Novel Screening Tests for Barrett's Esophagus

PURPOSE OF REVIEW

There has been an exponential increase in the incidence of esophageal adenocarcinoma (EAC) over the last half century. Barrett's esophagus (BE) is the only known precursor lesion of EAC. Screening for BE in high-risk populations has been advocated with the aim of identifying BE, followed by endoscopic surveillance to detect dysplasia and early stage cancer, with the intent that treatment can improve outcomes. We aimed to review BE screening methodologies currently recommended and in development.

RECENT FINDINGS

Unsedated transnasal endoscopy allows for visualization of the distal esophagus, with potential for biopsy acquisition, and can be done in the office setting. Non-endoscopic screening methods being developed couple the use of swallowable esophageal cell sampling devices with BE specific biomarkers, as well as trefoil factor 3, methylated DNA markers, and microRNAs. This approach has promising accuracy. Circulating and exhaled volatile organic compounds and the foregut microbiome are also being explored as means of detecting EAC and BE in a non-invasive manner. Non-invasive diagnostic techniques have shown promise in the detection of BE and may be effective methods of screening high-risk patients.

Alteration of the esophageal microbiota in Barrett's esophagus and esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased in recent decades, and its 5-year survival rate is less than 20%. As a well-established precursor, patients with Barrett's esophagus (BE) have a persistent risk of progression to EAC. Many researchers have already identified some factors that may contribute to the development of BE and EAC, and the identified risks include gastroesophageal reflux (GER), male sex, older age, central obesity, tobacco smoking, Helicobacter pylori (H. pylori) eradication, and the administration of proton pump inhibitors (PPIs) and antibiotics. The human gut harbors trillions of microorganisms, the majority of which are bacteria. These microorganisms benefit the human host in many ways, such as helping in digestion, assisting in the synthesis of certain vitamins, promoting the development of the gastrointestinal immune system, regulating metabolism and preventing invasion by specific pathogens. In contrast, microbial dysbiosis may play important roles in various diseases, such as inflammation and cancers. The composition of the microbiota located in the normal esophagus is relatively conserved without distinct microbial preferences in the upper, middle and lower esophagus. Six major phyla constitute the esophageal microbiota, including Firmicutes, Bacteroides, Actinobacteria, Proteobacteria, Fusobacteria and TM7, similar to the oral microbiota. Streptococcus dominates the esophageal microbiota. However, the microbiota varies in different esophageal diseases compared to that in the healthy esophagus. The type I microbiota, which is primarily composed of gram-positive bacteria, is closely associated with the normal esophagus, while type II microbiota has enriched gram-negative bacteria and is mainly associated with the abnormal esophagus. These increased gram-negative anaerobes/microaerophiles include Veillonella, Prevotella, Haemophilus, Neisseria, Granulicatella and Fusobacterium, many of which are associated with BE. The microbial diversity in the esophagus is decreased in EAC patients, and Lactobacillus fermentum is enriched compared to that in controls and BE patients. Furthermore, the microbiota may be associated with BE and EAC by interacting with their risk factors, including central obesity, GER, H. pylori, administration of PPIs and antibiotics. Therefore, a large gap in research must be bridged to elucidate the associations among these factors. Some studies have already proposed several potential mechanisms by which the microbiota participates in human carcinogenesis by complicated interactions with the human host immune system and signaling pathways. The activation of the LPS-TLR4-NF-κB pathway may contribute to inflammation and malignant transformation. This exciting field of gastrointestinal microbiota allows us to unravel the mystery of carcinogenesis from another perspective. Further studies are needed to explore whether the microbiota changes before or after disease onset, to improve our understanding of the pathogenesis, and to find novel targets for prevention, diagnosis and therapy, which could offer more cost-effective and relatively safe choices.

A non-endoscopic device to sample the oesophageal microbiota: a case-control study

BACKGROUND

The strongest risk factor for oesophageal adenocarcinoma is reflux disease, and the rising incidence of this coincides with the eradication of Helicobacter pylori, both of which might alter the oesophageal microbiota. We aimed to profile the microbiota at different stages of Barrett's carcinogenesis and investigate the Cytosponge as a minimally invasive tool for sampling the oesophageal microbiota.

METHODS

In this case-control study, 16S rRNA gene amplicon sequencing was done on 210 oesophageal samples from 86 patients representing the Barrett's oesophagus progression sequence (normal squamous controls [n=20], non-dysplastic [n=24] and dysplastic Barrett's oesophagus [n=23], and oesophageal adenocarcinoma [n=19]), relevant negative controls, and replicates on the Illumina MiSeq platform. Samples were taken from patients enrolled in the BEST2 study at five UK hospitals and the OCCAMS study at six UK hospitals. We compared fresh frozen tissue, fresh frozen endoscopic brushings, and the Cytosponge device for microbial DNA yield (qPCR), diversity, and community composition.

FINDINGS

There was decreased microbial diversity in oesophageal adenocarcinoma tissue compared with tissue from healthy control patients as measured by the observed operational taxonomic unit (OTU) richness (p=0·0012), Chao estimated total richness (p=0·0004), and Shannon diversity index (p=0·0075). Lactobacillus fermentum was enriched in oesophageal adenocarcinoma (p=0·028), and lactic acid bacteria dominated the microenvironment in seven (47%) of 15 cases of oesophageal adenocarcinoma. Comparison of oesophageal sampling methods showed that the Cytosponge yielded more than ten-times higher quantities of microbial DNA than did endoscopic brushes or biopsies using quantitative PCR (p<0·0001). The Cytosponge samples contained the majority of taxa detected in biopsy and brush samples, but were enriched for genera from the oral cavity and stomach, including Fusobacterium, Megasphaera, Campylobacter, Capnocytophaga, and Dialister. The Cytosponge detected decreased microbial diversity in patients with high-grade dysplasia in comparison to control patients, as measured by the observed OTU richness (p=0·0147), Chao estimated total richness (p=0·023), and Shannon diversity index (p=0·0085).

INTERPRETATION

Alterations in microbial communities occur in the lower oesophagus in Barrett's carcinogenesis, which can be detected at the pre-invasive stage of high-grade dysplasia with the novel Cytosponge device. Our findings are potentially applicable to early disease detection, and future test development should focus on longitudinal sampling of the microbiota to monitor for changes in microbial diversity in a larger cohort of patients.

FUNDING

Cancer Research UK, National Institute for Health Research, Medical Research Council, Wellcome Trust, The Scottish Government (RESAS).

Helicobacter pylori and Barrett’s esophagus: a protective factor or a real cause?

Notwithstanding the definite aetiopathogenetic path of certain diseases, the relationship between Helicobacter pylori (H. pylori) and Barrett’s esophagus (BE), a condition that increases the risk for dysplasia and consequently adenocarcinoma of the distal esophagus and esophagogastric junction, remains uncertain. This paper reviews the current scientific literature with emphasis on the protective correlation between H. pylori infection and BE and demonstrates that a causal relationship has not been disproved with certainty. Furthermore, H. pylori infection could pose a risk for the onset of gastroesophageal reflux disease (GERD), which could in turn trigger BE, a precancerous lesion, and subsequently cause cancer. By analyzing the current available data, this article tries to verify that H. pylori infection is the underlying cause of esophageal cancer.

Central Obesity and H. pylori Infection Influence Risk of Barrett's Esophagus in an Asian Population

Background and Aim

The prevalence rates of Barrett’s esophagus (BE) in western countries are higher than Asian ones, but little is known about their difference among risk factors of BE. The aim of this study is to investigate the associations of various risk factors including central obesity, body mass index (BMI), metabolic syndrome and H. pylori infection, with BE.

Methods

A total of 161 subjects with BE were enrolled and compared to age- and gender-matched controls randomly sampled (1:4) from check-up center in same hospital. Central obesity was defined by waist circumference (female>80cm; male>90cm), metabolic syndrome by the modified National Cholesterol Education Program Adult Treatment Panel III criteria in Taiwan. Independent risk factors for BE were identified by multiple logistic regression analyses.

