The significance of cagA(+) Helicobacter pylori in reflux oesophagitis

Management of Helicobacter pylori infection: Guidelines of the Italian Society of Gastroenterology (SIGE) and the Italian Society of Digestive Endoscopy (SIED)

Helicobacter pylori infection is very common and affects more than one-third of adults in Italy. Helicobacter pylori causes several gastro-duodenal diseases, such as gastritis, peptic ulcer and gastric malignancy, and extra-gastric diseases. The eradication of the bacteria is becoming complex to achieve due to increasing antimicrobial resistance. To address clinical questions related to the diagnosis and treatment of Helicobacter pylori infection, three working groups examined the following topics: (1) non-invasive and invasive diagnostic tests, (2) first-line treatment, and (3) rescue therapies for Helicobacter pylori infection. Recommendations are based on the best available evidence to help physicians manage Helicobacter pylori infection in Italy, and have been endorsed by the Italian Society of Gastroenterology and the Italian Society of Digestive Endoscopy.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Does a relationship still exist between gastroesophageal reflux and Helicobacter pylori in patients with reflux symptoms?

Background

The nature of the relationship between Helicobacter pylori and reflux esophagitis (RE) is not fully understood. In addition, the effect of H. pylori eradication on RE and gastroesophageal reflux disease (GERD) is unclear. This study was designed to investigate the relationship between H. pylori infection and the grade of GERD in patients with reflux symptoms.

Methods

Between January 2010 and July 2013, 184 consecutive patients with daily reflux symptoms for at least one year were evaluated at the ambulatory for functional esophageal disease, Tor Vergata University Hospital, Rome, Italy. All patients underwent a pretreatment evaluation, which included anamnesis, clinical examination, Esophagogastroduodenoscopy (EGDS) with biopsy, esophageal manometry and 24-hour pH-metry. All statistical elaborations were obtained using Statigraphies 5 plus for Window XP.

Results

There was no statistical difference regarding Lower Esophageal Sphincter (LES) pressure between patients who were H. pylori-positive and H. Pylori-negative (19.2 ± 9.5 (range: 3.7 to 46.2) and 19.7 ± 11.0 (range: 2.6 to 61), respectively). Further, no significant difference was evidenced in esophageal wave length (mean value: 3.1 seconds in H. pylori-negative patients versus 3.2 seconds in H. pylori-positive patients) or in esophageal wave height (mean value: 72.2 ± 39.3 in H. pylori-negative patients versus 67.7 ± 28.4 in H. pylori-positive patients). We observed that hiatal hernia (P = 0.01), LES opening (P = 0.05), esophageal wave length (P = 0.01) and pathological reflux number (P = 0.05) were significantly related to the presence of esophagitis. However, H. pylori infection was not significantly related to the presence of reflux esophagitis.

Conclusions

Our clinical, endoscopic, manometric and pH-metric data shows no significant role of H. pylori infection in the development of GERD or in the pathogenesis of reflux esophagitis. However, current data do not provide sufficient evidence to define this relationship and further prospective large studies are needed.

Gastric cancer epidemiology and risk factors

Gastric cancer is a prevalent yet heterogeneous disease. From diet and lifestyle to genetics and ethnicity, our appreciation of the complexity of gastric cancer has evolved. This review will discuss the epidemiology of gastric cancer focusing on trends across various risk categories. We realize that gastric cancer is not merely a single disease, but rather individual diseases within a single organ-a distinction that will aid our understanding of disease heterogeneity and its significance.

The relationship between helicobacter pylori infection and gastro-esophageal reflux disease

BACKGROUND

Gastro-esophageal reflux disease is a common condition, affecting 25%-40% of the population. Increasing attention has been paid to the relationship between Helicobacter pylori infection and reflux esophagitis.

AIM

The aim of this study was to investigate the association between CagA+ H. pylori and endoscopically proven gastro-esophageal reflux disease.

PATIENTS AND METHODS

The study group included 60 hospital patients with gastro-esophageal reflux disease between 2007 and 2009 as compared with 30 healthy patients from a control group that was age and sex matched. Helicobacter pylori CagA+ was identified by an immunological test (Immunochromatography test) (ACON, USA).

RESULTS

Helicobacter pyloriCagA+ was present in 42/60 (70%) of the patients with gastro-esophageal reflux disease and in 11/30 (36.6%) patients in the control group (p=0.002). The Odds ratio = 0.8004 with 95% Confidence Interval = from 0.3188 to 2.0094. The relative risk=1.35 that indicates an association between Helicobacter pylori and disease.

CONCLUSIONS

The presence of Helicobacter pylori is significantly increased in patients with gastro-esophageal reflux disease as compared with the control group.

Is Helicobacter pylori antibiotic resistance surveillance needed and how can it be delivered?

BACKGROUND

Most patients are prescribed Helicobacter pylori treatment without culture and antibiotic susceptibility testing, as current guidance recommends that patients with recurrent dyspepsia should be tested for H. pylori using a non-invasive breath or faecal antigen test.

AIMS

To determine the prevalence of H. pylori antibiotic resistance in patients attending endoscopy in England and Wales, and the feasibility of an antibiotic resistance surveillance programme testing.

METHODS

We tested the antibiotic susceptibility of H. pylori isolates from biopsy specimens from 2063 of 7791 (26%) patients attending for endoscopy in Gloucester and Bangor, and 339 biopsy specimens sent to the Helicobacter Reference Unit (HRU) in London. Culture and susceptibility testing was undertaken in line with National and European methods.

RESULTS

Helicobacter pylori were cultured in 6.4% of 2063 patients attending Gloucester and Bangor hospitals. Resistance to amoxicillin, tetracycline and rifampicin/rifabutin was below 3% at all centres. Clarithromycin, metronidazole and quinolone resistance was significantly higher in HRU (68%, 88%, 17%) and Bangor isolates (18%, 43%, 13%) than Gloucester (3%, 22%, 1%). Each previous course of these antibiotics is associated with an increase in the risk of antibiotic resistance to that agent [clarithromycin: RR = 1.5 (P = 0.12); metronidazole RR = 1.6 (P = 0.002); quinolone RR = 1.8 (P = 0.01)].

