Usefulness of small-bowel mucosal transglutaminase-2 specific autoantibody deposits in the diagnosis and follow-up of celiac disease

Celiac Disease: An Academy of Nutrition and Dietetics Evidence-Based Nutrition Practice Guideline

Celiac disease is an autoimmune disorder in which the immune system of genetically susceptible individuals elicits a reaction to gluten causing small intestine damage. If left undiagnosed and untreated, the resulting nutrition malabsorption can lead to anemia, bone disease, growth faltering, or other consequences. The condition is lifelong and lacks a cure; the only treatment is lifelong adherence to a gluten-free diet (GFD). This diet is challenging to follow and adversely influences quality of life; however, it is essential to ensure intestinal recovery and prevent future negative health consequences. The Academy of Nutrition and Dietetics convened an expert panel complemented by a celiac disease patient advocate to evaluate evidence for six topics, including medical nutrition therapy; the GFD; oat consumption; micronutrients; pro-/prebiotics; and the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet. This publication outlines the Academy of Nutrition and Dietetics Evidence Analysis Library methods used to complete the systematic review and guideline development, and summarizes the recommendations and supporting evidence. The guidelines affirm that all individuals with celiac disease should follow a GFD (1C, Imperative) that may include gluten-free oats in adults (2D, Conditional). Children should follow a nutritionally adequate GFD that supports healthy growth and development (Consensus, Imperative) and does not unnecessarily restrict gluten-free oats (Consensus, Conditional). The guidelines indicate nutritional care should include routine nutritional assessment (Consensus, Imperative) and medical nutrition therapy (Consensus, Imperative). At this time, the guidelines do not support a recommendation for the addition of the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet (2C, Conditional); prebiotic or probiotic supplementation (2D, Conditional); or micronutrient supplementation (in the absence of nutritional deficiency) (Consensus, Conditional). The 2021 Celiac Disease Evidence-Based Nutrition Guideline will assist registered dietitian nutritionists in providing appropriate evidence-based medical nutrition therapy to support people with celiac disease in achieving and maintaining nutritional health and avoiding adverse celiac disease consequences throughout their lives.

The role of gluten challenge in the diagnosis of celiac disease: a review

INTRODUCTION

Duodenal biopsy is the gold standard in the diagnosis of celiac disease, with increasing utilization of serology. A gluten challenge may be required, for example, when dietary gluten reduction precedes appropriate diagnostic evaluations. Evidence on the best challenge protocol is currently sparse. Pharmaceutical trials in recent years may have provided new insights into the challenge and advanced the development of novel sensitive histological and immunological methods.

AREAS COVERED

This review outlines the current perspectives on the use of gluten challenge in the diagnosis of celiac disease and explores future directions in this area.

EXPERT OPINION

Comprehensive elimination of celiac disease before dietary gluten restriction is essential to avoid diagnostic uncertainties. Gluten challenge continues to have an important role in certain clinical scenarios, although it is important to understand its limitations in the diagnostic evaluation. The evidence so far permits no unequivocal recommendation considering the timing, duration, and amount of gluten used in the challenge. Thus, these decisions should be made on a case-by-case basis. Further studies with more standardized protocols and outcome measures are called for. In the future novel immunological methods may help to shorten or even avoid gluten challenge.

Guidelines of the Italian societies of gastroenterology on the diagnosis and management of coeliac disease and dermatitis herpetiformis

INTRODUCTION

Coeliac disease and dermatitis herpetiformis are immune-mediated diseases triggered by the consumption of gluten in genetically predisposed individuals. These guidelines were developed to provide general practitioners, paediatricians, gastroenterologists, and other clinicians with an overview on the diagnosis, management and follow-up of coeliac patients and those with dermatitis herpetiformis.

METHODS

Guidelines were developed by the Italian Societies of Gastroenterology. Following a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the certainty of the evidence. Statements and recommendations were developed by working groups consisting of gastroenterologists and a paediatrician with expertise in this field.

RESULTS

These guidelines provide a practical guidance for the diagnosis, management and follow-up of coeliac patients and dermatitis herpetiformis in children and adults, both in primary care and in specialist settings. We developed four sections on diagnosis, gluten-free diet, follow-up and risk of complications in adults, one section focused on diagnosis and follow-up in children and one on the diagnosis and management of dermatitis herpetiformis.

CONCLUSIONS

These guidelines may support clinicians to improve the diagnosis and management of patients with coeliac disease.

Population-based screening for celiac disease reveals that the majority of patients are undiagnosed and improve on a gluten-free diet

The impact of a gluten-free diet (GFD) on screen-detected celiac disease (CD) is currently ambiguous. We aimed to identify the population-based prevalence of undiagnosed adult CD and examine the impact of a GFD on screen-detected CD. In total, 12,981 adults participated in a population-based health study in Tromsø, Norway. Participants with increased levels of anti-tissue transglutaminase-2 IgA or anti-deamidated gliadin peptide IgG were invited to undergo gastroduodenoscopy with both histological and immunohistochemical examination of small-bowel biopsies. The prevalence of previously diagnosed CD was 0.37%. Additionally, the prevalence of previously undiagnosed CD was 1.10%. Thus, 1.47% of the population had CD, of whom 75% were previously undiagnosed. A GFD resulted in significant improvements in overall gastrointestinal symptoms, diarrhea, and health-related quality of life, with reduced abdominal discomfort (76%) and improved levels of energy (58%). The large majority of patients with adult CD were undiagnosed and benefited from a GFD with reduced gastrointestinal symptoms and improved health-related quality of life. In clinical practice, there should be a low threshold for CD testing even in the absence of abdominal complaints because most adult patients appear to consider their symptoms a part of their normal state and therefore remain untested and undiagnosed.Trial registration: Clinical Trials. Gov Identifier: NCT01695681.

A new double immunohistochemistry method to detect mucosal anti-transglutaminase IgA deposits in coeliac children

BACKGROUND

Intestinal transglutaminase (TG2) IgA deposits represent early marker of coeliac disease (CeD) and can predict the evolution towards intestinal atrophy.

AIMS

To validate a double immunohistochemistry method for the determination of intestinal TG2 IgA deposits on formalin-fixed paraffin-embedded biopsies.

METHODS

Immunohistochemistry was tested on: 1) children with overt CeD [persistently positive serum IgA anti-tissue transglutaminase type 2 (TGA-IgA) with moderate or low titer, and histological findings of CeD]; 2) potential CeD (persistently positive serum TGA-IgA and normal intestinal mucosa) and 3) controls (negative serum TGA-IgA and normal intestinal mucosa).

RESULTS

Samples from 61 children were analyzed (32 overt CeD, 14 potential CeD, and 15 controls). Deposits appeared as focal, multifocal, or confluent extracellular foci of red and brown staining colocalization in the sub-epithelium and around mucosal vessels. Deposits were present in all 32 children with overt CeD and in 9/14 potential CeD. Deposits were never observed in the 15 controls. Patients with higher serum level of TGA-IgA and with mucosal atrophy showed mostly a multifocal/diffuse pattern of deposits distribution. The bulb appeared most severely involved. In potential CeD deposits showed mainly a focal distribution.

CONCLUSION

Our results indicate double immunohistochemistry as promising diagnostic tool to improve diagnosis of CeD.