Results

The mean age for BE was 53.8±13.7 years and 75.8% was male. H. pylori infection status was detected by the rapid urease test with the prevalence of 28.4% and 44.4% in the BE patients and controls, respectively. The univariate logistic regression analyses showed the risk was associated with higher waist circumference (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.78–3.60), metabolic syndrome (OR, 2.02; 95% CI, 1.38–2.96) and negative H. pylori infection (OR, 0.50; 95% CI, 0.34–0.74). However, multivariate logistic regression analyses revealed that BE associated with higher waist circumference (adjusted OR, 2.79; 95% CI, 1.89–4.12) and negative H. pylori infection (adjusted OR, 0.46; 95% CI, 0.30–0.70).

Conclusions

Central obesity is associated with a higher risk of BE whereas H. pylori infection with a lower risk in an ethnic Chinese population.

Prevalence of upper gastrointestinal endoscopic findings in the community: A systematic review of studies in unselected samples of subjects

BACKGROUND AND AIM

Upper gastrointestinal endoscopic findings, such as esophagitis, Barrett's esophagus, peptic ulcer, and malignancy, represent a public health problem. This systematic review aimed to evaluate the prevalence of upper gastrointestinal endoscopic findings in the community.

METHODS

A systematic search was conducted in PUBMED and EMBASE to May 2015. Studies were eligible if they reported the prevalence of upper gastrointestinal endoscopic findings in unselected samples of the community.

RESULTS

Twelve articles were eligible, nine reported data from three endoscopic surveys (n = 3063 subjects), and three from national screening programs (n = 84 153). The overall prevalence of upper gastrointestinal endoscopic findings in the community was 30% in the Kalixanda study (Sweden), 24.9% in the Loiano-Monghidoro study (Italy), and 68.9% in the Systematic Investigation of Gastrointestinal Diseases study (China). The pooled prevalence of esophagitis, endoscopically suspected esophageal metaplasia (ESEM), peptic ulcer, and gastric cancer in all studies was 11.2, 5.1, 6.8, and 0.33%, respectively. The most frequent finding was esophagitis in Europe, with a prevalence of 15.5% in Sweden and 11.8% in Italy, and peptic ulcer in China (17.1%), both in asymptomatic and symptomatic individuals. The prevalence of Helicobacter pylori was positively associated with the prevalence of peptic ulcer (r = 0.91) but negatively associated with the prevalence of both esophagitis (r = -0.99) and ESEM (r = -0.95).

CONCLUSIONS

Upper gastrointestinal endoscopic findings are present in at least a quarter of subjects in the community with different patterns in Western and Eastern countries, both in asymptomatic and symptomatic subjects. H. pylori prevalence negatively impacts on the prevalence of reflux-related esophageal findings.

Bacterial Composition of the Human Upper Gastrointestinal Tract Microbiome Is Dynamic and Associated with Genomic Instability in a Barrett's Esophagus Cohort

Background

The incidence of esophageal adenocarcinoma (EAC) has increased nearly five-fold over the last four decades in the United States. Barrett’s esophagus, the replacement of the normal squamous epithelial lining with a mucus-secreting columnar epithelium, is the only known precursor to EAC. Like other parts of the gastrointestinal (GI) tract, the esophagus hosts a variety of bacteria and comparisons among published studies suggest bacterial communities in the stomach and esophagus differ. Chronic infection with Helicobacter pylori in the stomach has been inversely associated with development of EAC, but the mechanisms underlying this association remain unclear.

Methodology

The bacterial composition in the upper GI tract was characterized in a subset of participants (n=12) of the Seattle Barrett’s Esophagus Research cohort using broad-range 16S PCR and pyrosequencing of biopsy and brush samples collected from squamous esophagus, Barrett’s esophagus, stomach corpus and stomach antrum. Three of the individuals were sampled at two separate time points. Prevalence of H. pylori infection and subsequent development of aneuploidy (n=339) and EAC (n=433) was examined in a larger subset of this cohort.

Results/Significance

Within individuals, bacterial communities of the stomach and esophagus showed overlapping community membership. Despite closer proximity, the stomach antrum and corpus communities were less similar than the antrum and esophageal samples. Re-sampling of study participants revealed similar upper GI community membership in two of three cases. In this Barrett’s esophagus cohort, Streptococcus and Prevotella species dominate the upper GI and the ratio of these two species is associated with waist-to-hip ratio and hiatal hernia length, two known EAC risk factors in Barrett’s esophagus. H. pylori-positive individuals had a significantly decreased incidence of aneuploidy and a non-significant trend toward lower incidence of EAC.

Esophageal Helicobacter pylori colonization aggravates esophageal injury caused by reflux

AIM: To investigate esophageal Helicobacter pylori (H. pylori) colonization on esophageal injury caused by reflux and the related mechanisms.

METHODS: An esophagitis model, with acid and bile reflux, was surgically produced in male rats. The rats were randomly divided into either: (1) an esophagogastroduodenal anastomosis (EGDA) group; (2) an EGDA with H. pylori infection group; (3) a pseudo-operation with H. pylori infection group; or (4) a pseudo-operation group. All rats were kept for 36 wk. Based on the location of H. pylori colonization, the EGDA rats with H. pylori infection were subdivided into those with concomitant esophageal H. pylori colonization or those with only gastric H. pylori colonization. The esophageal injuries were evaluated grossly and microscopically. The expressions of CDX2 and MUC2 were determined by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. Ki-67 antigen expression was determined by immunohistochemistry. The mRNA levels of cyclin D1, c-Myc, Bax and Bcl-2 were determined by RT-PCR. Cell apoptosis was evaluated using the TdT-mediated dUTP nick-end labeling method.

RESULTS: Esophagitis, Barrett’s esophagus (BE), and esophageal adenocarcinoma (EAC) developed in rats that underwent EGDA. When comparing rats with EGDA and concomitant esophageal H. pylori colonization to EGDA-only rats, the severity of injury (87.9 ± 5.2 vs 77.2 ± 8.6, macroscopically, 92.5 ± 8.0 vs 83.8 ± 5.5, microscopically, both P < 0.05) and the incidences of BE (80.0% vs 33.3%, P = 0.055) and EAC (60.0% vs 11.1%, P < 0.05) were increased. These increases were associated with upregulation of CDX2 and MUC2 mRNA (10.1 ± 5.4 vs 3.0 ± 2.9, 8.4 ± 4.6 vs 2.0 ± 3.2, respectively, Ps < 0.01) and protein (8.1 ± 2.3 vs 3.3 ± 3.1, 7.3 ± 4.0 vs 1.8 ± 2.7, respectively, all P < 0.05). The expression of Ki-67 (8.9 ± 0.7 vs 6.0 ± 1.7, P < 0.01) and the presence of apoptotic cells (8.3 ± 1.1 vs 5.3 ± 1.7, P < 0.01) were also increased significantly in rats with EGDA and concomitant esophageal H. pylori colonization compared with rats with EGDA only. The mRNA levels of cyclin D1 (5.8 ± 1.9 vs 3.4 ± 1.3, P < 0.01), c-Myc (6.4 ± 1.7 vs 3.7 ± 1.2, P < 0.01), and Bax (8.6 ± 1.6 vs 5.1 ± 1.3, P < 0.01) were significantly increased, whereas the mRNA level of Bcl-2 (0.6 ± 0.3 vs 0.8 ± 0.3, P < 0.01) was significantly reduced in rats with EGDA and concomitant esophageal H. pylori colonization compared with rats with EGDA only.

CONCLUSION: Esophageal H. pylori colonization increases esophagitis severity, and facilitates the development of BE and EAC with the augmentation of cell proliferation and apoptosis in esophageal mucosa.

