Conserved IFN Signature between Adult and Pediatric Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is an allergic inflammatory disease of the esophagus that occurs in both children and adults. Previous studies of affected tissue from pediatric cohorts have identified prominent signatures of eosinophilia and type 2 inflammation. However, the details of the immune response in adults with EoE are still being elucidated. To determine whether EoE in adults shares inflammatory profiles with those observed in children, we performed RNA sequencing of paired human esophageal biopsies and blood samples from adults with EoE or gastroesophageal reflux disease. Unbiased analysis of differentially expressed genes in tissue revealed a strong IFN signature that was significantly enriched in EoE patients as compared with patients with gastroesophageal reflux disease. Both type I and type II IFN-responsive genes were upregulated in adult biopsies, but not in blood. A similar increase in expression of IFN gene sets was observed in pediatric EoE biopsies as compared with non-EoE samples, and in public pediatric and adult RNA-sequencing data. Finally, we found that human peripheral CD4+ T cells from children with EoE produce IFN-γ upon activation with EoE-causal allergens. Together, this work identifies a conserved IFN signature in pediatric and adult EoE, highlighting a role for non-type 2 inflammatory networks in the disease process in humans.

Cow's Milk Allergy or Gastroesophageal Reflux Disease-Can We Solve the Dilemma in Infants?

Cow's milk allergy (CMA) and gastro-esophageal reflux disease (GERD) may manifest with similar symptoms in infants making the diagnosis challenging. While immediate reaction to cow's milk protein indicate CMA, regurgitation, vomiting, crying, fussiness, poor appetite, sleep disturbances have been reported in both CMA and GERD and in other conditions such as functional gastrointestinal disorders, eosinophilic esophagitis, anatomic abnormalities, metabolic and neurological diseases. Gastrointestinal manifestations of CMA are often non-IgE mediated and clinical response to cow's milk free diet is not a proof of immune system involvement. Neither for non-IgE CMA nor for GERD there is a specific symptom or diagnostic test. Oral food challenge, esophageal pH impedance and endoscopy are recommended investigations for a correct clinical classification but they are not always feasible in all infants. As a consequence of the diagnostic difficulty, both over- and under- diagnosis of CMA or GERD may occur. Quite frequently acid inhibitors are empirically started. The aim of this review is to critically update the current knowledge of both conditions during infancy. A practical stepwise approach is proposed to help health care providers to manage infants presenting with persistent regurgitation, vomiting, crying or distress and to solve the clinical dilemma between GERD or CMA.

Gastroesophageal reflux and asthma: when, how, and why.

PURPOSE OF REVIEW: Gastro-esophageal reflux is a possible cause of uncontrolled symptoms of asthma and should be actively investigated and treated before severe asthma is diagnosed and biological therapy started. RECENT FINDINGS: Recent investigations on esophageal function and tissue biomarkers in patients with asthma and associated GERD have established a relevant role for esophageal motility and neuronal sensory abnormalities in linking the two diseases. Characterization of the underpinning inflammatory substrate has showed mixed results as both neutrophilic and eosinophilic type 2 inflammatory changes have been described. SUMMARY: New findings regarding inflammatory mechanisms in GERD-associated asthma as well as new diagnostic tools to investigate functional esophageal abnormalities and characterize asthma endotype have identified potential treatable traits that may improve the clinical management and outcome of asthmatic patients with GERD.

CD8 T-Cell-Predominant Lymphocytic Esophagitis is One of the Major Patterns of Lymphocytic Inflammation in Gastroesophageal Reflux Disease.

