Epithelial overexpression of IL-33 induces eosinophilic esophagitis dependent on IL-13.

BACKGROUND: Eosinophilic esophagitis (EoE) is an increasingly common inflammatory condition of the esophagus; however, the underlying immunologic mechanisms remain poorly understood. The epithelium-derived cytokine IL-33 is associated with type 2 immune responses and elevated in esophageal biopsy specimens from patients with EoE. OBJECTIVE: We hypothesized that overexpression of IL-33 by the esophageal epithelium would promote the immunopathology of EoE. METHODS: We evaluated the functional consequences of esophageal epithelial overexpression of a secreted and active form of IL-33 in a novel transgenic mouse, EoE33. EoE33 mice were analyzed for clinical and immunologic phenotypes. Esophageal contractility was assessed. Epithelial cytokine responses were analyzed in three-dimensional organoids. EoE33 phenotypes were further characterized in ST2-/-, eosinophil-deficient, and IL-13-/- mice. Finally, EoE33 mice were treated with dexamethasone. RESULTS: EoE33 mice displayed ST2-dependent, EoE-like pathology and failed to thrive. Esophageal tissue remodeling and inflammation included basal zone hyperplasia, eosinophilia, mast cells, and TH2 cells. Marked increases in levels of type 2 cytokines, including IL-13, and molecules associated with immune responses and tissue remodeling were observed. Esophageal organoids suggested reactive epithelial changes. Genetic deletion of IL-13 in EoE33 mice abrogated pathologic changes in vivo. EoE33 mice were responsive to steroids. CONCLUSIONS: IL-33 overexpression by the esophageal epithelium generated immunopathology and clinical phenotypes resembling human EoE. IL-33 may play a pivotal role in the etiology of EoE by activating the IL-13 pathway. EoE33 mice are a robust experimental platform for mechanistic investigation and translational discovery.

Lymphocytic Esophagitis: Current Understanding and Controversy.

This review summarizes our current understanding of lymphocytic esophagitis (LE), a novel form of chronic esophagitis that incorporates distinctive histologic, clinical, and endoscopic features. First described as a histologic entity, a diagnosis of LE requires intraepithelial lymphocytosis without significant granulocytic inflammation and some evidence of epithelial damage; the rationale for and studies supportive of these histologic criteria are discussed within. Clinically, the majority of patients who present with histologically confirmed LE are older women or patients with underlying immunologic abnormalities, such as Crohn disease, rheumatologic disorders, or common variable immunodeficiency. The most common presenting symptom of LE is dysphagia, and the endoscopic findings can vary from normal mucosa to mucosal changes that resemble eosinophilic esophagitis: edema, rings, furrows, and plaques. The incidence of luminal strictures and the persistent dysphagia and/or lymphocytosis present in some patients provide evidence that LE is a chronic inflammatory disorder, at least within a subset of individuals. Several histologic mimics of LE are examined, as are disagreements surrounding the LE diagnosis.

Bidirectional crosstalk between eosinophils and esophageal epithelial cells regulates inflammatory and remodeling processes.

Eosinophils accumulate adjacent to epithelial cells in the mucosa of patients with eosinophilic esophagitis (EoE), yet the bidirectional communication between these cells is not well understood. Herein, we investigated the crosstalk between human eosinophils and esophageal epithelial cells. We report that blood-derived eosinophils have prolonged survival when cocultured with epithelial cells; 96 ± 1% and 30 ± 6% viability was observed after 7 and 14 days of coculture, respectively, compared with 1 ± 0% and 0 ± 0% of monoculture. In the presence of IL-13 and epithelial cells, eosinophils had greater survival (68 ± 1%) at 14 days compared with cocultures lacking IL-13. Prolonged eosinophil viability did not require cellular contact and was observed when eosinophils were cultured in conditioned media from esophageal epithelial cells; neutralizing GM-CSF attenuated eosinophil survival. The majority of eosinophil transcripts (58%) were dysregulated in cocultured eosinophils compared with freshly isolated cells. Analysis of epithelial cell transcripts indicated that exposure to eosinophils induced differential expression of a subset of genes that were part of the EoE esophageal transcriptome. Collectively, these results uncover a network of crosstalk between eosinophils and esophageal epithelial cells involving epithelial mediated eosinophil survival and reciprocal changes in cellular transcripts, events likely to occur in EoE.