Metagenomic analysis of the gastric microbiota cultivable from a patient with gastritis concomitant with Barrett's esophagus

Barrett's esophagus is a distal metaplasia characterized by the transformation of squamous mucosa into columnar mucosa. This esophageal phenotype is a product not only of the chronic reflux of gastric acids, but also by microorganisms that colonize the oral cavity and stomach. Two classes of microbiota can be identified in Barrett's esophagus; microbiota type I is associated with the normal esophagus and type II with an inflamed esophagus. The present study describes the gastric microbiota of a patient with antral gastritis concomitant with Barrett's esophagus absent infection with Helicobacter pylori. Gastric biopsies were obtained following the protocol of Sydney and following ethical practices. The isolates were cultivated under microaerophilic conditions on Columbia Agar supplemented with IsoVitaleX™ and 7% sterile blood. Extracted DNA was sequenced using 454-GS and the results analyzed on the MG-RAST server. Gram negative isolates were found and bacteria resistant to levofloxacin, amoxicillin, tetracycline, erythromycin, and clarithromycin. The phyla Bacteroidetes, Firmicutes, Fusobacteria and Proteobacteria, the genus Bacteroides and the species group Bacteroides fragilis were most abundant. Functionally, the metabolism of carbohydrates, amino acids, and to a lesser extent, the metabolism of cofactors and vitamins were most dominant, and of which the enzymes β-glucosidase (EC 3.2.1.21), β-galactosidase (EC 3.2.1.23) and β-N-acetylhexosaminidase (EC 3.2.1.52) were most dominant. The findings of this study, because they are of only one case may probably suggest a possible pathogenic role, previously undescribed for Bacteroides fragilis, associated with human gastritis when concomitant esophageal pathology exists.

Barrett's esophagus and intestinal metaplasia of gastric cardia: prevalence, clinical, endoscopic and histological features

BACKGROUND & AIMS

Over the past few decades, the incidence of adenocarcinomas of the gastroesophageal junction has rapidly increased. Barrett's esophagus is a risk factor for esophageal adenocarcinoma, but the role of intestinal metaplasia of the gastric cardia as a precursor in cardia-related cancer is controversial. The aims of the present study were to examine the prevalence of intestinal metaplasia in the gastroesophageal junction and to evaluate the clinical, endoscopical and histological features of patients with intestinal metaplasia in the gastric cardia and patients with Barrett's esophagus.

METHODS

286 consecutive patients undergoing gastroduodenoscopy were enrolled in a prospective study. Biopsy specimens were performed in the distal esophagus, squamocolumnar junction, gastric cardia, gastric corpus and antrum.

RESULTS

We identified 44 patients (15.3%) with intestinal metaplasia in biopsies from gastric cardia and 24 patients (8.3%) with Barrett's esophagus. Cardia intestinal metaplasia was significantly associated with older age (p=0.03), with intestinal metaplasia in the antrum (p=0.017) and H. pylori infection (p<0.0001). Severe chronic cardia inflammation increased the presence of cardia intestinal metaplasia 6.2 fold (OR=6.288; p<0.0001). Patients with Barrett's esophagus were predominantly men. Barrett's esophagus presence significantly correlated with reflux symptoms(p<0.0001), endoscopic esophagitis (p<0.0001) and hiatal hernia >2 cm (p=0.002). No patient had dysplasia in the gastroesophageal region.

CONCLUSIONS

Presence of intestinal metaplasia at the gastroesophageal region correlated with reflux symptoms and endoscopic signs of reflux disease in patients with Barrett's esophagus and with H.pylori infection and distal intestinal metaplasia in patients with cardia intestinal metaplasia.

Lysozyme is up-regulated in columnar-lined Barrett's mucosa: a possible natural defence mechanism against Barrett's esophagus-associated pathogenic bacteria

BACKGROUND

Lysozyme is a natural antimicrobial enzyme that is up-regulated in inflammatory diseases of the gastrointestinal tract. Pathogenic microbes have recently been identified in the esophageal mucosa in patients with Barrett's esophagus (BE). Lysozyme expression was evaluated in biopsies from patients with BE.

MATERIALS AND METHODS

Ninety-seven consecutive esophageal biopsies with columnar-lined Barrett's mucosa (BM) were investigated: 16 had oxyntic gland-only BM, 19 pyloric gland-only BM and 62, intestinal metaplasia BM. Twenty normal gastric biopsies and 20 normal duodenal biopsies were included as controls. Sections were stained with human lysozyme antiserum.

RESULTS

Lysozyme was up-regulated in the neck glands in 94% of the biopsies with oxyntic gland-only BM, in the pyloric gland in 79% of the biopsies with pyloric gland-only BM, and in goblet cells in 65% of the biopsies with intestinal metaplasia BM. Goblet cells with faint lysozyme expression were often found in glands overexpressing lysozyme in mucous secretions in the lumen. When compared to controls, lysozyme was up-regulated in all three BM phenotypes (p<0.05).

CONCLUSION

Lysozyme is up-regulated in BM. It is therefore, believed that lysozyme's up-regulation might mirror a molecular mechanism of self-defence aimed to safeguard the BM against the hostile pathogenic microbiota present in the esophageal microenvironment in patients with BE.

Risk factors for erosive esophagitis and Barrett's esophagus in a high Helicobacter pylori prevalence area

OBJECTIVE

To establish the prevalence and risk factors of erosive esophagitis (EE) and Barrett's esophagus (BE) among patients routinely referred for upper endoscopy.

MATERIAL AND METHODS

A total of 4032 consecutive patients referred to a regional hospital for upper endoscopy due to upper gastrointestinal and/or "alarm" symptoms were examined. Analysis was performed on the prospectively selected patients (40 in each group) with EE of different grades and BE.

RESULTS

EE was diagnosed in 474 patients (11.75%): grade A, in 194 (41%); grade B, in 167 (35%); grade C, in 65 (14%); and grade D, in 48 patients (10%). Increasing severity of erosive esophagitis and presence of its complication--Barrett's esophagus--were associated with the decreasing prevalence of H. pylori and increasing hiatal hernia size (P<0.05). Male gender (OR, 3.57; 95% CI, 1.12 to 10.62), hiatal hernia >2 cm (OR, 3.73; 95% CI, 1.60 to 8.68), and absence of H. pylori (OR, 4.24; 95% CI, 1.07 to 16.84) were the factors found to be associated with severe EE. The factors associated with BE were as follows: ulcer and/or stricture of esophagus (OR, 11.94; 95% CI, 2.51 to 41.37), age >60 years (OR, 1.06; 95% CI, 1.01 to 1.20), smoking >10 cigarettes per day (OR, 4.62; 95% CI, 1.01 to 12.50), hiatal hernia >2 cm (OR, 5.22; 95% CI, 1.86 to 14.64), and absence of H. pylori (OR, 5.60; 95% CI, 1.38 to 22.72).

CONCLUSIONS

The prevalence of EE was found to be low, and the prevalence of BE was found to be very low among routinely endoscoped patients in primary and secondary care settings in a Lithuanian rural area with high H. pylori prevalence. Increasing severity of gastroesophageal reflux disease was associated with the decreasing prevalence of Helicobacter pylori.

[Prevalence of intestinal metaplasia of the gastric cardia and its relation with Helicobacter pylori strains cagA and vacA]

BACKGROUND

Esophageal metaplasia progression is a consequence of chronic gastroesophageal reflux (CGR). Patients with this condition are frequently infected by Helicobacter pylori and show several symptoms including gastritis as well as ulcer formation. In addition, they present an increased risk for the development of gastric adenocarcinoma. Several pathogenic markers for Helicobacter pylori such as ureC, vacA and cagA genes have been described. Evidence indicates that direct injury to the epithelial mucosa is caused by cytotoxins and enzymes codified by these genes. We undertook this study to establish a relationship between the presence of pathogenic Helicobacter pylori strains and the presence of metaplasia progression in patients with CGR.

METHODS

We detected the presence of Helicobacter pylori cagA and vacA positive strains in patients with CGR. Using polymerase chain reaction, we analyzed 120 samples obtained from 60 patients with CGR and 60 control group patients, including samples from both anatomic areas: cardia and gastric antrum.

RESULTS

We detected 56% of Helicobacter pylori positive patients; 57.5% of these patients were positive for either cagA(+) and/or vacA(+) Helicobacter pylori strains. Cardiac intestinal metaplasia was observed in 35% of the patients. A marked tendency was observed to develop cardiac intestinal metaplasia in those patients diagnosed with high-pathogenicity strains infected in both anatomic areas.

CONCLUSIONS

These results suggest that infection with Helicobacter pylori can be considered a risk factor for developing gastric cardiac intestinal metaplasia.

