Small intestinal resident eosinophils maintain gut homeostasis following microbial colonization.

The intestine harbors a large population of resident eosinophils, yet the function of intestinal eosinophils has not been explored. Flow cytometry and whole-mount imaging identified eosinophils residing in the lamina propria along the length of the intestine prior to postnatal microbial colonization. Microscopy, transcriptomic analysis, and mass spectrometry of intestinal tissue revealed villus blunting, altered extracellular matrix, decreased epithelial cell turnover, increased gastrointestinal motility, and decreased lipid absorption in eosinophil-deficient mice. Mechanistically, intestinal epithelial cells released IL-33 in a microbiota-dependent manner, which led to eosinophil activation. The colonization of germ-free mice demonstrated that eosinophil activation in response to microbes regulated villous size alterations, macrophage maturation, epithelial barrier integrity, and intestinal transit. Collectively, our findings demonstrate a critical role for eosinophils in facilitating the mutualistic interactions between the host and microbiota and provide a rationale for the functional significance of their early life recruitment in the small intestine.

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

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

IL-10-producing regulatory cells impact on celiac disease evolution.

Celiac Disease (CD) is a T-cell mediated disorder caused by immune response to gluten, although the mechanisms underlying CD progression are still elusive. We analyzed immune cell composition, plasma cytokines, and gliadin-specific T-cell responses in patients with positive serology and normal intestinal mucosa (potential-CD) or villous atrophy (acute-CD), and after gluten-free diet (GFD). We found: an inflammatory signature and the presence of circulating gliadin-specific IFN-γ+ T cells in CD patients regardless of mucosal damage; an increased frequency of IL-10-secreting dendritic cells (DC-10) in the gut and of circulating gliadin-specific IL-10-secreting T cells in potential-CD; IL-10 inhibition increased IFN-γ secretion by gliadin-specific intestinal T cells from acute- and potential-CD. On GFD, inflammatory cytokines normalized, while IL-10-producing T cells accumulated in the gut. We show that IL-10-producing cells are fundamental in controlling pathological T-cell responses to gluten: DC-10 protect the intestinal mucosa from damage and represent a marker of potential-CD.

Impact of delay in the diagnosis on the severity of celiac disease.

BACKGROUND AND AIM: Celiac disease (CeD) has now become a global disease with a worldwide prevalence of 0.67%. Despite being a common disease, CeD is often not diagnosed and there is a significant delay in its diagnosis. We reviewed the impact of the delay in the diagnosis on the severity of manifestations of CeD. METHODS: We reviewed clinical records of 726 consecutive patients with CeD from the Celiac Clinic database and the National Celiac Disease Consortium database. We extracted specific data including the demographics, symptoms at presentation, time of onset of symptoms, time to diagnosis from the onset of the symptoms, and relevant clinical data including fold-rise in anti-tissue transglutaminase antibody (IgA anti-tTG Ab) and severity of villous and crypt abnormalities as assessed using modified Marsh classification. RESULTS: The median duration between the onset of symptoms and the diagnosis of CeD was 27 months (interquartile range 12-60 months). A longer delay in the diagnosis of CeD from the onset of symptoms was associated with lower height for age, lower hemoglobin, higher fold rise in IgA Anti tTG titers, and higher severity of villous and crypt abnormalities. About 18% of patients presented with predominantly non-gastrointestinal complaints and had a longer delay in the diagnosis of CeD. CONCLUSIONS: There is a significant delay in the diagnosis of CeD since the onset of its symptoms. The severity of celiac disease increases with increasing delay in its diagnosis. There is a need to keep a low threshold for the diagnosis of CeD in appropriate clinical settings.

Interferon-Driven Immune Dysregulation in Common Variable Immunodeficiency-Associated Villous Atrophy and Norovirus Infection.