Pathophysiology of reflux oesophagitis: role of Toll-like receptors 2 and 4 and Farnesoid X receptor.

The pathogenesis of gastroesophageal reflux disease (GERD) is not fully understood. It involves the activation of mucosal immune-mediated and inflammatory responses. Toll-like receptors (TLR) 2 and TLR4 are pattern-recognition receptors of the innate immune system; they recognize microbial and endogenous ligands. Farnesoid X receptor (FXR) is a bile acid receptor that regulates the inflammatory response. We aimed to evaluate TLR2, TLR4 and FXR expression patterns in GERD. We re-evaluated 84 oesophageal biopsy samples according to the global severity (GS) score, including 26 cases with histologically normal oesophagus, 28 with histologically mild oesophagitis and 30 with severe oesophagitis. We used immunohistochemistry and in situ hybridization to assess the expression patterns of TLR2, TLR4 and FXR in oesophageal squamous cells. Immunohistochemistry showed that nuclear and cytoplasmic TLR2 was expressed predominantly in the basal layer of normal oesophageal epithelium. In oesophagitis, TLR2 expression increased throughout the epithelium, and the superficial expression was significantly more intensive compared to normal epithelium, p <0.01. Nuclear and cytoplasmic TLR4 was expressed throughout the thickness of squamous epithelium, with no change in oesophagitis. FXR was expressed in the nuclei of squamous cells, and the intensity of the expression increased significantly in oesophagitis (p <0.05). FXR expression correlated with basal TLR2. In situ hybridization confirmed the immunohistochemical expression patterns of TLR2 and TLR4. In GERD, TLR2, but not TLR4, expression was upregulated which indicates that innate immunity is activated according to a specific pattern in GERD. FXR expression was increased in GERD and might have a regulatory connection to TLR2.

Novel Insights Into Tissue-Specific Biochemical Alterations in Pediatric Eosinophilic Esophagitis Using Raman Spectroscopy.

INTRODUCTION: Elucidating esophageal biochemical composition in eosinophilic esophagitis (EoE) can offer novel insights into its pathogenesis, which remains unclear. Using Raman spectroscopy, we profiled and compared the biochemical composition of esophageal samples obtained from children with active (aEoE) and inactive EoE (iEoE) with non-EoE controls, examined the relationship between spectral markers and validated EoE activity indices. METHODS: In vitro Raman spectra from children with aEoE (n = 8; spectra = 51) and iEoE (n = 6; spectra = 48) and from non-EoE controls (n = 10; spectra = 75) were acquired. Mann-Whitney test was used to assess the differences in their Raman intensities (median [interquartile range]) and identify spectral markers. Spearman correlation was used to evaluate the relationship between spectral markers and endoscopic and histologic activity indices. RESULTS: Raman peaks attributable to glycogen content (936/1,449 cm) was lower in children with aEoE (0.20 [0.18-0.21]) compared with that in non-EoE controls (0.24 [0.23-0.29]). Raman intensity of proteins (1,660/1,209 cm) was higher in children with aEoE compared with that in non-EoE controls (3.20 [3.07-3.50] vs 2.91 [2.59-3.05]; P = 0.01), whereas that of lipids (1,301/1,260 cm) was higher in children with iEoE (1.56 [1.49-1.63]) compared with children with aEoE (1.40 [1.30-1.48]; P = 0.02). Raman peaks attributable to glycogen and lipid inversely correlated with eosinophilic inflammation and basal zone hyperplasia. Raman mapping substantiated our findings. DISCUSSION: This is the first study to identify spectral traits of the esophageal samples related to EoE activity and tissue pathology and to profile tissue-level biochemical composition associated with pediatric EoE. Future research to determine the role of these biochemical alterations in development and clinical course of EoE can advance our understanding of EoE pathobiology.

Characterizing caspase-1 involvement during esophageal disease progression.

