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

Neither genotype nor the gastric colonization site of Helicobacter pylori are predictive factors for the development of erosive esophagitis in patients with peptic ulcer disease, 1 year after eradication

CONTEXT

Whether Helicobacter pylori infection is a protective or predisposing factor for the development of gastroesophageal reflux disease remains controversial. The most virulent strains, such as those expressing the cytotoxin-associated gene A (CagA), and the site of gastric colonization have been correlated with the prevention or development of esophagitis.

AIM

To determine the incidence of erosive esophagitis following eradication of H. pylori in patients with peptic ulcer disease and to evaluate the association of erosive esophagitis with virulent strains of H. pylori and the site of gastric colonization.

METHODS

Triple therapy with lansoprazole, amoxicillin and clarithromycin was administered to 159 patients with peptic ulcer disease. Endoscopy, histopathology, urease and carbon-14 urea breath tests were performed prior to treatment, at 3 months and 1 year following treatment. Genotyping of H. pylori strains using polymerase chain reaction was performed separately on samples from the corpus and antrum.

RESULTS

One year after treatment, 148 successfully treated patients were reevaluated. Twenty-eight patients (19%) had erosive esophagitis, classified as Los Angeles grade A in 24 and B in 4. The samples taken from the corpus were CagA-positive in 18 patients (64%), while the samples taken from the antrum were CagA-positive in 21 patients (75%).

CONCLUSIONS

The incidence of erosive esophagitis in peptic ulcer patients who had their H. pylori eradicated was 19%. No correlation was found between the gastric site colonized by H. pylori or strains expressing CagA and the prevention or development of erosive esophagitis in patients with peptic ulcer disease, 1 year after infection eradication.

Coadaptation of Helicobacter pylori and humans: ancient history, modern implications

Humans have been colonized by Helicobacter pylori for at least 50,000 years and probably throughout their evolution. H. pylori has adapted to humans, colonizing children and persisting throughout life. Most strains possess factors that subtly modulate the host environment, increasing the risk of peptic ulceration, gastric adenocarcinoma, and possibly other diseases. H. pylori genes encoding these and other factors rapidly evolve through mutation and recombination, changing the bacteria-host interaction. Although immune and physiologic responses to H. pylori also contribute to pathogenesis, humans have evolved in concert with the bacterium, and its recent absence throughout the life of many individuals has led to new human physiological changes. These may have contributed to recent increases in esophageal adenocarcinoma and, more speculatively, other modern diseases.

Coadaptation of Helicobacter pylori and humans: ancient history, modern implications

Humans have been colonized by Helicobacter pylori for at least 50,000 years and probably throughout their evolution. H. pylori has adapted to humans, colonizing children and persisting throughout life. Most strains possess factors that subtly modulate the host environment, increasing the risk of peptic ulceration, gastric adenocarcinoma, and possibly other diseases. H. pylori genes encoding these and other factors rapidly evolve through mutation and recombination, changing the bacteria-host interaction. Although immune and physiologic responses to H. pylori also contribute to pathogenesis, humans have evolved in concert with the bacterium, and its recent absence throughout the life of many individuals has led to new human physiological changes. These may have contributed to recent increases in esophageal adenocarcinoma and, more speculatively, other modern diseases.

The influence of deprivation and ethnicity on the incidence of esophageal cancer in England

The incidence of esophageal cancer (EC), particularly esophageal adenocarcinoma (EAC), has been rising dramatically. In the USA, esophageal squamous cell carcinoma (ESCC) is associated with deprivation and black ethnicity, while EAC is more common among whites. The influence of social deprivation and ethnicity has not been studied in England. West Midlands Cancer Intelligence Unit data were used to study the incidence of ESCC and EAC, and the influence of age, sex, socioeconomic status (Townsend quintiles by postcode) and ethnicity (to individual patients from Hospital Episode Statistics). From 1977 to 2004, a total of 15,138 EC were identified. Five-year directly age standardized incidence rates per 100,000 (95% CI) for men increased from 8.6 (8.0-9.1) in 1977-1981 to 13.7 (13.1-14.3) in 2000-2004 and for women from 5.0 (4.7-5.4) to 6.3 (5.9-6.6). ESCC incidence did not alter, but EAC incidence rose rapidly in males [2.1 (1.9-2.4) to 8.5 (8.1-9.0)] and in females [0.5 (0.4-0.6) to 1.7 (1.5-1.9)]. ESCC was strongly associated with the most socially deprived quintile. EAC was not associated with differences in socioeconomic status. EAC was significantly more common in white men 7.3 (6.9-7.7) and women 1.5 (1.3-1.6) when compared with black and Asian populations. In England the incidence of EAC has rapidly risen, particularly in men over the last three decades. ESCC was strongly associated with social deprivation. EAC was more common in white populations, but no association with the socioeconomic status was found.

Helicobacter pylori in health and disease

Helicobacter pylori is highly adapted for colonization of the human stomach and is present in about half of the human population. When present, H pylori is usually the numerically dominant gastric microorganism. H pylori typically does not cause any adverse effects, but it is associated with an increased risk of noncardia gastric adenocarcinoma, gastric lymphoma, and peptic ulcer. Disorders such as esophageal diseases and childhood-onset asthma were recently reported to occur more frequently in individuals who lack H pylori than in H pylori-positive persons. In this review, we discuss biologic factors that allow H pylori to colonize the human stomach, mechanisms by which H pylori increases the risk of peptic ulcer disease and noncardia gastric adenocarcinoma, and potential benefits that H pylori might confer to humans.

Risk factors for the detection of Barrett's esophagus in patients with erosive esophagitis

BACKGROUND

Barrett's esophagus (BE) results from metaplastic healing of injured esophageal mucosa after erosive esophagitis (EE).

OBJECTIVE

Our purpose was to determine whether severity of esophagitis, indication for endoscopy, or proton pump inhibitor treatment affects the subsequent incidence of BE diagnosis in patients found to have EE on EGD performed for any indication.

DESIGN

We identified patients with primary or secondary International Classification of Diseases, 9th revision diagnosis codes of EE from 1996 to 2006 who had at least 2 EGDs on record. Patients with prevalent BE on the first EGD were excluded.

SETTING

Inpatients and outpatients at Stanford University and Palo Alto Veterans Affairs Health Care System.

INTERVENTIONS

Retrospective review of EGD and pathology reports to confirm BE.

MAIN OUTCOME MEASUREMENTS

Detection of BE after diagnosis of EE.

RESULTS

A total of 1095 patients were identified between 1996 and 2000, and 102 (9%) were included. Sixty-two (61%) patients were veterans, 87 (85%) were male, and 83 (81%) were white. The mean (+/-SD) age was 58 +/- 14 years (range 24-83 years). BE was detected in 9 (9%) patients (95% CI, 4.5%-17.6%) over a mean of 13.3 +/- 5.7 months (range 1-53.5 months), and all had prior grade 4 esophagitis. The mean BE length was 4 +/- 1.8 cm (range 1-18 cm). Six patients had upper GI bleeding as the indication for EGD, whereas the other 3 complained of dysphagia. The association of grade 4 esophagitis (P = .01) and GI hemorrhage (P = .01) to the subsequent detection of BE was highly statistically significant.

LIMITATIONS

Retrospective study, small number of patients with BE after EE. All patients were receiving care at tertiary medical centers.