Keratin 7 expression as an early marker of reflux-related columnar mucosa without intestinal metaplasia in the esophagus

BACKGROUND

The role of Barrett esophagus in carcinogenesis is widely accepted, but the significance of esophageal columnar mucosa without histological intestinal metaplasia, known as columnar-lined esophagus, is debated.

MATERIAL/METHODS

We studied 128 patients free of Helicobacter pylori with reflux-related symptoms and columnar mucosa in the esophagus at endoscopy, 106 patients with Barrett esophagus (referred to as the Barrett group) and 22 patients without intestinal metaplasia (columnar group). Samples from 20 subjects free of H. pylori were used as controls. Immunostaining for keratin 7 (KRT7), keratin 20 (KRT20), caudal type homeobox 2 (CDX2), mucin 2, oligomeric mucus/gel-forming (MUC2), and tumor protein p53 (TP53) was assessed.

RESULTS

Samples taken 1 cm above the gastroesophageal junction showed KRT7 staining in all cases in the Barrett and columnar groups and none in the control group. Immunostaining for TP53 was absent in the control group, and more frequent in the columnar group (7, 31.8%) compared with the Barrett group (14, 13.2%, P=0.033). In the columnar group, low grade dysplasia and TP53 expression was seen in 7 of 22 biopsy specimens (31.8%) at baseline and in 4 additional specimens after 2 years, for a total of 11 specimens (50.0%).

CONCLUSIONS

The expression of KRT7 might help to explain the pathological, reflux-related nature of columnar-lined esophagus, as aberrant expression in a very early stage of the multistep Barrett esophagus progression. Expression of KRT7 may occur in basal glandular cells as a result of their multipotentiality and susceptibility to immunophenotype changes induced by reflux.

Microbial colonization of the upper gastrointestinal tract in patients with Barrett's esophagus

BACKGROUND

Barrett's esophagus (BE) is a complication of chronic gastroesophageal reflux disease, in which patients are at greatly increased risk of esophageal dysplasia and adenocarcinoma. Over the past 2 decades, there has been an increase in the incidence of both BE and adenocarcinoma; however, the involvement of microorganisms in BE is uncertain. The aim of this study was to characterize microbial communities in esophageal aspirate specimens and on distal esophageal mucosal samples from patients with BE.

METHODS

Biopsy and aspirate specimens were obtained by endoscopic examination from 7 patients with BE and 7 control subjects without BE. Samples were cultured under aerobic, anaerobic, and microaerophilic conditions for yeasts and bacteria, including Helicobacter pylori. Bacterial isolates were identified by 16S ribosomal RNA gene sequencing. Fluorescence microscopic examination was also used to determine the spatial localization of these organisms on mucosal surfaces. Significant colonization was detected in 6 patients with BE and in 4 control subjects.

RESULTS

Overall, 46 bacterial species belonging to 16 genera were detected, with 10 species being common in both groups. Both aspirate and biopsy samples from patients with BE contained complex populations of bacteria. Uniquely, high levels of Campylobacter species (Campylobacter concisus and Campylobacter rectus), which have been linked to enteritis, periodontal infections, and tumor formation in animals, were found in 4 (57%) of 7 patients with BE but in none of the control subjects. Microscopic examination revealed that bacteria on mucosal biofilms often occurred in microcolonies.

CONCLUSIONS

The occurrence of nitrate-reducing Campylobacter species in patients with BE may suggest that there is a link in either the initiation, maintenance, or exacerbation of disease processes leading to adenocarcinoma formation.

Helicobacter pylori, ethnicity, and the gastroesophageal reflux disease spectrum: a study from the East

BACKGROUND

Ethnic differences in gastroesophageal reflux disease (GERD) and its complications as well as racial variations in the prevalence of Helicobacter pylori infection are well documented. Nevertheless, the association between reflux disease, H. pylori, and race has not been adequately explored.

AIMS

We estimated the strength of the association between H. pylori, ethnicity, and the gastroesophageal reflux disease (GERD) spectrum, including Barrett's esophagus, in Asian patients presenting for endoscopy in a tertiary referral center.

METHODS

Prospectively, we studied 188 consecutive patients with GERD, short- and long-segment Barrett's esophagus, and controls. All patients underwent gastroscopy with gastric biopsies to assess H. pylori, gastritis, and atrophy. CagA status and H. pylori infection were determined by immunoblot assay.

RESULTS

The overall prevalence of H. pylori infection was 52.1% (of which 77.6% were cagA(+)) and was lowest in the long-segment Barrett's esophagus group (36.7%) (p = .048). When Barrett's esophagus was present, the length of abnormality was 44.8% shorter in the presence of H. pylori (p = .015). Indians had the highest prevalence of H. pylori (75%) and Malays the lowest (19.6%) (p < .001). In Indians, increased prevalence of H. pylori and cagA-positive strains was associated with reduced severity of GERD (p < .004 and p < .001, respectively), a trend not apparent in the other races. Corpus atrophy, which was almost exclusively associated with H. pylori, was highest in Indians as compared to the other races (p = .013).

CONCLUSIONS

Presence of H. pylori was associated with a reduced severity of GERD spectrum disease in Asians, especially Indians. H. pylori infection may protect against complicated reflux disease via induction of corpus atrophy.

[Clinical characteristics of gastroesophageal reflux diseases and association with Helicobacter pylori infection]

BACKGROUND/AIMS

The prevalence of gastroesophageal reflux disease (GERD) in Korea was believed to be low until now. Korea is now believed to be on the evolving stage of GERD in its' prevalence. The aims of this study were to evaluate the epidemiologic and clinicopathologic characteristics among the subgroups of GERD i.e. non-erosive GERD (NERD), erosive GERD (ERD) and Barrett's esophagus (BE), and the role of Helicobacter pylori (H. pylori) infection in the pathogenesis of GERD.

METHODS

A total of 253 patients with typical symptoms of GERD who underwent EGD were enrolled from October 2002 to January 2004. Patients were grouped as NERD, ERD or BE based on the symptoms and endoscopic findings. BE was histologically confirmed if necessary. Various clinical parameters including the status of H. pylori infection were analyzed.

RESULTS

Among 253 patients, 106 patients were classified as NERD while 116 and 31 patients were classified as ERD and BE group respectively. BE and ERD group showed no gender predilection while NERD showed female preponderance (2.31:1, p < 0.05). NERD group were younger (49.57 y.o.) than BE (57.87 y.o.) and ERD (52.30 y.o.) group. About three quarters of the patients of erosive esophagitis were LA-A (74.2%) grade. This suggests the mild nature of erosive esophagitis in Korea. ERD showed significantly higher BMI (kg/m2) compared to NERD (p < 0.05). Hiatal hernia was frequently associated with BE and ERD (p < 0.05), but less frequently in NERD. Overall H. pylori positivity among GERD was significantly lower than the age and gender matched control group (p < 0.05).

CONCLUSIONS

Subgroups of GERD in Korea showed different epidemiologic and clinical characteristics. Lower rate of H. pylori infection among GERD group may reflect the protective role of H. pylori infection regarding GERD prevalence in Korea.

[The prevalence, clinical and endoscopic characteristics of Barrett esophagus in Fujian]

OBJECTIVE

To investigate the incidence and clinical and endoscopic characteristics of Barrett's esophagus (BE) and the relationship between BE and reflux esophagitis (RE).

METHODS

Patients with BE were diagnosed according to new standard by endoscopy and histology. The prevalence, form in endoscopy, histology of biopsy, age, sex, symptom, Helicobacter pylori (Hp) infection and relationship between BE and RE were analyzed.

RESULTS

BE was 7.90% of the total endoscopy number, and male vs female was 1.98, mean age (45.1 +/- 14.8) years old. Only 19.15% of BE patients had typical reflux symptoms. 81.20% of BE patients were with short segment BE. Intestinal metaplasia was detected in 34.83% of BE and dysplasia 9.88%. 39.94% of BE patients were infected with Hp. Patients with RE (2.07%) were significantly less than those of BE (P < 0.01). 8.42% of BE patients were also with RE and 32.11% of RE patients were also with BE.

CONCLUSIONS

The incidence of BE in Fujian of China is high. Most of BE are short segment BE and male and have no typical reflux symptoms. Intestinal metaplasia is found in 1/3 of BE patients. There isn't a close association between BE and RE.