Expression of Selected Genes and Circulating microRNAs in Patients with Celiac Disease

Background and Objectives: Celiac disease (CD) is an immune-mediated enteropathy with characteristic intestinal alterations. CD occurs as a chronic inflammation secondary to gluten sensitivity in genetically susceptible individuals. Until now, the exact cause of the disease has not been established, which is why new studies have appeared that address the involvement of various genes and microRNAs (miRNAs) in the pathogenesis. The aim of the study is to describe the expression of selected genes (Wnt family member 3, WNT3; Wnt family member 11, WNT11; tumor necrosis factor alpha, TNFα; mitogen-activated protein kinase 1, MAPK1; AKT serine/threonine kinase 3, AKT3; phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha, PIK3CA; and cyclin D1, CCND1) and miRNAs (miR-192-5p, miR-194-5p, miR-449a and miR-638) in adult patients with CD. Materials and Methods: In total, 15 patients with CD at diagnosis (newly diagnosed), 33 patients on a gluten-free diet (GFD) for at least 1 year and 10 controls (control) were prospectively included. Blood samples were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Results: The results show that TNFα, MAPK1 and CCND1 were significantly overexpressed (p = 0.0249, p = 0.0019 and p = 0.0275, respectively) when comparing the newly diagnosed group to the controls. The other genes studied in CD patients were mostly with high values compared to controls, without reaching statistical significance. Among the miRNAs, the closest to a statistically significant value was miR-194-5p when the newly diagnosed group versus control (p = 0.0510) and GFD group versus control (p = 0.0671) were compared. The DIANA and miRNet databases identified significant functional activity for miR-449a and miR-192-5p and an interconnection of miR-194-5p and miR-449a with CCND1. Conclusions: In conclusion, genes and circulating miRNAs require further studies as they could represent important biomarkers in clinical practice.

Intestinal anti-tissue transglutaminase IgA deposits as a complementary method for the diagnostic evaluation of celiac disease in patients with low-grade histological lesions

Evaluating the usefulness of intestinal anti-transglutaminase IgA (anti-TG2 IgA) deposits detection as a complementary or decision-supporting tool in the diagnosis of celiac disease (CD) in patients with low degree of enteropathy. Small intestinal biopsies (SIB) were performed from 2008 to 2017 in patients on suspicion of CD (positive CD serology and/or symptoms) referred to our Pediatric Gastroenterology Unit. We determined anti-TG2 IgA deposits by using double immunofluorescence in all the patients in whom Marsh 0 or Marsh1 was detected in the conventional histological study and in a random selection of patients with clearly positive serology and histological Marsh 2-3 lesion. 75 pediatric patients were split into 3 groups according to the final diagnosis: 1) 13 children with a Marsh 0 or 1, negative CD serology and final non-CD diagnosis;none presented intestinal anti-TG2 IgA deposits; 2) 15 potential CD cases (Marsh 0 or 1 and CD-associated antibodies), detecting anti-TG2 IgA deposits in 12; on follow-up, another biopsy performed in 11/15 showed villi atrophy in 7 and a Marsh 2 lesion in two of them, patients being finally diagnosed as CD cases; and 3) 47 children with Marsh 2-3 histological lesion and final CD diagnosis; all of them had intestinal anti-TG2 IgA deposits. Anti-TG2 deposits are a useful complementary tool for CD diagnosis in pediatric population with digestive pathologies suggestive of CD. It is especially helpful in those with low grade lesion, in which anti-TG2 deposits are predictive of the development of more severe lesions on follow-up.

Liver involvement in patients with coeliac disease: proof of causality using IgA/anti-TG2 colocalisation techniques

AIMS

Despite clinical evidence of liver involvement in patients with coeliac disease (CeD), there is a lack of a method to prove this association.

METHODS

Of 146 treatment-naive patients with CeD, 26 had liver dysfunction. Liver biopsies and corresponding small intestinal biopsies were obtained from these 26 patients. Multicolour immunohistochemical and immunofluorescence confocal microscopic studies were performed on paraffin-embedded tissue to detect the IgA/anti-TG2 deposits. Follow-up liver biopsies were taken after a gluten-free diet.

RESULTS

Twenty-six out of the 146 patients (17.8%) with suspected coeliac-associated liver disease on histological examination revealed irregular sinusoidal dilatation in 15 (57.6%), steatohepatitis in 4 (15.3%), non-specific chronic hepatitis in 3 (11.5%), autoimmune hepatitis in 2 (7.6%) biopsies, including cirrhosis in one of them, irregular perisinusoidal fibrosis and changes of non-cirrhotic portal fibrosis in one biopsy each (3.8%). IgA/anti-tTG deposits were observed in 22 (84.6%) liver biopsies by dual immunohistochemistry technique, and in 24 (92.3%) by confocal immunofluorescence technique and in all corresponding duodenal biopsies (100%). Overall, IgA/anti-tTG deposits showed 100% sensitivity, 77% specificity and 85% positive predictive value for establishing an association of extraintestinal pathology and CeD using archived tissues. Follow-up liver biopsies could be obtained in five patients; four of them showed not only resolution of the histological lesions but disappearance of IgA/anti-tTG co-localisation.

CONCLUSIONS

Data of the present study adds to the body of evidence that liver lesions in patients with CeD are disease related and may have been caused by a similar pathogenic mechanism that causes intestinal changes.

Intestinal Anti-tissue Transglutaminase2 Autoantibodies: Pathogenic and Clinical Implications for Celiac Disease

Celiac disease (CD) is a systemic disease that primarily affects the small intestine. The presence of anti-tissue transglutaminase 2 (anti-TG2) antibodies in the serum, as well as the presence of autoimmune phenomena, account for the inclusion of CD among autoimmune diseases. Anti-TG2 autoantibodies are produced at intestinal level, where they are deposited even before they appear in circulation. The pathogenic events that lead to their production are still not completely defined, but a central role seems to be played by gliadin-specific T cells. Interestingly, limited somatic mutations have been observed in VH and VL genes in TG2-specific plasma cells, another important aspect being the biased use of a heavy chain encoded by the VH5 gene. Conflicting data have been produced over the years on the effect of anti-TG2 antibodies on TG2 function. Although the presence of anti-TG2 antibodies in serum is considered a hallmark of CD and relevant from a clinical viewpoint, the role of these autoantibodies in the development of the celiac lesion remains to be defined. In the years, different technical approaches have been implemented to detect and measure intestinal CD-associated autoantibody production. Two aspects can make intestinal anti-TG2 antibodies relevant: from a clinical viewpoint: the first is their proposed ability in potential coeliac patients to predict the development of a full-blown enteropathy; the second is their possible role in revealing a condition of reactivity to gluten in patients with no circulating CD-associated autoantibodies. In fact, the detection of CD-specific autoantibodies production in the intestine, in the absence of serum positivity for the same antibodies, could be suggestive of a very early condition of gluten reactivity; alternatively, it could be not specific for CD and merely attributable to intestinal inflammation. In conclusion, the role of mucosal anti-TG2 antibodies in pathogenesis of CD is unknown. Their presence, the modalities of their production, their gluten dependence render them a unique model to study autoimmunity.

Prevalence and diagnostic outcomes of children with duodenal lesions and negative celiac serology

BACKGROUND

Celiac disease diagnostics begin by measuring autoantibodies, which may fail to identify seronegative patients. Duodenal lesion in the absence of antibodies is scarcely studied, especially in children.

AIMS

To investigate the prevalence and diagnostic outcomes of children with seronegative duodenal lesion in two countries with different disease profiles.

METHODS

Medical data, including the results of histology and transglutaminase (tTGab) and endomysium (EmA) antibody measurements were collected from 1172 Finnish and 264 Romanian children with systematic duodenal sampling. Database of 509 Finnish children with celiac disease was examined to identify earlier seronegative patients.

RESULTS

Celiac disease was diagnosed in 307 Finnish and 83 Romanian children in the endoscopy cohorts. No seronegative patients were found among 899 celiac disease patients, although some were only tTGab or EmA positive. Non-celiac duodenal lesion was detected in eight Finnish and 32 Romanian children, their most common diagnoses being inflammatory bowel disease and infections, respectively. Six children with morphological lesion received no diagnosis. None of them developed celiac disease during a follow-up of 3-11 years.

CONCLUSION

Pediatric seronegative celiac disease is exceptional in the era of modern autoantibodies. Other reasons for duodenal lesion should therefore be sought, bearing in mind possible differences across countries.