CONCLUSIONS

Helicobacter pylori infection is now uncommon in dyspeptic patients at endoscopy. A surveillance system is feasible and necessary to inform dyspepsia management guidance. Clinicians should take a thorough antibiotic history before prescribing metronidazole, clarithromycin or levofloxacin for H. pylori.

Spatial autocorrelation calculations of the nine malignant neoplasms in Taiwan in 2005-2009: a gender comparison study

Spatial analytical techniques and models are often used in epidemiology to identify spatial anomalies (hotspots) in disease regions. These analytical approaches can be used to identify not only the location of such hotspots, but also their spatial patterns. We used spatial autocorrelation methodologies, including Global Moran's I and Local Getis-Ord statistics, to describe and map spatial clusters and areas in which nine malignant neoplasms are situated in Taiwan. In addition, we used a logistic regression model to test the characteristics of similarity and dissimilarity between males and females and to formulate the common spatial risk. The mean found by local spatial autocorrelation analysis was used to identify spatial cluster patterns. We found a significant relationship between the leading malignant neoplasms and well-documented spatial risk factors. For instance, in Taiwan, the geographic distribution of clusters where oral cavity cancer in males is prevalent was closely correspond to the locations in central Taiwan with serious metal pollution. In females, clusters of oral cavity cancer were closely related with aboriginal townships in eastern Taiwan, where cigarette smoking, alcohol drinking, and betel nut chewing are commonplace. The difference between males and females in the spatial distributions was stark. Furthermore, areas with a high morbidity of gastric cancer were clustered in aboriginal townships where the occurrence of Helicobacter pylori is frequent. Our results revealed a similarity between both males and females in spatial pattern. Cluster mapping clarified the spatial aspects of both internal and external correlations for the nine malignant neoplasms. In addition, using a method of logistic regression also enabled us to find differentiation between gender-specific spatial patterns.

Symptoms in patients on long-term proton pump inhibitors: prevalence and predictors

BACKGROUND

Symptom control in primary care patients on long-term proton pump inhibitor (PPI) treatment is poorly understood.

AIM

To explore associations between symptom control and demographics, lifestyle, PPI use, diagnosis and Helicobacter pylori status.

METHODS

A cross-sectional survey (n = 726) using note reviews, questionnaires and carbon-13 urea breath testing. Determinants of symptom control [Leeds Dyspepsia Questionnaire (LDQ), Carlsson and Dent Reflux Questionnaire (CDRQ), health-related quality-of-life measures (EuroQoL: EQ-5D and EQ-VAS)] were explored using stepwise linear regression.

RESULTS

Moderate or severe dyspepsia symptoms occurred in 61% of subjects (LDQ) and reflux symptoms in 59% (CDRQ). Age, gender, smoking and body mass index had little or no influence upon symptom control or PPI use. Average symptom scores and PPI use were lower in patients with non-ulcer dyspepsia and gastro-protection than gastro-oesophageal reflux disease (GERD) and uninvestigated dyspepsia. H. pylori infection was associated with lower reflux symptom scores only in patients with GERD and uninvestigated dyspepsia. EQ-5D was not able to discriminate between diagnostic groups, although the EQ-VAS performed well.

CONCLUSIONS

A majority of patients suffered ongoing moderate or severe symptoms. GERD and uninvestigated dyspepsia were associated with poorer long-term symptom control; H. pylori appeared to have a protective effect on reflux symptoms in these patients.

Asia-Pacific consensus guidelines on gastric cancer prevention

BACKGROUND AND AIM

Gastric cancer is a major health burden in the Asia-Pacific region but consensus on prevention strategies has been lacking. We aimed to critically evaluate strategies for preventing gastric cancer.

METHODS

A multidisciplinary group developed consensus statements using a Delphi approach. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded.

RESULTS

Helicobacter pylori infection is a necessary but not sufficient causal factor for non-cardia gastric adenocarcinoma. A high intake of salt is strongly associated with gastric cancer. Fresh fruits and vegetables are protective but the use of vitamins and other dietary supplements does not prevent gastric cancer. Host-bacterial interaction in H. pylori infection results in different patterns of gastritis and differences in gastric acid secretion which determine disease outcome. A positive family history of gastric cancer is an important risk factor. Low serum pepsinogens reflect gastric atrophy and may be useful as a marker to identify populations at high risk for gastric cancer. H. pylori screening and treatment is a recommended gastric cancer risk reduction strategy in high-risk populations. H. pylori screening and treatment is most effective before atrophic gastritis has developed. It does not exclude the existing practice of gastric cancer surveillance in high-risk populations. In populations at low risk for gastric cancer, H. pylori screening is not recommended. First-line treatment of H. pylori infection should be in accordance with national treatment guidelines.

CONCLUSION

A strategy of H. pylori screening and eradication in high-risk populations will probably reduce gastric cancer incidence, and based on current evidence is recommended by consensus.

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.

Risk of oesophageal cancer by histology among patients hospitalised for gastroduodenal ulcers

OBJECTIVE

The mechanism behind the epidemiologically evident inverse relation between Helicobacter pylori seropositivity and risk of oesophageal adenocarcinoma (OAC) remains obscure. Severe corpus gastritis is unlikely to be in the causal pathway. With the hypothesis of a uniformly low risk, the associations of OAC with duodenal ulcer and gastric ulcer were explored, both linked to H pylori infection but with different patterns of bacterial colonisation and intragastric acidity. Possible associations of oesophageal squamous cell carcinoma (OSCC) with these ulcer types were also addressed.

