double-Blind Randomized Placebo-Controlled Trial

Several studies have shown that a large number of patients who are fulfilling the criteria for irritable bowel syndrome (IBS) are sensitive to gluten. The aim of this study was to evaluate the effect of a gluten-free diet on gastrointestinal symptoms in patients with IBS. In this double-blind randomized, placebo-controlled trial, 148 IBS patients fulfilling the Rome III criteria were enrolled between 2011 and 2013. However, only 72 out of the 148 commenced on a gluten-free diet for up to six weeks and completed the study; clinical symptoms were recorded biweekly using a standard visual analogue scale (VAS). In the second stage after six weeks, patients whose symptoms improved to an acceptable level were randomly divided into two groups; patients either received packages containing powdered gluten (35 cases) or patients received placebo (gluten free powder) (37 cases). Overall, the symptomatic improvement was statistically different in the gluten-containing group compared with placebo group in 9 (25.7%), and 31 (83.8%) patients respectively (p < 0.001). A large number of patients labelled as irritable bowel syndrome are sensitive to gluten. Using the term of IBS can therefore be misleading and may deviate and postpone the application of an effective and well-targeted treatment strategy in gluten sensitive patients.

Non-celiac gluten sensitivity and rheumatic diseases

Celiac disease is an autoimmune systemic disease having among its clinical manifestations frequent symptoms common to rheumatologic diseases such as musculoskeletal pain, asthenia, and cognitive fatigue. It is associated with other autoimmune diseases like Sjögren disease. It is a well-characterized disease with specific diagnostic tests. Non-celiac gluten sensitivity is an emerging entity with symptoms similar to celiac disease, but without specific diagnostic tests. The concept of non-celiac gluten sensitivity and its diagnostic problems are reviewed, and the hypothesis of its association with fibromyalgia, spondyloarthritis, and autoimmune conditions is proposed. Clinical observations supporting the hypothesis are described, highlighting the benefit of treating non-celiac gluten sensitivity.

Assessing of Celiac Disease and Nonceliac Gluten Sensitivity

The publication of papers on the topic of gluten related disorders has substantially increased over the last few years. This has motivated healthcare professionals to pay attention not only to celiac disease and wheat allergy but also to a condition termed nonceliac gluten sensitivity (NCGS). Until now this condition has been diagnosed clinically on the basis of exclusion criteria and clinical response to gluten withdrawal. In addition, recent research in this field has shown that other food components distinct from gluten are implicated in NCGS cases, thereby changing our general understanding of NCGS diagnosis in either individuals on gluten containing diets or those already following a gluten-free diet with no proper diagnostic work-up of celiac disease. With this in mind, the assessment of NCGS will require extensive knowledge of celiac disease manifestations and the laboratory tests commonly performed during diagnosis of celiac disease.

Clinical and diagnostic aspects of gluten related disorders

Gluten is one of the most abundant and widely distributed components of food in many areas. It can be included in wheat, barley, rye, and grains such as oats, barley, spelt, kamut, and triticale. Gluten-containing grains are widely consumed; in particular, wheat is one of the world’s primary sources of food, providing up to 50% of the caloric intake in both industrialized and developing countries. Until two decades ago, celiac disease (CD) and other gluten-related disorders were believed to be exceedingly rare outside of Europe and were relatively ignored by health professionals and the global media. In recent years, however, the discovery of important diagnostic and pathogenic milestones led CD from obscurity to global prominence. In addition, interestingly, people feeding themselves with gluten-free products greatly outnumber patients affected by CD, fuelling a global consumption of gluten-free foods with approximately $2.5 billion in United States sales each year. The acknowledgment of other medical conditions related to gluten that has arisen as health problems, providing a wide spectrum of gluten-related disorders. In February 2011, a new nomenclature for gluten-related disorders was created at a consensus conference in London. In this review, we analyse innovations in the field of research that emerged after the creation of the new classification, with particular attention to the new European Society for Paediatric Gastroenterology, Hepatology and Nutrition guidelines for CD and the most recent research about non-celiac gluten sensitivity.

The effects of reduced gluten barley diet on humoral and cell-mediated systemic immune responses of gluten-sensitive rhesus macaques

Celiac disease (CD) affects approximately 1% of the general population while an estimated additional 6% suffers from a recently characterized, rapidly emerging, similar disease, referred to as non-celiac gluten sensitivity (NCGS). The only effective treatment of CD and NCGS requires removal of gluten sources from the diet. Since required adherence to a gluten-free diet (GFD) is difficult to accomplish, efforts to develop alternative treatments have been intensifying in recent years. In this study, the non-human primate model of CD/NCGS, e.g., gluten-sensitive rhesus macaque, was utilized with the objective to evaluate the treatment potential of reduced gluten cereals using a reduced gluten (RG; 1% of normal gluten) barley mutant as a model. Conventional and RG barleys were used for the formulation of experimental chows and fed to gluten-sensitive (GS) and control macaques to determine if RG barley causes a remission of dietary gluten-induced clinical and immune responses in GS macaques. The impacts of the RG barley diet were compared with the impacts of the conventional barley-containing chow and the GFD. Although remission of the anti-gliadin antibody (AGA) serum responses and an improvement of clinical diarrhea were noted after switching the conventional to the RG barley diet, production of inflammatory cytokines, e.g., interferon-gamma (IFN-γ), tumor necrosis factor (TNF) and interleukin-8 (IL-8) by peripheral CD4+ T helper lymphocytes, persisted during the RG chow treatment and were partially abolished only upon re-administration of the GFD. It was concluded that the RG barley diet might be used for the partial improvement of gluten-induced disease but its therapeutic value still requires upgrading—by co-administration of additional treatments.