Nutrition Assessment, Interventions, and Monitoring for Patients with Celiac Disease: An Evidence Analysis Center Scoping Review

The objectives of this scoping review were to identify and characterize studies examining nutrition assessment, interventions, and measures to monitor gluten-free diet (GFD) adherence/compliance in patients with celiac disease (CD). An electronic literature search of four databases (Cochrane Database for systematic reviews, CINAHL, Embase, and Ovid MEDLINE) was conducted to identify articles examining nutrition care in CD individuals. Except for narrative review, grey literature, and case study/report, all types of peer-reviewed articles published between January 2007 and August 2018 were eligible. There were a total of 10,823 records; 10,368 were excluded during the first round of screening due to irrelevancy and/or duplication. Of the 455 full-text articles that were assessed, 292 met the criteria and were included. Most of the studies were observational studies (n=212), followed by experimental trials (n=50), evidence-based practice guideline (EBPG)/report/statement (n=16), and systematic review (SR) (n=14). Nine original studies examined assessment, focusing mainly on different tools/ways to assess GFD adherence. The majority of the included original articles (n=235) were in the nutrition intervention category with GFD, oats, and prebiotics/probiotics as the top-three most studied interventions. There were eight SRs on GFD and five on oats. One SR and 21 original studies investigated the effectiveness of different measures to monitor GFD adherence/compliance. Although recent CD EBPGs were identified, different methods with varying levels of rigor, in terms of literature search and assessment of evidence strength, were used. Based on this scoping review, interventions focused on gluten-free diet and oats have been significantly covered by either SRs or EBPGs. Studies related to prebiotics/probiotics and education program/counseling focused interventions, as well as assessment, in CD patients have increased in recent years. Thus, it might be beneficial to conduct SRs/EBPGs focused on these topics to guide practitioners.

A Call for Research on the Prognostic Role of Follow-Up Histology in Celiac Disease: A Systematic Review

Background: Convincing evidence is lacking on the benefit of follow-up biopsy in celiac disease. Regardless, achieving mucosal recovery (MR) has remained a desirable goal of therapy. We aimed to conduct a systematic review to determine whether MR is a protective factor and persisting villous atrophy (PVA) has negative consequences on long-term outcomes of celiac disease.

Methods: Seven databases were searched for articles discussing celiac patients subjected to a gluten-free diet who had a follow-up biopsy, and clinical and laboratory characteristics were reported by follow-up histology (MR vs. PVA). Outcomes included clinical symptoms, mortality, malignant tumors, nutritional parameters, and metabolic bone disease. Comparative and descriptive studies were included. Since data proved to be ineligible for meta-analysis, the evidence was synthesized in a systematic review.

Results: Altogether, 31 studies were eligible for systematic review. Persisting symptoms were more frequently associated with PVA than with MR, although a lot of symptom-free patients had PVA and a lot of symptomatic patients achieved MR. PVA might be a risk factor of lymphomas, but mortality and the overall rate of malignant tumors seemed independent of follow-up histology. Patients with PVA tended to develop metabolic bone disease more often, although fracture risk remained similar in the groups except in hip fractures of which PVA was a risk factor. Reports on nutritional markers are only anecdotal.

Conclusions: The limited evidence calls for high-quality prospective cohort studies to be arranged to clarify the exact role of follow-up histology in celiac disease.

The Challenge of Treatment in Potential Celiac Disease

Potential celiac disease (PCD) is defined by the presence of positive serum antibodies, HLA-DQ2/DQ8 haplotypes, and a normal small intestinal mucosa (Marsh grade 0-1). This condition occurs in one-fifth of celiac disease (CD) patients and usually represents a clinical challenge. We reviewed genetic, histologic, and clinical features of this specific condition by performing a systematic search on MEDLINE, Embase, and Scholar database. Accordingly, we identified different genetic features in patients with PCD compared to the classical forms. Frequently, signs of inflammation (deposits of immunoglobulin A (IgA) and/or increased number of intraepithelial lymphocytes) can be clearly identify in the mucosa of PCD patients after an accurate histological assessment. Finally, the main challenge is represented by the treatment: the gluten-free diet should be considered only in the presence of gluten-dependent symptoms in both children and adults. What is known: (i) potential celiac disease (PCD) occurs in one-fifth of all celiac diseases (CD), and (ii) despite the absence of classical lesions, clear signs of inflammation are often detectable. What is new: (i) patients with PCD show different genetic features, and (ii) the presence of gluten-dependent symptoms is the main determinant to initiate the gluten-free diet, after a complete diagnostic work-up.

Dietary Factors and Mucosal Immune Response in Celiac Disease Patients Having Persistent Symptoms Despite a Gluten-free Diet

GOALS

The aim of this study was to investigate the role of dietary factors, distinct small-bowel mucosal immune cell types, and epithelial integrity in the perpetuation of gastrointestinal symptoms in treated celiac disease patients.

BACKGROUND

For unexplained reasons, many celiac disease patients suffer from persistent symptoms, despite a strict gluten-free diet (GFD) and recovered intestinal mucosa.

STUDY

We compared clinical and serological data and mucosal recovery in 22 asymptomatic and 25 symptomatic celiac patients on a long-term GFD. The density of CD3 and γδ intraepithelial lymphocytes (IELs), CD25 and FOXP3 regulatory T cells, and CD117 mast cells, and the expression of tight junction proteins claudin-3 and occludin, heat shock protein 60, interleukin 15, and Toll-like receptor 2 and 4 were evaluated in duodenal biopsies.

RESULTS

All subjects kept a strict GFD and had negative celiac autoantibodies and recovered mucosal morphology. The asymptomatic patients had higher mean fiber intake (20.2 vs. 15.2 g/d, P=0.028) and density of CD3 IELs (59.3 vs. 45.0 cell/mm, P=0.045) than those with persistent symptoms. There was a similar but nonsignificant trend in γδ IELs (17.9 vs. 13.5, P=0.149). There were no differences between the groups in other parameters measured.

CONCLUSIONS

Low fiber intake may predispose patients to persistent symptoms in celiac disease. There were no differences between the groups in the markers of innate immunity, epithelial stress or epithelial integrity. A higher number of IELs in asymptomatic subjects may indicate that the association between symptoms and mucosal inflammation is more complicated than previously thought.

Small-intestinal TG2-specific plasma cells at different stages of coeliac disease

Background

In coeliac disease, ingestion of gluten induces the production of transglutaminase 2 (TG2)-targeted autoantibodies by TG2-specific plasma cells present at high frequency in the small intestinal mucosa in untreated disease. During treatment with a gluten-free diet (GFD), the number of these cells decreases considerably. It has not been previously investigated whether the cells are also present prior to development of villous atrophy, or in non-responsive patients and those with dietary lapses. We aimed to define the frequency of small bowel mucosal TG2-specific plasma cells in coeliac disease patients with varying disease activity, and to investigate whether the frequency correlates with serum and small intestinal TG2-targeting antibodies as well as mucosal morphology and the number of intraepithelial lymphocytes.

Results

Mucosal TG2-specific plasma cells were found in 79% of patients prior to development of mucosal damage, in all patients with villous atrophy, and in 63% of the patients after 1 year on GFD. In these disease stages, TG2-specific plasma cells accounted for median of 2.3, 4.3, and 0.7% of all mucosal plasma cells, respectively. After long-term treatment, the cells were present in 20% of the patients in clinical remission (median 0%) and in 60% of the patients with poor dietary adherence (median 5.8%). In patients with non-responsive coeliac disease despite strict GFD, the cells were found in only one (9%) subject; the cells accounted for 2.4% of all plasma cells. A positive correlation between the percentage of TG2-specific plasma cells and serum TG2 antibody levels (r_S = 0.69, P < 0.001) and the intensity of mucosal TG2-targeting IgA deposits (r_S = 0.43, P < 0.001) was observed.

Conclusions

Our results show that TG2-specific plasma cells are already detectable prior to villous atrophy, and that generally their frequency increases during overt disease. By contrast, on GFD, the percentage of these cells decreases. Overall, the presence of TG2-specific plasma cells in the small bowel mucosa mirrors the presence of gluten in the diet, but the frequency is not always parallel to the level of serum or intestinal TG2 antibodies. These findings increase the knowledge about the development of the TG2 plasma cell responses especially in the early phases of coeliac disease.