Bacterial biota in reflux esophagitis and Barrett's esophagus

AIM

To identify the bacterial flora in conditions such as Barrettos esophagus and reflux esophagitis to determine if they are similar to normal esophageal flora.

METHODS

Using broad-range 16S rDNA PCR, esophageal biopsies were examined from 24 patients [9 with normal esophageal mucosa, 12 with gastroesophageal reflux disease (GERD), and 3 with Barrettos esophagus]. Two separate broad-range PCR reactions were performed for each patient, and the resulting products were cloned. In one patient with Barrettos esophagus, 99 PCR clones were analyzed.

RESULTS

Two separate clones were recovered from each patient (total = 48), representing 24 different species, with 14 species homologous to known bacteria, 5 homologous to unidentified bacteria, and 5 were not homologous (<97% identity) to any known bacterial 16S rDNA sequences. Seventeen species were found in the reflux esophagitis patients, 5 in the Barrettos esophagus patients, and 10 in normal esophagus patients. Further analysis concentrating on a single biopsy from an individual with Barrettos esophagus revealed the presence of 21 distinct bacterial species. Members of four phyla were represented, including Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria. Microscopic examination of each biopsy demonstrated bacteria in intimate association with the distal esophageal epithelium, suggesting that the presence of these bacteria is not transitory.

CONCLUSION

These findings provide evidence for a complex, residential bacterial population in esophageal reflux-related disorders. While much of this biota is present in the normal esophagus, more detailed comparisons may help identify potential disease associations.

Human defensin 5 expression in intestinal metaplasia of the upper gastrointestinal tract

BACKGROUND

Upper gastrointestinal tract intestinal metaplasia (IM) is termed Barrett's oesophagus (BO) or gastric intestinal metaplasia (GIM), depending on its location. BO and GIM are associated with chemical exposure resulting from gastro-oesophageal reflux and chronic Helicobacter pylori infection, respectively. Paneth cells (PCs), characterised by cytoplasmic eosinophilic granules, are found in a subset of IM at these sites, but histology may not accurately detect them.

AIM

To determine human defensin 5 (HD5; an antimicrobial peptide produced by PCs) expression in BO and GIM, and to investigate its association with H pylori infection.

METHODS

Endoscopic biopsies from 33 patients with BO and 51 with GIM, and control tissues, were examined by routine histology and for H pylori infection and HD5 mRNA and protein expression.

RESULTS

In normal tissues, HD5 expression was specific for PCs in the small intestine. Five patients with BE and 42 with GIM expressed HD5, but few HD5 expressing cells in IM had the characteristic histological features of PCs. Most HD5 positive specimens were H pylori infected and most HD5 negative specimens were not infected.

CONCLUSIONS

HD5 immunohistochemistry was often positive in IM when PCs were absent by conventional histology. Thus, HD5 immunohistochemistry may be superior to histology for identifying metaplastic PCs and distinguishing GIM from BO. The higher frequency of HD5 expression in GIM than in BO is associated with a higher frequency of H pylori infection, suggesting that in IM PCs may form part of the mucosal antibacterial response.

CagA in Barrett's oesophagus in Colombia, a country with a high prevalence of gastric cancer

BACKGROUND

In the USA, atrophic gastritis and gastric cancer are rare, whereas gastro-oesophageal reflux disease (GERD) is common. Infection with Helicobacter pylori, especially a CagA positive strain, is unusual in patients with GERD/Barrett's oesophagus in the USA.

AIM

To examine the relation between Barrett's oesophagus and CagA positive H pylori in Colombia, a country with a high prevalence of CagA positive H pylori associated atrophic gastritis and gastric cancer.

METHODS

Helicobacter pylori and CagA status was determined among Colombian patients with long segment Barrett's oesophagus and a control group with simple H pylori gastritis. Helicobacter pylori status was determined using a triple stain and CagA status was determined by immunohistochemistry using a specific rabbit anti-CagA serum.

RESULTS

Gastric and oesophageal mucosal biopsies were obtained from 51 patients--39 men (mean age, 57.8 years; SD, 13.1) and 12 women (mean age, 51.8 years; SD, 14.4)--with documented long segment Barrett's oesophagus. The results were compared with 24 Colombian patients with H pylori gastritis without oesophageal disease. Thirty two patients with Barrett's oesophagus had active H pylori infection. CagA status was evaluated in a subset of 23 H pylori infected patients with Barrett's oesophagus, and was positive in eight of these patients compared with 19 of 24 controls (p = 0.01).

CONCLUSIONS

Although most Colombian patients with Barrett's oesophagus had H pylori infection, CagA positive infections were unusual. These data illustrate how consistent corpus inflammation reduces acid secretion, which prevents Barrett's oesophagus among those with abnormal gastro-oesophageal reflux barriers.

Oesophageal adenocarcinoma or gastric cancer with or without eradication of Helicobacter pylori infection in chronic atrophic gastritis patients: a hypothetical opinion from a systematic review

BACKGROUND

As chronic atrophic gastritis is a precancerous condition for gastric cancer and the eradication of Helicobacter pylori infection halts chronic gastritis, eradication of infection may prevent gastric cancer. However, as chronic atrophic gastritis is a risk factor for reflux oesophagitis after eradication of infection, the risk of oesophageal adenocarcinoma may also increase.

METHODS

We systematically reviewed papers and estimated the expected annual incidence of oesophageal or gastric cancer with and without eradication of H. pylori infection in patients with chronic atrophic gastritis.

RESULTS

The expected annual incidence of gastric cancer in patients with corpus atrophy with persistent infection was at least 5.8-fold higher than that for oesophageal adenocarcinoma after the eradication of infection at all ages. Even for patients with accompanying reflux oesophagitis or Barrett's oesophagus, the expected incidence of either gastric or oesophageal adenocarcinoma with persistent infection was higher than that of oesophageal adenocarcinoma after eradication of infection.

CONCLUSION

If eradication of infection lowers the incidence of gastric cancer, it should be recommended for patients with corpus atrophy at all ages irrespective of the presence of reflux oesophagitis or Barrett's oesophagus, especially in populations having a high prevalence of gastric cancer.

Helicobacter pylori and gastro-oesophageal reflux disease: a cross-sectional epidemiological study

BACKGROUND

H. pylori infection is accompanied by a lower prevalence of reflux disease. There is still an ongoing debate as to whether H. pylori actually protects against the development of reflux oesophagitis or is merely an epiphenomenon. A cross-sectional study was performed to study the relation of H. pylori with reflux oesophagitis, hiatus hernia and Barrett's oesophagus.

MATERIAL AND METHODS

Consecutive patients undergoing upper gastrointestinal endoscopy in a period of ten years were studied. Included were patients with active reflux oesophagitis and/or hiatus hernia and/or Barrett's oesophagus. As a reference group, patients without macroscopic abnormalities were included. H. pylori was detected applying routine diagnostic modalities.

RESULTS

In the ten years 11,691 consecutive patients were studied. Reflux oesophagitis was seen in 1535 patients, 307 patients had Barrett's oesophagus and a hiatus hernia was present in 2116 patients. The reference group consisted of 5341 patients. H. pylori was significantly less often detected in patients with reflux oesophagitis or Barrett's oesophagus compared with the reference group, 20 vs 29% (p<0.001). Also presence of H. pylori was significantly lower in patients with hiatus hernia 20 vs 29% (p<0.0001).

CONCLUSION

The present study confirms, in a very large group of patients studied in one single centre, the findings of earlier papers. Patients without H. pylori gastritis suffer more often from reflux disease. There is a relation between H. pylori and reflux disease. However, the consequence of this relation will not be the same in every patient.

TFF3 expression at the esophagogastric junction is increased in gastro-esophageal reflux disease (GERD)

At the gastric cardia, the molecular mechanisms of inflammation and metaplasia are incompletely understood. Thus, the aim of this study was to determine the expression of TFF1, TFF2 and TFF3 at this site and correlate these data with Helicobacter pylori infection or gastro-esophageal reflux disease (GERD). In 27 patients without intestinal metaplasia at the cardia, endoscopic biopsies were obtained for histology and RT-PCR. TFF1 and TFF2 were expressed in all cardia samples. TFF3 expression was significantly more frequent at the cardia (n = 15/24) than in the corpus (n = 2/26). TFF3 expression at the cardia was mainly observed in GERD patients, and there was a clear tendency towards higher interleukin-8 (IL-8) transcription levels; whereas TFF3 expression was not correlated with the H. pylori status or to tumor necrosis factor-alpha (TNF-alpha) expression. The expression of TFF3 at the cardia may represent an adaptation to GERD and precede the development of Barrett's esophagus.