CONTEXT.­: Published reports have suggested an association of lymphocytic esophagitis (LyE) with gastroesophageal reflux disease (GERD) and primary motility disorders and have also shown that GERD and motility disorders frequently overlap. These findings make it difficult to determine the true relationship between LyE and GERD, which may be confounded by the presence of motility disorders with LyE. OBJECTIVE.­: To characterize patterns of lymphocytic inflammation in patients with GERD who have no motility abnormalities. DESIGN.­: We identified 161 patients seen at our institution from 1998 to 2014 who were diagnosed with GERD, had normal esophageal motility, and available esophageal biopsies. LyE was defined as peripapillary lymphocytosis with rare or absent granulocytes. CD4 and CD8 immunophenotype of lymphocytes was evaluated using immunohistochemistry. RESULTS.­: We found increased intraepithelial lymphocytes in 13.7% of patients with GERD. Two major patterns and 1 minor pattern of lymphocytic inflammation were observed as follows: (1) LyE (in 6.8% [11 of 161] of patients and typically focal), (2) dispersed lymphocytes in an area of reflux esophagitis (in 5.6% [9 of 161] and typically diffuse), and (3) peripapillary lymphocytes in an area of reflux esophagitis (in 1.2% [2 of 161]). CD8 T cells significantly outnumbered CD4 T cells in 91% of patients with lymphocytic esophagitis and 100% of patients with dispersed lymphocytes (9 of 9) or peripapillary lymphocytes (2 of 2) in the area of reflux esophagitis. CONCLUSIONS.­: These findings suggest that LyE is one of the major patterns of lymphocytic inflammation in GERD. CD8 T-cell-predominant immunophenotype may be useful as a marker of GERD in the differential diagnosis of LyE.

Reconsidering the "protective" hypothesis of Helicobacter pylori infection in eosinophilic esophagitis.

Since its discovery, Helicobacter pylori (H. pylori) has attracted attention in the biomedical world with its numerous pathophysiologic implications, both gastrointestinal and systemic. Beyond its well-established carcinogenic properties, emerging evidence also supports "harmful" proinflammatory and neurodegenerative roles of H. pylori. On the other hand, H. pylori infection has been proposed to be "protective" against several diseases, such as asthma and gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) is a relatively new, allergen/immune-mediated disease, which has also been linked to these considerations. Main arguments are a postulated shift of immune responses by H. pylori from T helper 2 (TH 2) to TH 1 polarization, as well as a potential decline of the H. pylori burden with the dramatic parallel rise of ΕοΕ: a series of observational studies reported an inverse association. In this review, we counter these arguments by providing further epidemiological data, which point out that this generalization might be rather incomplete. We also discuss the limitations of the existing studies evaluating a possible association. Furthermore, we provide current evidence on common pathogenetic components, which share both entities. In summary, the claim that H. pylori is protective against EoE is rather incomplete, and further mechanistic studies are necessary to elucidate a possible association.

Analysis of clinical characteristics of 2243 with positive anti-gastric parietal cell antibody.

BACKGROUND: To facilitate the early detection of chronic diseases, we analyzed the clinical characteristics of anti-gastric parietal cell antibody (PCA)-positive population, revealed the early characteristics of the population. METHODS: According to the retrospective analysis, current situation investigation and comparative analysis of the clinical characteristics and medical history of the subjects, the comparison between the groups was performed. RESULT: (a) The positive rate of PCA detection in department of gastroenterology in our hospital was 35.80%. Among the individuals who underwent PCA, esophagogastroduodenoscopy (EGD) and pathological examination at the same time, 33.59% of the patients with PCA positive were diagnosed as atrophic gastritis by gastroscopy, which was much higher than 9.09% of the patients with PCA negative. (b) The incidence of gastroesophageal reflux, hypertension, ischemic heart disease (IHD) and cerebral ischemia in PCA-positive population were 65.45%, 81.63%, 15.43%, and 31.61%, respectively, which were significantly higher than those in the control group. (c) The incidence rates of decreased red blood cells (RBC) and increased homocysteine (HCY) in laboratory-related tests were 38.30% and 69.15%, respectively, which were much higher than those in control group. CONCLUSION: PCA has predictive value for a variety of chronic diseases and timely detection is of great significance.

Considerations for the Child with Nonatopic Asthma.