Electronic supplementary material

The online version of this article (10.1186/s12865-018-0275-7) contains supplementary material, which is available to authorized users.

Outcome measures in coeliac disease trials: the Tampere recommendations

OBJECTIVE

A gluten-free diet is the only treatment option of coeliac disease, but recently an increasing number of trials have begun to explore alternative treatment strategies. We aimed to review the literature on coeliac disease therapeutic trials and issue recommendations for outcome measures.

DESIGN

Based on a literature review of 10 062 references, we (17 researchers and 2 patient representatives from 10 countries) reviewed the use and suitability of both clinical and non-clinical outcome measures. We then made expert-based recommendations for use of these outcomes in coeliac disease trials and identified areas where research is needed.

RESULTS

We comment on the use of histology, serology, clinical outcome assessment (including patient-reported outcomes), quality of life and immunological tools including gluten immunogenic peptides for trials in coeliac disease.

CONCLUSION

Careful evaluation and reporting of outcome measures will increase transparency and comparability of coeliac disease therapeutic trials, and will benefit patients, healthcare and the pharmaceutical industry.

The Innate Immune System in the Gastrointestinal Tract: Role of Intraepithelial Lymphocytes and Lamina Propria Innate Lymphoid Cells in Intestinal Inflammation

BACKGROUND

The gastrointestinal tract harbors the largest microbiota load in the human body, hence maintaining a delicate balance between immunity against invading pathogens and tolerance toward commensal. Such immune equilibrium, or intestinal homeostasis, is conducted by a tight regulation and cooperation of the different branches of the immune system, including the innate and the adaptive immune system. However, several factors affect this delicate equilibrium, ultimately leading to gastrointestinal disorders including inflammatory bowel disease. Therefore, here we decided to review the currently available information about innate immunity lymphocyte subsets playing a role in intestinal inflammation.

RESULTS

Intestinal innate lymphocytes are composed of intraepithelial lymphocytes (IELs) and lamina propria innate lymphoid cells (ILCs). While IELs can be divided into natural or induced, ILCs can be classified into type 1, 2, or 3, resembling, respectively, the properties of TH1, TH2, or TH17 adaptive lymphocytes. Noteworthy, the phenotype and function of both IELs and ILCs are disrupted under inflammatory conditions, where they help to exacerbate intestinal immune responses.

CONCLUSIONS

The modulation of both IELs and ILCs to control intestinal inflammatory responses represents a major challenge, as they provide tight regulation among the epithelium, the microbiota, and the adaptive immune system. An improved understanding of the innate immunity mechanisms involved in gastrointestinal inflammation would therefore aid in the diagnosis and further treatment of gastrointestinal inflammatory disorders.

Intestinal anti-transglutaminase 2 immunoglobulin A deposits in children at risk for coeliac disease (CD): data from the PreventCD study

In coeliac disease (CD), anti-tissue transglutaminase 2 immunoglobulin (Ig)A antibodies (anti-TG2) are produced and deposited in the intestine. PreventCD (www.preventcd.com) is a European multi-centre study, which investigates the influence of infant nutrition and that of genetic, immunological and other environmental factors on the risk of developing CD. The aim of the current study was to evaluate the appearance of intestinal anti-TG2 deposits in very early intestinal biopsies from at-risk infants and their predictive value for villous atrophy. Sixty-five small bowel biopsies, performed in 62 children, were investigated for the presence of intestinal anti-TG2 extracellular IgA deposits by using double immunofluorescence. The biopsies were performed in the presence of elevated serum levels of CD-associated antibodies and/or symptoms suggesting disease. Deposits of anti-TG2 IgA were present in 53 of 53 CD patients and three of three potential CD patients. In potential CD patients, mucosal deposits showed a patchy distribution characterized by some areas completely negative, whereas active CD patients had uniformly present and evident mucosal deposits. Only one of six patients without CD (negative for serum anti-TG2 and with normal mucosa) had intestinal deposits with a patchy distribution and a weak staining. Two of the 53 CD patients received a definitive diagnosis of CD after a second or third biopsy; mucosal deposits of anti-TG2 IgA were evaluated in all samples. Before developing villous atrophy, both patients had anti-TG2 deposits in normal mucosal architecture, antibodies in one patient being absent in serum. We demonstrated that in CD the intestinal deposits of anti-TG2 are a constant presence and appear very early in the natural history of disease.

Younger age at diagnosis predisposes to mucosal recovery in celiac disease on a gluten-free diet: A meta-analysis

Background and aims

Persistent intestinal damage is associated with higher complication rates in celiac disease. We aimed to assess the potential modifiers of mucosal recovery.

Materials and methods

We screened databases (PubMed, Embase, Cochrane Trials, and Web of Science) for papers on celiac disease. Papers discussing (1) celiac patients (2) follow-up biopsy and (3) mucosal recovery after commencement of a gluten-free diet were included. The primary outcome was to produce a comprehensive analysis of complete mucosal recovery (i.e., Marsh 0 on follow-up). We compared children’s recovery ratios to those of adults. Patients following a strict gluten-free dietary regimen were included in a subgroup. Summary point estimates, 95% confidence intervals (CIs), and 95% predictive intervals (PIs) were calculated. Heterogeneity was tested with I²-statistic. The PROSPERO registration number is CRD42016053482.

Results

The overall complete mucosal recovery ratio, calculated from 37 observational studies, was 0.36 (CI: 0.28–0.44, PI: -0.12–0.84; I²: 98.4%, p<0.01). Children showed higher complete mucosal recovery ratio than adults (p<0.01): 0.65 (CI: 0.44–0.85, PI: -0.10–1.39; I²: 96.5%, p<0.01) as opposed to 0.24 (CI: 0.15–0.33, PI: -0.19–1.08; I²: 96.3%, p<0.01). In the strict dietary adherence subgroup, complete mucosal recovery ratio was 0.47 (CI: 0.24–0.70, PI: -0.47–1.41; I²: 98.8%, p<0.001). On meta-regression, diagnostic villous atrophy (Marsh 3) ratio (-8.97, p<0.01) and male ratio (+6.04, p<0.01) proved to be a significant determinant of complete mucosal recovery, unlike duration of gluten-free diet (+0.01, p = 0.62). The correlation between complete mucosal recovery ratio and age on diagnosis is of borderline significance (-0.03, p = 0.05).

Conclusions

There is considerable heterogeneity across studies concerning complete mucosal recovery ratios achieved by a gluten-free diet in celiac disease. Several celiac patients fail to achieve complete mucosal recovery even if a strict dietary regimen is followed. Younger age on diagnosis, less severe initial histologic damage and male gender predispose for achieving mucosal recovery.

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.

Intraepithelial lymphocyte immunophenotype: a useful tool in the diagnosis of celiac disease

According to new ESPGHAN guidelines, gluten challenge is considered necessary when there is doubt about the initial diagnosis of celiac disease (CD). The main aim of this study was to quantify intraepithelial lymphocyte (IEL) immunophenotype on celiac patients on gluten-containing diet (GCD) compared to those on gluten-free diet (GFD). Another aim was to evaluate the clinical utility of IELs in the CD diagnosis, especially in selected patients on GFD where diagnostic uncertainty remains. IEL immunophenotype (TCRγδ and NK-like IELs) were studied by flow cytometry in 111 children with CD (81 children with CD on GCD and 30 celiac patients on GFD) and a control group (10 children). Duration of GFD was 5.4 ± 1.6 years. TCRγδ IELs in celiac patients receiving a GCD or GFD were significantly higher (p < 0.001) than in the control group. NK-like IELs in patients receiving a GCD or GFD were significantly lower than in the control group (p < 0.001). We observed a permanent decrease of NK-like IELs and an increment of TCRγδ IELs after following an adequate establishment and compliance of a long-term GFD in celiac patients. Recognition of IELs changes in the intestinal mucosa on celiac patients after long-term establishment of a GFD could constitute a useful tool for CD diagnosis in various situations: in which there is doubt about the initial diagnosis and repeat biopsy is necessary (avoiding the need of gluten challenges), and in those patients with symptoms/signs suggestive of CD who maintain a low gluten diet.

