Role of acid and bile reflux in development of specialised intestinal metaplasia in distal oesophagus

Helicobacter pylori infection is associated with reduced risk of Barrett's esophagus: a meta-analysis and systematic review

BACKGROUND

Helicobacter pylori (Hp) is a class I carcinogen in gastric carcinogenesis, but its role in Barrett's esophagus (BE) is unknown. Therefore, we aimed to explore the possible relationship.

METHODS

We reviewed observational studies published in English until October 2019. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for included studies.

RESULTS

46 studies from 1505 potential citations were eligible for inclusion. A significant inverse relationship with considerable heterogeneity was found between Hp (OR = 0.70; 95% CI, 0.51-0.96; P = 0.03) and BE, especially the CagA-positive Hp strain (OR = 0.28; 95% CI, 0.15-0.54; P = 0.0002). However, Hp infection prevalence was not significantly different between patients with BE and the gastroesophageal reflux disease (GERD) control (OR = 0.99; 95% CI, 0.82-1.19; P = 0.92). Hp was negatively correlated with long-segment BE (OR = 0.47; 95% CI, 0.25-0.90; P = 0.02) and associated with a reduced risk of dysplasia. However, Hp had no correlated with short-segment BE (OR = 1.11; 95% CI, 0.78-1.56; P = 0.57). In the present infected subgroup, Hp infection prevalence in BE was significantly lower than that in controls (OR = 0.69; 95% CI, 0.54-0.89; P = 0.005); however, this disappeared in the infection history subgroup (OR = 0.88; 95% CI, 0.43-1.78; P = 0.73).

CONCLUSIONS

Hp, especially the CagA-positive Hp strain, and BE are inversely related with considerable heterogeneity, which is likely mediated by a decrease in GERD prevalence, although this is not observed in the absence of current Hp infection.

Systematic review: duodenogastroesophageal (biliary) reflux prevalence, symptoms, oesophageal lesions and treatment

BACKGROUND

The prevalence of duodenogastroesophageal reflux (DGER) and its effect on symptoms and oesophageal lesions in gastroesophageal reflux disease (GERD) is unclear.

AIMS

To conduct a systematic review to determine the prevalence of DGER among patients with GERD, the effect of DGER on symptoms and oesophageal lesions, and the treatment of DGER.

METHODS

We searched Pubmed and MEDLINE for full text, English language articles until October 2020 that evaluated DGER prevalence among patients with GERD, the effect of DGER on symptoms and oesophageal lesions, and the treatment of DGER.

RESULTS

We identified 3891 reports and included 35 which analysed DGER prevalence in GERD, 15 which evaluated its effect in non-erosive reflux disease (NERD), 17 on erosive oesophagitis, 23 in Barrett's, and 13 which evaluated the treatment of DGER. The prevalence of DGER, when evaluated by Bilitec, among all GERD patients ranged from 10% to 97%, in NERD 10%-63%, in erosive oesophagitis 22%-80% and in Barrett's 50%-100%. There were no differences in the presence or degree of DGER among patients who were asymptomatic or symptomatic on proton pump inhibitors (PPI). The most commonly evaluated treatments for DGER were PPIs and DGER reduced post-PPI therapy in all studies.

CONCLUSIONS

The prevalence of DGER increased with more advanced oesophageal lesions and did not explain persisting symptoms among patients taking PPI therapy. PPIs appear to be effective in the treatment of DGER. DGER remains an important consideration in patients with GERD and future therapies deserve more study.

Esophageal Function Abnormalities in Patients With Barrett's Esophagus

Various esophageal functional abnormalities have been described in patients with Barrett's esophagus (BE). A significantly higher esophageal acid exposure especially in the supine position has been documented in BE, as compared with the other gastroesophageal reflux disease phenotypes. In addition, weakly acidic reflux and duodenogastroesophageal reflux are more common in BE patients. The presence of Barrett's mucosa reduces esophageal mucosal impedance, occasionally to a level that prevents detection of reflux episodes. Reduced amplitude contractions and lower esophageal sphincter basal pressure are more common in BE patients as compared with the other gastroesophageal reflux disease groups. Ineffective esophageal motility is the most commonly defined motor disorder in BE. Reduced chemoreceptor and mechanoreceptor sensitivity to acid and balloon distention, respectively, have been suggested to explain lack or significantly less reports of reflux-related symptoms by BE patients.

