Dilated Intercellular Spaces Research Articles

Tu1548 Defective Barrier Function in Neosquamous Epithelium: a Risk Factor for Recurrent Barrett's Esophagus: a BETRNet Pilot Project

After radiofrequency ablation (RFA) of Barrett's esophagus (BE), the epithelium reverts to neosquamous epithelium (NSE). However, NSE shows characteristics of defective barrier function (increased paracellular permeability and dilated intercellular spaces) similar to those seen in gastroesophageal reflux disease (GERD). These defects which may reflect exposure of NSE to refluxed acid, and may be a risk factor for recurrence of BE. Since defective barrier function in GERD involves cleavage of the junctional protein e-cadherin, we considered the possibility that a similar phenomenon also occurs in NSE.

117 Correlation of Histology to Endoscopic Mucosal Impedance in Patients With Eosinophilic Esophagitis

Background and Aim: An early event in the pathogenesis of eosinophilic esophagitis (EoE) is food antigen penetration of esophageal epithelium, but the precise relationship of eosinophilia, dilated intercellular spaces (DIS) and decreased barrier function is unclear. The aim of this study was to determine the correlation and accuracy of site-specific mucosal impedance (MI) measurement of ion flux with esophageal histology in distinguishing active from inactive EoE. Methods: In this study, 10 patients each with active and inactive EoE underwent MI measurement and mucosal biopsies at four esophageal sites (2, 5,10,15cm above the Zline). MI was compared to 10 control patients without esophageal symptoms. Data were analyzed by comparing MI values, Eos/HPF and DIS grade in the three groups at each level examined. Results: The esophageal MI values (ohms) were significantly lower in active when compared to inactive and control patients (1909 vs. 4349 and 5530 ohms, resp., p<.001). (Table) Four active patients had biopsies with eos< 15/HPF with lower DIS grade. There were significant and inverse correlations between MI and eos/HPF as well as DIS (rs=.584 and -.531, respectively, p<.001). Furthermore, MI cut off of 2300 ohms demonstrated 90% sensitivity and 91% specificity for diagnosis of active EoE and 89% and 82% for high grade DIS. Conclusions: In EoE, eosinophil eosinophilia and DIS correlate to MI measured ionic conductance and by inference barrier function. Endoscopic MI measurement in the esophagus is a promising, safe and easy to perform means to assess disease activity in diseases such as EoE. Impedance measurements in EoE patients and controls

118 Identification of a Novel Germ-Line Variant in an Uncharacterized Gene, FBE-1, and Its Putative Role in Familial Barrett's Esophagus

Background and Aim: An early event in the pathogenesis of eosinophilic esophagitis (EoE) is food antigen penetration of esophageal epithelium, but the precise relationship of eosinophilia, dilated intercellular spaces (DIS) and decreased barrier function is unclear. The aim of this study was to determine the correlation and accuracy of site-specific mucosal impedance (MI) measurement of ion flux with esophageal histology in distinguishing active from inactive EoE. Methods: In this study, 10 patients each with active and inactive EoE underwent MI measurement and mucosal biopsies at four esophageal sites (2, 5,10,15cm above the Zline). MI was compared to 10 control patients without esophageal symptoms. Data were analyzed by comparing MI values, Eos/HPF and DIS grade in the three groups at each level examined. Results: The esophageal MI values (ohms) were significantly lower in active when compared to inactive and control patients (1909 vs. 4349 and 5530 ohms, resp., p<.001). (Table) Four active patients had biopsies with eos< 15/HPF with lower DIS grade. There were significant and inverse correlations between MI and eos/HPF as well as DIS (rs=.584 and -.531, respectively, p<.001). Furthermore, MI cut off of 2300 ohms demonstrated 90% sensitivity and 91% specificity for diagnosis of active EoE and 89% and 82% for high grade DIS. Conclusions: In EoE, eosinophil eosinophilia and DIS correlate to MI measured ionic conductance and by inference barrier function. Endoscopic MI measurement in the esophagus is a promising, safe and easy to perform means to assess disease activity in diseases such as EoE. Impedance measurements in EoE patients and controls

500 The Induction of Pathological Acid Reflux With Acute Reflux Esophagitis in Humans Is Associated With T Lymphocyte-Predominant Inflammation of the Esophageal Mucosa: A New Paradigm for the Pathogenesis of Reflux Esophagitis