CONCLUSIONS

BE was detected in 9% of patients with prior EE and was detected exclusively on follow-up of patients with severe esophagitis. The majority of the patients found to have BE had upper GI bleeding as the presentation for EGD.

Barrett's oesophagus

Barrett's oesophagus is a metaplastic change of the lining of the oesophagus, such that the normal squamous epithelium is replaced by specialised or intestinalised columnar epithelium. The disorder seems to be a complication of chronic gastro-oesophageal reflux disease, although asymptomatic individuals might also be affected, and it is a risk factor for the development of oesophageal adenocarcinoma, a cancer with rapidly increasing incidence in developed societies. We review the presentation, epidemiology, and risk factors for this condition. We discuss the molecular changes necessary for the development of Barrett's oesophagus and its progression to cancer, and new strides in both the endoscopic detection of the lesion and the treatment of dysplastic disease. Also, we assess the effectiveness of efforts to screen patients at risk of Barrett's oesophagus, and whether such efforts avert cancer death. We conclude with a discussion of future directions for research, focusing on treatment of early neoplasia, and modifications of current practices to show our evolving understanding of this condition.

Helicobacter pylori infection and Barrett's esophagus: a systematic review and meta-analysis

OBJECTIVES

The majority of distal esophageal adenocarcinomas are believed to arise in patients with Barrett's esophagus (BE). Helicobacter pylori (H. pylori) infection plays an etiological role in gastric carcinogenesis, but any possible role in BE is uncertain. We aimed to explore the possible relationship between H. pylori infection and BE by meta-analysis.

METHODS

Observational studies comparing the prevalence of H. pylori infection in patients with BE and healthy controls conducted in adult populations and published in all languages were identified through MEDLINE, EMBASE, and Cochrane database searches up to week 5, 2008. H. pylori infection had to be confirmed by histology and/or serology and/or RUT and/or culture. Studies were excluded if no raw data for outcomes of interest were available or controls were patients with disease or duplicate publications. Summary effect size was calculated as odds ratio (OR) and 95% confidence intervals (CIs) by the random-effects model using Review Manager 4.2.8.

RESULTS

Of 519 citations identified, a total of 12 case-control studies compared the prevalence of H. pylori infection in BE (n=550) and controls (9 studies included controls with normal endoscopy and 3 studies used healthy blood donors as control, n=2,979). There was no significant difference in the overall prevalence of H. pylori infection between BE and controls (42.9% vs. 43.9%, OR=0.74, 95% CI 0.40-1.37, P=0.34), but with significant heterogeneity. Subgroup analysis showed that the prevalence of H. pylori infection was significantly lower in BE than in endoscopically normal healthy controls (23.1% vs. 42.7%, OR=0.50, 95% CI 0.27-0.93, P=0.03) with significant heterogeneity observed between studies. The heterogeneity was eliminated by excluding a single Asian outlier study. In contrast, H. pylori infection was significantly increased in BE patients in the three studies using healthy blood donors as "normal controls" (71.2% vs. 48.1%, OR=2.21, 95% CI 1.07-4.55). In BE patients, the prevalence of H. pylori infection was significantly lower in the esophagus than in the stomach (3.3% vs. 24.7%, OR=0.14, 0.03-0.67) in three studies.

CONCLUSIONS

H. pylori infection and BE are inversely related when compared with endoscopically normal controls but not blood donor controls. Limited evidence suggests that there is no clear association between H. pylori infection and BE. To determine more accurately the effect size of H. pylori infection in BE, high quality prospective case-control studies with age-matched, endoscopically normal healthy controls are needed.

Helicobacter pylori and gastroesophageal reflux disease: a case-control study

BACKGROUND

Gastric colonization with Helicobacter pylori is a proposed protective factor against gastroesophageal reflux disease (GERD), but little population-based data exist and other data conflict.

METHODS

We conducted a case-control study within the membership of a large integrated health-care system that compared GERD-free subjects with two groups: subjects with a physician-assigned GERD diagnosis and randomly selected members with self-described weekly GERD symptoms. Subjects completed interviews, GERD questionnaires, and antibody testing for H. pylori and its cagA protein.

RESULTS

Serologic data were available for 301 physician-assigned GERD patients, 81 general membership subjects with GERD symptoms, and 175 general membership subjects without GERD symptoms. Physician-assigned GERD patients were less likely to have H. pylori antibodies than GERD-free member controls (odds ratio (OR) = 0.27, 95% confidence interval (CI) 0.15-0.47); there was also an inverse association between H. pylori and GERD symptom severity (OR = 0.18, 95% CI 0.08-0.41; severe or very severe symptoms) and GERD frequency (OR = 0.18, 95% CI 0.09-0.38; for symptoms at least weekly). The association was stronger among persons with erosive GERD and was similar between H. pylori-positive subjects with and without cagA. There was no association among persons who were cagA positive, but H. pylori negative. Similar findings were found in analyses of the general membership with self-described GERD symptoms.

CONCLUSIONS

H. pylori antibody status was inversely associated with a GERD diagnosis and GERD symptoms compared with a general membership population.

International variation in Helicobacter pylori infection and rates of oesophageal cancer

AIM

To examine the association between gastric atrophy, Helicobacter pylori and CagA status, and ratio of oesophageal squamous cell carcinoma to oesophageal adenocarcinoma (OSCC:OAC) amongst international heterogeneous populations.

METHODS

Standardised protocols were used to collect and process questionnaire data and serum samples for PgA and PgC levels and H. pylori and CagA serology. The OSCC:OAC were used to construct appropriate models.

RESULTS

There were significant correlations between the OSCC:OAC and both rates of low PgA:PgC ratios and serological markers of H. pylori infection, in males, but not females. A significant correlation between OSCC:OAC and overall CagA-seropositivity was seen in males, but not females, but this was not independently associated with increasing OSCC:OAC.

CONCLUSIONS

In males, populations with higher rates of gastric atrophy or H. pylori infection have a higher OSCC:OAC. CagA seropositivity rates seem to have no additional effect.

The pathogenesis of Helicobacter pylori-induced gastro-duodenal diseases

Helicobacter pylori is the main cause of peptic ulceration, distal gastric adenocarcinoma, and gastric lymphoma. Only 15% of those colonized develop disease, and pathogenesis depends upon strain virulence, host genetic susceptibility, and environmental cofactors. Virulence factors include the cag pathogenicity island, which induces proinflammatory, pro-proliferative epithelial cell signaling; the cytotoxin VacA, which causes epithelial damage; and an adhesin, BabA. Host genetic polymorphisms that lead to high-level pro-inflammatory cytokine release in response to infection increase cancer risk. Pathogenesis is dependent upon inflammation, a Th-1 acquired immune response and hormonal changes including hypergastrinaemia. Antral-predominant inflammation leads to increased acid production from the uninflamed corpus and predisposes to duodenal ulceration; corpus-predominant gastritis leads to hypochlorhydria and predisposes to gastric ulceration and adenocarcinoma. Falling prevalence of H. pylori in developed countries has led to a falling incidence of associated diseases. However, whether there are disadvantages of an H. pylori-free stomach, for example increased risk of esosphageal adenocarcinoma, remains unclear.