Helicobacter pylori infection reduces the risk of Barrett's esophagus: A meta-analysis and systematic review

INTRODUCTION

The prevalence of Helicobacter pylori infection (HPI) has been decreasing in developed countries, with an increasing prevalence of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) at the same time. The aim of our meta-analysis was to quantify the risk of BE in the context of HPI.

METHODS

A systematic search was conducted in 3 databases for studies on BE with data on prevalence of HPI from inception until December 2016. Odds ratios for BE in HPI were calculated by the random effects model with subgroup analyses for geographical location, presence of dysplasia in BE, and length of the BE segment.

RESULTS

Seventy-two studies were included in the meta-analysis, including 84 717 BE cases and 390 749 controls. The overall analysis showed that HPI reduces the risk of BE; OR = 0.68 (95% CI: 0.58-0.79, P < .001). Subgroup analyses revealed risk reduction in Asia OR = 0.53 (95% CI: 0.33-0.84, P = .007), Australia OR = 0.56 (95% CI: 0.39-0.80, P = .002), Europe OR = 0.77 (95% CI: 0.60-0.98, P = .035), and North-America OR = 0.59 (95% CI: 0.47-0.74, P < .001). The risk was significantly reduced for dysplastic BE, OR = 0.37 (95% CI: 0.26-0.51, P < .001) for non-dysplastic BE, OR = 0.51 (95% CI: 0.35-0.75, P = .001), and for long segment BE, OR = 0.25 (95% CI: 0.11-0.59, P = .001) in case of HPI.

CONCLUSIONS

This extensive meta-analysis provides additional evidence that HPI is associated with reduced risk of BE. Subgroup analyses confirmed that this risk reduction is independent of geographical location. HPI is associated with significantly lower risk of dysplastic, non-dysplastic, and long segment BE.

Lack of correlation between gastroesophageal reflux disease symptoms and esophageal lesions after sleeve gastrectomy

BACKGROUND

The postoperative development or worsening of gastroesophageal reflux disease (GERD) represents the major drawback of laparoscopic sleeve gastrectomy (SG). A GERD diagnosis is often based only on symptoms and proton pump inhibitors (PPI) intake, while objective tests like esophagogastroduodenoscopy and pH measurements are performed less frequently.

OBJECTIVES

To evaluate the association between reflux symptoms and GERD-related esophageal lesions.

SETTINGS

University hospital, Rome, Italy.

METHODS

A comprehensive clinical control entailing GERD symptoms, PPI intake, and esophagogastroduodenoscopy was proposed to all patients who underwent SG between June 2007 and February 2011, irrespective of the presence of GERD symptoms. One hundred forty-four of 219 patients agreed to take part in the study (follow-up rate: 65.8%).

RESULTS

After a mean follow-up of 66 months, GERD symptoms and PPI intake were recorded in 70.2% and 63.9% of patients, respectively. Mean visual analogue scale score was 2.9 ± 3.3. The overall frequency of erosive esophagitis was 59.8%, while nondysplastic Barrett's esophagus was detected in 13.1%. The frequency of esophageal biliary reflux was 68%. GERD symptoms and visual analogue scale score were not significantly associated with the development of erosive esophagitis and Barrett's esophagus and the severity of the esophageal lesions. Moreover, the frequency of erosive esophagitis and Barrett's esophagus in patients consuming PPI were similar to that of patients without PPI.

CONCLUSION

Symptoms investigation alone is not a reliable tool to diagnose GERD after SG. The use of objective diagnostic tests, such as esophagogastroduodenoscopy, should be carefully considered in the postoperative follow-up schedule of SG patients.