Asthma guidelines provide clinicians with evidence-based management strategies for this chronic condition. The preferred therapy for patient with persistent asthma is inhaled corticosteroids. However, ∼40% of the patients with persistent asthma continue to present with symptoms while treated according to the guidelines. Multiple factors are being explored to explain the variability in response to inhaled corticosteroids including asthma phenotype and genetic predisposition among others. The nonatopic asthma phenotype has been described in the literature. These patients tend to have milder symptoms of asthma and typically outgrow their asthma by adolescence. They present with chronic asthma symptoms in the absence of a positive allergy test, either skin prick test or specific immunoglobulin E blood test. Although patients with nonatopic asthma share many characteristics with patients with atopic asthma, there are several studies that suggest a different inflammatory pathway may be involved in their pathophysiology. Therefore, it is possible that children with nonatopic asthma could respond differently to inhaled corticosteroids compared with those with atopic asthma. Currently there is a variable definition of this phenotype. Furthermore, there is a paucity of therapeutic trial directed toward the patients with nonatopic asthma specifically. Future research should be guided toward identifying the inflammatory pathways in nonatopic asthma and potential phenotype-guided therapies.

Effect of anti-reflux treatment on gastroesophageal reflux-associated chronic cough: Implications of neurogenic and neutrophilic inflammation.

Objective: Gastroesophageal reflux disease (GERD) is an important cause of chronic cough. Substance P (SP) has been implicated in the pathophysiology of cough. Proton pump inhibitors (PPIs) and prokinetic agents are the current treatment for GER-associated cough. The aim was to evaluate the effects of anti-reflux treatment and its associations with cellular and neurogenic inflammation.Methods: Thirty-seven patients with GER-associated cough suspected based on characteristic symptoms such as heartburn and worsening of cough by phonation and rising were recruited. A PPI, rabeprazole 20 mg daily, and a prokinetic agent, itopride 50 mg t.i.d., were administered for 4 weeks in a prospective, observational manner. Before and after treatment, subjective cough measures [visual analog scale (VAS) and the Japanese version of the Leicester Cough Questionnaire (J-LCQ)], the modified frequency scale for the symptoms of GERD [FSSG, consisting of 2 domains: acid-reflux (AR) and functional dyspepsia symptoms], sputum and plasma SP levels, and sputum cell differentials were examined. Patients with good response to treatment [Δ (decrease of) VAS >15 mm; n = 21) were compared with poor responders (ΔVAS ≤15 mm).Results: Anti-reflux treatment significantly improved the cough VAS, J-LCQ, and AR symptoms, and ΔVAS and ΔAR were significantly correlated. Decreases of plasma and sputum SP levels and sputum neutrophil counts were significantly greater in responders than in poor responders. Both baseline values and post-treatment changes of plasma SP and sputum neutrophils were significantly correlated for all patients.Conclusions: Successful treatment of GER-associated cough may be associated with the attenuation of neurogenic and neutrophilic inflammation.

Increased number of regulatory T cells in esophageal tissue of patients with eosinophilic esophagitis in comparison to gastro esophageal reflux disease and control groups

Background: Eosinophilic esophagitis (EoE) is a primarily polygenic allergic disorder. Although most patients have IgE sensitization, it seems that non-IgE mediated responses mainly contribute to the pathogenesis of EoE. Regulatory T cells (Tregs) may have an important role in allergies. There are limited data on the association of Tregs and EoE. In this study, we enumerated and compared T lymphocytes and Tregs in esophageal tissue of patients with EoE, gastroesophageal reflux disease (GERD) and normal controls. Methods: Ten patients with EoE, ten patients with GERD and eight normal controls were included. Immunohistochemistry staining was used to enumerate T lymphocytes and Tregs. CD3+ cells were considered as T cells and FOXP3+, CD3+ cells were considered as Tregs. T cells and Tregs were counted in 10 high power fields (HPF) (×400) for each patient and the average of 10 HPFs was recorded. Results: The mean±SEM of Tregs in esophageal tissue of patients with EoE (10.90 ± 2.14cells/HPF) was significantly higher than the GERD (2.77 ± 0.66 cells/HPF) and control groups (0.37 ± 0.08 cells/HPF) (P < 0.001). Additionally, the mean ± SEM of T lymphocytes in esophageal tissue of patients with EoE (24.39 ± 3.86 cells/HPF) were increased in comparison to the GERD (10.07 ± 2.65 cells/HPF) and control groups (3.17 ± 0.93 cells/HPF) (P < 0.001). Conclusion: There is an increase in the number of esophageal T lymphocytes and regulatory T cells in patients with EoE compared to the GERD and control groups