DESIGN AND PATIENTS

Retrospective cohorts of 61,548 and 81,379 unoperated patients with duodenal ulcer and gastric ulcer, respectively, recorded in the Swedish Inpatient Register since 1965, were followed from the first hospitalisation until the date of any cancer, death, emigration, definitive surgery, or 31 December 2003. Standardised incidence ratios (SIRs), with 95% CIs, expressed relative risk of oesophageal cancer, compared with the Swedish population matched for age, sex and calendar period.

RESULTS

Contrary to expectation, patients with duodenal ulcer had a significant 70% excess risk of OAC (SIR 1.7, 95% CI 1.1 to 2.5). Gastric ulcer was unrelated to OAC (SIR 1.1, 95% CI 0.6 to 1.7). Although duodenal ulcer was non-significantly associated with a small excess of OSCC (SIR 1.3, 95% CI 0.96 to 1.8), gastric ulcer was linked to 80% increased risk (SIR 1.8, 95% CI 1.4 to 2.3).

CONCLUSION

The inverse association between H pylori and OAC does not pertain to all infections. The pattern of gastric colonisation and/or impact on acidity may be important. With the reservation for the possibility of confounding, this study also provides some support for the importance of intragastric environment in the aetiology of OSCC.

The influence of Helicobacter pylori infection on the prevalence of endoscopic erosive esophagitis

OBJECTIVES

This study aimed to determine the frequency of endoscopic esophagitis and Helicobacter pylori infection in a large Turkish population over a 6-year period.

METHODS

We studied a consecutive series of 14,380 patients who had been newly referred for diagnostic esophagogastroduodenoscopy from 2000 to 2006. The mean age value was 45 +/- 10 (18-89) years. All endoscopic findings were retrospectively evaluated. Two antral and two corpus biopsies were taken from patients for rapid urease test. Endoscopic esophagitis was defined as the presence of erosions and/or ulceration. The relationship between erosive esophagitis and various relevant factors was analyzed.

RESULTS

The overall prevalence of endoscopic esophagitis was 7.8% (95% CI, 6.9-8.1). The prevalence of positive rapid urease test was 49% (95% CI, 38-53) in patients with esophagitis and 85% (95% CI, 70-96) in patients without esophagitis (p < .001). From 2000 to 2006, the frequency of endoscopic esophagitis and the rate of positive rapid urease test remained unchanged. After adjusting for the effects of mean age, male gender, and percentage of hiatal hernia, there was a 0.785% risk reduction in esophagitis with every 1% increase in the rate of positive rapid urease test result.

CONCLUSIONS

The frequency of endoscopic esophagitis is significantly lower in patients with a positive rapid urease test result. This negative correlation with H. pylori infection reflects a protective effect of H. pylori from endoscopic esophagitis in a Turkish population and deserves further investigation.

Epidemiology of gastric cancer

The incidence and mortality of gastric cancer have fallen dramatically in US and elsewhere over the past several decades. Nonetheless, gastric cancer remains a major public health issue as the fourth most common cancer and the second leading cause of cancer death worldwide. Demographic trends differ by tumor location and histology. While there has been a marked decline in distal, intestinal type gastric cancers, the incidence of proximal, diffuse type adenocarcinomas of the gastric cardia has been increasing, particularly in the Western countries. Incidence by tumor sub-site also varies widely based on geographic location, race, and socio-economic status. Distal gastric cancer predominates in developing countries, among blacks, and in lower socio-economic groups, whereas proximal tumors are more common in developed countries, among whites, and in higher socio-economic classes. Diverging trends in the incidence of gastric cancer by tumor location suggest that they may represent two diseases with different etiologies. The main risk factors for distal gastric cancer include Helicobacter pylori (H pylori) infection and dietary factors, whereas gastroesophageal reflux disease and obesity play important roles in the development of proximal stomach cancer. The purpose of this review is to examine the epidemiology and risk factors of gastric cancer, and to discuss strategies for primary prevention.

Lower prevalence of Helicobacter pylori infection with vacAs1a, cagA-positive, and babA2-positive genotype in erosive reflux esophagitis disease

BACKGROUND

Increased prevalence of esophagitis has been recognized in the West. Helicobacter pylori infection, particularly virulent strains, is proposed as a protective factor against the development of gastroesophageal reflux disease. To evaluate the relationship of reflux esophagitis with virulent H. pylori infection, we studied the prevalence of reflux esophagitis among H. pylori-infected and -uninfected patients and the genotype of isolates in Taiwan.

METHODS

Patients who had routine physical examination were investigated. The severity of esophagitis was evaluated using the Los Angeles grading system. H. pylori status was assessed by histology, rapid urease test, and bacterial culture. Genotyping of vacA, cagA, and babA2 was determined by polymerase chain reaction (PCR). Risk factors for severe esophagitis were evaluated.

RESULTS

Reflux esophagitis was found in 21.2% of 1622 patients. The prevalence of H. pylori infection was found in 33.0% of 276 patients with reflux esophagitis compared with 67.5% of 378 patients with normal esophagus (p < .001). Esophagitis occurred in a significantly lower rate among H. pylori-positive patients with peptic ulcer than those without peptic ulcer. cagA, babA2, and vacAs1a were detected in 100% of 143 isolates. Factors that predicted severe esophagitis included age, gender, and hiatus hernia but not H. pylori infection.

CONCLUSIONS

Our study suggests significantly lower incidence of H. pylori infection with the triple-positive virulent genotype in patients with reflux esophagitis in Taiwan.

23 years of the discovery of Helicobacter pylori: is the debate over?

The Gram negative curved bacillus H. pylori has become the prize bug of all times. Barry Marshall and Robin Warren the two discoverers of this organism have been awarded with this year's Nobel Prize. The Nobel committee at the Karolinska Institute of Sweden has selected this paradigm shift discovery of 1982 as the most impacting in medical sciences. This award has surprised many as the Nobel assembly has selected this 'Robert Koch styled medical detective work' for the prize as compared to many outstanding basic research stories on the waitlist. This editorial briefly touches the significant impact of H. pylori on gastroduodenal management and the path forward as the bug has become quite controversial in recent times.