Barrett's esophagus (BE) is an inflammatory condition and a neoplastic precursor to esophageal adenocarcinoma (EAC). Inflammasome signaling, which contributes to acute and chronic inflammation, results in caspase-1 activation leading to the secretion of IL-1ß and IL-18, and inflammatory cell death (pyroptosis). This study aimed to characterize caspase-1 expression, and its functional importance, during disease progression to BE and EAC. Three models of disease progression (Normal-BE-EAC) were employed to profile caspase-1 expression: (1) a human esophageal cell line model; (2) a murine model of BE; and (3) resected tissue from BE-associated EAC patients. BE patient biopsies and murine BE organoids were cultured ex vivo in the presence of a caspase-1 inhibitor, to determine the importance of caspase-1 for inflammatory cytokine and chemokine secretion.Epithelial caspase-1 expression levels were significantly enhanced in BE (p < 0.01). In contrast, stromal caspase-1 levels correlated with histological inflammation scores during disease progression (p < 0.05). Elevated secretion of IL-1ß from BE explanted tissue, compared to adjacent normal tissue (p < 0.01), confirmed enhanced activity of caspase-1 in BE tissue. Caspase-1 inhibition in LPS-stimulated murine BE organoids caused a significant reduction in IL-1ß (p < 0.01) and CXCL1 (p < 0.05) secretion, confirming the importance of caspase-1 in the production of cytokines and chemokines associated with disease progression from BE to EAC. Targeting caspase-1 activity in BE patients should therefore be tested as a novel strategy to prevent inflammatory complications associated with disease progression.

Immune microenvironment in Barrett's esophagus adjacent to esophageal adenocarcinoma: possible influence of adjacent mucosa on cancer development and progression.

The immune microenvironment plays a pivotal role in cancer development and progression. Therefore, we studied the status of immune cells in esophageal adenocarcinoma (EAC) and adjacent Barrett's esophagus (BE) and their association with the clinical course of patients. We included 87 patients with EAC who underwent surgical resection or endoscopic submucosal dissection. CD3, CD8, Foxp3, p53, and Ki-67 were immunolocalized in EAC and adjacent BE (N = 87) and BE without EAC (N = 13). BE adjacent to EAC exhibited higher CD3+ lamina propria lymphocyte (LPL) numbers than BE without EAC. Abundant Foxp3+ LPLs in BE were associated with dysplasia and increased Ki-67 labeling index (LI) in BE glandular cells and tended to link to aberrant p53 expression. Abundant CD8+ LPLs in adjacent BE were associated with worse prognosis of EAC patients (P = 0.019). Results of our present study firstly revealed the potential influence of the tissue immune microenvironment of BE adjacent to EAC on cancer development and eventual clinical outcome of EAC patients. T cell infiltration could play pivotal roles in facilitating the dysplasia-adenocarcinoma sequence in BE. The number of Foxp3+ T cells is increased at the early stage of carcinogenesis and could help identify patients harboring dysplastic and highly proliferating cells. CD8+ T cells could reflect unfavorable inflammatory response in adjacent tissue microenvironment and help predict worse prognosis of EAC patients.

Disodium cromoglycate treatment reduces TH2 immune response and immunohistopathological features in a murine model of Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is an emergent chronic disease of the esophagus. The immunopathological process in EoE is characterized by Th2 immune response and prominent eosinophilic influx, in response to common food allergens. The classical treatment consists of allergen elimination diet and systemic/topical corticosteroid therapy. Nevertheless, patients do not always comply to treatment, and the prolonged corticosteroid therapy can cause side effects, therefore, there is an immediate need for new therapeutic approach for EoE. Disodium cromoglicate (DSCG) is a substance broadly used in allergic asthma treatment, and a well-known mast cell activation stabilizer. However, its effect in EoE have not been evaluated yet. This study aimed to assess the effects of DSCG treatment in an EoE experimental model. Male Balb/C mice were subcutaneously sensitized for five days with OVA, and subsequently orally OVA-challenged, DSCG administration was performed between the OVA-challenges. DSCG treatment not only reduced eosinophilic and mast cell influx, as well as reduced fibrosis. In addition, tslp, GATA3, IL-5, FoxP3 and IL-10 mRNA expression were reduced in esophageal mucosa, associated with lower Th2 (CD3+CD4+GATA3+IL4+) and B cells (CD19+CD40+) number in peripheral lymphoid organs. In conclusion, the data demonstrate DSCG treatment was effective in reducing mast cell activation and Th2 immune response, important immunopathological EoE features. Therefore, the use of DSCG as an EoE treatment can be considered a promising therapeutic approach to treat this disease.

Immunoglobulin G4-Related Disease Manifesting as Isolated, Typical, and Nontypical Gastroesophageal Lesion: A Research of Literature Review.