Development of autoantibodies precedes clinical manifestations of autoimmune diseases: A comprehensive review

The etiology of autoimmune diseases is due to a combination of genetic predisposition and environmental factors that alter the expression of immune regulatory genes through various mechanisms including epigenetics. Both humoral and cellular elements of the adaptive immune system play a role in the pathogenesis of autoimmune diseases and the presence of autoantibodies have been detected in most but not all autoimmune diseases before the appearance of clinical symptoms. In some cases, the presence or levels of these autoantibodies portends not only the risk of developing a corresponding autoimmune disease, but occasionally the severity as well. This observation is intriguing because it suggests that we can, to some degree, predict who may or may not develop autoimmune diseases. However, the role of autoantibodies in the pathogenesis of autoimmune diseases, whether they actually affect disease progression or are merely an epiphenomenon is still not completely clear in many autoimmune diseases. Because of these gaps in our knowledge, the ability to accurately predict a future autoimmune disease can only be considered a relative risk factor. Importantly, it raises the critical question of defining other events that may drive a patient from a preclinical to a clinical phase of disease.

Double-Blind Randomized Clinical Trial: Gluten versus Placebo Rechallenge in Patients with Lymphocytic Enteritis and Suspected Celiac Disease

BACKGROUND

The role of gluten as a trigger of symptoms in non-coeliac gluten sensitivity has been questioned.

AIM

To demonstrate that gluten is the trigger of symptoms in a subgroup of patients fulfilling the diagnostic criteria for non-coeliac gluten sensitivity (NCGS), which presented with lymphocytic enteritis, positive celiac genetics and negative celiac serology.

METHODS

Double-blind randomized clinical trial of gluten vs placebo rechallenge.

INCLUSION CRITERIA

>18 years of age, HLA-DQ2/8+, negative coeliac serology and gluten-dependent lymphocytic enteritis, and GI symptoms, with clinical and histological remission at inclusion. Eighteen patients were randomised: 11 gluten (20 g/day) and 7 placebo. Clinical symptoms, quality of life (GIQLI), and presence of gamma/delta+ cells and transglutaminase deposits were evaluated.

RESULTS

91% of patients had clinical relapse during gluten challenge versus 28.5% after placebo (p = 0.01). Clinical scores and GIQLI worsened after gluten but not after placebo (p<0.01). The presence of coeliac tissue markers at baseline biopsy on a gluten-free diet allowed classifying 9 out of the 18 (50%) patients as having probable 'coeliac lite' disease.

CONCLUSION

This proof-of-concept study indicates that gluten is the trigger of symptoms in a subgroup of patients fulfilling the diagnostic criteria for NCGS. They were characterized by positive celiac genetics, lymphocytic enteritis, and clinical and histological remission after a gluten-free diet.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02472704.

Novel diagnostic techniques for celiac disease

The diagnosis of celiac disease has long been based on the demonstration of gluten-induced small-bowel mucosal damage. However, due to the constantly increasing disease prevalence and limitations in the histology-based criteria there is a pressure towards more serology-based diagnostics. The serological tools are being improved and new non-invasive methods are being developed, but the constantly refined endoscopic and histologic techniques may still prove helpful. Moreover, growing understanding of the disease pathogenesis has led researchers to suggest completely novel approaches to celiac disease diagnostics regardless of disease activity. In this review, we will elucidate the most recent development and possible future innovations in the diagnostic techniques for celiac disease.

Pathological and Clinical Correlation between Celiac Disease and Helicobacter Pylori Infection; a Review of Controversial Reports

There are overwhelming reports and descriptions about celiac associated disorders. Although there is a clear genetic association between celiac disease (CD) and some gastrointestinal disorders, there are controversial reports claiming an association between CD and Helicobacter pylori (H. pylori) infection. Different studies indicated the possible association between lymphocytic gastritis and both CD and H. pylori infection, although this evidence is not consistently accepted. Also it was shown that an increase in intraepithelial lymphocytes count is associated with both H. pylori infection and celiac disease. Therefore the following questions may raise: how far is this infection actually related to CD?, which are the underlying patho-mechanisms for these associations? what are the clinical implications? what is the management? and what would be the role of gluten free diet in treating these conditions? PubMed (PubMed Central), Ovid, ISI of web knowledge, and Google scholar were searched for full text articles published between 1985 and 2015. The associated keywords were used, and papers described particularly the impact of pathological and clinical correlation between CD and H. pylori infection were identified. In this review we tried to answer the above questions and discussed some of the recent developments in the pathological and clinical aspects of CD and H. pylori infection.

A Prospective Study on the Usefulness of Duodenal Bulb Biopsies in Celiac Disease Diagnosis in Children: Urging Caution

OBJECTIVES

Several recent celiac disease guidelines recommend the acquisition of duodenal bulb biopsies for diagnostics. This is in conflict with previously reported evidence and routine practice from the 1960s onward. We reopened the issue in a prospective multicenter study and used morphometric variables in evaluating the usefulness of bulb biopsies in children. We further sought to establish whether deposits of IgA targeting bulb transglutaminase 2 (TG2) could be of diagnostic help.

METHODS

Diagnoses of celiac disease were based on clinic and distal duodenal histopathology statements. Centralized reading of villous height (VH) to crypt depth (CrD) ratios and IgA deposits was performed on anatomical duodenal bulb specimens. All children participating also underwent routine investigations for other diseases.

RESULTS

Twenty-two children had celiac disease, and another 22 served as non-celiac disease controls. The quality of the anatomical bulb specimens was unsatisfactory for reliable morphometric measurements in 20 out of 44 (45%) patients even after recuttings. All celiac disease patients had VH:CrD<2.0 (mean 0.2) but also 10 out of 13 (77%) non-celiac control patients had an injured bulb mucosal lining (mean 1.3) even up to false-positive "flat lesion". Bulb IgA deposits were able to separate celiac disease from disease controls.

CONCLUSIONS

Morphological injury is common in the anatomical bulb even without celiac disease, increasing the risk of false-positive diagnoses. Premature conclusions might have been drawn on current care guidelines as to celiac disease diagnosis based solely on anatomical bulb specimens. Bulb mucosal IgA targeting TG2 in poor quality biopsy specimens is a powerful clinical tool in finding celiac disease patients.

Distal duodenum versus duodenal bulb: intraepithelial lymphocytes have something to say in celiac disease diagnosis

BACKGROUND AND AIM

After clinical screening and the serological test, many patients still require a duodenal biopsy for celiac disease diagnosis. Mild histological lesions, unspecific findings and patchiness are frequent outcomes of this mandatory diagnostic tool, thus complicating clinical decisions.

METHODS

We analyzed the lymphoid components [number of total intraepithelial lymphocytes (IELs), TcR-γδ and CD3(-)IELs] of the duodenal epithelium by flow cytometry in samples obtained from bulb and distal duodenum during upper gastrointestinal endoscopies performed for diagnostic purposes.

RESULTS

IEL counts and IEL subset distribution (IEL lymphogram) remain invariant along duodenal mucosa revealing a specific profile (immunophenotype) that characterizes either a healthy mucosa or a celiac mucosa. The celiac immunophenotype persists regardless of the biopsy's anatomical location or the corresponding histological findings.

CONCLUSIONS

We propose the IEL lymphogram by flow cytometry as an immunological parameter to discern celiac condition from healthy mucosa. This obviates not only misinterpretation of minor histological changes, but also patchiness and the concerns about the location and number of biopsies.

Effect of one year of a gluten-free diet on the clinical evolution of irritable bowel syndrome plus fibromyalgia in patients with associated lymphocytic enteritis: a case-control study

Introduction

Irritable bowel syndrome (IBS), lymphocytic enteritis (LE) and fibromyalgia syndrome (FMS) are three common disorders. Since a gluten-free diet (GFD) has been shown to be helpful in LE, we aimed to assess its effect in a series of LE patients also diagnosed with IBS and FMS.