PURPOSE: About 15% of patients with common variable immunodeficiency (CVID) develop a small intestinal enteropathy, which resembles celiac disease with regard to histopathology but evolves from a distinct, poorly defined pathogenesis that has been linked in some cases to chronic norovirus (NV) infection. Interferon-driven inflammation is a prominent feature of CVID enteropathy, but it remains unknown how NV infection may contribute. METHODS: Duodenal biopsies of CVID patients, stratified according to the presence of villous atrophy (VA), IgA plasma cells (PCs), and chronic NV infection, were investigated by flow cytometry, multi-epitope-ligand cartography, bulk RNA-sequencing, and RT-qPCR of genes of interest. RESULTS: VA development was connected to the lack of intestinal (IgA+) PC, a T helper 1/T helper 17 cell imbalance, and increased recruitment of granzyme+CD8+ T cells and pro-inflammatory macrophages to the affected site. A mixed interferon type I/III and II signature occurred already in the absence of histopathological changes and increased with the severity of the disease and in the absence of (IgA+) PCs. Chronic NV infection exacerbated this signature when compared to stage-matched NV-negative samples. CONCLUSIONS: Our study suggests that increased IFN signaling and T-cell cytotoxicity are present already in mild and are aggravated in severe stages (VA) of CVID enteropathy. NV infection preempts local high IFN-driven inflammation, usually only seen in VA, at milder disease stages. Thus, revealing the impact of different drivers of the pathological mixed IFN type I/III and II signature may allow for more targeted treatment strategies in CVID enteropathy and supports the goal of viral elimination.

The role of histopathology in the diagnosis and management of coeliac disease and other malabsorptive conditions.

Most absorption of nutrients takes place in the proximal small intestine, and the most common disorders leading to malabsorption are associated with a morphological abnormality in the duodenal mucosa that is appreciable in histological sections of biopsy specimens. Coeliac disease is the most well-known example, causing intraepithelial lymphocytosis, inflammation and villous atrophy in the duodenum. Remarkably similar inflammatory changes can be induced by other processes, including medications, e.g. angiotensin II receptor blockers and immune checkpoint inhibitors, immune dysregulation disorders, e.g. common variable immunodeficiency and autoimmune enteropathy, infections, collagenous sprue, and tropical sprue. However, there are often subtle histological differences from coeliac disease in the type of inflammatory infiltrate, the presence of crypt apoptosis, and the extent and type of inflammation beyond the duodenum. The clinical setting and serological investigation usually allow diagnostic separation, but some cases remain challenging. Histopathology is also important in assessing the response to treatment, such as the change in villous architecture caused by a gluten-free diet, or the response to cessation of a potentially causative medication. This review examines the practical role that histopathology of duodenal biopsy specimens plays in the assessment and management of inflammatory malabsorptive processes of the proximal small intestine, with a particular emphasis on coeliac disease.

Diagnostic and therapeutic challenge of unclassifiable enteropathies with increased intraepithelial CD103+ CD8+ T lymphocytes: a single center case series.

OBJECTIVES: Chronic diarrhea, villous atrophy and/or increased intraepithelial T-lymphocytes (IEL) occur in many inflammatory disorders including celiac disease (CD). However, a definite diagnosis is difficult to make in some patients despite an extensive diagnostic work-up. Clinical outcomes and histological phenotypes of such patients we refer to as unclassifiable enteropathy (UEP) remain unclear. MATERIAL AND METHODS: We performed a retrospective single-center analysis of patients with chronic diarrhea, weight loss and increased IEL. Patients with defined etiologies including infections, CD, drugs, immunodeficiencies or neoplasms were excluded. Clinical and histologic/immunophenotypic parameters were analyzed. RESULTS: Nine patients with UEP were identified. Small intestinal damage ranged from minor villous abnormalities to complete atrophy while all patients displayed high numbers of CD103+ CD8+ IELs. In contrast to CD, these CD8+ T cells were not confined to the surface epithelium, but also infiltrated the crypts. Additional histological features included apoptotic crypt epithelial cells and mixed inflammatory infiltrates in the tunica propria. Involvement of other segments of the gastrointestinal tract was observed in 7/9 patients. A clonal intestinal T-cell lymphoproliferative disorder developed in 2 patients, one of which had a fatal disease course. The majority of patients responded to corticosteroids, while response to immunosuppressive medications yielded heterogeneous results. CONCLUSIONS: We report a patient population with 'difficult-to-classify' enteropathies characterized by various degrees of villous atrophy and strongly increased intraepithelial CD103+ CD8+ T cells in the small intestine which harbor an increased risk for T-cell lymphoproliferative disorders. Clinical course, histology, and response to immunosuppressive therapy all suggest an autoimmune pathogenesis.