Esophageal bacteria and Barrett's esophagus: a preliminary report

The objective of this study was to investigate if esophageal bacteria are associated with Barrett's esophagus (BE). This study was comprised of a retrospective (Part 1) and a subsequent prospective (Part 2) study. In Part 1, Gram stains were performed on esophageal biopsy specimens obtained in 47 patients. Bacteria were quantitated from 0 to 4. In Part 2, Gram stains and cultured bacterial counts of esophageal biopsies were obtained in 18 GERD patients (9 with BE and 9 without BE). Part 1 results were as follows. Bacteria were found in 37 of 47 esophageal biopsies. Quantitative bacterial stain scores for BE (2.5 +/- 0.2) were higher than for non-BE (1.5 +/- 0.3; P = 0.02). The quantitative bacterial stain scores correlated with increasing severity of dysplasia (r = 0.37, P = 0.028). In Part 2, bacteria were found in 8 of 18 esophageal biopsies by Gram stain (6 of 9 patients with BE vs. 2 of 9 non-BE). The distal esophageal bacterial stain scores in BE patients (1.6 +/- 0.5) were higher than in those without BE (0.4 +/- 0.3; P = 0.07). Patients on proton pump inhibitors tended to have higher bacterial stain scores (1.2 +/- 0.4) than patients who were not (0.7 +/- 0.3; P = 0.45). Bacterial colony counts were similar in patients with BE compared to those without BE. In conclusion, bacteria in esophageal biopsies were detected more often in BE than non-BE. Increasing bacterial stain scores were associated with metaplasia and increasing dysplasia. Esophageal bacteria, possibly related to stasis or gastric acid suppression therapy, may play a role in the pathogenesis of BE and dysplasia.

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.

Outcomes of pediatric gastroesophageal reflux disease: in the first year of life, in childhood, and in adults...oh, and should we really leave Helicobacter pylori alone?

The prevalence of gastroesophageal reflux (GER) in childhood varies by age. As in adults, GER can result in a spectrum of disease manifestations. Children with gastroesophageal reflux disease (GERD) may become adults with GERD, as suggested by the frequency of childhood reflux symptoms reported by adults with reflux disease. Some studies suggest a causative association between Helicobacter pylori infection and GERD, whereas others postulate a protective role for H. pylori. To better understand pediatric GERD, age-appropriate case definitions and multicenter randomized controlled treatment trials are critically needed.

The MUC5AC glycoprotein is the primary receptor for Helicobacter pylori in the human stomach

BACKGROUND AND OBJECTIVES

Helicobacter pylori shows a characteristic tropism for the mucus-producing gastric epithelium. In infected patients, H. pylori colocalizes in situ with the gastric secretory mucin MUC5AC. The carbohydrate blood-group antigen Lewis B (LeB) was deemed responsible for the adherence of H. pylori to the gastric surface epithelium. We sought to determine if MUC5AC is the carrier of LeB, and thus if MUC5AC is the underlying gene product functioning as the main receptor for H. pylori in the stomach.

METHODS

We studied three types of human tissue producing MUC5AC: Barrett's esophagus (BE), normal gastric tissue, and gastric metaplasia of the duodenum (GMD). Tissue sections were immuno-fluorescently stained for MUC5AC or LeB, and subsequently incubated with one of three strains of Texas red-labeled H. pylori, one of which was unable to bind to LeB. We determined the colocalization of MUC5AC or LeB with adherent H. pylori.

RESULTS

The binding patterns for the two LeB-binding strains to all tissues were similar, whereas the strain unable to bind to LeB did not bind to any of the tissues. In normal gastric tissue, the LeB-binding strains always bound to MUC5AC- and LeB-positive epithelial cells. In four nonsecretor patients, colocalization of the LeB-binding strains was found to MUC5AC-positive gastric epithelial cells. In BE, the LeB-binding H. pylori strains colocalized very specifically to MUC5AC-positive cells. MUC5AC-producing cells in GMD contained LeB. Yet, LeB-binding H. pylori not only colocalized to MUC5AC or LeB present in GMD, but also bound to the LeB-positive brush border of normal duodenal epithelium.

CONCLUSIONS

Mucin MUC5AC is the most important carrier of the LeB carbohydrate structure in normal gastric tissue and forms the major receptor for H. pylori.

Intestinal metaplasia in the distal esophagus and correlation with symptoms of gastroesophageal reflux disease

Barrett's esophagus is a metaplastic condition that occurs in patients with gastroesophageal reflux disease (GERD) and its importance lies in its potential to develop adenocarcinoma of the esophagus. The diagnosis of Barrett's esophagus is based on finding of intestinal metaplasia of at least 3 cm of the distal esophagus. The diagnosis of intestinal metaplasia of less than 3 cm of the distal esophagus is controversial, regarding implications with GERD, adenocarcinoma, and Helicobacter pylori. The aims of the study were to determine the prevalence of intestinal metaplasia in the distal esophagus in patients with short segments of esophageal columnar-appearing mucosa (less than 3 cm), diagnosed endoscopically, in two groups of patients, with and without symptoms of GERD. In total, 97 patients were examined, with endoscopic finding of esophageal columnar-appearing mucosa less than 3 cm. From the total, 52 patients had symptoms of GERD and 45 patients were without these symptoms. These patients were subjected to distal esophageal biopsies obtained immediately below the epithelial transition. The biopsies were stained with hematoxylin-eosin and alcian blue at pH 2.5. Urease test for H. pylori detection in two fragments of gastric antrum was carried out. The presence of intestinal metaplasia in the distal esophagus was diagnosed in 16 (30.8%) patients in the GERD group and 12 (26.7%) patients without GERD symptoms. No statistical differences were observed (P = 0.82; 95% CI: 0.61-2.17). The variables sex, mean age and positivity for H. pylori did not show statistical differences. This study diagnosed high prevalence of intestinal metaplasia in the distal esophagus with columnar-appearing mucosa, less than 3 cm, with no statistical differences in the two groups studied with and without GERD symptoms.

Effect of Helicobacter pylori infection in Barrett's esophagus and the genesis of esophageal adenocarcinoma

The relation between Helicobacter pylori and gastroesophageal reflux disease is unclear. Recent reports have suggested a possible protective role for H. pylori, particularly in preventing the complications of gastroesophageal reflux disease (GERD). The purpose of this article is to present a brief overview of the recent literature regarding the role of H. pylori in the genesis of the complications of GERD, focusing on Barrett's esophagus and esophageal adenocarcinoma. The prevalence of H. pylori infection in the population of the West is around 40% and is not different in cohorts of patients with GERD. When the infection induces pangastritis or corpus-predominant gastritis, there may be concomitant reduced gastric acid secretion. Eradication of the bacteria in this subgroup of patients may enhance gastric acid secretion and provoke reflux symptoms. H. pylori organisms do not colonize the specialized intestinal metaplasia characteristic of Barrett's esophagus. H. pylori infection rates in gastric mucosa of patients with Barrett's esophagus occur at a similar or slightly lower frequency than is found in controls. Gastric infection with cagA-positive strains of H. pylori appears to be uncommon in patients with Barrett's esophagus. Furthermore, epidemiologic studies indicate that cagA-positive strains are protective against esophageal adenocarcinoma. Several investigators have proposed that the decreasing prevalence of H. pylori infection might be an important factor in the rising incidence of this tumor.