Introduction: Reflux esophagitis (RE) traditionally has been assumed to start when acid and pepsin destroy esophageal squamous cells at the luminal surface, inducing an acute, granulocyte-predominant inflammatory response. However, recent studies in animal RE models have challenged this traditional notion, suggesting that refluxed gastric juice does not destroy squamous cells directly, but instead stimulates them to secrete chemokines, which attract lymphocytes that mediate tissue damage. Patients typically have months to years of GERD symptoms before seeking medical attention, and so the early histologic changes of RE have not been evaluated prospectively in humans. To elucidate those changes, we induced acute RE by discontinuing PPIs in patients with healed RE. Methods: Patients with a prior endoscopy showing LA grade C RE were treated with PPIs BID for at least 1 month before a baseline endoscopy to document healing. PPIs then were stopped and endoscopy repeated 1 and 2 weeks later. At each endoscopy, 4 biopsies were taken from nonulcerated mucosa in the distal esophagus for histology and immunohistochemical staining for lymphocyte markers (CD3, CD20). Esophageal pH monitoring and GERD-HRQL symptom scoring were performed at baseline and 2 weeks. Biopsies were scored for type and degree of inflammation, for basal and papillary hyperplasia, and for spongiosis (dilated intercellular spaces) on a scale of 0 to 3. Results: 9 patients (8 men; mean age 67 years) had mean esophageal acid exposure (total % time pH<4) that increased from 6.6% at baseline to 28.4% at 2 weeks (p=.002), and mean GERD-HRQL scores that increased from 8.3 to 13.4 (p= .03). All patients developed endoscopic RE by 2 weeks (2 LA-A, 3 LA-B, 4 LA-C). Lymphocytes were by far the predominant type of inflammatory cell. Lymphocytes, basal and papillary hyperplasia, and spongiosis increased significantly from baseline to week 1, but not from week 1 to 2 (see Table). Lymphocytes were almost exclusively CD3+T cells, and found predominantly in peripapillary areas. There were few eosinophils in any biopsy at any time point. Neutrophils were also few in number and generally found only in association with micro-erosions at weeks 1 and 2; 4 of the 9 patients had no neutrophils in any biopsy at any time. Conclusions: In patients with severe RE healed by PPI therapy, stopping PPIs for 2 weeks causes a profound increase in acid reflux with acute RE that is characterized histologically by infiltration of the esophageal mucosa with T lymphocytes. Neutrophils and eosinophils do not appear to play an important role. The finding that acute RE in humans is a form of lymphocytic esophagitis supports the new paradigm for RE pathogenesis suggested by animal studies in which reflux does not destroy esophageal squamous cells directly, but rather stimulates them to secrete chemokines that attract lymphocytes.

Mast cell activation is involved in stress-induced epithelial barrier dysfunction in the esophagus.

We aimed to investigate the role of mast cell in stress-induced barrier dysfunction in the esophagus and its possible pathway involved using mast cell-deficient (Ws/Ws) rats. Ws/Ws rats and normal (+/+) rats were submitted to chronic restraint stress (CRS) 2 h/day for 7 days. Tissues were obtained from distal esophagus. Mast cells were counted under Alcian blue-safranin O stain. Activation of mast cells was assessed using transmission electron microscope. Esophageal epithelial barrier dysfunction was evaluated by measuring intercellular spaces (ICS) and by quantifying tight junction (TJ) proteins. The localization and expression of mast cell-derived tryptase and proteinase activated receptor 2 (PAR-2) were assessed. A higher number of mast cells and higher proportion of activated mast cells were observed in CRS +/+ rats compared with non-stress controls. Increased ICS and decreased expression of some TJ proteins were observed in the CRS +/+ rats but not in the CRS Ws/Ws rats. Tryptase and its receptor PAR-2 were found elevated concomitantly by nearly 100% in CRS +/+ rats, but not in CRS Ws/Ws rats. Mast cells play an important role in stress-induced epithelial barrier dysfunction in esophagus. The mechanism may involve the activation of PAR-2 by mast cell-derived tryptase, causing proinflammatory responses and the subsequent disruption of the epithelial TJ proteins and a disturbed cytoskeleton function, resulting in dilated intercellular spaces.

Mo1133 Narrow-Band Imaging Demonstrates Abnormalities in NERD: The ‘Linear Furrow Sign’