Severe spruelike enteropathy and collagenous colitis caused by olmesartan.

BACKGROUND: Olmesartan, which is an angiotensin II receptor blocker, reportedly causes spruelike enteropathy, with intestinal villous atrophy as its typical histopathological finding. Interestingly, collagenous and/or lymphocytic gastritis and colitis occur in some patients. We report the case of a 73-year-old Japanese man with a 2-month clinical history of severe diarrhea and weight loss. There were few reports in which spruelike enteropathy and collagenous colitis were both observed and could be followed up. CASE PRESENTATION: We report a case of a 73-year-old man with a 2-month clinical history of severe diarrhea and weight loss. He had taken olmesartan for hypertension treatment for 5 years. Endoscopic examination with biopsies revealed intestinal villous atrophy and collagenous colitis. Suspecting enteropathy caused by olmesartan, which was discontinued on admission because of hypotension, we continued to stop the drug. Within 3 weeks after olmesartan discontinuation, his clinical symptoms improved. After 3 months, follow-up endoscopy showed improvement of villous atrophy but not of the thickened collagen band of the colon. However, the mucosa normalized after 6 months, histologically confirming that the preexistent pathology was finally resolved. CONCLUSIONS: This report presents a case in which spruelike enteropathy and collagenous colitis were both observed and could be followed up. In unexplained cases of diarrhea, medication history should be reconfirmed and this disease should be considered a differential diagnosis.

Assessment of disease severity on capsule endoscopy in patients with small bowel villous atrophy.

BACKGROUND AND AIM: There is a lack of uniformity of reporting on features of celiac disease (CD) on small bowel capsule endoscopy (SBCE). This makes determining extent of disease and comparison of severity of disease challenging. METHODS: De-identified SBCEs of 300 patients (78 CD [26%], 18 serology negative villous atrophy [6%], and 204 controls with normal duodenal histology [68%]) were included. Videos were reviewed by two experts. All patients had duodenal histology taken within 2 weeks of SBCE. The degree of agreement in CD features and extent of disease was then determined. The resulting score for each factor was used to determine overall severity of disease. RESULTS: There was substantial agreement in the kappa coefficient for the detection of CD features between reviewers (0.67). Agreement for extent of affected small bowel (SB) mucosa was high (0.97). On multiple regression analysis, several features of CD correlated with extent of affected SB mucosa for both reviewers. The odds ratios derived from this analysis were then used to score features of CD, enabling scores of severity to be calculated for each patient. The median overall scores for patients increased significantly according to the independent classification of severity by the capsule reviewers: mild (20, 0-79), moderate (45, 25-123), and severe (89, 65-130) (P = 0.0001). CONCLUSION: The good correlation of CD scores between expert reviewers confirms the validity of features of CD on SBCE. An objective score of CD features in the SB is useful in the follow up of patients with CD and serology negative villous atrophy.

Anaemia in Dermatitis Herpetiformis: Prevalence and Associated Factors at Diagnosis and One-year Follow-up.

Dermatitis herpetiformis is a cutaneous manifestation of coeliac disease. Anaemia is a common finding in patients with untreated coeliac disease, but little is known about the occurrence of anaemia in those with dermatitis herpetiformis. This study investigated the prevalence of anaemia and factors associated with anaemia in 250 patients with dermatitis herpetiformis, at diagnosis and one year after diagnosis. As controls, 139 patients with coeliac disease were included. Patient records were reviewed to gather baseline clinical, histological, and laboratory data. Follow-up data for patients with dermatitis herpetiformis were collected from patient records and via questionnaires or at follow-up visits. The prevalence of anaemia was 12% in patients with dermatitis herpetiformis and 17% in patients with coeliac disease at diagnosis (p = 0.257). Anaemia in patients with dermatitis herpetiformis was not associated with the severity of skin symptoms or small bowel damage. The prevalence of anaemia at a 1-year follow-up had increased to 19%, but it was associated mainly with dapsone treatment.