Relationship between Helicobacter pylori infection and esophageal neoplasia: a meta-analysis

BACKGROUND & AIMS

Helicobacter pylori is an important causative factor in gastric carcinogenesis. However, its role in extragastric gastrointestinal malignancies, such as esophageal cancer, is controversial. The aim of this study was to explore the relationship of H. pylori infection and H. pylori cagA-positive strain with this malignancy by performing meta-analysis of all relevant studies.

METHODS

Extensive MEDLINE English language medical literature searches for human studies were performed through February 2007 with suitable keywords. Pooled estimates were obtained by using fixed or random-effects model as appropriate. Heterogeneity between studies was evaluated with the Cochran Q test, whereas the likelihood of publication bias was assessed by constructing funnel plots. Their symmetry was estimated by the Begg and Mazumdar adjusted rank correlation test.

RESULTS

In adenocarcinoma patients there were inverse significant relationships with both the H. pylori prevalence (pooled odds ratio [OR], 0.52; 95% confidence interval [CI], 0.37-0.73; P < .001) and the prevalence of H. pylori cagA-positive strain (pooled OR, 0.51; 95% CI, 0.31-0.82; P = .006). Similarly in patients with Barrett's esophagus there were inverse significant relationships (pooled OR, 0.64; 95% CI, 0.43-0.94; P = .025 and pooled OR, 0.39; 95% CI, 0.21-0.76; P = .005, respectively). In patients with squamous cell carcinoma there were no significant relationships with both H. pylori prevalence (pooled OR, 0.85; 95% CI, 0.55-1.33; P = .48) and the prevalence of H. pylori cagA-positive strains (pooled OR, 1.22; 95% CI, 0.7-2.13; P = .48).

CONCLUSIONS

The results showed an inverse statistically significant relationship of H. pylori infection with both esophageal adenocarcinoma and Barrett's esophagus, which might suggest a protective role of the infection in these entities. On the contrary, no statistically significant relationship with squamous cell carcinoma was found.

Aneuploidy in upper gastro-intestinal tract cancers--a potential prognostic marker?

Chromosomal instability manifesting as aneuploidy is the most frequently observed abnormality in solid tumours. However, the role of aneuploidy as a cause or consequence of cancer remains a controversial topic. In this review, we focus on the karyotypic imbalances recorded for cancers of the upper gastro-intestinal (GI) tract, together with their associated pre-malignant lesions and the potential of aneuploidy as a clinical tool for patient management. Numeric chromosomal aberrations are common throughout gastro-oesophageal cancers and their precursor lesions. Additionally, specific chromosomal aneusomies have been identified as early changes in pre-dysplastic tissues suggesting they may be actively involved in driving tumourigenesis. As a progressive increase in the severity of aneuploidy with neoplastic progression has also been observed, it has thus been shown to be a useful prognostic indicator for patient classification as low or high-risk cases for cancer development. However, the biological basis for the aneuploidy in cancers of the upper GI tract needs to be established to understand its consequences and role during carcinogenesis, which is necessary for improving diagnostics and establishing novel targeted therapies.

Subsite-specific risk factors for esophageal and gastric adenocarcinoma

BACKGROUND

The incidence rates of adenocarcinoma involving specific gastric and esophageal subsites are changing significantly, but the risk factors associated with those subsite changes remain controversial. We aimed to describe the site-specific risk factors associated with adenocarcinoma of the stomach and esophagus.

METHODS

Using the Rochester Epidemiology Project, all cases of gastric and esophageal adenocarcinoma among Olmsted County, Minnesota, residents first diagnosed between 1971 and 2000 were identified. Complete inpatient and outpatient records were reviewed and specific subsites defined. Risk factors were assessed in cases, and age- and sex-matched controls.

RESULTS

A total of 186 incident cases of gastric or esophageal adenocarcinoma were identified between 1971 and 2000, in Olmsted County. Gastroesophageal reflux disease (GERD) was a significant risk factor for both esophageal (OR 5.5, 95% CI 1.2-25) and esophagogastric junction adenocarcinoma (OR 13.0, 95% CI 1.7-99), but not for either proximal or distal gastric cancer. Smoking (OR 2.8, 95% CI 1.0-7.8) was associated with distal gastric cancer. Proton pump inhibitor (PPI) exposure was limited and was not a significant risk factor at any subsite.

CONCLUSIONS

This identification of distinct risk factors by subsite supports the concept that esophageal and gastric adenocarcinomas are two different diseases. Adenocarcinoma of the junction is probably a form of esophageal cancer and should not be coded with gastric neoplasms.

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 and benign upper digestive disease

Acute infection with Helicobacter pylori causes hypochlorhydria and gastrointestinal upset. As the infection persists, patients develop chronic antral-predominant or pangastritis. Gastric and duodenal ulcers arise from chronic mucosal inflammation and disordered acid secretion in the stomach. With successful eradication of H. pylori, non-NSAID-related gastric and duodenal ulcers heal even without long-term acid suppression. More importantly, peptic ulcers and their complications rarely recur. Clearing H. pylori infection also reduces the risk of mucosal injury in NSAID and aspirin users; the protective effects are more pronounced in NSAID-naïve and aspirin users. H. pylori is unlikely to be the cause of gastro-oesophageal reflux disease. However, a patient's reflux symptoms may be more difficult to control after clearing the infection. Although there is little evidence to support a causal relationship between H. pylori and non-ulcer dyspepsia, treatment of the infection gives a modest improvement of symptoms.

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.

The changing incidence of oesophageal and gastric adenocarcinoma by anatomic sub-site

BACKGROUND

The incidence rates of gastric and oesophageal adenocarcinoma are changing significantly, but little is known about specific sub-sites.

AIM

To use a population-based approach to describe the trends in the site-specific incidence of oesophageal and gastric adenocarcinoma.

METHODS

Using the Rochester Epidemiology Project, all cases of gastric and oesophageal adenocarcinoma among Olmsted County, Minnesota, residents first diagnosed between 1971 and 2000 were identified (n = 186). Complete in-patient and out-patient records were reviewed and site determined from pathological, surgical, endoscopic and radiological reports.

RESULTS

Between the decades of 1971-1980 and 1991-2000, the incidence of oesophageal adenocarcinoma increased significantly from 0.4 to 2.5 per 100 000 person-years. The incidence of adenocarcinoma of the oesophagogastric junction also increased from a rate of 0.6 to 2.2 per 100 000 person-years. The incidence rate of cancer involving the gastric cardia was stable but the incidence of adenocarcinoma involving distal gastric sites declined. Combined oesophageal and oesophagogastric junction adenocarcinoma (4.7 per 1 000 000 person-years) was as common as gastric adenocarcinoma (3.4 per 100 000 person-years) in 1991-2000.

CONCLUSIONS

The incidence rates of adenocarcinoma involving proximal gastric sub-sites do not appear to be increasing in a manner similar to those involving oesophageal sub-sites.