Methods

The study sample comprised 97 IBS plus FMS adult females, of whom 58 had LE (Marsh stage 1), and 39 had a normal duodenal biopsy (Marsh stage 0). All patients fulfilled the Rome III and American College of Rheumatology 1990 criteria. All participants followed a GFD, the effectiveness of which was assessed by changes in the results of several tests, including those of the Fibromyalgia Impact Questionnaire (FIQ), the Health Assessment Questionnaire (HAQ), tender points (TPs), the Short Form Health Survey (SF-36), and the Visual Analogue Scales (VAS) for gastrointestinal complaints, pain and fatigue.

Results

At baseline, all patients had a poor quality of life (QoL) and high VAS scores. After one year on a GFD, all outcome measures were somewhat better in the Marsh stage 1 group, with a mean decrease of 26 to 29% in the TPs, FIQ, HAQ and VAS scales, accompanied by an increase of 27% in the SF-36 physical and mental component scores. However, in the IBS plus FMS/Marsh stage 0 group, the GFD had almost no effect.

Conclusions

This pilot study shows that a GFD in the LE-related IBS/FMS subgroup of patients can produce a slight but significant improvement in all symptoms. Our findings suggest that further studies of this subject are warranted.

Early microbial markers of celiac disease

BACKGROUND AND GOALS

Seroreactivity against the Saccharomyces cerevisiae (ASCA), Pseudomonas fluorescens-associated sequence (I2), and Bacteroides caccae TonB-linked outer membrane protein (OmpW) has been detected in celiac disease patients with small-bowel mucosal atrophy. Levels of these antibodies decrease during a gluten-free diet, but their functions and time of appearance in celiac disease are not known. We aimed to search for evidence of possible microbial targets of the immune responses in the early-stage celiac disease patients who showed normal small-bowel mucosal architecture at the time of the first investigations, but later on a gluten-containing diet developed mucosal atrophy.

MATERIALS AND METHODS

Forty-four cases with proven early-stage celiac disease and normal mucosal morphology were enrolled. Patients' sera were tested for celiac disease antibodies against tissue transglutaminase (tTG-ab), endomysium, and for microbial antibodies against I2, OmpW, and ASCA IgG and IgA isotypes in both at the time of diagnosis and while on a gluten-free diet.

RESULTS

Thirty-four (77%) of 44 patients with early-stage celiac disease had elevated serum antibodies to one or more of the antibodies ASCA, I2, and OmpW. Furthermore, 5 of 6 cases negative for both tTG-ab and endomysium showed positivity for the microbial markers. Seroreactivity to ASCA IgA, ASCA IgG, and OmpW decreased significantly during gluten-free diet.

CONCLUSIONS

Seroreactivity to different microbial antigens is evident already in patients with early-stage celiac disease. ASCA antibodies seem to be gluten-dependent. The results indicate that the microbial targets might have a role in the early development of celiac disease.

Diagnosis and management of adult coeliac disease: guidelines from the British Society of Gastroenterology

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

Intestinal intraepithelial lymphocyte cytometric pattern is more accurate than subepithelial deposits of anti-tissue transglutaminase IgA for the diagnosis of celiac disease in lymphocytic enteritis

BACKGROUND & AIMS

An increase in CD3+TCRγδ+ and a decrease in CD3- intraepithelial lymphocytes (IEL) is a characteristic flow cytometric pattern of celiac disease (CD) with atrophy. The aim was to evaluate the usefulness of both CD IEL cytometric pattern and anti-TG2 IgA subepithelial deposit analysis (CD IF pattern) for diagnosing lymphocytic enteritis due to CD.

METHODS

Two-hundred and five patients (144 females) who underwent duodenal biopsy for clinical suspicion of CD and positive celiac genetics were prospectively included. Fifty had villous atrophy, 70 lymphocytic enteritis, and 85 normal histology. Eight patients with non-celiac atrophy and 15 with lymphocytic enteritis secondary to Helicobacter pylori acted as control group. Duodenal biopsies were obtained to assess both CD IEL flow cytometric (complete or incomplete) and IF patterns.

RESULTS

Sensitivity of IF, and complete and incomplete cytometric patterns for CD diagnosis in patients with positive serology (Marsh 1+3) was 92%, 85 and 97% respectively, but only the complete cytometric pattern had 100% specificity. Twelve seropositive and 8 seronegative Marsh 1 patients had a CD diagnosis at inclusion or after gluten free-diet, respectively. CD cytometric pattern showed a better diagnostic performance than both IF pattern and serology for CD diagnosis in lymphocytic enteritis at baseline (95% vs 60% vs 60%, p = 0.039).

CONCLUSIONS

Analysis of the IEL flow cytometric pattern is a fast, accurate method for identifying CD in the initial diagnostic biopsy of patients presenting with lymphocytic enteritis, even in seronegative patients, and seems to be better than anti-TG2 intestinal deposits.

Beyond the Intestinal Celiac Mucosa: Diagnostic Role of Anti-TG2 Deposits, a Systematic Review

Aim: To review the existing literature on the role and significance of intestinal transglutaminase 2 immunoglobulin A deposits (TG2 deposits) in patients with overt celiac disease (CD), potential celiac disease (PCD), and other autoimmune or gluten-related conditions.

Methods: We conducted a systematic review of studies published in English, evaluating presence and characteristics of TG2 deposits in subjects with overt CD, PCD, gluten-related diseases [dermatitis herpetiformis (DH), gluten-ataxia (GA)], autoimmune disorders (type-1 diabetes), and other conditions. Studies were identified through a MEDLINE search (1950–2013).

Results: Twenty-three studies were included in the review. Eleven studies were performed in children. Overall TG2 deposits were present in 100% of adults with overt CD, while in children prevalence ranged from 73.2 to 100%. Six studies with an established definition of PCD were considered, prevalence of deposits ranging from 64.7 to 100%. A single study followed-up PCD patients with repeated biopsies and identified presence of intestinal deposits as the best marker to reveal progression toward villous atrophy. Two studies investigated presence of deposits in DH, reporting prevalence between 63 and 79%. A single study documented TG2 deposits in 100% of patients with GA. In children with type-1 diabetes (T1D), positivity of intestinal TG2 deposits ranged from 25 to 78%.

Conclusion: Transglutaminase 2 IgA deposits seem to be a constant feature in overt CD patients and are frequently detectable in other gluten-related conditions (DH and GA). The vast majority of PCD patients express TG2 deposits at the intestinal level, but no sufficient data are available to exactly define their prognostic role as a marker of evolution toward overt CD. The frequent finding of TG2 deposits in the intestinal mucosa of patients with T1D is an interesting observation deserving further evaluation.

Sampling of proximal and distal duodenal biopsies in the diagnosis and monitoring of celiac disease

BACKGROUND

Since celiac disease-associated mucosal lesions are patchy, the diagnosis of the disease requires histological evaluation of multiple duodenal biopsies.

AIM

To examine whether adequate biopsy sampling in either the bulb or distal duodenum is sufficient to diagnose celiac disease.

METHODS

Twenty-five patients with positive celiac disease-specific serology and 17 patients with negative serology, who were on a gluten-containing diet, and 13 celiac disease patients on a gluten-free diet were consecutively and prospectively enrolled. Mucosal damage, anti-transglutaminase-2 IgA deposits, interferon-γ, interleukin-17A and interleukin-15 transcripts were evaluated in bulb and distal duodenal biopsies.

RESULTS

All patients with positive celiac disease-specific serology exhibited villous atrophy in both duodenal sites. In this group, mucosal anti-transglutaminase-2 IgA deposits were found in 24/25 (96%) bulb samples and 22/25 (88%) distal duodenal samples. No villous atrophy was documented in patients with negative serology. Interferon-γ and interleukin-17A were over-expressed in both duodenal sites of patients with villous atrophy, unlike patients with normal duodenal morphology (p<0.001). Among treated celiac disease patients, 2 (15.4%) had villous atrophy exclusively in the bulb and 6 (46.2%) had minimal histological abnormalities at both sites.