Helicobacter pylori eradication has the potential to prevent gastric cancer: a state-of-the-art critique

Helicobacter pylori infection continues to play a key role in gastric diseases. Colonization of the gastric mucosa with the bacterium invariably results in the development of chronic gastritis and subsets of patients have a progression of the chronic gastritis to either ulcer or cancer. Epidemiological evidence indicates that the proportion of all gastric cancers attributable to H. pylori infection, and hence potentially preventable upon elimination of this risk factor, is somewhere in the range of 60% to 90%. This portends significant benefit in terms of morbidity and mortality, not least in populations with high prevalence of H. pylori infection coupled with high incidence of gastric cancer. The effect of prophylactic H. pylori eradication on gastric cancer incidence in humans remains unknown, however. Results from randomized trials are eagerly awaited, but availability of strong conclusive results may take many years. A growing number of studies show considerable variation in risk for gastric cancer development, depending on H. pylori strain type and the genetic predisposition of the host. There is also a remote possibility that elimination of the infection may have adverse health implications (e.g., antibiotic resistance), and therefore "simple" risk stratification and targeted chemoprevention is required. Based on "in depth" evidence presented at this workshop, the majority of the scientific task force favored a search-and-treat strategy in first-degree relatives of gastric cancer patients and an overwhelming majority felt that a more general screen-and-treat strategy should be focused in the first instance on a population with a high incidence of H. pylori-associated diseases.

Review article: Helicobacter pylori and gastro-oesophageal reflux disease

Epidemiological studies demonstrate a negative association between Helicobacter pylori infection and gastro-oesophageal reflux disease and its complications. This might represent a protective effect because of the tendency for H. pylori infection to lower gastric acid secretion with advancing age. However, studies of the effect of H. pylori eradication on gastro-oesophageal reflux disease have failed to show any worsening of gastro-oesophageal reflux disease symptoms. Several interactions between H. pylori and proton-pump inhibitor therapy used to treat gastro-oesophageal reflux disease need to be considered. Helicobacter pylori infection improves the control of gastric acidity by proton-pump inhibitors and this produces a small advantage in clinical control of reflux disease. The infection prevents rebound acid hypersecretion occurring when proton-pump inhibitor therapy is discontinued. However, concerns have been expressed that the body gastritis induced by proton-pump inhibitor therapy in H. pylori-infected subjects might increase the risk of gastric cancer. At present, it is unclear whether H. pylori should be eradicated in gastro-oesophageal reflux disease patients.

Characteristics of gastritis in patients with Helicobacter pylori-positive reflux esophagitis

BACKGROUND AND AIM

The influence of Helicobacter pylori on gastric acid secretion differs with the status of gastritis. The histological characteristics of gastritis in H. pylori-positive patients with reflux esophagitis have not been fully investigated. We therefore studied the pattern of endoscopic gastric mucosal atrophy and degree of histological gastritis in such patients.

METHODS

Subjects comprised 41 H. pylori-positive patients with reflux esophagitis, 41 age- and sex-matched patients with duodenal ulcer, and 41 patients with early gastric cancer. The endoscopic pattern of gastric mucosal atrophy was reviewed, and the degree of histological gastritis in biopsy specimens from the antrum and corpus was assessed in accordance with the updated Sydney system.

RESULTS

The grade of endoscopic and histological gastric mucosal atrophy in patients with reflux esophagitis was significantly lower than that in patients with gastric cancer, and the histological scores for antral atrophy and metaplasia in patients with reflux esophagitis tended to be lower than those in patients with duodenal ulcer. In patients with reflux esophagitis and duodenal ulcer, the scores for antral inflammation and activity tended to be higher than those for the corpus. Conversely, the inflammation and activity score in patients with early gastric cancer showed a corpus-predominant gastritis pattern.

CONCLUSION

In H. pylori-positive patients with reflux esophagitis, the degree of endoscopic gastric mucosal atrophy is low and histologically there is an antral-predominant gastritis pattern. Therefore, gastric acid secretion in H. pylori-positive patients with reflux esophagitis may be augmented by H. pylori infection.

Helicobacter pylori and gastroduodenal pathology: new threats of the old friend

The human gastric pathogen Helicobacter pylori causes chronic gastritis, peptic ulcer disease, gastric carcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma. It infects over 50% of the worlds' population, however, only a small subset of infected people experience H. pylori-associated illnesses. Associations with disease-specific factors remain enigmatic years after the genome sequences were deciphered. Infection with strains of Helicobacter pylori that carry the cytotoxin-associated antigen A (cagA) gene is associated with gastric carcinoma. Recent studies revealed mechanisms through which the cagA protein triggers oncopathogenic activities. Other candidate genes such as some members of the so-called plasticity region cluster are also implicated to be associated with carcinoma of stomach. Study of the evolution of polymorphisms and sequence variation in H. pylori populations on a global basis has provided a window into the history of human population migration and co-evolution of this pathogen with its host. Possible symbiotic relationships were debated since the discovery of this pathogen. The debate has been further intensified as some studies have posed the possibility that H. pylori infection may be beneficial in some humans. This assumption is based on increased incidence of gastro-oesophageal reflux disease (GERD), Barrett's oesophagus and adenocarcinoma of the oesophagus following H. pylori eradication in some countries. The contribution of comparative genomics to our understanding of the genome organisation and diversity of H. pylori and its pathophysiological importance to human healthcare is exemplified in this review.