Epidemiology and molecular biology of Barrett esophagus

Over the past three decades, there has been a marked change in the epidemiology of esophageal malignancy, with an increasing incidence of esophageal adenocarcinoma. The reasons for this are largely unknown and remain controversial, but several lifestyle risk factors have been proposed, including gastroesophageal reflux disease (GERD). It is hypothesized that chronic GERD results in acute mucosal injury, promotes cellular proliferation, and induces specialized columnar metaplasia (Barrett esophagus). Progression of Barrett esophagus to invasive adenocarcinoma is reflected histologically by the metaplasia-dysplasia-carcinoma sequence. Dysplasia is widely regarded as the precursor of invasive cancer, and high-grade dysplasia in Barrett epithelium is frequently associated with esophageal adenocarcinoma. Although several molecular alterations have been described in Barrett esophagus, it is anticipated that relatively few will prove to be clinically useful. To date, biomarkers which currently appear to predict the progression of Barrett esophagus to invasive malignancy include aneuploidy, loss of heterozygosity of 17p (implicating the p53 tumor suppressor gene), and cyclin D1 protein overexpression, and with further validation, will most likely be incorporated into routine clinical practice. It is anticipated that models incorporating objective scores of sociodemographic and lifestyle risk factors (ie, age, gender, body mass index), severity of reflux symptoms, endoscopic and histologic findings, and an assessment of a panel of biomarkers will be developed to further define subsets of patients with Barrett esophagus at increased risk for malignant progression, thereby permitting the development of more rational endoscopic surveillance and screening programs.

CagA positivity and its association with gastroduodenal disease in Turkish children undergoing endoscopic investigation

BACKGROUND

Cytotoxin-associated gene A (CagA) product is a bacterial virulence factor contributing to the pathogenicity of Helicobacter pylori (HP) infection in humans. Host factors, which vary in different countries, interact with bacterial factors to determine the disease state. Our objective was to investigate the frequency of CagA-positive HP strains and evaluate the contribution of CagA positivity to symptoms and development of mucosal lesions in HP-infected Turkish children.

METHODS

We conducted a prospective clinical trial in 240 consecutive Turkish children undergoing endoscopy (110 girls, 130 boys; mean age, 8.7 +/- 4.3 years). HP infection was diagnosed on the basis of a positive rapid urease test and histology of the mucosal specimens. HP IgG and CagA IgG antibodies were measured by enzyme-linked immunosorbent assay in HP-positive children.

RESULTS

The HP positivity rate was 50.4% in our study group (51 girls, 70 boys; mean age, 9.9 +/- 3.9 years). CagA was positive in 74.4%. HP infection was less common in children with vomiting (25.9%, P < 0.05). CagA positivity was not associated with any clinical symptom. HP positivity was higher in children with duodenal ulcer (80% vs. 49.1%, P = 0.05); while CagA positivity was similar. Antral nodularity was strongly associated with HP positivity and CagA positivity (30.6% vs. 3.4% and 36.7% vs. 12.9%, respectively, P < 0.05). A negative association between CagA positivity and esophagitis was observed (20% vs. 76.7%, P < 0.05).

CONCLUSIONS

CagA positivity is common in HP-infected Turkish children. Esophageal lesions are less common in children infected with CagA-positive strains. Although HP is associated with duodenal ulcer disease, CagA positivity does not seem to contribute to development of ulcers in children in our series.

Preservation of gastric acid secretion may be important for the development of gastroesophageal junction adenocarcinoma in Japanese people, irrespective of the H. pylori infection status

BACKGROUND

We have previously reported that Helicobacter pylori infection prevents reflux esophagitis (RE) and Barrett's esophagus (BE) by decreasing gastric acid secretion. Gastroesophageal (GE) junction adenocarcinoma, including Barrett's adenocarcinoma, has been thought to be a complication of gastroesophageal reflux disease (GERD). However, the relationship between H. pylori infection, gastric acid secretion, and GE junction adenocarcinoma has not yet been investigated in Japan. The aim of this study was to evaluate this relationship in the Japanese population.

METHODS

A total of 168 Japanese patients (RE alone: 80, short-segment BE (SSBE): 16, long-segment BE (LSBE): 20, GE junction adenocarcinoma: 12, distal early gastric cancer (EGC): 40; male/female = 106/62; mean age 61.5 yr) and 80 Japanese control subjects who had no localized lesions in the upper gastrointestinal tract (male/female = 43/37, mean age 58.1 yr) were enrolled for this study. The prevalence of H. pylori infection was determined by biopsy, the rapid urease test, and measurement of the serum H. pylori IgG antibody. Gastric acid secretion was assessed by the endoscopic gastrin test (EGT). RE was diagnosed according to the Los Angeles classification.

RESULTS

The prevalence of H. pylori infection in the patients with RE alone (30%) was significantly lower than that in control subjects (71.2%). There was also a tendency for the prevalence of H. pylori infection to be lower in patients with BE (SSBE, 18.7%; LSBE, 0%) when compared to that in patients with RE alone. On the other hand, while the prevalence of H. pylori infection in patients with GE junction adenocarcinoma (58.3%) was significantly lower than that in patients with EGC (87.5%), it tended to be higher than that in patients with RE alone or BE. The mean EGT value in patients with RE alone (3.74 mEq/10 min) was significantly higher than that in control subjects (1.83). The mean EGT value in patients with BE (SSBE, 4.74; LSBE, 4.76) tended to be even higher than that in patients with RE alone. The mean EGT value in patients with GE junction adenocarcinoma (3.94) was significantly higher than that in control subjects and patients with EGC (0.67), but it was comparable to that independent of the H. pylori infection status in patients with RE alone or BE.

CONCLUSION

Preservation of gastric acid secretion may be important for the development of GE junction adenocarcinoma in Japanese people, irrespective of the H. pylori infection status.

CagA-positive Helicobacter pylori infection is not associated with decreased risk of Barrett's esophagus in a population with high H. pylori infection rate

BACKGROUND & AIM

The role that H. pylori infection plays in the development of and Barrett's esophagus (BE) is uncertain. We tested the hypothesis that infection with cagA+ Helicobacter pylori strains protects against the development of BE.

METHODS

We studied 104 consecutive patients, residents in an area with a high prevalence of H. pylori infection, with BE and 213 sex- and age-matched controls. H. pylori infection and CagA antibody status were determined by western blot serology.

RESULTS

H. pylori prevalence was higher in patients with BE than in controls (87.5% vs. 74.6%; OR. 2.3; 95% CI: 1.23-4.59). Increasing age was associated with a higher prevalence of H. pylori (p < 0.05). The prevalence of CagA+ H. pylori serology was similar in patients with BE and controls (64.4% vs. 54.5%; NS). Type I H. pylori infection (CagA+ and VacA+) was similar in patients with BE and controls (44.2% vs. 41.3%; NS). Logistic regression analysis identified alcohol (O.R. 7.09; 95% CI 2.23-22.51), and H. pylori infection (OR: 2.41; 95%CI: 1.20-4.84) but not CagA+ serology as independent factors.

CONCLUSION

Neither H. pylori infection nor H. pylori infection by CagA+ strains reduce the risk of BE in a population with high prevalence of H. pylori infection.