BACKGROUND: Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune inflammatory and fibrotic condition. The disease is characterized by tissue infiltration with dense lymphoplasmacytes and IgG4-positive plasma cells. SUMMARY: The aim of this study was to provide gastroenterologists with novel insights into evaluating the gastroesophageal involvement with IgG4-RD or mimickers of this condition and to give special attention to clinicopathological features. A literature review was performed using the PubMed database. A total of 39 studies presenting cases in the form of isolated, typical, and nontypical gastroesophageal involvement with IgG4-RD published between 2010 and 2018 were included. These studies were thoroughly reviewed for symptoms, lesion location, lesion type, lesion size, immune-histopathology, associated diseases, treatment, and follow-up. Of the 39 studies reviewed, 9 were esophageal IgG4-RD lesions, isolated esophageal IgG4-RD 66.66% (6/9), a typical form of esophageal IgG4-RD 11.11% (1/9), and nontypical form esophageal IgG4-RD 22.22% (2/9). The 30 gastric IgG4-RD that include isolated gastric IgG4-RD 46.66% (14/30), typical gastric IgG4-RD 40% (12/30), and nontypical gastric IgG4-RD 13.33% (4/30). The majority of lesions were inflammatory tumors, ulceration, nodular lesions, chronic gastritis, and malignant lesions. Key Messages: IgG4-RD may be manifested by isolated, typical and nontypical forms of gastroesophageal lesions and should be taken into consideration in the differential diagnosis. Corticosteroids may be the sole diagnostic treatment for this condition.

Efficacy of Dupilumab in a Phase 2 Randomized Trial of Adults With Active Eosinophilic Esophagitis.

BACKGROUND & AIMS: Eosinophilic esophagitis (EoE) is an allergen-mediated inflammatory disease with no approved treatment in the United States. Dupilumab, a VelocImmune-derived human monoclonal antibody against the interleukin (IL) 4 receptor, inhibits IL4 and IL13 signaling. Dupilumab is effective in the treatment of allergic, atopic, and type 2 diseases, so we assessed its efficacy and safety in patients with EoE. METHODS: We performed a phase 2 study of adults with active EoE (2 episodes of dysphagia/week with peak esophageal eosinophil density of 15 or more eosinophils per high-power field), from May 12, 2015, through November 9, 2016, at 14 sites. Participants were randomly assigned to groups that received weekly subcutaneous injections of dupilumab (300 mg, n = 23) or placebo (n = 24) for 12 weeks. The primary endpoint was change from baseline to week 10 in Straumann Dysphagia Instrument (SDI) patient-reported outcome (PRO) score. We also assessed histologic features of EoE (peak esophageal intraepithelial eosinophil count and EoE histologic scores), endoscopically visualized features (endoscopic reference score), esophageal distensibility, and safety. RESULTS: The mean SDI PRO score was 6.4 when the study began. In the dupilumab group, SDI PRO scores were reduced by a mean value of 3.0 at week 10 compared with a mean reduction of 1.3 in the placebo group (P = .0304). At week 12, dupilumab reduced the peak esophageal intraepithelial eosinophil count by a mean 86.8 eosinophils per high-power field (reduction of 107.1%; P < .0001 vs placebo), the EoE-histologic scoring system (HSS) severity score by 68.3% (P < .0001 vs placebo), and the endoscopic reference score by 1.6 (P = .0006 vs placebo). Dupilumab increased esophageal distensibility by 18% vs placebo (P < .0001). Higher proportions of patients in the dupilumab group developed injection-site erythema (35% vs 8% in the placebo group) and nasopharyngitis (17% vs 4% in the placebo group). CONCLUSIONS: In a phase 2 trial of patients with active EoE, dupilumab reduced dysphagia, histologic features of disease (including eosinophilic infiltration and a marker of type 2 inflammation), and abnormal endoscopic features compared with placebo. Dupilumab increased esophageal distensibility and was generally well tolerated. ClinicalTrials.gov, Number: NCT02379052.

Arginase-1 and Treg Profile Appear to Modulate Inflammatory Process in Patients with Chronic Gastritis: IL-33 May Be the Alarm Cytokine in H. pylori-Positive Patients.