Review article: Helicobacter pylori and gastro-oesophageal reflux disease--the European perspective

There is substantive epidemiological evidence of a negative association between Helicobacter pylori infection and reflux disease and its malignant complications. A plausible mechanism by which the infection might protect against reflux disease is by its propensity to produce atrophic gastritis and consequently reduce gastric acid secretion. Gastric acid is a key factor in the pathophysiology of reflux oesophagitis. It is well recognised that acid secretion decreases with age in H. pylori infected populations whereas acid secretion is maintained throughout life in H. pylori negative populations. The tendency for H. pylori infection to induce atrophy and reduce acid secretion is more marked in Eastern Europe and the Far East than in Western Europe, and this may be due to the influence of environmental and host genetic co-factors. This difference may also explain why the negative association between H. pylori infection and reflux disease is more marked in these areas than in Western Europe. If H. pylori infection is indeed protecting against reflux disease, then one would predict a rise in incidence of this disease and its malignant complications in these Eastern countries as the incidence of H. pylori infection decreases.

Differential Effects of Helicobacter pylori Eradication on Oxidative DNA Damage at the Gastroesophageal Junction and at the Gastric Antrum

Background and Aim: Helicobacter pylori–associated gastritis causes accumulation of reactive oxygen species in the mucosal compartment. This prospective study evaluates DNA oxidative damage in biopsy samples obtained from both the antrum and the gastroesophageal junction (GEJ) before and after H. pylori eradication.

Patients and Methods: Thirty-two consecutive H. pylori–positive patients underwent endoscopy with multiple biopsy sampling (i.e., antrum, incisura angularis, fundus, and cardia at the GEJ). After H. pylori eradication, 32 patients underwent a checkup endoscopy (mean interval, 5.7 months); in a subgroup of 13 subjects, a third endoscopy procedure was also performed (mean interval, 18 months). Additional biopsy samples (two from the antrum and two from the GEJ) were used to assess 8-hydroxydeoxyguanosine (8OHdG) levels using both high-pressure liquid chromatography with electrochemical detector and ELISA.

Results: In the antral compartment, no significant modifications of 8OHdG levels were assessed after H. pylori eradication. Conversely, following eradication, 8OHdG levels significantly increased (high-pressure liquid chromatography with electrochemical detector, P = 0.04; ELISA method, P = 0.05) in biopsy samples taken from the GEJ, and a further increase was documented in the subgroup of patients who underwent a third endoscopy (P = 0.01). The increasing trend was more relevant in patients in whom H. pylori-cagA–positive strains were eradicated and in those affected by hiatal hernia.

Conclusions: The levels of DNA adducts in the antral mucosa are not modified by H. pylori eradication; conversely, H. pylori eradication significantly increases the oxidative adducts at the GEJ. The clinical and biological importance of this situation and whether and how it relates to a higher risk of precancerous lesions is open to debate.

Systematic review: the effect of Helicobacter pylori and its eradication on gastro-oesophageal reflux disease in patients with duodenal ulcers or reflux oesophagitis

BACKGROUND

The effect of Helicobacter pylori in provoking or protecting against gastro-oesophageal reflux disease is unclear and studies have given conflicting results. Recent guidelines recommend H. pylori eradication in patients on long-term proton pump inhibitors.

AIM

To ascertain the effect of H. pylori eradication on gastro-oesophageal reflux disease outcomes (reflux oesophagitis and heartburn) in patients with duodenal ulcer disease, and to ascertain the effect of H. pylori infection on reflux oesophagitis concerning heartburn, pH, severity, healing and relapse rates.

METHODS

A systematic review of electronic databases was undertaken to September 2003. Experts in the field, pharmaceutical companies and journals were contacted about unpublished trials. Studies were reviewed according to predefined eligibility and quality criteria. Twenty-seven studies/trials were included in the systematic review.

RESULTS

Study variation rather than therapy-influenced results in relation to the presence or absence of oesophagitis in patients with duodenal ulcer who underwent H. pylori eradication at 6-48 months follow-up. In patients with reflux oesophagitis no obvious differences were discovered in heartburn scores, 24-h pH values, healing and relapse rates between H. pylori-positive and -negative cases.

CONCLUSION

There is no evidence to indicate that H. pylori eradication in duodenal ulcer disease provokes reflux oesophagitis or worsens heartburn; (ii) there are insufficient data to draw firm conclusions about the impact of H. pylori in patients with reflux oesophagitis.

Review article: trials on reflux disease -- the role of acid secretion and inhibition

The importance of gastric acid in the pathophysiology of gastro-oesophageal reflux disease is substantiated by the extraordinary therapeutic success of acid inhibition in the management of the disease. The influence of many risk factors for gastro-oesophageal reflux disease is also mediated through their effect on gastric acid secretion and acid reflux. Helicobacter pylori reduces the risk of gastro-oesophageal reflux disease by causing corpus gastritis and reducing gastric acid output. The geographical and temporal trends of H. pylori infection in human populations and its influence on gastric acid secretion are responsible for much of the apparent epidemiology of gastro-oesophageal reflux disease. On average, intra-oesophageal exposure to acid is higher in patients who respond poorly to antisecretory medication. It also tends to increase with increasing severity of reflux disease. However, gastric acid secretion and intra-oesophageal acid exposure vary markedly in reflux patients. The degrees of gastric or intra-oesophageal acidity do not allow the prediction of the presence or severity of gastro-oesophageal reflux disease in the individual subject. The many clinical trials on gastro-oesophageal reflux disease indicate that the reflux of gastric acid constitutes an essential mechanism in the development of this disease, but that additional and partly unknown risk factors must contribute to its aetiology and promote its occurrence in the individual patient.

cagA-positive Helicobacter pylori strains and gastro-oesophageal reflux disease: still puzzling?