Heterogeneity of cag genotypes and clinical outcome of Helicobacter pylori infection

Helicobacter pylori infecting strains may include colony subtypes with different cytotoxin-associated gene (cag) genotypes. We sought to determine whether the cag heterogeneity of infecting strains is related to the clinical outcome of infection. Gastric biopsies for culture and histologic study were taken from 19 patients infected with cagA-positive strains (6 with duodenal ulcer, 8 with atrophic gastritis, and 5 with nonatrophic gastritis). For each biopsy, DNA was extracted from 10 single colonies and from a sweep of colonies. Polymerase chain reaction (PCR) for cagA and cagE (both located in the right half of cag) and virB11 (located in the left half of cag) was performed. Random amplified polymorphic DNA PCR (RAPD-PCR) and sequencing of glmM PCR product were performed to verify strain identity of colonies with different cag genotypes. In all patients, PCR from sweeps were positive for cagA, showing that all specimens contained cagA-positive H. pylori subtypes. In 11 patients, PCR products from all colonies were positive for cagA, cagE, and virB11, but in 8 patients, PCR products from varying numbers of colonies were negative for 1 or more cag genes. RAPD-PCR and sequencing of glmM PCR product confirmed the strain identities of colonies with different cag genotypes. We detected cag deletions in 6 of 8, 2 of 5, and 0 of 6 patients with atrophic gastritis, nonatrophic gastritis, and duodenal ulcer, respectively (P = .02). In conclusion, changes in cag genotype in single colony isolates from subjects infected with cagA-positive H. pylori strains are more common in atrophic than in nonatrophic gastritis or duodenal ulcer. These findings are consistent with host-induced (acid secretion?) adaptive changes in cag genotype during infection.

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.

Epidemiologic risk factors for Barrett's esophagus and associated adenocarcinoma

The incidence of esophageal adenocarcinoma (AC) has increased dramatically in the Western world over the past 20 years and the majority of these cancers arise on the background of the preinvasive lesion Barrett's esophagus. The epidemiologic factors that contribute to an individual's susceptibility for Barrett's esophagus and associated cancer are likely to be multifactorial. However, the short time frame over which the incidence of adenocarcinoma has increased, and the increase across populations, provides a strong argument for environmental factors as etiologic agents, perhaps interacting with genetically determined characteristics that define personal susceptibility. In this review we discuss the epidemiologic evidence for the proposed demographic and environmental risk factors for the development of both Barrett's esophagus and AC. The current evidence suggests that significant risk factors include male sex, Caucasian race, and the presence of duodenogastroesophageal reflux disease. The susceptibility for reflux disease may in turn be influenced by factors such as obesity, the use of drugs that lower the lower-esophageal sphincter tone, and a protective effect of Helicobacter pylori colonization. There appears to be a weak association between smoking and AC. The role of dietary factors has not been studied adequately and deserves further attention. An understanding of the factors that predispose to the development and progression of Barrett's esophagus is crucial to the implementation of effective screening and prevention programs.

Review article: influence of Helicobacter pylori on gastro-oesophageal reflux disease in Japan

There is circumstantial evidence that infection with Helicobacter pylori is relatively protective for the occurrence of gastro-oesophageal reflux disease (GERD). It has been suggested that the Japanese population are protected against reflux oesophagitis by their high prevalence of H. pylori associated gastritis. Such gastritis, when becoming chronic, can lead to gastric atrophy, thereby reducing the likelihood of GERD. If this hypothesis is correct, the effects of H. pylori induced gastritis may be an important factor determining the earlier lower prevalence of oesophagitis in Japan, where this infection is especially common. In support of this idea a reduced prevalence of H. pylori infection in Japan, as is now being observed in young Japanese adults, may be, at least in part, responsible for the upsurge in the number of cases of reflux disease in Japan. Concomitantly, H. pylori eradication therapy in patients with gastritis or peptic ulcer disease, which is associated with an increase in gastric acid secretion, may also be at least partly responsible for the increased prevalence of reflux oesophagitis in the Japanese population.

Review article: the patient with gastro-oesophageal reflux disease--lifestyle advice and medication

Gastro-oesophageal reflux disease (GERD) is a highly prevalent disorder in all Western countries. Interestingly, prevalence rates appear to be increasing in these countries, with a remarkable increase of GERD-related lethal and nonlethal complications. However, these complications are rare on a global scale. This review aims to summarize the current concepts of genetic, lifestyle and environmental factors that need to be considered whilst caring for patients with these disorders. GERD is defined by the augmented exposure of oesophageal mucosa to acidic content, and is associated with specific symptoms or mucosal lesions. A number of factors may contribute to the manifestation of GERD. Although recent studies emphasize the role of genetic factors, there are many other risk factors that play a pivotal role in the development of GERD and GERD complications. Some nutritional factors are believed to aggravate acidic reflux either by delaying gastric emptying or diminishing the pressure of the lower oesophageal sphincters. Patients are often advised to sleep with their heads elevated, but this advice is not easy to follow and has not been proven effective with regard to long-term outcome. Other lifestyle modifications include changes to the patient's diet, which are important but not frequently sufficient. Thus, medication is usually necessary for symptom control. Proton pump inhibitors are now mainstream treatment for the reduction of acid secretion in patients with severe manifestations and 4-week healing rates are approaching 90%.

H. pylori and GERD: is less more?

Does chronic Helicobacter pylori gastritis prevent gastroesophageal reflux disease (GERD) and its sequelae? Yes, no, life should be so simple. A quick Medline search on the paired terms identified 527 citations since 1988 and that tells you something right there. Evidently, this is a complex relationship and attempting to reduce it to a yes/no answer is just not going to work. Perusing the literature, it becomes apparent that some combination of three component questions are in fact being asked: (i) Is it biologically plausible that H. pylori gastritis will reduce the occurrence of GERD? (ii) Is there an inverse epidemiological relationship between H. pylori infection and GERD? and (iii) Will the eradication of H. pylori unleash an epidemic of GERD? Each of these questions entails a unique set of consideration. We will consider each in turn.

The prevalence of Helicobacter pylori infection and the status of gastric acid secretion in patients with Barrett's esophagus in Japan

OBJECTIVES

The acidity of the refluxate into the esophagus is a key factor for the pathogenesis of gastroesophageal reflux disease. Helicobacter pylori (H. pylori) infection can influence gastric acid secretion. We have reported that H. pylori infection prevents reflux esophagitis by decreasing gastric acid secretion in Japanese patients, but the role of this organism in Barrett's esophagus is unclear. The aim of this study was to investigate the prevalence of H. pylori infection and gastric acid secretion in Japanese patients with reflux esophagitis with or without Barrett's esophagus.

METHODS

We enrolled 112 reflux esophagitis patients who were examined for the status of H. pylori and acid secretion in this study. They were divided into three groups, according to the presence or absence of Barrett's esophagus as follows: reflux esophagitis group without Barrett's esophagus (reflux esophagitis alone) (80 patients); short-segment Barrett's esophagus group (16 patients); and long-segment Barrett's esophagus group (LSBE) (16 patients). Age- and sex-matched control subjects were also assigned to the 80 patients with reflux esophagitis alone. The prevalence of H. pylori infection was determined by histology, rapid urease tests, and serum IgG antibodies. Gastric acid secretion was evaluated by the endoscopic gastrin test (EGT).

RESULTS

The overall prevalence of H. pylori infection in the reflux esophagitis patient group (24.1%) was significantly lower than the control group (71.2%) (odds ratio 0.13, 95% confidence interval 0.07-0.24; p < 0.0001). The prevalence of H. pylori infection in the patients with Barrett's esophagus tended to be lower than that in the patients with reflux esophagitis alone (reflux esophagitis alone; 30.0%, SSBE; 18.7%, LSBE; 0%), especially in the patients with LSBE compared with the reflux esophagitis alone group (p < 0.01). The EGT value of the respective reflux esophagitis patient group was significantly higher than the control group. The EGT value in the patients with Barrett's esophagus tended to be higher than that in the patients with reflux esophagitis alone, but the difference was not statistically significant. When examined in H. pylori-negative subjects, no difference was found in the EGT value between the control subjects and the patients with reflux esophagitis alone, but it was significantly higher in patients with Barrett's esophagus than the control subjects (p < 0.05). On the other hand, when examined in the H. pylori-positive subjects, the EGT value was significantly higher in the patients with reflux esophagitis alone than in the control subjects (p < 0.01).