Barrett’s esophagus in 2016: From pathophysiology to treatment

Esophageal complications caused by gastroesophageal reflux disease (GERD) include reflux esophagitis and Barrett’s esophagus (BE). BE is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). The carcinogenic sequence may progress through several steps, from normal esophageal mucosa through BE to EAC. A recent advent of functional esophageal testing (particularly multichannel intraluminal impedance and pH monitoring) has helped to improve our knowledge about GERD pathophysiology, including its complications. Those findings (when properly confirmed) might help to predict BE neoplastic progression. Over the last few decades, the incidence of EAC has continued to rise in Western populations. However, only a minority of BE patients develop EAC, opening the debate regarding the cost-effectiveness of current screening/surveillance strategies. Thus, major efforts in clinical and research practice are focused on new methods for optimal risk assessment that can stratify BE patients at low or high risk of developing EAC, which should improve the cost effectiveness of screening/surveillance programs and consequently significantly affect health-care costs. Furthermore, the area of BE therapeutic management is rapidly evolving. Endoscopic eradication therapies have been shown to be effective, and new therapeutic options for BE and EAC have emerged. The aim of the present review article is to highlight the status of screening/surveillance programs and the current progress of BE therapy. Moreover, we discuss the recent introduction of novel esophageal pathophysiological exams that have improved the knowledge of the mechanisms linking GERD to BE.

Farnesoid X receptor signal is involved in deoxycholic acid-induced intestinal metaplasia of normal human gastric epithelial cells

The farnesoid X receptor (FXR) signaling pathway is known to be involved in the metabolism of bile acid, glucose and lipid. In the present study, we demonstrated that 400 µmol/l deoxycholic acid (DCA) stimulation promotes the proliferation of normal human gastric epithelial cells (GES-1). In addition, DCA activated FXR and increased the expression of intestinal metaplasia genes, including caudal-related homeobox transcription factor 2 (Cdx2) and mucin 2 (MUC2). The treatment of FXR agonist GW4064/antagonist guggulsterone (Gug.) significantly increased/decreased the expression levels of FXR, Cdx2 and MUC2 protein in DCA-induced GES-1 cells. GW4064/Gug. also enhanced/reduced the nuclear factor-κB (NF-κB) activity and binding of the Cdx2 promoter region and NF-κB, the most common subunit p50 protein. Taken together, the results indicated that DCA is capable of modulating the expression of Cdx2 and the downstream MUC2 via the nuclear receptor FXR-NF-κB activity in normal gastric epithelial cells. FXR signaling pathway may therefore be involved in the intestinal metaplasia of human gastric mucosa.

WHAT IS THE REAL IMPAIRMENT ON ESOPHAGEAL MOTILITY IN PATIENTS WITH GASTROESOPHAGEAL REFLUX DISEASE?

Context Impairment of esophageal motility is a common finding in patients with gastroesophageal reflux disease (GERD) as reduced lower esophageal sphincter (LES) basal pressure. A very low LES pressure might facilitate the occurrence of more gastroesophageal reflux whereas abnormal esophageal peristalsis may contribute to impaired esophageal clearance after reflux. Objective Evaluate the esophageal motor function of the lower esophageal sphincter and esophageal body in the various forms of gastroesophageal reflux disease. Methods The manometrics records of 268 patients, who had evaluation of the esophageal motility as part of the diagnostic gastroesophageal reflux disease were split into four groups, as follows: 33 patients who had no esophagitis; 92 patients who had erosive esophagitis; 101 patients who had short Barrett's esophagus and 42 patients who had long Barrett's esophagus. Results The group who had long Barrett's esophagus showed smaller mean LES pressure and higher percentage of marked LES hypotonia; in the distal segment of the esophageal body the this group showed higher percentage of marked hypocontractility of the distal segment (<30 mm Hg); this same group showed higher percentage of esophageal motility disorders. Conclusions The most intense esophageal motility disorders and lower pressure of lower esophageal sphincter were noted in the group with long Barrett's esophagus. Those with reflux esophagitis and short Barrett's esophagus had esophageal motility impairment, intermediate among patients with esophagitis and long Barrett's esophagus. Patients with typical symptoms of gastroesophageal reflux but without esophagitis by endoscopy study showed no impairment of esophageal motility.