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Increased number of regulatory T cells in esophageal tissue of patients with eosinophilic esophagitis in comparison to gastro esophageal reflux disease and control groups.

BACKGROUND: Eosinophilic esophagitis (EoE) is a primarily polygenic allergic disorder. Although most patients have IgE sensitization, it seems that non-IgE mediated responses mainly contribute to the pathogenesis of EoE. Regulatory T cells (Tregs) may have an important role in allergies. There are limited data on the association of Tregs and EoE. In this study, we enumerated and compared T lymphocytes and Tregs in esophageal tissue of patients with EoE, gastroesophageal reflux disease (GERD) and normal controls. METHODS: Ten patients with EoE, ten patients with GERD and eight normal controls were included. Immunohistochemistry staining was used to enumerate T lymphocytes and Tregs. CD3+ cells were considered as T cells and FOXP3+, CD3+ cells were considered as Tregs. T cells and Tregs were counted in 10 high power fields (HPF) (×400) for each patient and the average of 10 HPFs was recorded. RESULTS: The mean±SEM of Tregs in esophageal tissue of patients with EoE (10.90±2.14cells/HPF) was significantly higher than the GERD (2.77±0.66cells/HPF) and control groups (0.37±0.08cells/HPF) (P<0.001). Additionally, the mean±SEM of T lymphocytes in esophageal tissue of patients with EoE (24.39±3.86cells/HPF) were increased in comparison to the GERD (10.07±2.65cells/HPF) and control groups (3.17±0.93cells/HPF) (P<0.001). CONCLUSION: There is an increase in the number of esophageal T lymphocytes and regulatory T cells in patients with EoE compared to the GERD and control groups.

Duodenal eosinophilia is associated with functional dyspepsia and new onset gastro-oesophageal reflux disease.

BACKGROUND: It is unexplained why functional dyspepsia and gastro-oesophageal reflux disease (GERD) overlap more often than expected by chance. Post-prandial distress syndrome has been linked to impaired gastric fundic accommodation which may induce increased transient lower oesophageal sphincter relaxations and consequent GERD. Duodenal eosinophilia has been linked to functional dyspepsia and post-prandial distress syndrome. AIM: To identify if there is an association between duodenal eosinophilia in functional dyspepsia and symptoms of GERD and whether post-prandial distress syndrome or epigastric pain syndrome are associated with new onset GERD. METHODS: Participants (n = 1000) were randomly selected from the national Swedish population register and surveyed by questionnaires and oesophagogastroduodenoscopy in 1999-2001. All eligible subjects (n = 887) were invited to a follow-up study in 2010 (response rate 79%). In a case-control study of 213 subjects (functional dyspepsia vs healthy controls), histology from the duodenum was evaluated at baseline and the possible association of eosinophilia to new onset GERD symptoms was analysed. RESULTS: Functional dyspepsia (OR 7.6; 95% CI 2.93-19.4, P < 0.001) and post-prandial distress syndrome at baseline (OR 9.0, 95% CI 3.36-24.0, P < 0.001) were associated with an increased risk of GERD at follow-up. Eosinophilia in the second part of duodenum only was independently associated with an increased risk of GERD amongst those with functional dyspepsia (OR 4.2; 95% CI 1.2-4.77, P = 0.024) and post-prandial distress syndrome at baseline (OR 6.0; 95% CI 1.50-23.6, P = 0.011), respectively. CONCLUSIONS: Duodenal eosinophilia is associated with increased risk of GERD at 10-year follow-up in those with functional dyspepsia and post-prandial distress syndrome at baseline. Duodenal eosinophilia may explain the link between GERD and functional dyspepsia, suggesting subsets of functional dyspepsia and GERD may be part of the same disease spectrum.