Deciphering the Transcriptomic Heterogeneity of Duodenal Coeliac Disease Biopsies.

Coeliac disease (CD) is a clinically heterogeneous autoimmune disease with variable presentation and progression triggered by gluten intake. Molecular or genetic factors contribute to disease heterogeneity, but the reasons for different outcomes are poorly understood. Transcriptome studies of tissue biopsies from CD patients are scarce. Here, we present a high-resolution analysis of the transcriptomes extracted from duodenal biopsies of 24 children and adolescents with active CD and 21 individuals without CD but with intestinal afflictions as controls. The transcriptomes of CD patients divide into three groups-a mixed group presenting the control cases, and CD-low and CD-high groups referring to lower and higher levels of CD severity. Persistence of symptoms was weakly associated with subgroup, but the highest marsh stages were present in subgroup CD-high, together with the highest cell cycle rates as an indicator of virtually complete villous atrophy. Considerable variation in inflammation-level between subgroups was further deciphered into immune cell types using cell type de-convolution. Self-organizing maps portrayal was applied to provide high-resolution landscapes of the CD-transcriptome. We find asymmetric patterns of miRNA and long non-coding RNA and discuss the effect of epigenetic regulation. Expression of genes involved in interferon gamma signaling represent suitable markers to distinguish CD from non-CD cases. Multiple pathways overlay in CD biopsies in different ways, giving rise to heterogeneous transcriptional patterns, which potentially provide information about etiology and the course of the disease.

May Antitransglutaminase Levels Predict Severity of Duodenal Lesions in Adults with Celiac Disease?

Background and Objective: Pediatric guidelines on celiac disease (CD) state that children with anti-transglutaminase antibodies (TGAs) >×10 upper limit of normal (ULN) may avoid endoscopy and biopsy. We aimed to evaluate whether these criteria may be suitable for villous atrophy diagnosis in CD adults. Materials and Methods: We retrospectively enrolled patients with CD aged >18 years. TGAs were expressed as xULN. Duodenal lesions were classified as atrophic or non-atrophic according to Marsh-Oberhuber. Fisher's exact and t-test were used for variables comparison. Receiver operating characteristics (ROC) curve analysis was performed with estimation of area under the curve (AUC), sensitivity, specificity, and positive and negative predictive value (PPV/NPV). Results: One hundred and twenty-one patients were recruited. Sixty patients (49.6%) had TGA >×10 ULN, and 93 (76.8%) had villous atrophy. The cut-off of >×10 ULN had sensitivity = 53.7%, specificity = 64.3%, PPV = 83.3%, and NPV = 29.5% to predict atrophy. Therefore, considering pediatric criteria, in 50 (41.3%) patients, biopsy could have been avoided. Patient subgroup with atrophy had higher TGA levels despite being not significant (37.2 ± 15.3 vs. 8.0 ± 1.3 ULN, p = 0.06). In adults, a slightly better diagnostic performance was obtained using a cut-off of TGA >×6.2 ULN (sensitivity = 57.1%, specificity = 65.6%, and AUC = 0.62). Conclusions: Despite our confirmation that villous atrophy is linked to high TGA levels, CD and atrophy diagnosis based only on serology is not reliable in adults.

[Celiac crisis in patients with celiac disease. Case report].

Celiac crisis (CC) is a rare life-threatening course of celiac disease, observed mainly in children. In adults, CK can be the first manifestation of the disease and, very rarely, a relapse that occurs in patients who do not follow the gluten-free diet (AGD). Triggers can be stress, surgery, childbirth, etc. A clinical observation of CC developed in a 49-year-old patient with previously established latent celiac disease with subtotal villous atrophy, stage Marsh III C is presented. The patient did not comply with AHD. After severe angina, she developed anorexia, diarrhea, emaciation, coagulopathy, bilateral pulmonary embolism, infarction pneumonia, and enterogenic sepsis. As a result of intensive therapy with prednisolone, Fraxiparine, antibiotics, fresh frozen plasma and strict adherence to hypertension, remission of the disease was achieved.