Gastro-oesophageal reflux disease (GORD) and Helicobacter pylori infection are both common in Western countries. A recently published meta-analysis has shown an association between an absence of H. pylori infection and GORD symptoms. Infection with cagA-positive H. pylori strains is a causative factor for the development of duodenal ulcer and is a risk factor for gastric cancer. Data about a protective role of cagA-positive H. pylori strains against more severe reflux oesophagitis are documented in several studies, but questioned by some other studies. There is a need for further studies to clear the definite role of cagA-positive H. pylori strains in severe reflux oesophagitis and their possible effect on the development of Barrett's adenocarcinoma. The role of Helicobacter pylori in gastro-oesophageal reflux disease (GORD) is still discussed controversially. Different factors might be responsible for the remarkably heterogeneous results of previously performed studies (e.g. location, environmental factors and different virulence factors of H. pylori strains). A very recently published meta-analysis has shown a significant association between the absence of H. pylori infection and GORD symptoms, and a positive correlation between anti-H. pylori therapy and the occurrence of both de-novo and rebound/exacerbated GORD. The results of this meta-analysis are questioned by some authors because of single larger trials and geographical variations of the studies analysed. Data on the role of the cytotoxic-associated antigen (cagA)-positive H. pylori strains are contradictory. Several studies have provided evidence supporting the protecting role of cagA-positive H. pylori strains against GORD, but these results were not confirmed by all studies. A multitude of patients suffer from H. pylori infection and GORD, simultaneously. Therefore, further studies are needed to clearly answer the question whether infection with cagA-positive H. pylori strains, which bear a well-documented risk for gastric cancer and gastro-duodenal ulcer, is really helpful against more severe reflux oesophagitis and, in consequence, perhaps protective against Barrett's oesophagus and Barrett's adenocarcinoma.

IL1B and IL1RN polymorphic genes and Helicobacter pylori cagA strains decrease the risk of reflux esophagitis

BACKGROUND & AIMS

Proinflammatory interleukin (IL)-1 gene polymorphisms associated with high levels of IL-1beta activity increase the risk for hypochlorhydria and distal gastric carcinoma. The aim of this study was to evaluate whether carriers of these polymorphic genes are protected against gastroesophageal reflux disease (GERD). TNFA-308 polymorphisms were also studied.

METHODS

We prospectively evaluated 385 patients without gastric cancer and peptic ulcer. Of these patients, 383 (98 with GERD and 285 controls) were successfully genotyped for all cytokines studied. The cagA status of Helicobacter pylori isolates was determined by polymerase chain reaction (PCR). IL1B-511/-31, IL1RN, and TNFA-308 polymorphisms were genotyped by PCR, PCR/restriction fragment length polymorphism, or PCR/confronting 2-pair primers. Histologic gastritis was assessed according to the updated Sydney system. The role of the proinflammatory cytokine genotypes in the genesis of GERD was evaluated before and after stratification by H. pylori status in logistic regression models controlling for confounding factors.

RESULTS

IL1B-31 (a near-complete linkage disequilibrium between polymorphism at -31 and -511 was found) and IL1RN*2 allele polymorphisms were associated with GERD. After stratification, in the group of H. pylori-positive patients, cagA-positive status, IL1B-31 polymorphic alleles, IL1RN*2 alleles, and the degree of corpus gastritis were negatively associated with GERD. In the H. pylori-negative group, IL1B-31C/C genotype was inversely associated with GERD even after adjustment for age and sex.

CONCLUSIONS

This study provides evidence supporting the independent protective role of cagA-positive H. pylori status and IL1B and ILRN allele polymorphisms against GERD.

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.

Randomised controlled trial of effects of Helicobacter pylori infection and its eradication on heartburn and gastro-oesophageal reflux: Bristol helicobacter project

OBJECTIVES

To investigate the effects of Helicobacter pylori infection and its eradication on heartburn and gastro-oesophageal reflux.

DESIGN

Cross sectional study, followed by a randomised placebo controlled trial.

SETTING

Seven general practices in Bristol, England.

PARTICIPANTS

10,537 people, aged 20-59 years, with and without H pylori infection (determined by the (13)C-urea breath test).

MAIN OUTCOME MEASURES

Prevalence of heartburn and gastro-oesophageal acid reflux at baseline and two years after treatment to eradicate H pylori infection.

RESULTS

At baseline, H pylori infection was associated with increased prevalence of heartburn (odds ratio 1.14, 95% confidence interval 1.05 to 1.23) but not reflux (1.05, 0.97 to 1.14). In participants with H pylori infection, active treatment had no effect on the overall prevalence of heartburn (0.99, 0.88 to 1.12) or reflux (1.04, 0.91 to 1.19) and did not improve pre-existing symptoms of heartburn or reflux.

CONCLUSIONS

H pylori infection is associated with a slightly increased prevalence of heartburn but not reflux. Treatment to eradicate H pylori has no net benefit in patients with heartburn or gastro-oesophageal reflux.

Helicobacter pylori eradication does not exacerbate gastro-oesophageal reflux disease

The reciprocal influence of Helicobacter pylori infection and gastro-oesophageal reflux disease (GORD), if both conditions occur concomitantly, has been an issue of debate for many years. The critical question is whether eradication of H pylori has a more beneficial, harmful, or simply no effect on the course of GORD.

Helicobacter pylori and Gastroesophageal Reflux Disease

Since the rediscovery of Helicobacter pylori two decades ago, it has become increasingly clear that the true relationships between this organism and diseases of the upper gastrointestinal tract are highly complex. H. pylori colonization is a strong risk factor for peptic ulceration and distal gastric cancer; however, gastritis has no adverse consequences for most hosts, and the prevalence of H. pylori is inversely related to gastroesophageal reflux disease (GERD) and its sequelae, which include Barrett's esophagus and esophageal adenocarcinoma. One clinical implication stemming from these data is that H. pylori eradication may not be appropriate in certain human populations due to potential beneficial effects conferred by persistent gastric inflammation. However, the majority of published intervention trials indicate that H. pylori treatment neither leads to the development of clinically significant de novo esophagitis nor exacerbates existing reflux disease. Superimposed upon these observations are reports that long-term acid suppression induced by proton-pump inhibitors (PPIs) in conjunction with H. pylori colonization may enhance the development of atrophic gastritis, a well-recognized histologic step in the progression to intestinal-type gastric cancer. Therefore, current evidence-based recommendations regarding management of H. pylori-positive individuals with GERD include the following. H. pylori should not be treated with the intent to either improve reflux symptoms or prevent the development of reflux complications. However, if patients are to receive long-term acid suppressive therapy, they should be tested for H. pylori and treated if positive, due to the potential for PPIs to accelerate atrophy within H. pylori-infected mucosa. Optimal first-line regimens in this country consist of a PPI in combination with clarithromycin and either amoxicillin or metronidazole (triple therapy) for at least 7, but preferably 10, days. Because the most effective second-line regimens contain metronidazole, it is advisable to use amoxicillin instead of metronidazole as first-line therapy in order to optimize results should subsequent therapy be required. If first-line regimens fail to eliminate H. pylori, patients should receive quadruple therapy consisting of a PPI, bismuth subsalicylate, metronidazole, and tetracycline for 14 days. Due to the availability and accuracy of noninvasive diagnostic tests for H. pylori, it is recommended that successful cure be confirmed after intervention.