Introduction Two-thirds of patients with reflux symptoms will have a normal white light endoscopy (WLE). Using high definition narrow-band imaging (NBI), however, we found abnormalities in the distal oesophagus correlating with histologic findings of reflux. A common appearance was noted in patients referred for investigation of reflux (where endoscopy was otherwise normal). This was termed the ‘linear furrow’ sign (LFS) as it comprised of linear, alternating lighter and darker ‘ridges’ of mucosa resembling furrows in a ploughed field. This observational cohort study was conducted prospectively to establish the relevance of the LFS. Method Consecutive patients referred for investigation of reflux underwent endoscopy (BH or AH) to the institution protocol: a pair of routine, non-targetted distal and mid-esophageal biopsies were taken to examine for microscopic changes of reflux and to exclude eosinophilic esophagitis (EoE). Prior to biopsies, the oesophagus was examined using NBI. The endoscopist’s opinion as to whether the LFS was present was recorded in the routine report and digital still images captured. Histology was reported in the routine clinical service, then reviewed by a single experienced Histopathologist (HAA), blinded to endoscopic findings. Positive biopsies were those initially reported as “findings compatible with reflux”, but in each case the reviewing Histopathologist recorded the changes contributing to this overall impression. Sensitivity and specificity of the LFS was calculated using biopsies as the gold standard. Results n = 31 with normal WLE were examined (13F; mean age 44.3 ± 15.0 yrs). The LFS was present (LFS+) in 25 patients, extending approximately 4–5 cm above the squamocolumnar junction. Histologic examination of biopsies from this region demonstrated changes consistent with reflux in 23/25. 6 patients were LFS-, with normal histology in 5. Mid-esophageal biopsies were positive in only three patients. In one, diagnostic criteria for EoE were met (responding completely to acid suppression). Magnification endoscopy with NBI demonstrated that the changes seen arise from the impression of a ridged appearance to the mucosal surface – most likely reflecting elongation of papillae and basal cell hyperplasia. Spongiosis (dilated intercellular spaces; DIS) was demonstrable in 75% of LFS+. Although reflux symptoms were not systematically evaluated, a self-reported response to PPI was noted in 70% of such patients (LFS+, DIS+) and only 10% of those without (LFS-, DIS-; p Conclusion The LFS was detected in 80% of patients, achieving diagnostic accuracy of 90% and appears to relate to self-reported symptomatic response to PPI. A further prospective study is under way to determine the clinical significance of this finding. Disclosure of interest None Declared.

Endoscopic Mucosal Impedance Measurements Correlate With Eosinophilia and Dilation of Intercellular Spaces in Patients With Eosinophilic Esophagitis

Penetration of the esophageal epithelium by food antigens is an early event in the pathogenesis of eosinophilic esophagitis (EoE), but the precise relationship among eosinophilia, dilated intercellular spaces (DIS), and decreased barrier function is unclear. We investigated the correlation between site-specific mucosal impedance (MI) measurements of ion flux and esophageal histology, and whether MI measurements can be used to distinguish between patients with active and inactive EoE. MI was measured (in Ω) in 10 patients with active EoE (>15 eosinophils [eos]/high-power field [HPF]) and in 10 with inactive EoE (<15 eos/HPF, as a result of treatment), and mucosal biopsy specimens were collected from 4 esophageal sites (2, 5, 10, and 15 cm above the Z-line). MI also was measured in 10 individuals without esophageal symptoms (controls). MI measurements, eos/HPF, and DIS grade were compared among patients with EoE and controls. The esophageal MI values were significantly lower in patients with active EoE (1909 Ω) compared with inactive EoE (4349 Ω) or controls (5530 Ω) (P < .001). Biopsy specimens from 4 patients with active EoE contained fewer than 15 eos/HPF and lower-grade DIS than in patients with active disease. There were significant inverse correlations between MI and eos/HPF (rs = -.584), as well as between MI and DIS (rs = -.531; P < .001). The MI cut-off value of 2300 Ω identified patients with active EoE with 90% sensitivity and 91% specificity, and high-grade DIS with 89% sensitivity and 82% specificity. In patients with EoE, eosinophilia and DIS correlate with MI measurements of ion flux. Endoscopic MI measurement in the esophagus is safe and easy to perform, and can be used to assess activity of diseases such as EoE.

The Status of Histopathology in the Diagnosis of Gastroesophageal Reflux Disease – Time for Reappraisal?

The histological diagnosis of gastroesophageal reflux disease is generally believed to be a tool of limited value. Recent data, however, indicate that histology may be useful for the management of patients with non-erosive reflux disease, who account for up to 60% of all patients with reflux symptoms. Early diagnosis of gastroesophageal reflux disease is crucial because chronic reflux esophagitis is a key risk factor for the development of Barrett´s esophagus, which predisposes to esophageal adenocarcinoma. Histologically, reflux esophagitis is characterized by basal cell hyperplasia, papillary elongation, dilation of intercellular spaces, and inflammatory infiltration. These reflux-induced changes of the squamous epithelium are mainly related to the diagnosis of acute and/or active reflux. The chronic consequences of gastroesophageal reflux disease are mainly characterized by metaplatic mucosal replacement. The origin and significance of cardiac mucosa at the gastroesophageal junction are still controversial However, evidence is accumulating that injury and repair related to gastroesophageal reflux disease contribute to its development and/or expansion. Multilayered epithelium, defined as hybrid epithelium with characteristics of both squamous and columnar epithelium has been identified as a new sensitive marker of gastroesophageal reflux disease. This epithelium may be the precursor of metaplastic cardiac mucosa, and ultimately Barrett’s esophagus.