Intestinal metaplasia at the gastroesophageal junction: Barrett's, bacteria, and biomarkers

For patients found to have intestinal metaplasia at the gastroesophageal junction, technical problems can make it difficult to distinguish short-segment Barrett's esophagus from intestinal metaplasia of the gastric cardia. Whereas the risk of malignancy for the former condition seems to be higher than that for the latter, the distinction between these conditions can have practical clinical implications. Immunostaining for cytokeratins has been proposed as a means to distinguish intestinal metaplasia of esophageal and gastric origins. We review recent data on this issue, and conclude that immunostaining for cytokeratins has no clear advantages over other biomarkers that have been proposed for identifying Barrett's esophagus (e.g., mucin histochemistry, mAb Das-1 immunoreactivity). Presently, the importance of intestinal metaplasia at the gastroesophageal junction remains unclear, and the clinical utility of biomarkers in distinguishing short-segment Barrett's esophagus from intestinal metaplasia of the gastric cardia has not yet been established.

Review article: Helicobacter pylori and reflux disease

The falling prevalence of Helicobacter pylori infection and related diseases (peptic ulcer disease, gastric cancer) in developed countries has been paralleled by an increased recognition of gastro-oesophageal reflux and its complications. These epidemiological data do not support a role for H. pylori in the pathogenesis of reflux disease, but suggest a negative association with the increasing incidence of oesophageal diseases. This has led some investigators to propose a 'protective' role of H. pylori infection against the development of oesophageal diseases. In these patients, pre-existing lower oesophageal sphincter dysfunction, susceptibility to reflux, unmasking of latent reflux and the patterns and severity of gastritis are probably important factors contributing to the development of oesophageal diseases. The most likely mechanism by which H. pylori infection may protect against reflux is by decreasing the potency of the gastric refluxate in patients with corpus-predominant gastritis. The prevalence of H. pylori infection in patients with reflux disease is probably no greater than that in those without reflux, and there are conflicting data indicating that reflux symptoms or erosive oesophagitis develop after H. pylori eradication. It is also unclear whether H. pylori augments the antisecretory effects of proton pump inhibitors or accelerates the development of atrophic gastritis.

Helicobacter pylori induces apoptosis in Barrett's-derived esophageal adenocarcinoma cells

Helicobacter pylori may protect against the development of dysplasia in Barrett's epithelium of patients with gastroesophageal reflux disease. The aim of this study was to determine whether H. pylori preferentially induces apoptosis in Barrett's-derived cancer cells compared to normal cells. A Barrett's-derived adenocarcinoma cell line (OE33) was grown. H. pylori wild-type, isogenic vacA-, cagA(-), and picB-/cagE- mutant strains were grown on agar plates. Intact or sonicated bacteria were used to treat normal and OE33 cells for 24 hours, and Hoechst dye binding was performed to measure apoptosis. FAS protein expression was determined by Western immunoblotting. OE33 cells treated with intact H. pylori wild-type strains produced significant (P < 0.05) dose-dependent increases in apoptosis compared to normal esophageal cells. H. pylori wild-type and vacA- isogenic strains were more effective than cagA- and picB-/cage- isogenic strains in inducing apoptosis in OE33 cells. In OE33 cells, H. pylori sonicates produced lower levels of apoptosis than intact bacteria. Wild-type H. pylori strains increased Fas protein expression in OE33 cells at 18 hours. H. pylori induced apoptosis at a higher rate in the Barrett's-derived human esophageal adenocarcinoma cells than in normal esophageal cells. The H. pylori-induced apoptosis was primarily dependent on intact bacteria and the presence of the cagA and picB/cagE gene products. H. pylori-induced apoptosis may involve the Fas-caspase cascade.

Barrett's esophagus is characterized by expression of gastric-type mucins (MUC5AC, MUC6) and TFF peptides (TFF1 and TFF2), but the risk of carcinoma development may be indicated by the intestinal-type mucin, MUC2

Barrett's esophagus (BE) consists of metaplastic epithelium of the esophagus, generally diagnosed by mucin histochemistry. We aimed to determine which mucins were expressed in BE, and to relate their expression to BE pathology. Archival biopsies of 4 patient groups were selected, based on standard histochemistry: BE without inflammation, BE with inflammation, ulcerating BE, and BE with dysplasia. Sections were stained by immunohistochemistry for secretory mucins (MUC2, MUC5AC, MUC5B, and MUC6), the proliferation marker Ki-67, and mucin-associated trefoil factor family (TFF) peptides (TFF1, TFF2, and TFF3). MUC5AC and TFF2 were expressed at similar high levels in each clinical group. Intestinal metaplasia (IM), detected both histochemically and by the intestinal mucin MUC2, was lowest in inflamed BE. The expression of the intestinal-type TFF3 did not differ among the groups. Ulcerating BE was distinguished by very low expression of MUC6 and MUC5B, but very high expression of TFF1. Proliferation was not different among the groups. In the total group of BE patients, H. pylori infection of the stomach correlated with decreased TFF2 expression in the BE epithelium. We conclude that BE is best characterized by the specific expression of the gastric-type markers, MUC5AC, MUC6, TFF1, and TFF2. Ulcerating BE constitutes the most distinguished group with respect to mucin and TFF expression. Of the intestinal markers, MUC2 is very specific for IM in BE, whereas TFF3 is not a marker for IM. The low occurrence of IM in inflamed BE suggests that these patients may have the lowest risk of developing carcinoma.

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

BACKGROUND

Barrett's oesophagus is defined as specialised intestinal metaplasia in the distal oesophagus, regardless of extension.

AIM

To study distal oesophagus function, and acid and bile exposure in patients with Long Segment (>3 cm), Short Segment (1 to 2 cm) and Ultra-short Segment (<1 cm) Barrett's Oesophagus, and in patients with gastro-oesophageal reflux disease without intestinal metaplasia.

PATIENTS

Study population comprised 17 patients with Long, 8 with Short, 9 with Ultra-Short Segment Barrett's oesophagus, 32 with reflux disease and 12 healthy volunteers.

METHODS

Patients were evaluated by manometry and by 24-hour pH and bile monitoring.

RESULTS

Patients with intestinal metaplasia had greater acid exposure of the distal oesophagus than healthy volunteers. Patients with Long Segment Barrett's oesophagus had a longer history of symptoms, worse lower oesophageal sphincter pressures and longer bile and acid exposure than the other patients. Long Segment Barrett's oesophagus was predicted by low oesophageal pressure and increased bile exposure, age and male sex.

CONCLUSION

Acid exposure in the distal oesophagus is probably the aetiological factor behind intestinal metaplasia, but a severely damaged antireflux barrier and bile in the refluxate are necessary for Long Segment Barrett's Oesophagus to develop.

The prevalence of Helicobacter pylori infection and the pattern of gastritis in Barrett's esophagus

BACKGROUND/AIM

Acid output is related to the gastritis pattern in Helicobacter pylori infection. The hypothesis to be tested is that gastritis in patients with Barrett's esophagus, defined as columnar epithelia lined lower esophagus (CELLO) with intestinal metaplasia (IM), is antrum predominant.

PATIENTS AND METHODS

Patients undergoing esophagogastroduodenoscopy were investigated for CELLO. The gastritis parameters H. pylori density, activity, and chronicity were graded in biopsy specimens of antrum and corpus. IM was assessed in biopsies from CELLO patients. In a prospective part, 19 patients with CELLO with IM were compared with 38 age-matched control patient with dyspepsia.

RESULTS

Of 200 patients with CELLO, 85% had a short segment (<3 cm), 15% a segment of > or =3 cm. IM was present in 36% of cases with a short CELLO and in 84% of patients with a long segment. The H. pylori prevalence was 50%, independent of the length of CELLO or the presence of IM. The gastritis phenotype was minimally antrum predominant. The antrum/corpus distribution was not related to the length of CELLO or the presence of IM and not different from controls. The activity in corpus and antrum was lower in patients with CELLO with IM as compared with patients with CELLO without IM or controls.

CONCLUSIONS

A high proportion of patients with CELLO are H. pylori infected. The pattern of H. pylori gastritis is characterized by a pangastritis with low activity which is not likely to predispose to an increase in acid output after eradication.

The phenotype of gastric mucosa coexisting with Barrett's oesophagus

BACKGROUND/AIMS

Barrett's oesophagus complicates the gastro-oesophageal acid reflux. Helicobacter pylori infection, particularly with cagA positive strains, induces inflammatory/atrophic lesions of the gastric mucosa, which may impair acid output. No systematic study has investigated the phenotype of the gastric mucosa coexisting with Barrett's oesophagus. This study was designed to identify the phenotype of gastric mucosa associated with Barrett's oesophagus.