Plasma levels of TNF-α, IL-6, IFN-γ, IL-12, IL-17, IL-22, and IL-23 in achalasia, eosinophilic esophagitis (EoE), and gastroesophageal reflux disease (GERD).

An elevation of serum inflammatory biomarkers in achalasia patients compared with controls recently was demonstrated. It has not been determined whether the elevation of inflammatory cytokines is unique to achalasia or occurs with other diseases involving the esophagus. The primary aim of our study was to compare the differences in plasma immunological profiles (TNF- α receptor, IL-6, IFN-γ, IL-12, IL-17, IL-22, and IL-23) of patients with achalasia, eosinophilic esophagitis (EoE), and gastroesophageal reflux disease (GERD). A secondary aim of this study was to classify these same plasma cytokine profiles in the three achalasia subtypes. METHODS: Plasma from 53 patients with achalasia, 22 with EoE, and 20 with GERD (symptoms plus esophagitis or + reflux study) were analyzed. EXCLUSION CRITERIA: malignancy, autoimmune condition, immunodeficiency disorder, and treatment with steroids/immune modulating drugs. Cytokine levels were assayed via multiplex enzyme-linked immunosorbent assay (ELISA). RESULTS: Our key finding revealed significant elevations in IL- 6 (p = 0.0158) in achalasia patients compared with EoE patients. Overall, plasma inflammatory biomarker patterns were not different in the three subtypes of achalasia. CONCLUSION: There were no differences between the cytokine levels of any of the measured biomarkers between the achalasia and GERD groups suggesting that luminal stasis does increase biomarker levels for any of the cytokines examined in our study. While these results are an early first step towards clarifying some aspects of the pathogenesis of achalasia, they bring about many more questions that require further investigation and expansion. Further investigation with a larger cohort and a broader panel of biomarkers is needed.

Effect of Acid Suppression on Peripheral T-Lymphocyte Subsets and Immunohistochemical Esophageal Mucosal Changes in Patients With Gastroesophageal Reflux Disease.