Prevalence of eosinophilic oesophagitis in adults presenting with oesophageal food bolus obstruction.

To look at the relationship between eosinophilic oesophagitis (EO) and food bolus impaction in adults. We retrospectively analysed medical records of 100 consecutive patients who presented to our hospital with oesophageal food bolus obstruction (FBO) between 2012 and 2014. In this cohort, 96 were adults (64% male), and 4 paediatric patients were excluded from the analysis as our centre did not have paediatric gastroenterologists. Eighty-five adult patients underwent emergency gastroscopy. The food bolus was either advanced into the stomach using the push technique or retrieved using a standard retrieval net. Biopsies were obtained in 51 patients from the proximal and distal parts of the oesophagus at initial gastroscopy. All biopsy specimens were assessed and reviewed by dedicated gastrointestinal pathologists at the Department of Pathology, University Hospital Geelong. The diagnosis of EO was defined and established by the presence of the following histological features: (1) peak eosinophil counts > 20/hpf; (2) eosinophil microabscess; (3) superficial layering of eosinophils; (4) extracellular eosinophil granules; (5) basal cell hyperplasia; (6) dilated intercellular spaces; and (7) subepithelial or lamina propria fibrosis. The histology results of the biopsy specimens were accessed from the pathology database of the hospital and recorded for analysis. Our cohort had a median age of 60. Seventeen/51 (33%) patients had evidence of EO on biopsy findings. The majority of patients with EO were male (71%). Classical endoscopic features of oesophageal rings, furrows or white plaques and exudates were found in 59% of patients with EO. Previous episodes of FBO were present in 12/17 patients and 41% had a history of eczema, hay fever or asthma. Reflux oesophagitis and benign strictures were found in 20/34 patients who did not have biopsies. EO is present in approximately one third of patients who are admitted with FBO. Biopsies should be performed routinely at index endoscopy in order to pursue this treatable cause of long term morbidity.

Esophageal Intraluminal Baseline Impedance Differentiates Gastroesophageal Reflux Disease From Functional Heartburn

Mucosal integrity can be assessed in patients with gastroesophageal reflux disease (GERD) by measuring intraluminal baseline impedance (BI). However, it is not clear whether BI is abnormal in patients with functional heartburn (FH), or can be used to distinguish them from patients with GERD. We compared differences in BI between patients with FH vs GERD. We performed a prospective study of 52 patients (16 men; mean age, 55 y; range, 23-78 y) seen at a tertiary university hospital from February 2009 through December 2012. Thirty-five patients had GERD (19 had nonerosive reflux disease [NERD], 16 had erosive reflux disease [ERD]) and 17 had FH. All patients discontinued proton pump inhibitor therapy and then underwent esophagogastroduodenoscopy and multichannel intraluminal impedance and pH monitoring. BI was assessed at 3, 5, 7, 9, 15, and 17 cm proximal to the lower esophageal sphincter in recumbent patients. Biopsy specimens were taken from 3 cm above the gastroesophageal junction; histology analysis was performed to identify and semiquantitatively score (scale, 0-3) dilated intercellular spaces. Baseline impedance in the distal esophagus was significantly lower in patients with NERD or erosive reflux disease (ERD) than FH (P= .0006). At a cut-off value of less than 2100 Ω, BI measurements identified patients with GERD with 78% sensitivity and 71% specificity, with positive and negative predictive values of 75%. Also in the proximal esophagus, reduced levels of BI levels were found only in patients with ERD. There were negative correlations between level of BI and acid exposure time (r=-0.45; P= .0008), number of acidic reflux episodes (r=-0.45; P= .001), and proximal extent (r= -0.40; P= .004). Biopsy specimens from patients with NERD or ERD had significant increases in dilation of intercellular spaces, compared with those from patients with FH; there was an inverse association between dilated intercellular spaces and BI in the distal esophagus (r= -0.28; P= .06). Measurement of BI in the lower esophagus can differentiate patients with ERD or NERD from patients with FH (78% sensitivity and 71% specificity), and therefore should be considered as a diagnostic tool for patients with proton pump inhibitor-refractory reflux. Low levels of BI are associated with increased exposure to acid and dilation of intercellular spaces, indicating that BI is a marker of mucosal integrity.

Impact of hiatal hernia on pediatric dyspeptic symptoms.