The association between Barrett's esophagus and Helicobacter pylori infection: a meta-analysis

OBJECTIVE

The effect of Helicobacter pylori on Barrett's esophagus is poorly understood. We conducted a meta-analysis to summarize the existing literature examining the effect that H. pylori has on Barrett's esophagus.

DESIGN

 We performed a comprehensive search to identify studies pertaining to the association between H. pylori and Barrett's esophagus. We conducted meta-regression analyses to identify sources of variation in the effect of H. pylori on Barrett's esophagus.

RESULTS

 Our analysis included a total of 49 studies that examined the effect of H. pylori on Barrett's esophagus and seven studies that examined the effect of cag A positivity on Barrett's esophagus. Overall, H. pylori, and even more so cag A, tended to be protective for Barrett's esophagus in most studies; however, there was obvious heterogeneity across studies. The effect of H. pylori on Barrett's esophagus varied by geographic location and in the presence of selection and information biases. Only four studies were found without obvious selection and information bias, and these showed a protective effect of H. pylori on Barrett's esophagus (Relative risk = 0.46 [95% CI: 0.35, 0.60]).

CONCLUSIONS

 Estimates for the effect of H. pylori on Barrett's esophagus were heterogeneous across studies. We identified selection and information bias as potential sources of this heterogeneity. Few studies without obvious selection and information bias have been conducted to examine the effect of H. pylori on Barrett's esophagus, but in these, H. pylori infection is associated with a reduced risk of Barrett's esophagus.

Long-term follow-up of Barrett's epithelium: medical versus antireflux surgical therapy

BACKGROUND

Barrett's esophagus (BE) is the most serious complication of GERD. In BE patients, this observational study compares the effects of antireflux surgery versus antisecretory medical therapy.

METHODS

Overall, 89 BE patients (long BE = 45; short BE = 44) were considered: 45 patients underwent antireflux surgery and 44 underwent medical therapy. At both initial and follow-up endoscopy, symptoms were assessed using a detailed questionnaire; BE phenotypic changes [intestinal metaplasia (IM) presence/type, Cdx2 expression] were assessed by histology (H&E), histochemistry (HID), and immunohistochemistry. Surgical failures were defined as follows: (1) abnormal 24-h pH monitoring results after surgery, (2) endoscopically evident recurrent esophagitis, and (3) recurrent hiatal hernia or slipped fundoplication on endoscopy or barium swallow.

RESULTS

Reversion of IM was observed in 12/44 SSBE and 0/45 LSBE patients (p < 0.01). Reversion was more frequently observed after effective antireflux surgery than after medical treatment (p = 0.04). In patients with no further evidence of IM after therapy, Cdx2 expression was also absent (p = 0.02). The extent of IM was reduced, and the IM phenotype improved in SSBE patients after surgery.

CONCLUSIONS

Patients with short BE (but not those with long BE) may benefit from surgically reducing the esophagus' exposure to GE reflux; among these patients, successful surgery carries a higher IM reversion rate than medical treatment.

Impact of the composition of gastric reflux bile acids on Barrett's oesophagus

BACKGROUND

The effect of the composition of reflux bile acids, especially the ratio of hydrophobic to hydrophilic ones, on the development of Barrett's oesophagus has not been fully investigated in human studies.

AIMS

To evaluate the influence of the bile acid composition of gastric juice on Barrett's oesophagus, a prospective study was designed.

METHODS

Fifty patients with and 100 patients without Barrett's oesophagus were enrolled. For all enrolled patients, gastric juice was collected by the endoscopic procedure for bile acid analysis. The ratio of hydrophobic to hydrophilic bile acids (bile hydrophobicity ratio, BHR) was calculated from 6 kinds of bile acids analysed in gastric juice. The relationship between the ratio and clinico-pathological factors of Barrett's oesophagus was investigated.