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.

Section I: epidemiological review

The incidence of esophageal adenocarcinoma has increased tremendously in the United States and other Western countries over the past 30 years while the incidence of esophageal squamous cell carcinoma has remained unchanged. The rate of increase in incidence is higher than for any other cancer. The reasons for this are multifactorial. Despite this, esophageal cancer remains a relatively uncommon malignancy. Barrett's esophagus (BE) is the most important risk factor for the development of esophageal adenocarcinoma and is believed to be the precursor lesion for most. The risk of developing esophageal adenocarcinoma from known BE is estimated to be 0.5% per patient year. Persistent high-grade dysplasia in BE is a sensitive indicator for the development of esophageal adenocarcinoma. However, only a minority of patients with BE are ever diagnosed and, therefore, surveillance endoscopy in Barrett's patients has failed to affect the incidence of esophageal adenocarcinoma. The relationship of Helicobacter pylori to esophageal adenocarcinoma is complex, but nonsteroidal antiinflammatory drugs may confer protection against the development of this cancer. Fortunately, improved survival is being seen with both squamous cell esophageal carcinoma and esophageal adenocarcinoma. Additional study is required to better determine the risk factors for the development of esophageal cancer, and epidemiologic understanding will prove important in developing methods of detection and therapeutic intervention for this disease.

How Helicobacter Pylori changed the life of surgeons

Helicobacter Pylori infection has been identified as a pathogenic factor in a number of gastroduodenal diseases, most importantly in gastric and duodenal ulcer disease. This association and the development of H. PYLORI eradication therapies has had a tremendous influence on the surgical therapy for these disorders. Decades ago, surgery was the therapy of choice for gastric and duodenal ulcers. Now, however, the first line of therapy includes treatment of H. PYLORI infection, suppression of gastric acid secretion, and protection of gastric mucosal barriers combined with a range of endoscopic procedures. These developments have had a major impact on the indications for surgery in benign gastroduodenal diseases. In addition, advances in our understanding of the pathogenetic mechanisms of H. PYLORI infection have also changed our views of gastric mucosa-associated lymphoid tissue lymphoma, gastric cancer, and gastroesophageal reflux disease.

The prevalence of clinically significant endoscopic findings in primary care patients with uninvestigated dyspepsia: the Canadian Adult Dyspepsia Empiric Treatment - Prompt Endoscopy (CADET-PE) study

BACKGROUND

Uninvestigated dyspepsia is common in family practice. The prevalence of clinically significant upper gastrointestinal findings (CSFs) in adult uninvestigated dyspepsia patients, and their predictability based on history, is unknown.

METHODS

Prompt endoscopy was performed within 10 days of referral, in 1040 adult patients presenting with uninvestigated dyspepsia at 49 Canadian family practitioner centres. Subsequent management strategies during a 6-month follow-up period were determined by the individual family practitioners.

RESULTS

CSFs were identified in 58% (603/1040) of patients. Erosive oesophagitis was most common (43%; N = 451); peptic ulcer was uncommon (5.3%; N = 55). Alarm symptoms were uncommon (2.8%; N = 29). Most patients had at least three dyspepsia symptoms, more than 80% had at least six, and approximately half had eight or more. Based on the dominant symptom, 463 (45%) patients had ulcer-like, 393 (38%) had reflux-like and 184 (18%) had dysmotility-like dyspepsia. The patients' dominant symptom was not predictive of endoscopic findings. Oesophagitis was more common in those with dominant reflux-like symptoms and was the most common finding in all subgroups. The prevalence of gastroduodenal findings was similar in all symptom subgroups. Helicobacter pylori (H. pylori) infection (30%; 301/1013) was associated with gastroduodenal findings.

CONCLUSIONS

Dyspepsia subclassifications, based on dominant symptom, are of limited value in predicting the presence and nature of CSFs. Oesophagitis was by far the most common diagnosis (43% of patients). CSFs were common in uninvestigated dyspepsia patients and their nature suggests patients could be initially treated effectively, without endoscopy, using empirical acid suppressive therapy.

Helicobacter pylori genotypes and expression of gastritis in erosive gastro-oesophageal reflux disease

BACKGROUND

Epidemiological studies suggest a negative association between Helicobacter pylori and gastro-oesophageal reflux disease (GORD). Moreover, cagA-positive strains are reported to protect from complications of GORD. The aim of this study was to determine virulence factors (cagA, vacA and iceA) of H. pylori strains and the pattern of gastritis in patients with GORD in comparison with patients with duodenal ulcer (DU) or functional dyspepsia (FD).

METHODS

H. pylori strains isolated from gastric biopsies of 105 consecutive patients with mild to moderate erosive GORD (n = 35, LA grade A-B), and from sex- and age-matched patients with DU (n = 35) or FD (n = 35 without reflux symptoms) were investigated. CagA, vacA, and iceA genotypes were determined by PCR analysis of the isolates. Gastritis was classified in accordance with the updated Sydney classification.