Helicobacter pylori (H. pylori) is a highly prevalent bacterium in our environment, directly involved in various upper digestive tract diseases, such as gastritis, peptic ulcer, and gastric cancer. Several molecules activating the immune system have been reported to be involved in containing H. pylori infection. This study is aimed at analyzing the mRNA expression of the cytokines IFN-γ, IL-17, IL-10, TGF-ß, IL-6, IL-22, IL-23, and IL-33; transcription factors T-bet, RORC, and FOXP3; enzymes ARG1, ARG2, and NOS2; and neuropeptides VIP and TAC and their respective receptors VIPR1 and TACR1 in the stomach lining of patients with severe digestive disorders. One hundred and twenty six patients have been evaluated, presenting with symptoms in the upper digestive tract, with the clinical indication for an Upper Digestive Endoscopy exam. Two fragments of the mucosa of the gastric body and antrum have been collected for anatomopathological examination and to analyze the expression of enzymes, cytokines, and transcription factors using qPCR. Expression of the ARG1 gene was seen as significantly higher in the group of patients with chronic inactive gastritis than in the control group. Expression of the TGF-ß gene and its FOXP3 transcription factor was significantly higher in the group of chronic inactive gastritis patients than in the control. Expression of IFN-γ, IL-17, IL-10, and TGF-ß and the transcription factors, T-bet and RORC, in the presence or absence of H. pylori showed no significant difference. However, the expression of FOXP3 was significantly lower in H. pylori-positive patients than that in H. pylori-negative patients. ARG1 and Treg profile appeared to be modulating the inflammatory process, protecting patients from the tissue lesions with chronic inactive gastritis. Furthermore, we suggest that IL-33 may be a crucial mediator of the immune response against an infection, after gastric mucosal damage.

Esophageal IgE, IgG4, and mucosal eosinophilia in individuals with dysphagia.

BACKGROUND: Eosinophilic esophagitis (EoE) is an inflammatory disease of the esophagus, producing failure to thrive in infants and dysphagia with food impaction in older children and adults. Although most people with EoE manifest atopic/allergic disease, the specific allergens to which immunoglobulin E (IgE) is directed, if any, have not yet been characterized. METHODS: Mucosal brush biopsy (MBB) and solid tissue biopsy (STB) specimens were prospectively obtained from 25 individuals with dysphagia and suspicion of EoE. Specific IgE (sIgE) against 112 epitopes from airborne and food proteins, antigens known to cause a polyclonal IgE response and IgG4 to food allergens, were measured. RESULTS: There was no difference in total IgE harvested between the 2 biopsy methods (p > 0.05) or between the EoE-positive (N = 12) and EoE-negative (N = 13) groups (p > 0.05). None of the samples in either group contained measurable serum IgE to any of the airborne or food proteins tested, but low levels of IgE specific to Candida and Staphylococcus enterotoxins were detected. Low levels of IgG4 specific to wheat, soy, peanut, and egg were also detected. CONCLUSIONS: Both MBB and STB are able to harvest measureable levels of IgE and IgG4 from the esophageal mucosa. Low levels of serum-specific IgE suggest that other inflammatory mechanisms, besides type I, IgE-mediated, allergen-specific hypersensitivity, may act as the primary catalyst for mucosal eosinophilia. Clarifying the role of both IgE-mediated and non-IgE-mediated inflammatory mechanisms will help identify more targeted diagnostic and treatment strategies for individuals who present with dysphagia and esophageal eosinophilia.

Germination of pollen grains in the oesophagus of individuals with eosinophilic oesophagitis.