RESULTS

The mean of BHR of patients with Barrett's oesophagus was significantly higher than that of patients without Barrett's oesophagus (0.26 ± 0.05 vs. 0.08 ± 0.02, p<0.05). In multivariate analysis, a high BHR value was a predictor for the presence of Barrett's oesophagus (OR 5.74, p<0.001). In patients with Barrett's oesophagus, the BHR correlated with COX-2 protein expression and with accelerated cellular proliferation.

CONCLUSIONS

Patients with Barrett's oesophagus had a higher BHR in the gastric juice than those without.

MicroRNA-196a & microRNA-101 expression in Barrett's oesophagus in patients with medically and surgically treated gastro-oesophageal reflux

Background

Proton pump inhibitor (PPI) medication and surgical fundoplication are used for the control of gastro-oesophageal reflux in patients with Barrett's oesophagus, but differ in their effectiveness for both acid and bile reflux. This might impact on the inflammatory processes that are associated with progression of Barrett's oesophagus to cancer, and this may be evident in the gene expression profile and microRNA expression pattern in Barrett's oesophagus mucosa. We hypothesised that two miRNAs with inflammatory and oncogenic roles, miR-101 and miR-196a, are differentially expressed in Barrett's oesophagus epithelium in patients with reflux treated medically vs. surgically.

Findings

Mucosal tissue was obtained at endoscopy from patients with Barrett's oesophagus whose reflux was controlled by proton pump inhibitor (PPI) therapy (n = 20) or by fundoplication (n = 19). RNA was extracted and the expression of miR-101 and miR-196a was measured using real-time reverse transcription - polymerase chain reaction. There were no significant differences in miR-101 and miR-196a expression in Barrett's oesophagus epithelium in patients treated by PPI vs. fundoplication (p = 0.768 and 0.211 respectively). Secondary analysis showed a correlation between miR-196a expression and Barrett's oesophagus segment length (p = 0.014).

Conclusion

The method of reflux treatment did not influence the expression of miR-101 and miR-196a in Barrett's oesophagus. This data does not provide support to the hypothesis that surgical treatment of reflux better prevents cancer development in Barrett's oesophagus. The association between miR-196a expression and Barrett's oesophagus length is consistent with a tumour promoting role for miR-196a in Barrett's oesophagus.

Characteristics of gastro-esophageal reflux episodes in Barrett's esophagus, erosive esophagitis and healthy volunteers

BACKGROUND

Gastro-esophageal reflux is considered a major culprit in the pathogenesis of Barrett's esophagus (BE). Still, there is controversy on the role of weakly acidic and weakly alkaline reflux in BE. To compare characteristics of reflux episodes patients with BE, erosive esophagitis (EE), and healthy volunteers (HV).

METHODS

One hundred consecutive patients with BE (75 short-segment BE, 25 long-segment BE), 50 with EE and 48 HV underwent multichannel intraluminal impedance-pH off-therapy. We quantified esophageal acid exposure, characteristics, and proximal extension of reflux episodes.

KEY RESULTS

Total and acid reflux episodes gradually increased from HV [28 (17.5-43) and 18 (8-31)] to EE [73.5 (54-96) and 52 (39-68)], short-segment BE (SSBE) [83 (73.2-131) and 65 (43.3-95)] and long-segment BE (LSBE) [105 (102-187) and 77 (75-107)]. Weakly acidic reflux episodes were significantly higher (P < 0.05) in LSBE [36 (27.5-50.5)] and SSBE [34 (18.5-41)] compared to EE [21.5 (15-37)] and HV [19 (14-25)]. No differences in terms of proportion of acid, weakly acidic and weakly alkaline reflux were found [HV (49%-49%-2%) vs EE (68%-32%-1%) vs SSBE (65%-34%-1%) vs LSBE (69%-30%-1%); P = ns]. In LSBE, a higher percentage of reflux episodes (P < 0.05) reached the proximal esophagus (59%) compared with SSBE (43%).

CONCLUSIONS & INFERENCES

 Barrett esophagus patients have more severe reflux as shown by the number of acid and weakly acidic reflux episodes, re-reflux episodes and proximal migration. Given that PPI change only the pH of the refluxate, the role of weakly acidic reflux in Barrett's patients on acid suppressive therapy warrants further investigation.