BACKGROUND AND AIMS: Gastroesophageal reflux disease (GERD) is a common prevalent disease. We aimed to assess the dynamic changes in the peripheral T lymphocytes and lymphocytes infiltrating the esophageal mucosa after treatment with proton-pump inhibitor (PPI) in patients with GERD. PATIENTS AND METHODS: A total of 200 patients who presented with upper GIT symptoms were included in this prospective study. All patients were subjected to full history taking, clinical examination, and complete blood count. Upper endoscopy was performed to detect the grade of GERD, followed by 4 quadrant biopsies before and 1 month after acid suppressive drug therapy. Histopathologic and immunohistochemical examination were carried out for all biopsies. Flow cytometry analysis for the peripheral T lymphocytes and cytokine profile assay before therapy and after therapy were also carried out. RESULTS: In total, 200 patients comprising 132 male individuals (66%) and 68 female individuals (34%) with a mean age of 47.9±18.3 were included. The risk factors for development of GERD were smoking in 87 (43.5%), spicy food intake in 26 (13%), analgesics in 46 (23%), excessive tea and coffee in 35 (17.5%), and nondetected risk factors in 6 (3%). Endoscopic examination using Los Angeles grading system revealed that 102 patients (51%) were grade A, 57 patients (28.5%) were grade B, 38 patients (19%) were grade C, and 3 patients (1.5%) were grade D. No statistically significant differences could be detected in HGB levels and WBC, PLT, monocyte, granulocyte, and eosinophil counts before and after treatment with PPI. Histopathologic examination of esophageal biopsies showed significant posttreatment improvement in 132 cases (66%); however, 66 cases (33%) including the 2 cases (1%) of Barrett's esophagus showed nonsignificant pathologic improvement compared with the pretreatment picture. Immunohistochemical staining of esophageal biopsies with CD3 (T-cell marker) and CD20 (B-cell marker), before and 1 month after treatment, showed the presence of a very large number of infiltrating B cells in the esophageal mucosa (700±30/10 HPF) with large aggregations; in contrast, T-cell infiltration appeared less marked (570±23/10 HPF), and they formed smaller aggregates than those of B cells in pretreated patients, with P<0.01. However, 1 month after treatment with PPI, esophageal biopsies revealed a marked decrease in the number of both B (10±2/10 HPF) and T (290±12/HPF) cells in 66% of patients, with a P<0.01 in comparison with the pretherapy pattern. However, the remaining 33% of patients still showed a significantly high number of T cells (490±28/HPF), with a P <0.05 in comparison with the responder group that formed small aggregates with larger cell sizes, indicating their activation. Cytokine profiles before and after treatment revealed significant posttreatment reduction in their levels in the 132 cases with improvement in their clinical manifestations, and endoscopic and histopathologic findings, but there is no obvious change in the measured cytokine levels in 66 patients who simultaneously had no improvement in their endoscopic, histopathologic findings and mild improvement in their clinical manifestations. Moreover, significant posttreatment reduction of IL-8 and IL-1ß in the 98 (49%) patients with Los Angeles grading B, C, and D was observed. With regard to serum levels of IL-10 and IL-4, there were no statistically significant differences before and after treatment with PPI. Peripheral blood immunologic parameters revealed a statistically significant reduction of the total CD3 absolute count, T-helper lymphocyte (CD4/CD3) percentage, T-helper lymphocyte absolute count, and the percentage and absolute cytotoxic T-lymphocyte count (CD8/CD3) after treatment with PPI. Moreover, the same significant difference of peripheral blood lymphocytes was detected after exclusion of patients with Los Angeles grade A, which may be considered normal. CONCLUSIONS: Acid-induced T-cell-related cytokine production plays an important role in inflammation occurring in patients with GERD. Mucosal and peripheral inflammation reduces with PPI use.

Impact of Gastroesophageal Reflux Disease on Mucosal Immunity and Atopic Disorders.

Atopic disorders and gastroesophageal reflux disease (GERD) are some of the most common medical conditions treated by primary care physicians and specialists alike. The observation that atopic disorders, like asthma, allergic rhinitis and sinusitis, food allergies, atopic dermatitis, contact dermatitis, and eosinophilic esophagitis are common comorbidities in patients with GERD raises the question of the nature of the relationship that may exist between GERD and atopic disorders. In this article, we review the pathophysiology of GERD, its effect on the immune system, the effect of acid-blocking medications on allergic responses, as well as several common atopic conditions that have been associated with GERD including asthma, chronic rhinosinusitis (CRS), allergic rhinitis (AR), atopic dermatitis (AD), contact dermatitis (CD), food allergies, proton pump inhibitor (PPI)-responsive esophageal eosinophilia (PPI-REE), and eosinophilic esophagitis (EoE). In each condition, the evidence of a causal link is not definitive. Although the relationship between asthma and GERD remains controversial, evidence suggests that a subset of asthma patients with documented GERD may experience improved asthma control following appropriate treatment of GERD. The relationship of GERD to allergic rhinitis and chronic sinusitis is weak; however, studies support the concept that treatment of frequent episodes of GERD can have a positive effect on rhinitis and sinusitis overall. The relationship between allergic sensitization and GERD is likely bidirectional. GERD may induce changes in the mucosal immune system that may favor the development of food allergy and allergic sensitization to aeroallergens; however, the underlying mechanisms have not been established.