RESULTS

The prevalence of all three H. pylori virulence factors was higher in patients with GORD (cagA+ 80%, vacA s1 77%, iceA1 71%) and DU (cagA+ 83%, vacA s1 80%, iceA1 74%) than in patients with FD (cagA+ 40%, vacA s1 49%, iceA1 46%). Gastritis activity in the antrum and corpus did not differ between the three groups. However, lymphocytic infiltration of the gastric antral mucosa was more pronounced in DU patients than in those with GORD or FD.

CONCLUSIONS

H. pylori strains obtained from patients with mild to moderate erosive GORD show a virulence pattern similar to that found in DU patients. The presence of these virulence factors does not appear to protect against erosive lesions in the oesophagus.

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: 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 and nonmalignant disease

Helicobacter pylori eradication has become the recognized standard and widely adopted therapy to cure peptic ulcer disease. Other H. pylori associated conditions with potential benefit from eradication therapy are still subject to clinical investigations. The current state of evidence for these indications is summarized in this article. For NSAID associated peptic ulcer disease the current evidence needs to be grouped in three subsets of clinical conditions: a) H. pylori eradication for prevention of ulcers before starting NSAIDs therapy is advisable; b) eradication during PPI treatment for NSAID associated active ulcer shows no advantage on healing; and c) eradication alone is not sufficient for secondary prevention of ulcer complications induced by NSAID, however it appears to protect from further episodes of aspirin induced bleeding. In nonulcer dyspepsia the latest Cochrane collaboration review supports a small benefit in favour of H. pylori eradication. New insight in the relationship of H. pylori with GERD is provided from clinical trials which show that H. pylori eradication does not influence the clinical course of patients with reflux esophagitis. Finally important new data are presented regarding the management of dyspepsia at the primary care level with the confirmation that the H. pylori 'test and treat' strategy in the appropriate setting is more cost-effective than endoscopy.

Helicobacter pylori: consensus and controversy

Helicobacter pylori is uniquely adapted to colonize the human stomach. Infection leads to a range of subclinical and clinical outcomes that depend on properties of the infecting strain, the host, and the environment. Eradication therapy is indicated for infected persons who develop peptic ulcer disease or gastric lymphoma or who are beginning long-term treatment with nonsteroidal anti-inflammatory drugs. However, treatment may worsen gastroesophageal reflux disease and increase the risk of esophageal cancer. H. pylori infections can be diagnosed noninvasively and can be eradicated with approximately 85% success by a variety of multidrug, 7-14-day regimens. Unfortunately, antibiotic resistance is affecting treatment effectiveness in the United States and abroad. A more complete understanding of the variation in H. pylori pathogenesis should lead to clearer recommendations about treatment for infected persons who have neither peptic ulcer disease nor gastric lymphoma.

Role of corpus gastritis and cagA-positive Helicobacter pylori infection in reflux esophagitis

Considering that the role of Helicobacter pylori infection in gastroesophageal reflux and reflux esophagitis (GERD) is still controversial and that the role of virulence markers of the bacterium has not been evaluated in most studies of GERD, we investigated the association among H. pylori infection with cagA-positive and -negative strains, corpus gastritis, and GERD in a large group of patients by controlling for confounding factors. We studied prospectively 281 consecutive adult patients: 93 with GERD and 188 controls. H. pylori infection status was diagnosed by culture, by the preformed urease test, with a carbolfuchsin-stained smear, and by histology. The cagA status was determined by PCR of H. pylori isolates and gastric biopsy specimens. H. pylori infection was diagnosed in 191 (68.0%) of 281 patients. Among the 93 patients with GERD, 84 presented with mild or moderate esophagitis and 9 presented with severe esophagitis. In the multivariate analysis, the age of the patients and the degree of oxyntic gastritis were associated with GERD. Among the strains isolated from patients with GERD and from the control group, 24.4 and 66.9%, respectively, were positive for cagA (P < 0.001). Compared to infection with cagA-negative strains, infection with cagA-positive H. pylori strains was associated with a more intense gastritis in the corpus (P = 0.001). cagA status (odds ratio [OR] = 0.16, 95% confidence interval [CI] = 0.07 to 0.40), gastritis of the corpus (OR = 0.69, 95% CI = 0.48 to 0.99), and age (OR = 1.04, 95% CI = 1.01 to 1.07) were associated with GERD. In conclusion, the study provides evidence supporting the independent protective roles of cagA-positive H. pylori strains and the degree of corpus gastritis against GERD.

Reflux esophagitis facilitates low Helicobacter pylori infection rate and gastric inflammation

BACKGROUND

Helicobacter pylori is regarded as an important pathogen in upper gastrointestinal diseases. However, little is known about the relationship between H. pylori infection and reflux esophagitis. Therefore, an investigation was undertaken in Korean subjects regarding the incidence of H. pylori infection, and a histopathological study of reflux esophagitis was also carried out.

METHODS

Analysis of gastric biopsy specimens was conducted for 73 patients with reflux esophagitis and 132 control subjects without reflux esophagitis. The H. pylori infection was assessed by using rapid urease test and the immunohistochemical method, and gastric mucosal morphologic change was analyzed according to the updated Sydney system.

RESULTS

The prevalence of H. pylori infection was significantly lower in patients with reflux esophagitis than in the non-reflux group. Grade of inflammation and glandular atrophy in the antrum and body were higher in patients in the non-reflux group compared with those in the reflux esophagitis group.

CONCLUSIONS

It is suggested that H. pylori infection decreases the risk of reflux esophagitis by inducing atrophic gastritis.

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.

Helicobacter pylori and gastrointestinal tract adenocarcinomas

Although gastric adenocarcinoma is associated with the presence of Helicobacter pylori in the stomach, only a small fraction of colonized individuals develop this common malignancy. H. pylori strain and host genotypes probably influence the risk of carcinogenesis by differentially affecting host inflammatory responses and epithelial-cell physiology. Understanding the host-microbial interactions that lead to neoplasia will improve cancer-targeted therapeutics and diagnostics, and provide mechanistic insights into other malignancies that arise within the context of microbially initiated inflammatory states.