Hiatal hernia (HH) affects from 10% to 50% of adult population. The correlation between HH, gastroesophageal reflux disease, dyspeptic symptoms, and esophagitis has long been known in adults. The primary objective of our prospective observational study was to estimate the prevalence of HH in children undergoing esophagogastroduodenoscopy (EGD), irrespective of their symptoms. We prospectively enrolled 111 consecutive children (48 boys and 63 girls; mean age 94.9 ± 52.3 months) referred for EGD. In all of the patients a symptomatic score assessment based on the Rome III criteria was used to measure frequency, severity, and duration of gastrointestinal symptoms. HH presence was endoscopically defined; esophagitis presence was evaluated either endoscopically and histologically. Children were divided in 2 age-range groups: <48 months (group 1) and >48 months (group 2). Twenty-three patients of 111 (20.7%) had evidence of a sliding HH at EGD. In children from group 2, we found a statistically significant association of HH with heartburn (P = 0.03, 95% confidence interval 1-9.3, r = 0.1) and regurgitation (P = 0.003, 95% confidence interval 1.7-20.4, r = 0.3). Regarding esophagitis presence, no association was found at any age either with defined esophagitis or with dilated intercellular spaces. Prevalence of HH in our study population was 20.7%. According to our data, HH correlates with the presence of heartburn and regurgitation in children, but not in toddlers. No association was found with esophagitis at any age.

Is it possible to diagnose infectious oesophagitis without seeing the causative organism? A histopathological study.

We investigated the utility of using histological changes to diagnose infectious oesophagitis when causative organisms cannot be seen. Sixty-seven endoscopic biopsy specimens (51 Candida, 9 herpes simplex virus, 4 tuberculosis, and 3 cytomegalovirus oesophagitis) collected from 2000-2010 that matched the investigative criteria were included in the study. Cases were re-evaluated for histological changes observed in oesophagitis, and the findings were statistically compared using nonparametric tests. Thirty-nine cases occurred in male patients, and 28 occurred in female patients; the mean age of the patients was 51±20.1 years (range, 5-94 years). All cases showed lymphocytic and neutrophilic infiltration; while 27 (40.3%) showed eosinophilic infiltration. The density of lymphocytes and eosinophils were 8.43±6 and 1.07±1.62 per high power field, respectively, and these rates were higher in tuberculosis oesophagitis cases. Lamina propria infiltration was present in herpes simplex virus and Candida oesophagitis. Dense neutrophilic infiltration (>50/high power field) was noted in herpes simplex virus oesophagitis. Candida colonization was observed in 82% of cases with eosinophilic infiltration, and 80% of cases with erosion. Ulceration was present in all tuberculosis oesophagitis cases (p<0.001). Basal cell hyperplasia, papillary elongation, and dilated intercellular spaces were seen in all cases except for 2 Candida oesophagitis cases. Lamina propria fibrosis was especially noted in cytomegalovirus oesophagitis cases. It is not possible to distinguish infectious oesophagitis from other subtypes, especially reflux oesophagitis, if the causative organism is not detected. Clinicopathological correlation and control with repeat targeted biopsies are essential for diagnosis.

Dilated intercellular spaces in eosinophilic esophagitis.

Dilated intercellular spaces (DIS) in the esophageal epithelium can be induced by acid and reduced by proton pump inhibitors (PPI), and are thus considered a marker of gastroesophageal reflux disease (GERD). Over the years, however, DIS have also been reported in esophagitis unrelated to GERD. Because DIS have never been formally measured in eosinophilic esophagitis (EoE), we aimed at detecting and measuring DIS in EoE before and after nutritional or pharmacological therapy. In 22 children with EoE, DIS were measured by morphometry and transmission electron microscopy (TEM), before and after treatment with topical steroids (n = 16) and/or exclusion diet (n = 13). A total of 30 children undergoing upper gastrointestinal endoscopy with biopsy for nonesophageal disorders acted as controls. In controls, the mean (± standard deviation [SD]) number of esophageal eosinophils was 0.91 (± 0.47) and the mean DIS values were 0.62 (± 0.08) μm at morphometry and 0.33 (± 0.24) μm at TEM. In patients with EoE, the mean (± SD) number of esophageal eosinophils decreased from 31.8 (± 6.96) to 6.64 (± 5.01) (P < 0.0001), and the mean DIS values decreased from 2.26 (± 0.21) to 1.23 (± 0.20) μm at morphometry (P < 0.0001), and from 2.24 (± 0.28) to 0.98 (± 0.19) μm at TEM (P < 0.0001), respectively, before and after treatment. DIS are a prominent morphological feature of EoE, in which they can be significantly reduced by an appropriate non-PPI therapy.

Diagnostic value of dilated intercellular space and histopathologic scores in gastroesophageal reflux disease.