Involvement of the TLR4/NF-κB Signaling Pathway in the Repair of Esophageal Mucosa Injury in Rats with Gastroesophageal Reflux Disease.

BACKGROUND/AIMS: Numerous studies have highlighted the activation of NF-κB in the esophageal mucosa during the early stages of gastroesophageal reflux disease (GERD). The present study aimed to investigate the role of the TLR4/NF-κB signaling pathway in GERD rat models. METHODS: Wistar rats (n = 60) were recruited to establish a GERD animal model. Distal esophageal pH was assessed, followed by determination of the contents of thiobarbituric acid-reactive species (TBARS) and reactive oxygen species (ROS) in esophageal mucosa homogenate. ELISA was employed to detect the levels of inflammatory factors (IL-6, IL-8, IL-10 and TNF-α) in esophageal mucosa. The expression of MMP-3, MPP-9, Cldn1 and Cldn4 was determined by immunohistochemistry. RT-qPCR and western blot analysis were applied to evaluate the protein expressions in TLR4/NF-κB signaling pathway, while TUNEL staining was utilized to examine the apoptosis rate in the esophageal mucosal tissues. RESULTS: Distal esophageal pH of the rats was higher in the GERD + PDTC group than in other groups. Levels of inflammatory factors in esophageal mucosal tissues were downregulated with the inhibition of NF-κB, which was determined to be associated with the decreased contents of TBARS and ROS. Moreover, decreased MMP-3 and MPP-9 in addition to elevated Cldn1 and Cldn4 were detected in the esophageal mucosa as a result of the inactivation of NF-κB. The TLR4/NF-κB signaling pathway-related proteins (TLR4, NF-κB and IκBα); the rate of apoptosis was demonstrated to be suppressed in the GERD + PDTC group, while inactivating NF-κB was found to alleviate the tissue damage observed in the esophageal mucosa. CONCLUSION: The key findings of the current study demonstrate that the inactivation of the TLR4/NF-κB signaling pathway alleviates oxidative stress injury and promotes the repair of esophageal mucosal injury among rats with GERD, highlighting a potential novel GERD mechanism.

Developing a diagnostic understanding of GERD phenotypes through the analysis of levels of mucosal injury, immune activation, and psychological comorbidity.

Patients with gastroesophageal reflux disease (GERD) can present with typical or atypical symptoms. The aim of this study is to explore the underlying physiological and psychological mechanisms that lead to different symptomatic manifestations of GERD. A total of 238 patients diagnosed with GERD underwent gastroscopy, 24 h multichannel intraluminal impedance-pH (MII-pH) monitoring, and psychological assessment with questionnaires. Patient symptoms were used to classify GERD into phenotypes of typical reflux syndrome (TRS, n = 87), reflux chest pain syndrome (RCS, n = 98), and extraesophageal syndromes (EES, n = 53). 38 healthy volunteers served as controls. Reflux parameters and baseline impedance values (BIVs) were acquired from MII-pH monitoring results. A subset of subjects were biopsied from the lower esophagus; certain immune cells were stained with immunohistochemistry. BIVs in GERD patients (TRS, RCS, and EES) were significantly lower than in healthy controls and TRS patients exhibited the lowest BIVs (all P < 0.01). This indicated that the extent of mucosal injury differed across groups. TRS patients had higher acid exposure time (AET) compared to RCS, EES and controls (all P < 0.05). RCS patients had more intraepithelial T lymphocyte (IEL) and mast cell (MC) infiltration, and higher psychometric scores compared to TRS patients and controls (all P < 0.05), suggesting a possible stress-related esophageal hypersensitivity basis. TRS patients are characterized by acid reflux and correlated mucosal injury, which explains their typical reflux symptoms. RCS patients exhibit less acid-related injury but possible psychological stress-related esophageal hypersensitivity, which could be the main cause of their esophageal pain.

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.