Nitric oxide-mediated invasion in Barrett's high-grade dysplasia and adenocarcinoma

Nitric oxide (NO) has been shown to induce double strand DNA breaks in Barrett's oesophagus (BO) and in other cancers has a role in invasion. The specific aims of this study were to investigate whether NO can induce invasion in cells representative of different stages of Barrett's progression and to determine possible underlying mechanisms. Physiological concentrations of NO that mimic luminal production of NO from dietary sources enhanced invasion in cell lines from high-grade dysplasia (GihTERT) and oesophageal adenocarcinoma (FLO) but not a non-dysplastic Barrett's cell line (QhTERT). Real-time reverse transcription-polymerase chain reaction revealed that NO induced expression of matrix metalloproteinase (MMP)-1, -3, -7, -9 and -10 and tissue inhibitor of metalloproteinase (TIMP)-1, -2 and -3 in these cell lines. Furthermore, ex vivo treatment of Barrett's biopsy samples with NO induced increases in MMP-1 and TIMP-1 expression, suggesting that NO enhances invasion through deregulating MMP and TIMP expression in epithelial cells. In keeping with these findings, microarray analysis and immunohistochemistry performed on biopsy samples showed enhanced expression of MMP-1, -3, -7 and -10 and TIMP-1 in the progression from non-dysplastic BO to adenocarcinoma, although this could not be directly attributed to the effect of NO. Thus, NO may play a role in Barrett's carcinogenesis through deregulating MMP and TIMP expression to enhance invasive potential.

The effect of oral administration of ursodeoxycholic acid and high-dose proton pump inhibitors on the histology of Barrett's esophagus

Bile acids may play a role in the pathogenesis of Barrett's esophagus (BE). Bile composition can be influenced by oral administration of ursodeoxycholic acid (UDCA). We prospectively investigated the effect of proton pump inhibitors (PPI) supplemented with UDCA in vivo in patients with BE. Patients with no or low-grade dysplasia who were clinically asymptomatic on PPI were eligible for the study. In order to exclude the effects of acid reflux, all patients were initially treated with 40 mg esomeprazole (ESO) twice daily for 6 months and continued on this dose till the end of the study (t = 12 months). During a period of 6 months (t = 6 month - t = 12 month) patients were treated with oral UDCA (600 mg twice daily). Patients underwent endoscopy at t = 0 months, t = 6 months and t = 12 months with multiple biopsies of the distal and proximal BE segment, normal squamous and gastric cardia. In addition, pH was measured at t = 0 months and t = 6 months using a BRAVO wireless pH capsule. Bile was sampled at the beginning of the UDCA treatment and 6 months later (t = 6 month and t = 12 month). All biopsies were reviewed for the extent of metaplasia, dysplasia, and acute and chronic inflammation. In addition, proliferation (Ki67), differentiation (villin, cytokeratins 7 and 20) and inflammation (COX-2) were investigated by immunohistochemistry (IHC). Nine patients (mean age 60 years, median BE length 7 cm) were included, of whom six had no dysplasia and three had low-grade dysplasia. pH measurements revealed a normal acid exposure in most patients at t = 0 and t = 6 months. In addition, bile composition analysis demonstrated the efficacy of UDCA. Combining the results of both phases of the study, no significant changes were seen in any of the histological or IHC parameters. Differentiation and proliferation parameters showed no significant changes. In this study, in BE patients who were clinically asymptomatic on PPI, increasing the PPI dose to the maximum for 6 months followed by the addition of UDCA for 6 months did not result in significant histological or IHC changes in their BE.