CONCLUSIONS

H. pylori infection may play a protective role in the development of Barrett's esophagus, especially in the development of LSBE in Japan. Gastric acid hypersecretion may be concerned with the development of Barrett's esophagus in addition to the absence of H. pylori infection.

The role of cagA Helicobacter pylori strains in gastro-oesophageal reflux disease

BACKGROUND AND AIMS

The role of Helicobacter pylori infection in gastro-oesophageal reflux disease is controversial. The aim of this study was to evaluate the prevalence of colonization by cagA-positive and cagA-negative H. pylori strains in the spectrum of gastro-oesophageal reflux disease.

METHODS

A total of 108 patients (50 male/58 female; mean age, 50.3 years) with dyspepsia and peptic ulcer or erosive gastritis/duodenitis were categorized into patients without reflux and patients with reflux oesophagitis graded from I to IV. All patients underwent upper endoscopy with biopsies of the antrum. H. pylori was detected by histology, urease test and polymerase chain reaction. The cagA status was diagnosed in the gastric biopsy by polymerase chain reaction.

RESULTS

The overall prevalence of H. pylori colonization in patients with reflux was 68.6% and was 70.2% in those without oesophageal disease (P = 0.862). Colonization by cagA-positive strains was also not statistically different between the two groups (31.4% versus 40.4%, P = 0.332). However, patients with grades II-IV reflux oesophagitis were less colonized by the bacterium (36.4%) than patients with grade I oesophagitis (77.5%) (P = 0.009). H. pylori cagA-positive strains were also less likely to colonize the stomach of patients with grades II-IV oesophagitis (0%), than grade I reflux oesophagitis (40%) patients and controls (40.4%).

CONCLUSIONS

Infection of the stomach by H. pylori and especially by H. pylori cagA strains may play a protective role against the development of the most severe forms of gastro-oesophageal reflux disease.

The implications of Helicobacter pylori infection for gastroesophageal reflux disease: studies presented at Digestive Disease Week 2003

The relationship between Helicobacter pylori infection and gastroesophageal reflux disease (GERD) remains controversial. Over 20 studies presented at the 2003 Digestive Disease Week meeting examined the implications of H. pylori infection for GERD. Although the findings were not uniform, most of the studies presented indicated a negative association between the presence of H. pylori and the presence of GERD symptoms, signs, or complications. In addition, eradication of H. pylori infection was related to the emergence of GERD and its complications. However, most studies favored a role for H. pylori rather than GERD in the development of pathologic changes in the gastric cardia. Finally, a few studies suggested the intriguing possibility that the modulation of GERD by H. pylori could be through the effects of H. pylori eradication on weight gain.

Celiac disease and glycogenic acanthosis: a new association?

A 6-y-old boy and an 8-y-old girl were admitted to our clinic with anaemia and failure to thrive. Laboratory tests revealed iron deficiency anaemia and positive antigliadin antibodies in both of the patients. Slightly raised grey-white plaques were observed on oesophageal mucosa during endoscopical investigation of the patients. While intestinal mucosal samples confirmed diagnosis of celiac disease histologically, histopathological assessment of oesophageal lesions demonstrated glycogenic acanthosis. Since glycogenic acanthosis associated with celiac disease hasn't been reported in the literature previously to our knowledge, case reports of our patients were presented.

CONCLUSION

We suggest that glycogenic acanthosis needs to be investigated as a possible new association of celiac disease in greater paediatric series.

Helicobacter pylori persistence: biology and disease

Helicobacter pylori are bacteria that have coevolved with humans to be transmitted from person to person and to persistently colonize the stomach. Their population structure is a model for the ecology of the indigenous microbiota. A well-choreographed equilibrium between bacterial effectors and host responses permits microbial persistence and health of the host but confers risk of serious diseases, including peptic ulceration and gastric neoplasia.

Helicobacter pylori persistence: biology and disease

Helicobacter pylori are bacteria that have coevolved with humans to be transmitted from person to person and to persistently colonize the stomach. Their population structure is a model for the ecology of the indigenous microbiota. A well-choreographed equilibrium between bacterial effectors and host responses permits microbial persistence and health of the host but confers risk of serious diseases, including peptic ulceration and gastric neoplasia.

Personal view: to treat or not to treat? Helicobacter pylori and gastro-oesophageal reflux disease - an alternative hypothesis

Helicobacter pylori causes acute on chronic gastritis and is responsible for most peptic ulcers and gastric cancer. However, recent papers have suggested that it may protect against gastro-oesophageal reflux, Barrett's oesophagus and oesophageal cancer. Furthermore, the rapid increase in gastro-oesophageal reflux disease, Barrett's oesophagus and adenocarcinoma of the oesophagus in the developed world has been attributed by some to the falling prevalence of H. pylori. These considerations have led to the suggestion that H. pylori infection should not necessarily be treated, especially in patients with gastro-oesophageal reflux disease. Conversely, data from prospective randomized studies have shown that H. pylori eradication does not cause gastro-oesophageal reflux disease in patients with duodenal ulcer or in the normal population, nor does it worsen the outcome of pre-existing gastro-oesophageal reflux disease. Therefore, although H. pylori is negatively associated with gastro-oesophageal reflux disease, its eradication does not induce the disease. A hypothesis is presented suggesting that the increased prevalence of gastro-oesophageal reflux disease is a result of rising acid secretion in the general population, which, in turn, is a consequence of the increased linear height (a predictor of acid secretion). The greater acid secretion could also explain the decline in the prevalence of H. pylori and perhaps account for the inverse relationship between H. pylori and gastro-oesophageal reflux disease. These considerations are explored in discussing whether H. pylori infection should be treated in infected patients presenting with gastro-oesophageal reflux disease.

Gastroesophageal reflux disease and Helicobacter pylori infection in neurologically impaired children: inter-relations and therapeutic implications

BACKGROUND

The aim of this retrospective study was to assess the relationship between Helicobacter pylori infection and gastroesophageal reflux disease in a high-risk population of children.

METHODS

Forty-three neurologically impaired pediatric patients with H. pylori had upper gastrointestinal endoscopy between 1990 and 2000. Infection was confirmed by positive H. pylori culture or by identification of organisms in gastric biopsy specimens (fundus, n = 2; antrum, n = 3). Reflux esophagitis was diagnosed by ulceration of the esophageal mucosa at endoscopy. Four to 6 weeks after the completion of antibiotic treatment of H. pylori, a second endoscopy was performed and the gross appearance of the esophagus was recorded.

RESULTS

At the first endoscopy, esophagitis was noted in 14 of 43 patients. After treatment, H. pylori infection was eradicated in all 14 patients with esophagitis but in only 19 of 29 (66%) of those with normal esophagus (P = 0.01). Esophagitis was still present in 4 of 14 (29%) patients who had esophagitis at the first endoscopy. Persistent esophagitis was only related to the presence of esophagitis before treatment (P = 0.02). In 29 patients with a normal esophagus at the first endoscopy, only one case of esophagitis was observed after H. pylori eradication.