METHODS

In this retrospective case control study, the phenotype of the gastric mucosa was histologically characterised in 53 consecutive patients with Barrett's oesophagus and in 53 (sex and age matched) non-ulcer dyspeptic controls. Both patients and controls underwent extensive sampling of the gastric mucosa (two antral, one incisural, and two oxyntic biopsies). Intestinal metaplasia (IM) was categorised (type I, complete IM; types II and III, incomplete IM) by the high iron diamine stain; cagA status was ascertained by genotyping.

RESULTS

Helicobacter pylori was present in 19 of the 53 patients with Barrett's oesophagus and in 30 of the 53 controls (p < 0.02); eight of the 19 patients with Barrett's oesophagus and 28 of the 35 controls harboured cagA positive H pylori (p < 0.03). The histological severity of non-atrophic gastritis detected in the controls was significantly higher than that detected in the patients with Barrett's oesophagus (p < 0.0001). Multifocal atrophic gastritis was present in 4% of the patients with Barrett's oesophagus and in 23% of controls (p < 0.01). The odds ratio for the association between multifocal atrophic gastritis and Barrett's oesophagus was 0.20 (95% confidence interval, 0.006 to 0.60). Gastric IM was detected in 13.2% of the patients with Barrett's oesophagus and in 30.1% of the controls (p < 0.03). Type III IM at the gastric mucosa was only detected among controls.

CONCLUSIONS

Barrett's oesophagus is associated with a low prevalence of H pylori cagA positive infection and multifocal atrophic gastritis. This pathobiological pattern is considered to be associated with a low risk of distal gastric cancer.

Pathogenesis of gastroesophageal reflux and Barrett esophagus

Barrett esophagus is a metaplastic condition that affects the lower esophagus and is a complication of gastroesophageal reflux disease (GERD). Under normal circumstances, the reflux of gastric contents into the esophagus is prevented by a complex barrier at the esophagogastric junction. Dysfunction of the lower esophageal sphincter and the presence of a hiatal hernia lead to failure of this barrier. Esophageal mucosal damage results from the chronic exposure of the esophageal mucosa to gastroduodenal contents and the lack of an effective mucosal defense. This article is an overview of the dysfunction of the esophagogastric junction that leads to GERD. The role of the contents of the reflux and that of Helicobacter pylori infection in the pathogenesis of Barrett esophagus are also summarized.

Salivary growth factors and cytokines are not deficient in patients with gastroesophageal reflux disease or Barrett's esophagus

Growth factors, such as epidermal growth factor (EGF), are known to protect upper gut mucosa against irritants and to enhance healing of ulcerative lesions in animal models. A number of salivary growth factors are found in human saliva. The aim of this study was to determine if salivary growth factors and cytokines are deficient in patients with esophagitis or with Barrett's metaplasia. Fifteen healthy subjects, eight patients with esophagitis, and 13 patients with Barrett's metaplasia were included. Salivary concentration of EGF, FGF, IL-1, and IL-6 were measured during esophageal saline and hydrochloric acid perfusion and in the postprandial state. There was no statistically significant difference in the concentration of EGF or cytokines among the three study groups in each experimental condition or among the three experimental conditions in each group. FGF basic could not be detected in saliva. In conclusion, these findings do not support the hypothesis that a deficiency in salivary growth factors or cytokines plays a significant role in the development of mild to moderate reflux esophagitis or Barrett's metaplasia.

Colonization with cagA-positive Helicobacter pylori strains inversely associated with reflux esophagitis and Barrett's esophagus

AIM

The hypothesis that colonization with cagA(+) Helicobacter pylori strains protects against the development of gastroesophageal reflux disease (GERD) and its complications is tested.

METHODS

Patients with reflux esophagitis and Barrett's esophagus were studied. Antral biopsy specimens were obtained for detection of H. pylori. A serum sample was obtained for determination of IgG antibodies to H. pylori and to the CagA protein.

RESULTS

736 patients were studied. 118 patients had reflux esophagitis, 36 had Barrett's esophagus, 108 had hiatal hernia without signs of inflammation (the reflux group), and 20 patients had esophageal or stomach cancer. The remaining 454 patients had no signs of GERD. The 262 patients with reflux disease had a significantly lower prevalence of H. pylori (34.9%) than the 454 controls (54.6%; p<0. 001). Among 310 H. pylori-positive patients from whom serum was available, colonization with cagA(+) strains was detected in 59% in the control group versus 35% in the reflux group (p<0.001).

CONCLUSION

Patients with reflux esophagitis and Barrett's esophagus have a significantly lower prevalence of H. pylori colonization than controls, in particular of the cagA(+) type. These data suggest that colonization with cagA(+) H. pylori strains may be protective against the development of GERD

Pathogenesis of gastroesophageal reflux and Barrett esophagus

Barrett esophagus is a metaplastic condition that affects the lower esophagus and is a complication of gastroesophageal reflux disease (GERD). Under normal circumstances, the reflux of gastric contents into the esophagus is prevented by a complex barrier at the esophagogastric junction. Dysfunction of the lower esophageal sphincter and the presence of a hiatal hernia lead to failure of this barrier. Esophageal mucosal damage results from the chronic exposure of the esophageal mucosa to gastroduodenal contents and the lack of an effective mucosal defense. This article is an overview of the dysfunction of the esophagogastric junction that leads to GERD. The role of the contents of the reflux and that of Helicobacter pylori infection in the pathogenesis of Barrett esophagus are also summarized.

GERD and H. pylori: is there a link?

The incidence of gastroesophageal reflux disease (GERD) and esophageal adenocarcinoma have increased in recent years as the incidence of peptic ulcer disease and distal gastric cancer have declined. Given the simultaneous decline in Helicobacter pylori infection, it is tempting to propose a relationship between H. pylori infection and these opposing time trends. Although H. pylori infection clearly does not cause GERD, it may protect certain susceptible individuals from developing GERD and its complications. The most likely mechanism in which H. pylori infection protects against GERD is by decreasing the potency of the gastric refluxate in patients with corpus predominant gastritis. A variety of implications of H. pylori infection on GERD treatment have also arisen in recent years. These focus on the risk of gastric atrophy while on proton pump inhibitor therapy and the efficacy of proton pump inhibitors before and after eradication of H. pylori. This article puts into perspective our current understanding of the complex, incompletely understood relationship between H. pylori infection and GERD.

CagA-positive strains of Helicobacter pylori may protect against Barrett's esophagus

OBJECTIVE

Helicobacter pylori (H. pylori) colonization is associated with chronic gastritis, peptic ulcer disease, and adenocarcinoma of the distal stomach. However, the role of H. pylori strain variation in complicated gastroesophageal reflux disease, especially Barrett's esophagus, is unknown. Therefore, the aim of this study was to evaluate the prevalence of colonization by cagA+ and cagA- H. pylori strains in the spectrum of gastroesophageal reflux disease, including Barrett's esophagus.

METHODS

A total of 251 patients undergoing endoscopy were categorized into four groups: controls, patients with gastroesophageal reflux disease alone, and patients with short- and long-segment Barrett's esophagus. All patients underwent upper endoscopies with biopsies and serum collections. H. pylori and degree of mucosal inflammation in gastric biopsies were assessed and serological assessment made for H. pylori and cagA status.

RESULTS

The overall prevalence of H. pylori colonization in the study population was 35% (95% confidence interval = 29.5-41.4%) which did not differ significantly among the groups. However, colonization by cagA+ H. pylori strains was significantly more prevalent among controls (11/25; 44%) and patients with gastroesophageal reflux disease (13/36; 36%) than in patients with short-segment (2/10; 20%) or long-segment Barrett's esophagus (0/18; 0%). Patients with Barrett's esophagus were less likely to be colonized by cagA+ H. pylori strains than reflux patients without Barrett's esophagus (odds ratio = 0.27, 95% confidence interval = 0.11-0.67, p = 0.004).

CONCLUSIONS

Colonization by cagA+ H. pylori strains may be protective against the formation of short- and long-segment Barrett's esophagus and its malignant complications.