Increased Prevalence of Celiac Disease in School-age Children in Italy.

BACKGROUND & AIMS: Celiac disease is one of the most common diseases worldwide, with an apparent trend of increasing prevalence. We investigated the prevalence of celiac disease in children in Italy in 2015-2016 and compared that with data from 25 years ago. METHODS: We screened 4570 children (5-11 years old, 80.1% of the eligible population) from metropolitan areas of Ancona and Verona for HLA genes associated with increased risk of celiac disease, and for total serum levels of IgA and IgA class anti-tissue transglutaminase in HLA positives. Diagnoses of celiac disease were confirmed by detection of anti-endomysial antibody and analysis of intestinal biopsies. The prevalence of celiac autoimmunity and celiac disease were calculated and compared with values from the same geographical area during the years 1993-1995, after adjustment for the different diagnostic algorithm. RESULTS: We identified 1960 children with celiac disease-associated haplotypes (43% of children screened; 95% CI, 40.8%-45.2%). The prevalence of celiac disease autoimmunity in the HLA-positive subjects was 96/1706 (5.62%; 95% CI, 4.53%-6.71%) and 54 of these children satisfied the diagnostic criteria for celiac disease. In the eligible population there were other 23 known cases of celiac disease. The overall estimated prevalence of celiac disease was 1.58% (95% CI, 1.26%-1.90%); this value is significantly higher than the 1993-1995 adjusted prevalence (0.88%; 95% CI, 0.74%-1.02%). CONCLUSIONS: We found the prevalence of celiac disease in children in Italy to be greater than 1.5%; this value has increased significantly over the past 25 years. Studies are needed to determine the causes of this large increase.

Histological and magnified endoscopic evaluation of villous atrophy in gastrointestinal graft-versus-host disease.

AIM:  To measure histological villous atrophy and to clarify the diagnostic accuracy of endoscopic villous atrophy in gastrointestinal graft-versus-host disease. METHODS:  Data for patients who underwent upper and/or lower endoscopic examinations after hematopoietic stem cell transplantation were retrospectively collected. In study 1, group A included 56 patients in whom GI-GVHD was histologically confirmed and group B included 60 patients in whom GI-GVHD was not histologically confirmed. Group C included 59 patients before HSCT. The lengths of villi and crypts in the duodenum and terminal ileum were histologically measured. In study 2, the diagnostic accuracies of villous atrophy of the duodenum and of the terminal ileum using magnifying endoscopy were evaluated. RESULTS:  In study 1, the lengths of villi and the villi/crypt (V/C) ratios of the duodenum and terminal ileum in group A were significantly smaller than those in the other groups (p < 0.05). V/C ratio was moderately correlated with clinical severity, histological grades, and endoscopic grades in the terminal ileum. In study 2, the diagnostic accuracies of magnified images for villous atrophy were 83.8% in the duodenum and 94.9% in the terminal ileum. CONCLUSION:  Magnifying endoscopy enables evaluation of villous atrophy and is useful for optical biopsy of GVHD.

Current Concepts of Dermatitis Herpetiformis.

Dermatitis herpetiformis (DH) is an autoimmune skin disease that causes itchy, blistering rash, typically on the elbows, knees and buttocks. DH and coeliac disease share the same genetic background, gluten-dependent enteropathy and antibody response against tissue transglutaminase. DH is currently considered a cutaneous manifestation of coeliac disease, and the prevailing hypothesis is that DH develops as a late manifestation of subclinical coeliac disease. The incidence of DH is decreasing contemporarily with the increasing incidence of coeliac disease. The IgA immune response in DH skin is directed against epidermal transglutaminase, while the autoantigen in the gut is tissue transglutaminase. Granular IgA deposition in the papillary dermis is pathognomonic for DH, and is a finding used to confirm the diagnosis. The treatment of choice for DH is a life-long gluten-free diet, which resolves the rash and enteropathy, increases quality of life, and offers a good long-term prognosis.

