Effect of Helicobacter pylori eradication on development of dyspeptic and reflux disease in healthy asymptomatic subjects

Endoscopic Reflux Esophagitis and Reflux-Related Symptoms after Helicobacter pylori Eradication Therapy: Meta-Analysis

Backgrounds: The etiology of gastroesophageal reflux disease (GERD) including reflux esophagitis and non-erosive reflux disease is multifactorial and a recent meta-analysis showed no association between the development of GERD and Helicobacter pylori eradication in both Western and East-Asian populations. However, the problem remains that various inclusion criteria are used in these studies, which hinders meta-analysis. With a focus on reflux esophagitis with endoscopic mucosal injury, we meta-analysed to evaluate the association between eradication and reflux esophagitis and symptoms using a clearly defined set of inclusion criteria. Methods: We conducted a meta-analysis of studies published up until March 2020, which compared the incidence of reflux esophagitis and symptoms between patients undergoing H. pylori eradication therapy in a randomized placebo-controlled trial (Category A); between patients with successful and failed eradication (Category B); and between patients with successful vs. failed eradication, receipt of placebo, or no-treatment H. pylori-positives (Category C). Results: A total of 27 studies were included. Significant statistical effects were found for development of endoscopic reflux esophagitis [relative risk (RR): 1.46, 95% confidence interval (CI): 1.16-1.84, p = 0.01] or de novo reflux esophagitis (RR: 1.42, 95% CI: 1.01-2.00, p = 0.03) in the case group that received eradication in all studies, especially in Western populations. There was no significant difference in the incidence of symptoms after eradication between patient and control groups, regardless of category, location of population, or baseline disease. Conclusions: Eradication therapy for H pylori increases the risk of reflux esophagitis, irrespective of past history of esophagitis. In contrast, no effect was seen on reflux-related symptoms.

Interactions between Helicobacter pylori and gastroesophageal reflux disease

Interactions between Helicobacter Pylori (HP) and gastroesophageal reflux disease (GERD) are a complex issue. Several pathophysiological factors influence the development and the course of GERD, HP infection might be only one of these. Many studies emphasize the co-existence of these diseases. HP infection could contribute to GERD through both a protective and an aggressive role. Gastric acid secretion is a key factor in the pathophysiology of reflux esophagitis. Depending on the type of gastritis related to HP, acid secretion may either increase or decrease. Gastritis in corpus leads to hypoacidity, while antrum gastritis leads to hyperacidity. In cases of antral gastritis and duodenal ulcers which have hyperacidity, the expectation is an improvement in pre-existing reflux esophagitis after eradication of HP. In adults, HP infection is often associated with atrophic gastritis in the corpus. Atrophic gastritis may protect against GERD. Pangastritis which leads to gastric atrophy is commonly associated with CagA strains of HP and it causes more severe gastric inflammation. In case of HP-positive corpus gastritis in the stomach, pangastritis, and atrophic gastritis, reflux esophagitis occurs frequently after eradication of HP. Nonetheless, as a predisposing disease of gastric cancer, HP should be treated. In conclusion, as the determinative factors affecting GERD involving in HP, detailed data on the location of gastric inflammation and CagA positivity should be obtained by the studies at future.

Helicobacter pylori and gastroesophageal reflux disease

PURPOSE OF REVIEW

The purpose of the review is to discuss key studies conducted on the intriguing relationship between Helicobacter pylori and gastroesophageal reflux disease.

RECENT FINDINGS

Epidemiological studies have repeatedly described a negative association between H. pylori infection and erosive esophagitis, Barrett's esophagus, and esophageal adenocarcinoma, but not between H. pylori and gastroesophageal reflux disease symptoms. Especially, infection with CagA-positive strains appears to protect the distal esophagus by causing fundic gland atrophy and impaired gastric acid secretion. Although earlier reports suggested the development of erosive esophagitis after H. pylori eradication, more recent studies discuss that H. pylori eradication usually does not have an important clinical impact on gastroesophageal reflux disease.

SUMMARY

Gastric atrophy is the most widely accepted mechanism by which the distal esophagus is protected from abnormal acid exposure in patients with H. pylori infection. The clinical impact of H. pylori infection on the prevalence of erosive esophagitis and Barrett's esophagus remains a matter of debate. In areas with a high prevalence of H. pylori-induced atrophic gastritis, the protection that this infection may afford against gastroesophageal reflux disease is not comparable to the risk that H. pylori poses for the development of gastric cancer.