The aim of this paper is to investigate the diagnostic value of histopathologic score and the dilated intercellular space (DIS) in patients with gastroesophageal reflux disease (GERD) and functional heartburn (FH). Participants with GERD symptoms including reflux esophagitis, non-erosive reflux disease (NERD), Barrett's esophagus (BE), functional heartburn (FH), along with a control group with atypical GERD-like symptom (Sym-C), and asymptomatic healthy volunteers (H-C) were administered GERD questionnaire, and subjected to endoscopy and biopsies, as well as 24-hour pH-impedance monitoring. Biopsies were evaluated using standards from the 2011 Esohisto Project after Hematoxylin-Eosin staining. DIS was measured quantitatively under light microscopy. Among the total of 565 participants with qualified biopsy specimens, the mean DIS of the reflux esophagitis (RE) group was significantly wider compared with the other five groups. DIS in patients with GERD-like symptoms was significantly wider compared with the H-C. No significant differences were observed between NERD and FH. Results from 24-hour pH-impedance monitoring indicated that only the DIS of patients with acid reflux or the amount of acid reflux episodes in patients with DIS was significantly wider compared with patients with nonacid reflux or patients without DIS (P < 0.001). With DIS = 0.9 μm as the cutoff value, the sensitivity and specificity were 62.6% and 54.1%, respectively. Using the total histopathologic score > 3 as the diagnostic criterion, the sensitivity and specificity were 71.7% and 47.4%. DIS is closely associated with GERD and acid reflux. The diagnostic value of histological scores in lower esophagus in GERD is very similar to that of the quantitative measurement of DIS.

ERK1/2 participates in regulating the expression and distribution of tight junction proteins in the process of reflux esophagitis.

To investigate the alterations of esophageal epithelial barrier during the process of reflux esophagitis (RE). In total, 85 Sprague-Dawley rats were randomly divided into two groups, the sham-operation group (n = 25) and the RE group induced by incomplete pyloric ligation (n = 60). The establishment of RE model and the severity of esophagitis were evaluated by hematoxylin and eosin stain. Dilated intercellular spaces (DIS) in the esophageal epithelium were observed by transmission electron microscopy. The cellular distributions of ZO-1, occludin and claudin-1 were assessed by immunohistochemical stain. The expressions of these tight junction (TJ) proteins and the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), myosin light chain (MLC) and nonmuscular myosin light chain kinase (nmMLCK) were analyzed by Western blot. DIS occurred gradually in the RE group. ZO-1, occludin and claudin-1 were incompletely or even not expressed in the RE group. TJ proteins were expressed in the membrane instead of the cytoplasm in many epithelial cells in RE. With Western, the expression of ZO-1, occludin and claudin-1 was increased gradually in the RE group (P < 0.05). The phosphorylation levels of nmMLCK, MLC and ERK1/2 were also increased (P < 0.05). There was no marked changes in the esophageal epithelium in the sham-operation group. TJ proteins could be used as sensitive markers of RE instead of DIS. ERK1/2 may participate in regulating TJ proteins in esophageal epithelia in RE.

PTU-169 Long-lasting Oesophageal Mucosal Protction With Alginates: A Potential For Topical Mucosal Therapy In Gastro-oesophageal Reflux

IntroductionPatients with non-erosive reflux disease (NERD) exhibit impaired oesophageal mucosal barrier integrity in the form of dilated intercellular spaces and low transepithelial electrical resistance (TER). Such refluxate-induced changes to the...

664 Newly Developed Bioelectrical Admittance Measurement Distinguishes Patients With Non-Erosive Reflux Disease From Those With Functional Heartburn

Background & Aims: Almost 70% of patients complaining of heartburn have no macroscopic evidence of esophageal mucosal damage, and are termed as having either non-erosive reflux disease (NERD) or functional heartburn (FH). Microscopic esophagitis (ME) is common in patients with NERD, and the succeeding changes of dilation of intercellular spaces (DIS) has been regarded as the potential main mechanism of symptom generation. It has been reported that edema and inflammation as well as DIS in the tissue are related to the decreasing electrical impedance. The aim of this study was to validate our newly developed bioelectrical admittance method (BAM) as a measure of admittance (numerically equal to the reciprocal of the impedance) of esophageal wall and investigate the differences in bioelectrical admittance between NERD and FH patients. Methods: The BAM was performed at the distal esophagus during upper endoscopy in consecutive 25 patients with heartburn. In each patient, three specimens were taken from the same lesion where the BAM was performed. The histological alterations and gene expression levels of mediators of inflammation and tight junction proteins such as claudin1, claudin4, ZO-1 and occludin were evaluated, and DIS was also evaluated by an electron microscope. The correlation between bioelectrical admittance and tissue resistance measured by an Ussing chamber was investigated for 5 subjects. All patients were prescribed double doses of proton pump inhibitor (PPI) for 2 weeks, and after that patients were divided into 2 groups: good response to PPI (Group A) and poor response to PPI (Group B). Results: There were17 patients in the Group A and 18 patients in the Group B. Symptom severity of heartburn was not significantly different between the two groups. The histopathological findings showed that the prevalence of ME was significantly higher (p<0.05) in the Group A (65%) than in the Group B (10%). DIS also showed similar rates of prevalence. There were differences in expression levels of tight junction proteins between the two groups. Furthermore, patients in the Group A were characterized by the increase in the mRNA expression level of TNFα. There was a significant negative correlation between bioelectrical admittance and tissue resistance evaluated by an Ussing chamber (p<0.05). Patients in the Group A displayed significant higher bioelectrical admittance than those in the Group B (p<0.05), and a significant association between the severity of lowgrade inflammation and the extent of increased bioelectrical admittance of esophageal wall (r=0.45, p<0.05). Conclusions: The BAM is a new method to evaluate esophageal mucosal integrity during upper endoscopy. The low-grade inflammation on esophageal mucosa and electrical conductivity are good clinical markers for the assessment of the responsiveness to PPI in patients with heartburn.