Olmesartan-associated duodenal villous atrophy, an emerging clinical issue.

Duodenal villous atrophy with olmesartan was described in 2012, 10 years following registration of olmesartan. Clinical features are severe watery diarrhoea, usually occurring in association with weight loss. Onset is delayed, with a mean duration of prior exposure to olmesartan of 3 years. Diagnosis may be delayed. Symptoms resolve over weeks following cessation of olmesartan. Epidemiological studies suggest increased risk with olmesartan, rather than a class effect of all angiotensin receptor blockers. Post-marketing surveillance for drug safety remains important.

[Autoimmune enteropathy in adults : A rare and difficult but relevant differential diagnosis of chronic diarrhea]. / Die Autoimmunenteropathie beim Erwachsenen : Eine seltene und schwierige, aber relevante Differenzialdiagnose der chronischen Diarrhö.

Autoimmune enteropathy (AIE) was originally believed to be a pediatric disease until there were increasing numbers of adult cases reported over the last 20 years. AIE is an autoimmune disease that manifests as severe chronic diarrhea.The histological hallmark is villous atrophy. Histology alone is not sufficiently sensitive and consistent. Four different histological patterns are known. There are many differential diagnoses to be considered relating to both histology and symptoms.We present the case of a young woman with fatal AIE and homozygous germline-mutation of the CLEC7A gene. The course of disease is documented in multiple intestinal biopsies, which show a morphological change over time.Histology and symptoms often resemble celiac disease. In order to recognize this rare disease early in its course there is a need for a special awareness among attending physicians and pathologists.

Towards the Probabilistic Analysis of Small Bowel Capsule Endoscopy Features to Predict Severity of Duodenal Histology in Patients with Villous Atrophy.

Small bowel capsule endoscopy (SBCE) can be complementary to histological assessment of celiac disease (CD) and serology negative villous atrophy (SNVA). Determining the severity of disease on SBCE using statistical machine learning methods can be useful in the follow up of patients. SBCE can play an additional role in differentiating between CD and SNVA. De-identified SBCEs of patients with CD and SNVA were included. Probabilistic analysis of features on SBCE were used to predict severity of duodenal histology and to distinguish between CD and SNVA. Patients with higher Marsh scores were more likely to have a positive SBCE and a continuous distribution of macroscopic features of disease than those with lower Marsh scores. The same pattern was also true for patients with CD when compared to patients with SNVA. The validation accuracy when predicting the severity of Marsh scores and when distinguishing between CD and SNVA was 69.1% in both cases. When the proportions of each SBCE class group within the dataset were included in the classification model, to distinguish between the two pathologies, the validation accuracy increased to 75.3%. The findings of this work suggest that by using features of CD and SNVA on SBCE, predictions can be made of the type of pathology and the severity of disease.

Two cases of monomorphic epitheliotropic intestinal T-cell lymphoma associated with coeliac disease.

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is an aggressive type of intestinal lymphoma which affects individuals without evidence of enteropathy. In this single-centre case series, we describe the first two cases of MEITL in Caucasian patients suffering from histologically-proven coeliac disease (CD). Original medical records were retrieved and anonymised. All biopsy and surgical MEITL specimens were reviewed by three haematopathologists. Two patients aged 63- and 55-year old at CD diagnosis, subsequently developed a MEITL. MEITL always involved the ileum and was multifocal. Both patients died from complications after surgery, including gastrointestinal bleeding, septic shock and multiorgan failure, with a mean survival since MEITL diagnosis of 15.5 ± 16.3 months. In one case, array-CGH revealed a large deletion on chromosome nine between 9p13.1 and 9p24.1, and a recurrent chromosome gain at 9q33-q34. Our cases indicate that a subset of MEITL may arise in Caucasian patients suffering from CD. The clinical, pathological and molecular features of these cases show a partial overlap with enteropathy-associated T-cell lymphoma.