BACKGROUND: Eosinophilic oesophagitis (EoE) is characterized by oesophageal dysfunction and, histologically, by eosinophilic inflammation. There is no a clear aetiologic treatment. EoE exacerbations are often seasonal. We hypothesized that the inflammatory response of the oesophageal mucosa in patients with high levels of antibodies to pollen allergens and worsened seasonal EoE might be due to swallowing airborne pollen and the intrusion into the oesophageal mucosa of pollen allergens and pollen tubes, which encounter a pH and humidity resembling the stigma at pollination. OBJECTIVE: The aim of our study was to demonstrate the possible pathogenic role of environmental allergens in EoE through molecular and anatomopathological studies METHODS: One hundred and twenty-nine patients with EoE were tested for environmental and food allergens. Component resolved diagnosis (CRD), histological and botanical analysis was performed. Microscopic examination of oesophageal biopsies of 129 adults patients with EoE, 82 of them with seasonal exacerbation, and 100 controls, with gastroesophageal reflux without eosinophilic infiltrate, were made to verify the presence of callose (polysaccharide abundant in pollen tubes but absent in animal tissues) in the oesophagus. RESULTS: Component resolved diagnosis detected pollen allergens in 87.6% of patients with EoE. The predominant allergens were group 1 grass (55%), Art v 3 (11.3%) and lipid transfer proteins (LTPs) (19.4%) of common Mediterranean foods such as peach, hazelnuts, walnuts and wheat. Callose from pollen tubes was found in 65.6% of biopsies. CONCLUSION: Alteration of the mucosal barrier in EoE might cause the penetration of pollen grains into the oesophageal tissues. In EoE patients, anatomopathological studies searching for intrusion to plant foods and pollen, and specific-guided diet and immunotherapy after plant structures detection in biopsies, might be effective. CLINICAL RELEVANCE: It is possible to see the intrusion into animal tissues (oesophagus mucosa) of plant structures (pollen grains or pollen tubes) using an adecuate histologic botanical analysis. Molecular and anatomopathological studies can help to demonstrate a possible pathogenic role of environmental allergens in EoE.

Observation of the cytoarchitecture of the human esophageal mucosa with special attention to the lamina muscularis mucosae and the distribution of lymphatic vessels.

The cytoarchitecture of the esophageal mucosa was examined by using light microscopy, transmission electron microscopy, and scanning electron microscopy. The cytoarchitecture of the muscularis mucosae varied greatly among the cervical, thoracic, and abdominal esophagus, especially in the cervical esophagus, the muscularis mucosae suffered a loss and the distribution of lymphatic vessels also varied according to the site. It was suggested that these morphological differences would have a strong influence on the infiltration of esophageal cancer and the mode of lymph node metastasis.

Esophageal IgG4 levels correlate with histopathologic and transcriptomic features in eosinophilic esophagitis.

BACKGROUND: Recent data associate eosinophilic esophagitis (EoE) with IgG4 rather than IgE, but its significance and function have not been determined. Our aims were to measure esophageal IgG4 levels and to determine functional correlations as assessed by histologic and transcriptome analyses. METHODS: This case-control study included pediatric subjects with EoE (≥15 eosinophils/HPF) and non-EoE controls. Protein lysates were analyzed for IgA, IgM, and IgG1-IgG4 using the Luminex 100 system; IgE was quantified by ELISA. Esophageal biopsies were scored using the EoE histology scoring system. Transcripts were probed by the EoE diagnostic panel, designed to examine the expression of 96 esophageal transcripts. RESULTS: Esophageal IgG subclasses, IgA, and IgM, but not IgE, were increased in subjects with EoE relative to controls. The greatest change between groups was seen in IgG4 (4.2 mg/g protein [interquartile range: 1.0-13.1 mg/g protein] vs 0.2 mg/g protein [0.1-0.9]; P < .0001). Tissue IgG4 levels correlated with esophageal eosinophil counts (P = .0006); histologic grade (P = .0011) and stage (P = .0112) scores; and IL4, IL10, IL13, but not TGFB1, expression and had strong associations with a subset of the EoE transcriptome. Esophageal IgG4 transcript expression was increased and correlated with IgG4 protein levels and IL10 expression. CONCLUSION: These findings extend prior studies on IgG4 in adult EoE to the pediatric population and provide deeper understanding of the potential significance and regulation of IgG4, demonstrating that IgG4 is a relevant feature of the disease; is closely related to esophageal eosinophil levels, type 2 immunity and T regulatory cytokines; and is likely produced locally.

Toll-like receptors-mediated pathways activate inflammatory responses in the esophageal mucosa of adult eosinophilic esophagitis.