CONCLUSION

The data suggest that treatment of H. pylori infection should be considered in children with concomitant GERD, and such treatment is unlikely to either induce or exacerbate peptic esophagitis.

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.

Colonization with cagA-positive Helicobacter pylori strains in intestinal metaplasia of the esophagus and the esophagogastric junction

OBJECTIVES

Recent studies indicate that colonization with cagA-positive Helicobacter pylori (H. pylori) strains may protect against gastroesophageal reflux disease (GERD) and its complications, but the role of cagA in the etiology of Barrett's esophagus has so far been poorly investigated. The pathogenesis of intestinal metaplasia (IM) at an endoscopically normal esophagogastric junction (EGJ) is still unclear, and the role of the H. pylori virulence factor cagA in it has not been investigated. The aim of our study was to assess the relationship between H. pylori and cagA-positive H. pylori in particular and IM at an endoscopically normal EGJ and Barrett's esophagus.

METHODS

Serum samples were obtained from 62 patients without IM, 43 patients with IM at an endoscopically normal junction, and 51 patients with Barrett's esophagus. IM was defined as presence of goblet cells with positive staining with Alcian blue. The prevalence of H. pylori and cagA was investigated by assessment of IgG antibody levels as determined by ELISA.

RESULTS

The overall H. pylori prevalence was 59% (92/156), and the cagA prevalence was 29% (46/156). Although 63% (39/62) of IM negative subjects and 74% (32/43) of those with IM at the junction were H. pylori positive, only 41% (21/51) of Barrett's patients tested positive. The differences between the IM negative and the Barrett's group (p = 0.02) and between IM at the junction and Barrett's were significant (p = 0.002). The relative cagA prevalence (percentage with cagA positivity and H. pylori positivity) was 56% (22/39) in patients who were IM negative, 59% (19/32) in those with IM at the junction, and 24% (5/21) in those with Barrett's. The prevalence of anti-CagA was significantly lower in patients with Barrett's esophagus compared with patients who were IM negative (p = 0.002) and those who had IM at the junction (p < 0.001). No difference in cagA prevalence was seen between the latter groups.

CONCLUSIONS

These findings are in line with the concept that H. pylori and cagA-positive strains in particular protect against the development of Barrett's esophagus. In contrast, our findings do not support the theory that IM at an endoscopically normal esophagogastric junction is associated with H. pylori or cagA-positive strains. IM at the junction and Barrett's esophagus seem to have different etiologies.

Association of CagA and VacA presence with ulcer and non-ulcer dyspepsia in a Turkish population

AIM: The mostly known genotypic virulence features, of H. pylori are cytotoxin associated gene A (CagA) and Vacuolating cytotoxin gene A (VacA). We investigated the association of these major virulence factors with ulcer and non-ulcer dyspepsia in our region.

METHODS: One hundred and forty two dyspeptic patients were studied (average age 44.8 ± 15.9 years, range 15-87 years, 64 males and 78 females). Antral and corpus biopsies were taken for detecting and genotyping of H. pylori. 107 patients who were H. pylori positive by histological assessment were divided into three groups according to endoscopic findings: Duodenal ulcer (DU), gastric ulcer (GU) and non-ulcer dyspepsia (NUD). The polymerase chain reaction (PCR) was used to detect CagA and VacA genes of H. pylori using specific primers.

RESULTS: H. pylori was isolated from 75.4% (107/142) of the patients. Of the 107 patients, 66 (61.7%) were CagA-positive and 82 (76.6%) were VacA-positive. CagA gene was positively associated with DU and GU (P < 0.01, P < 0.02), but not with NUD (P > 0.05). Although VacA positivity in ulcer patients was higher than that in NUD group, the difference was not statistically significant (P > 0.05).

CONCLUSION: There is a significantly positive association between CagA genes and DU and GU. The presence of VacA is not a predictive marker for DU, GU, and NUD in our patients.

Increased risk of noncardia gastric cancer associated with proinflammatory cytokine gene polymorphisms

BACKGROUND & AIMS

Genetic variations in proinflammatory and anti-inflammatory cytokine genes influence individual response to carcinogenic exposures. Polymorphisms in interleukin (IL)-1 beta and its endogenous receptor antagonist are associated with risk of Helicobacter pylori-related gastric cancer. The aim of this study was to evaluate the role of proinflammatory cytokine gene polymorphisms in gastric and esophageal cancers defined by anatomic subsite.

METHODS

We assessed polymorphisms of the IL-1 gene cluster and 4 other cytokine genes in a population-based case-control study of upper gastrointestinal cancers, including gastric cardia (n = 126) and noncardia adenocarcinoma (n = 188), esophageal squamous cell carcinoma (n = 53), and adenocarcinoma (n = 108), and frequency-matched controls (n = 212). ORs for the different cancers were computed from logistic regression models adjusted for potential confounding factors.

RESULTS

Proinflammatory genotypes of tumor necrosis factor alpha and IL-10 were each associated with more than doubling of the risk of noncardia gastric cancer. Carriage of multiple proinflammatory polymorphisms of IL-1B(o) IL-1 receptor antagonist, tumor necrosis factor A, and IL-10 conferred greater risk, with ORs (and 95% confidence intervals) of 2.8 (1.6-5.1) for one, 5.4 (2.7-10.6) for 2, and 27.3 (7.4-99.8) for 3 or 4 high-risk genotypes. In contrast, these polymorphisms were not consistently related to the risks of esophageal or gastric cardia cancers. Polymorphisms in IL-4 and IL-6 were not associated with any of the cancers studied.

CONCLUSIONS

A proinflammatory cytokine genetic profile increases the risk of noncardia gastric adenocarcinoma but not other upper gastrointestinal cancers, possibly by inducing a hypochlorhydric and atrophic response to gastric H. pylori infection.

Prevalence of Helicobacter pylori in patients with gastro-oesophageal reflux disease: systematic review

OBJECTIVES

To ascertain the prevalence of Helicobacter pylori in patients with gastro-oesophageal reflux disease and its association with the disease.

DESIGN

Systematic review of studies reporting the prevalence of H pylori in patients with and without gastro-oesophageal reflux disease.

DATA SOURCES

Four electronic databases, searched to November 2001, experts, pharmaceutical companies, and journals.

MAIN OUTCOME MEASURE

Odds ratio for prevalence of H pylori in patients with gastro-oesophageal reflux disease.

RESULTS

20 studies were included. The pooled estimate of the odds ratio for prevalence of H pylori was 0.60 (95% confidence interval 0.47 to 0.78), indicating a lower prevalence in patients with gastro-oesophageal reflux disease. Substantial heterogeneity was observed between studies. Location seemed to be an important factor, with a much lower prevalence of H pylori in patients with gastro-oesophageal reflux disease in studies from the Far East, despite a higher overall prevalence of infection than western Europe and North America. Year of study was not a source of heterogeneity.

CONCLUSION

The prevalence of H pylori infection was significantly lower in patients with than without gastro-oesophageal reflux, with geographical location being a strong contributor to the heterogeneity between studies. Patients from the Far East with reflux disease had a lower prevalence of H pylori infection than patients from western Europe and North America, despite a higher prevalence in the general population.