CONCLUSION

Sampling in the bulb and distal duodenum could be sufficient to diagnose/exclude celiac disease.

Prospective antibody case finding of coeliac disease in type-1 diabetes children: need of biopsy revisited

AIM

To evaluate whether coeliac disease (CD) can be diagnosed by measuring autoantibodies without small-intestinal mucosal biopsies in children with type 1 diabetes.

METHODS

Case finding of CD was undertaken in 181 consecutive IgA-competent children with type 1 diabetes using transglutaminase 2 (TG2) and endomysial IgA antibody (EMA) tests in serum and the rapid point of care test in fingertip whole-blood sample. Endoscopy with intestinal biopsies was recommended for patients with high TG2-IgA titres (>96 U) and in children with lower positive tests if either the EMA test or the rapid point of care test was additionally positive. The duodenal mucosal biopsies were graded according to the Marsh classification.

RESULTS

The TG2-IgA test had a 15.5% and the EMA test a 6.0% seropositivity. All seven biopsied high-titre TG2-IgA-positive children were symptom free and found to have CD (Marsh 3 type lesion). These patients were also positive for EMA and in the rapid point of care test. Lower titre TG2-IgA-positive children had histological Marsh 1 to 3a lesions.

CONCLUSIONS

None of the type 1 diabetes children with high TG2-IgA titres would have needed endoscopy with duodenal biopsies to reach a CD diagnosis. Lower TG2-IgA-positive patients need to be biopsied.

Serum I-FABP as marker for enterocyte damage in coeliac disease and its relation to villous atrophy and circulating autoantibodies

BACKGROUND

Enterocyte damage is the hallmark of coeliac disease (CD) resulting in malabsorption. Little is known about the recovery of enterocyte damage and its clinical consequences. Serum intestinal fatty acid binding protein (I-FABP) is a sensitive marker to study enterocyte damage.

AIMS

To evaluate the severity of enterocyte damage in adult-onset CD and its course upon a gluten-free diet (GFD). Furthermore, the correlation among enterocyte damage, CD autoantibodies and histological abnormalities during the course of disease is studied.

METHODS

Serum I-FABP levels were determined in 96 biopsy-proven adult CD patients and in 69 patients repeatedly upon a GFD. A total of 141 individuals with normal antitissue transglutaminase antibody (IgA-tTG) levels served as controls. I-FABP levels were related to the degree of villous atrophy (Marsh grade) and IgA-tTG.

RESULTS

I-FABP levels were elevated in untreated CD (median 691 pg/mL) compared with controls (median 178 pg/mL, P < 0.001) and correlated with Marsh grade (r = 0.265, P < 0.05) and IgA-tTG (r = 0.403, P < 0.01). Upon a GFD serum levels decreased significantly, however, not within the range observed in controls, despite the common observed normalisation of IgA-tTG levels and Marsh grade. CD patients with elevated I-FABP levels nonresponding to GFD showed persistent histological abnormalities.

CONCLUSIONS

Enterocyte damage assessed by serum I-FABP correlates with the severity of villous atrophy in coeliac disease at the time of diagnosis. Although enterocyte damage improves upon treatment, substantial enterocyte damage persists despite absence of villous atrophy and low IgA-tTG levels in the majority of cases. Elevated I-FABP levels nonresponding to gluten-free diet are indicative of histological abnormalities and warrant further evaluation.

Persistent duodenal intraepithelial lymphocytosis despite a long-term strict gluten-free diet in celiac disease

OBJECTIVES

In celiac disease, complete histological normalization of the small-intestinal mucosa occurs in only 8-20% of adult patients after commencing a gluten-free diet. Intraepithelial lymphocytosis may persist for years while villous morphology normalizes. Factors contributing to this and the clinical relevance of persistent intraepithelial lymphocytosis were here investigated.

METHODS

Altogether 177 adult celiac disease patients adhering to a long-term strict gluten-free diet were enrolled. Co-morbidities, ongoing medications, and consumption of oats and wheat-starch were recorded. Small-bowel morphology and intraepithelial lymphocyte count as well as laboratory parameters of malabsorption were evaluated. Gastrointestinal symptoms and psychological well-being were measured by structured questionnaires.

RESULTS

In all, 170 (96%) out of the 177 patients evinced normal villous architecture and 7 (4%) villous atrophy. Among patients with normal villous structure, 96 (56%) had persistent intraepithelial lymphocytosis and 74 (44%) completely normal small-intestinal mucosa. Consumption of oats was the only factor contributing to the persistent intraepithelial lymphocytosis. Co-morbidities, Helicobacter pylori gastritis, drugs, or wheat-starch in the diet had no effect. The clinical outcome of the patients with persistent intraepithelial lymphocytosis was good, since no signs of malabsorption, excess malignancies, increase in gastrointestinal symptoms, or impaired quality of life were associated with it when compared to subjects with completely normal mucosa. The only outcome found in this study was a significantly lower, although normal villous height-crypt depth ratio among the patients with persistent intraepithelial lymphocytosis as compared to those with completely normal mucosa.

CONCLUSIONS

Despite excellent villous recovery in this study, persistent intraepithelial lymphocytosis was still common among celiac disease patients on a long-term strict gluten-free diet. Consumption of oats was associated with persistent duodenal lymphocytosis and this calls for further investigations. The prognosis of patients with persistent intraepithelial lymphocytosis seems to be good while adhering to a gluten-free diet for a mean of 11 years.

Gastrointestinal symptoms and quality of life in screen-detected celiac disease

BACKGROUND

Active serological screening has proved an effective means of increasing the diagnostic rate in celiac disease. The effects of a long-term gluten-free diet on possible gastrointestinal symptoms and psychological well-being in screen-detected patients have nevertheless remained obscure.

METHODS

Abdominal symptoms and quality of life were measured in a large cohort of treated screen-detected celiac adults. Comparisons were made with corresponding symptom-detected patients and with non-celiac controls. Dietary adherence was assessed both by structured interview and by serological testing.

RESULTS

In both screen- and symptom-detected celiac groups, 88% of the patients were adherent. On a diet, both screen- and symptom-detected patients reported significantly more gastrointestinal symptoms than non-celiac controls. Those screen-detected patients who reported having no symptoms at the time of diagnosis, also remained asymptomatic during the diet. Despite persistent symptoms, psychological well-being in screen-detected patients was comparable with that in non-celiac controls, whereas the symptom-detected patients showed lower quality of life.

CONCLUSION

Long-term treated screen-detected celiac patients, especially women, suffer from gastrointestinal symptoms on a gluten free diet similarly to symptom-detected patients. However, despite a similar frequency of persistent symptoms, the quality of life was unimpaired in the screen found, but remained low in the symptom-detected group.

A novel algorithm for the diagnosis of celiac disease and a comprehensive review of celiac disease diagnostics

There is an urgent clinical need for a better laboratory celiac disease diagnosis with both less false positive results and minimal underdetection. The aim of the present study was to evaluate the performance and diagnostic accuracy of different assays in an outpatient population setting for the diagnosis for celiac disease (CD) in order to design an optimal algorithm. We used 15 different ELISA assays to assess 47 blood samples of newly diagnosed children (positive biopsy results) and 52 samples from age- and sex-matched children with negative biopsy results for CD. Scoring criteria were established for grading the assays performance and characteristics. The combined gliadin and tTG assays exhibited the best sensitivity (100%). The addition of other assays to the CeliCheck neo-epitopes assay improved specificity so that the final algorithm had 100% sensitivity, 96.2% specificity, and 98.1% accuracy. The clinical demand for both maximal sensitivity and maximal specificity cannot be achieved with a single test. Using a combination of a sensitive assay together with specific assays improved celiac disease detection rates, with an acceptable number of false positive results. This model, however, needs to be confirmed prospectively in both children and adults.

Is a gluten-free diet necessary in Marsh I intestinal lesions in patients with HLADQ2, DQ8 genotype and without gastrointestinal symptoms?