Tu1101 Basal Cell Hyperplasia and Dilation of Intercellular Spaces Are the Main Histologic Features Associated to the Endoscopic/Impedance-pH Diagnosis of GERD and Its Related Mucosal Integrity Impairment

Background: During pathological assessment of esophageal biopsies several histological features characterizing the diagnosis of microscopic esophagitis [basal cell hyperplasia (BCH), papillary enlongation (PE), dilated intercellular spaces (DIS) and epithelial neutrofilic/eosinophilic infiltration (Neu/Eos)] can be assessed. Limited data are available about the single contribution of these histological abnormalities on the diagnosis of GERD and its related mucosal integrity in well-defined patients with reflux disease. Aim: To determine whether these histological features contribute differently to the diagnosis GERD and to the impairment of mucosal integrity as expressed by baseline impedance (BI) levels. Methods:One hundred and four consecutive patients with typical reflux symptoms underwent upper endoscopy and multiple biopsies were taken at Z-line and 2 cm above it, in order to assess the presence and severity of BCH, PE, DIS and Neu/Eos [0 (absent), 1 (mild), and 2 (marked)]. Within 3 days from endoscopy, patients underwent impedance-pH testing off-therapy. During manual analysis of the impedance-pH tracings, we measured the esophageal acid expsosure time (AET) over the 24 hours and the total (acid + non-acid) number of impedance-detected reflux episodes. We evaluated BI values at 3 and 5cm above the LES, during the overnight rest, for at least 30 minutes after excluding swallows and reflux induced changes. Twenty healthy volunteers (HVs; 11F/9M; mean age 44) who underwent the same procedures were also enrolled as controls. Results:We included 85 patients with an endoscopic/impedancepH diagnosis of GERD (45F/40M; mean age 46) who had esophageal mucosal breaks at upper endoscopy or an abnormal esophageal acid exposure or a normal esophageal acid exposure but a positive reflux-symptom association at impedance-pH testing. Among these patients, BI values at both 3 and 5 cm above the LES positively correlated with the esophageal AET (r2=0.2033, P<0.001 and r2=0.1859, P<0.001, respectively) and the number of impedance-detected reflux episodes (r2=0.1373, P<0.001 and r2=0,1526, P<0.001, respectively). Moreover, as shown in the Table, BCH and DIS were the lesions more significantly correlated with the endoscopic/impedance-pH diagnosis of GERD. No significant correlation was observed between BI values and impedance-pH parameters or histological lesions in HVs (p=ns). Conclusions: BCH and DIS contribute more than PE and Eos/Neu to the endoscopic/ impedance-pH diagnosis of GERD. Moreover, the same lesions seem to play a greater role than PE and Eos/Neu in determining mucosal integrity impairment as expressed by BI values in GERD patients. Overall, BCH and DIS can be considered the histological markers requiring more carefully evaluation during pathologic assessment in order to help the diagnosis of GERD. Correlation of BI levels with ME histologic features

Tu1102 A New Method for Constant Mucosal Contact and Reliable Measurement of Esophageal Mucosal Impedance