Review article: gastro-oesophageal reflux disease--pathophysiological issues of clinical relevance

Gastro-oesophageal reflux disease is a multifactorial disorder in which the pathophysiological mechanisms are variably combined in different patients. Motor dysfunction of the lower oesophageal sphincter (LOS) and, possibly, the proximal stomach is a major cause of the increase in the number of reflux episodes. Transient LOS relaxation is the main mechanism of reflux in many patients with endoscopically negative disease, whereas a hypotensive LOS becomes relevant only in patients with oesophagitis. Alterations in primary and secondary peristalsis contribute to the increased oesophageal acid exposure by delaying clearance. The presence of a hiatus hernia, especially when voluminous and/or non-reducible, increases the number of reflux episodes by mechanically weakening the oesophago-gastric junction, and impairs oesophageal clearance. Hypersensitivity to acid is often present and contributes to the clinical manifestations of the disease, whereas oesophageal hypersensitivity, both to chemical and mechanical stimuli, plays a predominant role in a subset of patients. Increased concentrations of noxious compounds in the oesophageal refluxate may contribute to the development of anatomical lesions, but this is still a matter for debate. The clinical relevance of Helicobacter pylori infection and of mucosal defensive factors still needs to be fully elucidated.

Genetic pathways involved in the progression of Barrett's metaplasia to adenocarcinoma

BACKGROUND

The prediction of which patients with Barrett's metaplasia will develop cancer is difficult. Better genetic characterization of the condition may aid clinicians in devising more effective management and follow-up strategies.

METHODS

A review was undertaken of the accumulated genetic data relating to the progression of squamous epithelium to adenocarcinoma. The normal functions of a number of cancer-related genes are described and an explanation is given of how alterations in these genes interfere with normal cell processes and lead to cancer.

RESULTS AND CONCLUSION

The main genetic alterations accompanying the progression through dysplasia to adenocarcinoma were collated from 135 papers. The principal genetic changes implicated are the loss of p16 gene expression (by deletion or hypermethylation), the loss of p53 expression (by mutation and deletion), the increase in cyclin D1 expression, the induction of aneuploidy and the losses of the Rb, DCC and APC chromosomal loci.

Symposium: Helicobacter pylori and clinical risks--focus on gastro-oesophageal reflux disease

Helicobacter pylori is a gastric pathogen that is a major cause of peptic ulcer disease, has a role in mucosa-associated lymphoid tissue (MALT) lymphoma and is associated with gastric cancer. Yet, in a large proportion of the human population, H. pylori infection has no apparent adverse clinical consequences. Furthermore, recent research suggests that H. pylori may even confer protection against gastroesophageal reflux disease. The conflicting evidence surrounding H. pylori infection was discussed at a sponsored symposium in Helsinki, introduced by Professor P. Malfertheiner, with papers presented by Dr H. J. O'Connor, Professor R. M. Genta, Dr P. Unge and Professor A. T. R. Axon. Emerging epidemiological and retrospective evidence suggests that the presence of H. pylori infection may provide some protection against gastroesophageal reflux disease, but there is other evidence that shows no benefit of H. pylori for the protection of the oesophagus. It was felt that prospective, multicentre studies are needed to explore the H. pylori-gastroesophageal disease relationship further, to avoid confusing potential benefits with known risks. Following the symposium, a discussion on the relative risks and benefits for H. pylori eradication was provided by Professor Axon and Professor Blaser. Eradication of H. pylori has been recommended in a series of management guidelines issued by consensus groups. However, accurate estimates of the relative risks and benefits of H. pylori infection in the general population, as well as in specific patient groups, is essential in order to develop a management strategy.

Effect of Helicobacter pylori eradication on oesophageal acid exposure in patients with reflux oesophagitis

BACKGROUND

The effect of Helicobacter pylori eradication on reflux oesophagitis is unclear.

AIM

To study the effect of H. pylori eradication on oesophageal acid exposure and disease severity in patients with reflux oesophagitis.

METHODS

Patients with reflux oesophagitis and H. pylori infection were recruited for 24-h oesophageal pH-metry. They were then randomly assigned to receive either treatment for H. pylori eradication (1-week omeprazole-based triple therapy, followed by 7-week omeprazole) or omeprazole alone (8-week omeprazole). Uninfected patients were recruited as controls. Endoscopy, pH monitoring and symptom assessment were repeated at 26 weeks.

RESULTS

Forty patients (25 H. pylori-positive and 15 uninfected) with erosive oesophagitis were studied. Fourteen were randomized to receive treatment for H. pylori eradication and 11 to receive omeprazole alone. There was no difference in the percentage of time the oesophageal pH < 4 before and 26 weeks after treatment among the three groups. However, the percentage of time the oesophageal pH < 2 (P=0.01) and pH < 3 (P=0.02) was significantly increased in patients receiving treatment for H. pylori eradication. Three (21%) patients in the group receiving treatment for H. pylori eradication had worsening of reflux oesophagitis.

CONCLUSIONS

H. pylori eradication increases oesophageal acid exposure and may adversely affect the clinical course of reflux disease in a subset of patients.

Rosacea: current thoughts on origin

Rosacea is a clinical pattern beginning and evolving in the genetically susceptible individual in response to a host of exposures. It produces a variety of clinical presentations, which vary over time and with age. Recently, many specific mediators of rosacea development have been described. A primary genetic cause for rosacea is suggested as single genes often control such mediators: enzymes, neuroendocrine transmitters, and cytokines are found in pathways to rosacea signs and symptoms. Currently, neither a specific cause nor a laboratory indicator of rosacea has been suggested. However, broadening interest in rosacea portends future increase in knowledge.

Outcomes of Helicobacter pylori treatment in community practice and impact of therapeutic effectiveness information on physician behaviour

BACKGROUND

The effect of knowledge of Helicobacter pylori eradication rates on physician choice of treatment regimen is unknown. As practice variation results in differences in outcome, it is important to determine whether physician behaviour can be altered by such knowledge.

AIMS

(i) To determine whether dissemination of practice variation and effectiveness data regarding H. pylori changes subsequent prescribing behaviour and (ii) whether this change results in an improvement in the effectiveness of therapy.

METHODS

Community gastroenterologists in the Portland metropolitan area enrolled patients being treated for H. pylori. The regimen used, diagnostic method, indication and success in eradication was measured. Patient-centred factors were also measured, including symptoms, interest in post-treatment diagnostic testing and willingness to pay.

RESULTS

Significantly more physicians participating in both studies used proton pump inhibitor-triple therapy based regimens in this trial (46% vs. 85%, P=0.01), although the overall difference between the two trials was not significant (62% vs. 83%, P=0.11). There was no change in overall eradication rates by per protocol analysis between trials (84% vs. 85%, P=0.78), but a significant decrease in effectiveness by intention-to-treat analysis observed in this study (80% vs. 71%, P=0.03). Significantly more patients were treated for reasons other than peptic ulcer disease in this study (P=0.0003).

CONCLUSIONS

The overall effectiveness of H. pylori therapy in practice remains good. There has been a shift in the choice of treatment regimen and indication for therapy between the time periods of the two studies. Dissemination of treatment data appears to effect prescribing behaviour, but whether it has a beneficial effect on treatment outcome remains unproven.