PURPOSE OF REVIEW

To describe whether a gluten-free diet (GFD) is indicated in Marsh I gluten-sensitive enteropathy where gastrointestinal symptoms are not present. Arguments are provided to prescribe a GFD to manage extraintestinal symptoms. By contrast, there are not enough reasons to prescribe a GFD to prevent long-term complications.

RECENT FINDINGS

Population-based and prospective observational studies have found that lymphocytic duodenosis may be due to not just gluten-sensitive enteropathy but also due to other aetiologic factors. Marsh I type lesions may be the cause of iron-deficiency anaemia of unknown aetiology which is reverted by a GFD. A similar effect seems to occur with bone mineralization and hypertransaminasemia. The beneficial influence of a GFD reducing lymphoma and coeliac disease-related mortality remains controversial.

SUMMARY

An appropriate differential diagnosis of the lymphocytic duodenosis is essential before a GFD is indicated. As a third of patients remained undiagnosed, in spite of genetic study and specific coeliac serology, flow cytometry and transglutaminase antibodies in duodenal tissue may be helpful in establishing gluten-sensitive enteropathy diagnosis. Future studies should assess whether lymphoma risk is reduced by a GFD in Marsh I patients. Also a more precise benefit in bone mineralization in this setting is needed.

European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the diagnosis of coeliac disease

OBJECTIVE

Diagnostic criteria for coeliac disease (CD) from the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) were published in 1990. Since then, the autoantigen in CD, tissue transglutaminase, has been identified; the perception of CD has changed from that of a rather uncommon enteropathy to a common multiorgan disease strongly dependent on the haplotypes human leukocyte antigen (HLA)-DQ2 and HLA-DQ8; and CD-specific antibody tests have improved.

METHODS

A panel of 17 experts defined CD and developed new diagnostic criteria based on the Delphi process. Two groups of patients were defined with different diagnostic approaches to diagnose CD: children with symptoms suggestive of CD (group 1) and asymptomatic children at increased risk for CD (group 2). The 2004 National Institutes of Health/Agency for Healthcare Research and Quality report and a systematic literature search on antibody tests for CD in paediatric patients covering the years 2004 to 2009 was the basis for the evidence-based recommendations on CD-specific antibody testing.

RESULTS

In group 1, the diagnosis of CD is based on symptoms, positive serology, and histology that is consistent with CD. If immunoglobulin A anti-tissue transglutaminase type 2 antibody titers are high (>10 times the upper limit of normal), then the option is to diagnose CD without duodenal biopsies by applying a strict protocol with further laboratory tests. In group 2, the diagnosis of CD is based on positive serology and histology. HLA-DQ2 and HLA-DQ8 testing is valuable because CD is unlikely if both haplotypes are negative.

CONCLUSIONS

The aim of the new guidelines was to achieve a high diagnostic accuracy and to reduce the burden for patients and their families. The performance of these guidelines in clinical practice should be evaluated prospectively.

Intestinal deposits of anti-tissue transglutaminase IgA in childhood celiac disease

BACKGROUND

High serum levels of anti-tissue-transglutaminase-2 IgA antibodies (anti-TG2), which are produced and deposited in the intestine, characterize celiac disease.

AIM

To assess the diagnostic value of intestinal deposits of anti-TG2 IgA for celiac disease in a paediatric population.

METHODS

344 children underwent duodenal biopsy for the suspicion of CD, and were divided into 3 groups: group A, 144 celiac subjects with villous atrophy (Marsh 3b-c); group B, 109 subjects with high serum levels of anti-TG2 but normal intestinal mucosa (Marsh 0-1) (potential celiac disease patients); group C, 91 subjects with normal levels of serum anti-TG2: 70 with Marsh 0-1 and 21 with Marsh 3a mucosa. All duodenal sections were evaluated for the presence of intestinal deposits of anti-TG2 IgA by double immunofluorescence.

RESULTS

Deposits of anti-TG2 IgA were present in 96%, 68%, 12% of patients from groups A, B, C, respectively. Diagnostic sensitivity and specificity for celiac disease were 96% and 88% vs. 97% and 100% for serum anti-TG2, respectively. The degree of concordance with serum anti-TG2 was 85%.

CONCLUSION

Detection of intestinal deposits of anti-TG2 IgA is a useful diagnostic tool. Further research is needed regarding their ability to predict evolution to villous atrophy in potential celiac disease.

Editorial: Celiac disease in Turkey: lessons from the fertile crescent

Celiac disease (CD) is as frequent in Turkey as in Western countries. This finding challenges old theories hypothesizing a selective effect of agriculture spreading on the predisposition to develop CD. Despite the availability of reliable serological tests, e.g., the anti-transglutaminase and antiendomysial antibodies, gray areas of CD diagnosis are increasingly encountered in clinical practice. The diagnostic process must take into consideration the antibody level. The small intestinal biopsy is not the gold standard but one of the important investigations of the diagnostic paraphernalia. New evidence-based guidelines for CD diagnosis are urgently needed for both children and adults.

Celiac disease, gluten-free diet, and oats

Oats in a gluten-free diet increase the diet's nutritional value, but their use remains controversial. Contamination with prolamins of other cereals is frequent, and some clinical and experimental studies support the view that a subgroup of celiac patients may be intolerant to pure oats. Thus, this issue is more complex than previously suggested. In order to produce oats that are safe for all celiac patients, the following topics should be addressed: selection of oat cultivars with low avenin content, research on such recombinant varieties of oats, development of assay methods to detect avenins in oat products, guidelines for the agricultural processing of oats and the manufacture of oat products, as well as guidelines for following up with celiac patients who consume oats.

Antibodies in celiac disease: implications beyond diagnostics

Celiac disease is a multisystemic dietary, gluten-induced autoimmune disorder characterized by the presence of transglutaminase (TG) 2 serum autoantibodies. Distinct autoantibodies targeting members of the TG family (TG2, TG3 and TG6) are found deposited in small-bowel mucosa and in extraintestinal tissues affected by the disease. Serum autoantibodies against other self-antigens also emerge in untreated celiac disease patients. Although villous atrophy and crypt hyperplasia in small-bowel biopsy samples are still the gold standards in diagnostics, celiac disease-specific antibodies are widely used as diagnostic aids. Gluten-induced small-bowel mucosal T-cell response is the cornerstone in the pathogenesis of the disorder, but humoral immunity may also play a central role. This review article is focused on the autoantibodies that occur in the context of celiac disease. The article summarizes the diagnostic utility of different celiac-related antibodies and discusses their roles in the pathogenesis of the disease.

Intestinal transglutaminase 2 specific antibody deposits in non-responsive coeliac disease

BACKGROUND AND AIMS

The diagnosis of coeliac disease is problematic in individuals not responding to a gluten-free diet. Small-bowel villous atrophy occurs in other enteropathies and non-responsive patients are often seronegative. We investigated whether small-bowel mucosal transglutaminase-2 specific autoantibody deposits distinguish non-responsive coeliac disease from other enteropathies.

METHODS

Small-bowel mucosal autoantibody deposits were determined in 27 non-responsive, 28 responsive coeliac patients and 10 controls with other enteropathies. Of the non-responsive coeliac patients six were adhering poorly and 21 strictly to the diet; six of the 21 had enteropathy-associated lymphoma, five refractory coeliac disease and 10 otherwise persistent villous atrophy. The presence of mucosal autoantibody deposits was compared to serology, villous morphology, densities of intraepithelial lymphocytes (IELs) and markers of refractory coeliac disease.

RESULTS

Twenty out of 21 well-adhering, all six poorly adhering non-responsive and all 28 untreated responsive coeliac patients had small-bowel mucosal autoantibody deposits present, while controls with other enteropathies were negative. Small-bowel mucosal autoantibody deposits were more accurate in detecting coeliac disease than serology or IEL densities. Refractory coeliac markers revealed only cases with the most severe condition.

CONCLUSIONS

Small-bowel mucosal autoantibody deposits differentiate coeliac disease from other enteropathies, enabling the design of appropriate therapeutic strategies.