Phenotypic differences between esophageal and gastric intestinal metaplasia

Intestinal metaplasia is a cancer precursor in the esophagus and the stomach. Marked differences exist between the carcinogenic processes in the two locations in terms of natural history and clinical significance. We investigated biopsies from 52 patients with Barrett's esophagus and from 50 patients with gastric intestinal metaplasia in an attempt to throw light on their pathogenic processes. Morphologic characteristics, presence of Helicobacter pylori (H. pylori), and markers of differentiation, inflammation, and proliferation were evaluated by histochemical and immunohistochemical techniques. The area covered by incomplete type of intestinal metaplasia and the proportion of sulfomucins were significantly higher in the esophagus than in the stomach. Immunoreactivity with MUC1, MUC2, MUC5AC, Das-1, cytokeratins 7 and 20, inducible nitric oxide synthase and cyclooxygenase-2 antibodies was also significantly greater in Barrett's esophagus than in gastric intestinal metaplasia. In gastric intestinal metaplasia, the presence of MUC1, MUC5AC, Das-1 and cytokeratin 7 was restricted to areas with the incomplete type of metaplasia. Cell proliferation (Ki-67) was significantly higher in Barrett's esophagus than in gastric intestinal metaplasia. H. pylori was absent in all of the patients with Barrett's esophagus, while it was present in 70% of the patients with gastric intestinal metaplasia. Our observations made clear that Barrett's esophagus shares some phenotypic characteristics with gastric intestinal metaplasia, leading us to suggest that both could arise in response to injuries with eventual carcinogenic potential. However, the progression to more advanced lesions could be modulated by the nature of the carcinogenic insult.

Do acid and bile reflux into the esophagus simultaneously? Temporal relationship between duodenogastro-esophageal reflux and esophageal pH

BACKGROUND

Duodenogastro-esophageal reflux (DGER) is an important factor in the pathogenesis of reflux esophagitis. Animal studies have demonstrated that the injurious effect of duodenal juice components depends on pH. The purpose of the present study was to investigate the temporal relationship between DGER and esophageal pH.

METHODS

Seventy-six children with symptoms of gastro-esophageal reflux disease (27 without, 31 with mild, 18 with severe esophagitis) underwent 24 h simultaneous esophageal pH and bilirubin monitoring with Bilitec 2000. The recordings were analyzed for (i) pH at the beginning of DGER episodes; (ii) relative duration of DGER in eight defined pH intervals of 1 pH unit; and (iii) differences in relative duration of DGER between the three groups of children.

RESULTS

DGER episodes most frequently began at pH between 6 and 7. DGER was present in the esophagus across the spectrum of esophageal pH, with the biggest relative duration between pH 3 and 5. However, in children without esophagitis relative duration of DGER was longest between pH 5 and 6, in children with mild esophagitis between pH 4 and 5, while in those with severe esophagitis it was between pH 2 and 4 (P < 0.001).

CONCLUSIONS

DGER appears across the whole esophageal pH spectrum. The more severe the esophagitis, the lower the pH at which DGER occurs, resulting in simultaneous damaging effects of acid and duodenal juice components.

Barrett's epithelium after antireflux surgery

Barrett's epithelium (BE), defined as endoscopically visible, histologically proved intestinal-type epithelium in the esophagus, is considered the ultimate consequence of long-standing gastro(duodeno)esophageal reflux disease (GERD). Recent reports suggest that effective antireflux therapy may promote the regression of this metaplastic process. This study aimed to establish whether antireflux surgery (laparoscopic fundoplication) can induce any endoscopic and/or histologic changes in BE. Thirty-five consecutive cases of BE (11 short-segment [SBE] and 24 long-segment [LBE]) were considered. All patients underwent extensive biopsy sampling before and after surgery (mean follow-up, 28 months; range, 12-99 mo). In all cases, (a) intestinal metaplasia (IM) extension (H&E), (b) IM phenotype (high-iron diamine [HID]), and (c) Cdx2 immunohistochemical expression were histologically scored in the biopsy material obtained before and after fundoplication. After surgery, a significant decrease in IM extension and a shift from incomplete- to complete-type IM were documented in SBE. No significant changes occurred in the LBE group in terms of IM extension or histochemical phenotype. A drop in the immunohistochemical expression of Cdx2 protein was also only documented in the SBE group. Antireflux surgery significantly modifies the histologic phenotype of SBE, but not of LBE.