Background: During pathological assessment of esophageal biopsies several histological features characterizing the diagnosis of microscopic esophagitis [basal cell hyperplasia (BCH), papillary enlongation (PE), dilated intercellular spaces (DIS) and epithelial neutrofilic/eosinophilic infiltration (Neu/Eos)] can be assessed. Limited data are available about the single contribution of these histological abnormalities on the diagnosis of GERD and its related mucosal integrity in well-defined patients with reflux disease. Aim: To determine whether these histological features contribute differently to the diagnosis GERD and to the impairment of mucosal integrity as expressed by baseline impedance (BI) levels. Methods:One hundred and four consecutive patients with typical reflux symptoms underwent upper endoscopy and multiple biopsies were taken at Z-line and 2 cm above it, in order to assess the presence and severity of BCH, PE, DIS and Neu/Eos [0 (absent), 1 (mild), and 2 (marked)]. Within 3 days from endoscopy, patients underwent impedance-pH testing off-therapy. During manual analysis of the impedance-pH tracings, we measured the esophageal acid expsosure time (AET) over the 24 hours and the total (acid + non-acid) number of impedance-detected reflux episodes. We evaluated BI values at 3 and 5cm above the LES, during the overnight rest, for at least 30 minutes after excluding swallows and reflux induced changes. Twenty healthy volunteers (HVs; 11F/9M; mean age 44) who underwent the same procedures were also enrolled as controls. Results:We included 85 patients with an endoscopic/impedancepH diagnosis of GERD (45F/40M; mean age 46) who had esophageal mucosal breaks at upper endoscopy or an abnormal esophageal acid exposure or a normal esophageal acid exposure but a positive reflux-symptom association at impedance-pH testing. Among these patients, BI values at both 3 and 5 cm above the LES positively correlated with the esophageal AET (r2=0.2033, P<0.001 and r2=0.1859, P<0.001, respectively) and the number of impedance-detected reflux episodes (r2=0.1373, P<0.001 and r2=0,1526, P<0.001, respectively). Moreover, as shown in the Table, BCH and DIS were the lesions more significantly correlated with the endoscopic/impedance-pH diagnosis of GERD. No significant correlation was observed between BI values and impedance-pH parameters or histological lesions in HVs (p=ns). Conclusions: BCH and DIS contribute more than PE and Eos/Neu to the endoscopic/ impedance-pH diagnosis of GERD. Moreover, the same lesions seem to play a greater role than PE and Eos/Neu in determining mucosal integrity impairment as expressed by BI values in GERD patients. Overall, BCH and DIS can be considered the histological markers requiring more carefully evaluation during pathologic assessment in order to help the diagnosis of GERD. Correlation of BI levels with ME histologic features

Tu1104 Objective Identification of Common Daily Activities by Their Manometric Signatures Using Ambulatory Pressure Recording

Background: During pathological assessment of esophageal biopsies several histological features characterizing the diagnosis of microscopic esophagitis [basal cell hyperplasia (BCH), papillary enlongation (PE), dilated intercellular spaces (DIS) and epithelial neutrofilic/eosinophilic infiltration (Neu/Eos)] can be assessed. Limited data are available about the single contribution of these histological abnormalities on the diagnosis of GERD and its related mucosal integrity in well-defined patients with reflux disease. Aim: To determine whether these histological features contribute differently to the diagnosis GERD and to the impairment of mucosal integrity as expressed by baseline impedance (BI) levels. Methods:One hundred and four consecutive patients with typical reflux symptoms underwent upper endoscopy and multiple biopsies were taken at Z-line and 2 cm above it, in order to assess the presence and severity of BCH, PE, DIS and Neu/Eos [0 (absent), 1 (mild), and 2 (marked)]. Within 3 days from endoscopy, patients underwent impedance-pH testing off-therapy. During manual analysis of the impedance-pH tracings, we measured the esophageal acid expsosure time (AET) over the 24 hours and the total (acid + non-acid) number of impedance-detected reflux episodes. We evaluated BI values at 3 and 5cm above the LES, during the overnight rest, for at least 30 minutes after excluding swallows and reflux induced changes. Twenty healthy volunteers (HVs; 11F/9M; mean age 44) who underwent the same procedures were also enrolled as controls. Results:We included 85 patients with an endoscopic/impedancepH diagnosis of GERD (45F/40M; mean age 46) who had esophageal mucosal breaks at upper endoscopy or an abnormal esophageal acid exposure or a normal esophageal acid exposure but a positive reflux-symptom association at impedance-pH testing. Among these patients, BI values at both 3 and 5 cm above the LES positively correlated with the esophageal AET (r2=0.2033, P<0.001 and r2=0.1859, P<0.001, respectively) and the number of impedance-detected reflux episodes (r2=0.1373, P<0.001 and r2=0,1526, P<0.001, respectively). Moreover, as shown in the Table, BCH and DIS were the lesions more significantly correlated with the endoscopic/impedance-pH diagnosis of GERD. No significant correlation was observed between BI values and impedance-pH parameters or histological lesions in HVs (p=ns). Conclusions: BCH and DIS contribute more than PE and Eos/Neu to the endoscopic/ impedance-pH diagnosis of GERD. Moreover, the same lesions seem to play a greater role than PE and Eos/Neu in determining mucosal integrity impairment as expressed by BI values in GERD patients. Overall, BCH and DIS can be considered the histological markers requiring more carefully evaluation during pathologic assessment in order to help the diagnosis of GERD. Correlation of BI levels with ME histologic features