OBJECTIVES: Esophageal microbiota and regulation of adaptive immunity are increasingly being investigated in eosinophilic esophagitis (EoE). Toll-like receptors (TLRs) play a central role in the initiation and maintenance of innate immune activity. Our objective was to characterize the esophageal and duodenal innate immune response in EoE and its modulation by dietary therapy. METHODS: Esophageal and duodenal biopsy samples were collected from 10 adults with untreated EoE, before and after effective treatment with a six-food elimination diet (SFED), and 10 controls with normal esophagus. In all cases, bacterial load (by mRNA expression of 16S), TLRs, mucins, transcription factors, interleukins, components of the NKG2D system, and innate immunity effectors were assessed by qPCR. Protein expression of TLRs were also determined by immunofluorescence. RESULTS: Bacterial load and TLR1, TLR2, TLR4, and TLR9 were overexpressed on biopsies with active EoE compared with controls. Muc1 and Muc5B genes were downregulated while Muc4 was overexpressed. Upregulation of MyD88 and NFκB was found together with IL-1ß, IL-6, IL-8, and IL-10 mediators and PER-1, iNOS, and GRZA effectors. NG-K2D components (KLRK1, IL-15, MICB) were also upregulated. In all cases, changes in active EoE were normalized following SFED and mucosal healing. Duodenal samples also showed increased expressions of TLR-1, TLR-2, and TLR-4, but not 16S or any other mediators nor effectors of inflammation. CONCLUSIONS: Esophageal TLR-dependent signaling pathways in EoE support the potential implication of microbiota and the innate immune system in the pathogenesis of this disease.

Structured Diagnostic Approach and Risk Assessment in Mucous Membrane Pemphigoid with Oesophageal Involvement.

Oesophageal involvement in mucous membrane pemphigoid is considered rare, but it may be underdiagnosed. To assess the incidence of oesophageal involvement in a group of patients with newly diagnosed mucous membrane pemphigoid we retrospectively analysed the medical records of 30 consecutive patients with mucous membrane pemphigoid diagnosed between 2006 and 2016 at the Department of Dermatology, University Hospital Würzburg. Twenty-one patients (70%) reported symptoms indicative of oesophageal mucous membrane pemphigoid. Twelve patients (40%) underwent oesophagogastroduodenoscopy, and oesophageal pathology compatible with mucous membrane pemphigoid was endoscopically found in 9 cases (30%). In all patients indirect and direct immunofluorescence were performed. Patients with and without oesophageal involvement did not differ with regard to the results of indirect immunofluorescence on salt-split human skin and monkey oesophagus. Study results demonstrate the necessity of a standardized diagnostic work-up, including adequate tissue samples for direct immunofluorescence, to prevent underdiagnosis of oesophageal mucous membrane pemphigoid.

Mucosal Two-Step Pathogenesis in Gastroesophageal Reflux Disease: Repeated Weakly Acidic Stimulation and Activation of Protease-Activated Receptor-2 on Mucosal Interleukin-8 Secretion.

BACKGROUND: Activation of protease-activated receptor-2 (PAR2) is involved in the mucosal immune pathogenesis of gastroesophageal reflux disease (GERD) that is characterized by proinflammatory cytokines such as interleukin-8 (IL-8). PAR2 activation on epithelial cells induces epithelial IL-8 secretion and initiates mucosal inflammation. METHODS: A human primary esophageal epithelial cell model was established to investigate the effects of repeated stimulation with weakly acidic solutions and subsequent PAR2 activation. After creating a monolayer, cells were incubated under weakly acidic conditions for 7 h followed by 17 h at pH 7.4. This short-term exposure was repeated once. After weakly acidic stimulation, PAR2 activation was achieved by a synthetic agonist at pH 7.4. RESULTS: After repeated weakly acidic incubation, PAR2 transcript levels were 3.6-fold upregulated (p = 0.001) and IL-8 transcripts were 2.4-fold enhanced (p = 0.034) compared to nonstimulated controls, while IL-8 protein in the cell pellet and supernatant was not increased. Only the additional PAR2 activation upon pH stimulation led to increased IL-8 secretion into the supernatant. CONCLUSIONS: We propose a 2-step mechanism in which repeated weakly acidic exposure leads to the upregulation of epithelial PAR2 expression. The subsequent activation of upregulated PAR2 contributes to the initiation of mucosal inflammation, which underlies the important role of esophageal epithelium in GERD pathogenesis.

Cellular and molecular mechanisms of inflammation of esophageal mucosa under different.

The review presents modern data on the cellular and molecular mechanisms of inflammatory changes of esophageal mucosa exposed to different types of reluctate (gastric, biliary or duodenal/mixed). The authors describe data on key mediators of inflammation in gastroesophageal reflux disease (GERD) and their major cellular sources, changes of the immune profile of patients. Discusses the possible impact of changes in the cellular and molecular components in the development of the inflammatory response in the esophagus on the clinical features of GERD and its therapy-refractory forms.