[Correct diagnosis for indication in gastroesophageal reflux disease]

For diagnosis and quantitation of gastroesophageal reflux disease, a number of different examinations are available. The simplest are the patient's history and complaints as well as the proton pump inhibitor test; both methods have a positive predictive value of 65% to 70%. Esophagogastroduodenoscopy is the gold standard for differentiation between erosive and nonerosive reflux disease. Biopsy does not enhance the significance of endoscopy except for proof of Barrett's epithelium or malignant degeneration. Twenty-four-hour pH monitoring has the highest sensitivity and specificity for the diagnosis of gastroesophageal reflux disease. Barium swallow provides only additional information concerning hiatal hernia or stenosis. Manometry can clarify lower esophageal sphincter insufficiency or motility disorders of the tubular esophagus. However, the available studies show that manometry has no influence on postoperative outcome after fundoplication. The indication for medical therapy can primarily be based only on the history and complaints of the patient. As surgical therapy affords a high degree of diagnostic accuracy, at least endoscopy and 24-h pH monitoring are necessary for indication.

Clinical predictors of Barrett's esophagus length

BACKGROUND

Assessment of clinical factors associated with Barrett's esophagus (BE) length remained within the realm of anecdotal reports or one center's experience. The aim of this multicenter study was to determine which clinical factors are highly correlated with the length of BE.

METHODS

Patients diagnosed with BE were recruited into the study from 5 academic centers in the United States. All patients had an upper endoscopy that documented BE by the presence of intestinal metaplasia in biopsy specimens. All patients were evaluated by a validated demographic questionnaire and the GERD Symptom Checklist.

RESULTS

A total of 263 patients with BE were recruited into the study. Mean BE length length for the entire sample was 4 +/- 3.3 cm. A longer hiatal hernia (r = 0.22, p < 0.01), any dysplasia (t = -2.3, p < 0.05), H2 receptor antagonist (H2-RA) consumption (t = 1.98, p < 0.05), and nonsmoking (t = -2.5, p < 0.05) were correlated with a longer segment of BE. Proton pump inhibitors (PPI) (t = 1.96, p < 0.05) were correlated with a shorter segment of BE.

CONCLUSIONS

PPIs were correlated with shorter lengths of BE. In contrast, a longer hiatal hernia, any dysplasia, nonsmoking, or use of H2-RAs were correlated with a longer BE segment.

Low circulating levels of gastrin-17 in patients with Barrett's esophagus

AIM: To examine whether the fasting levels of serum gastrin-17 (G-17) are lower in Barrett's esophagus (BE) patients than in non-Barrett controls.

METHODS: Nineteen patients with BE (presenting with a tubular segment ≥2 cm long in lower esophagus and intestinal metaplasia of incomplete type ("pecialized columnar epithelium") in endoscopic biopsies from the tubular segment below the squamocolumnar junction were collected prospectively from outpatients referred to diagnostic gastroscopy. The controls comprised 199 prospectively collected dyspeptic outpatients without BE or any endoscopically visible lesions in the upper GI tract. Fasting levels of serum G-17 (G-17fast) were assayed with an EIA test using a Mab highly specific to amidated G-17. None of the patients and controls received therapy with PPIs or other antisecretory agents.

RESULTS: The mean and median levels of G-17fast in serum were significantly lower (P = 0.001) in BE patients than in controls. The positive likelihood ratios (LR+) of low G-17fast to predict BE in the whole study population at G-17fast levels <0.5, <1, or <1.5 pmol/L were 3.5, 3.0, and 2.8, respectively. Among patients and controls with healthy stomach mucosa, the LR+ were 5.6, 3.8, and 2.6, respectively. In the whole study population, serum G-17 was below 2 pmol/L in 15 of 19 BE patients (79%). The corresponding prevalence was 66 of 199 (33%) in controls (P<0.001). The G-17fast was 5 pmol/L or more in only one of the 19 BE patients (5%). In controls, 76 of the 199 patients (38%) had such high serum G-17fast levels (P<0.01).

CONCLUSION: Serum levels of G-17fast tend to be lower in native patients with BE than in healthy controls.