Helicobacter pylori infection has no impact on manometric and pH-metric findings in adolescents and young adults with gastroesophageal reflux and antral gastritis: eradication results to no significant clinical improvement

The relationship between Helicobacter pylori (Hp) gastritis and gastroesophageal reflux disease (GERD) remains controversial. The aim was to investigate the association between Hp infection and gastroesophageal reflux (GER) and the impact of Hp eradication on esophageal acid exposure and motility in adolescents and young adults with Hp gastritis and GERD. Sixty-four patients with symptoms suggestive for GERD, of which 40 Hp-positive (group A) and 24 Hp-negative (group B), underwent endoscopy-biopsy, esophageal manometry and 24-hour pH-metry. All group A patients received eradication treatment and were re-evaluated six months later again with 24-hour pH-metry, esophageal manometry, endoscopy-biopsy and clinical assessment. At inclusion, there were no significant differences between the two groups regarding sex, age, grade of endoscopic esophagitis, manometric and pH-metry findings. All Hp-positive patients had an antral predominant gastritis. Eradication of Hp was successful in all patients, and gastritis and esophagitis were healed in all patients. The mean lower esophageal sphincter pressure (LESP) increased significantly from 11.25 mmHg before to 11.71 mmHg after eradication (P<0.05). A significant decrease in reflux index was observed (mean RI 6.02% before versus 4.96% after eradication (P<0.05). However clinical symptoms of GER improved not significantly after 6 months follow up. Conclusively, in children and young adults with GER symptoms and GERD, the presence or absence of Hp has no impact on manometric and pH-metric findings. Eradication of Hp infection results in increase in LESP with a consequent decrease in esophageal acid exposure but not significant clinical improvement.

Is there an increased risk of GERD after Helicobacter pylori eradication?: a meta-analysis

OBJECTIVES

Some studies suggest that eradication of Helicobacter pylori (Hp) might increase the risk of gastroesophageal reflux disease (GERD) in a portion of patients. We aimed to conduct a meta-analysis to investigate this.

METHODS

A comprehensive, English, multiple-source literature search was performed from 1983 to February 2007. Only randomized controlled trial (RCT) and cohort studies comparing the prevalence of GERD in patients free from GERD at baseline with Hp eradication vs. those with persistent Hp were included. Quality of RCTs and cohorts was assessed by Jadad and New Castle-Ottawa scores, respectively. Meta-analysis of pooled odds ratios (ORs) was performed using Review Manager 4.2.10.

RESULTS

Twelve (7 RCTs and 5 cohorts) of 271 articles were included. In six RCTs using erosive GERD as outcome, the OR for the frequency of GERD in Hp eradicated group vs. persistent Hp group was 1.11 (0.81-1.53, P=0.52). In five RCTs using symptomatic outcome, the OR for the frequency of GERD in Hp eradicated group vs. persistent Hp was 1.22 (0.89-1.69, P=0.22). In cohort studies, the OR for the frequency of GERD in Hp eradicated group vs. persistent Hp was 1.37 (0.89-2.12; P=0.15). Test of heterogeneity was not significant for any analyses. The results were consistent in subgroup and sensitivity analyses, including cohort studies vs. RCTs, high-quality studies vs. low-quality studies, and use of endoscopic vs. symptomatic outcomes except for the subgroup of patients with peptic ulcer disease (PUD) in cohort studies (OR: 2.04 (1.08-3.85); P=0.03).

CONCLUSIONS

There is no association between Hp eradication and development of new cases of GERD in the population of dyspeptic patients. However, in cohort studies, there seems to be a twofold higher risk of development of erosive GERD in patients with PUD. The effect in RCTs of patients with PUD did not show a significant difference.

Alteration of correlation between serum pepsinogen concentrations and gastric acid secretion after H. pylori eradication

PURPOSE

The measurement of serum pepsinogens is clinically useful to represent gastric acid secretion. Since both serum pepsinogens and gastric acid secretion are considerably altered by H. pylori eradication, the correlation between these two parameters could be different prior to and after eradication. In this study, we investigated the correlation between the two parameters prior to and after eradication.

METHODS

One hundred eighteen H. pylori-positive patients with peptic ulcers or chronic gastritis were enrolled in this retrospective analysis. In all participants both the measurement of serum pepsinogens and the determination of gastric acid secretion were performed prior to and at 1 month after successful eradication. In 85 subjects, the same assessments were repeated at 7 months. Correlations between serum pepsinogens and gastric acid secretion were assessed using linear regression analysis.

RESULTS

The pepsinogen I/II ratio (r = 0.56) was a better indicator of gastric acid secretion in H. pylori-infected subjects than pepsinogen I itself (r = 0.31). Eradication of H. pylori altered the association, causing pepsinogen I (r = 0.55) to become a better indicator of gastric acid secretion compared with the pepsinogen I/II ratio (r = 0.40) at 1 month after eradication, followed by similar tendencies at 7 months.

CONCLUSION

Using different serum biomarkers (pepsinogen I/II ratio prior to eradication or pepsinogen I after eradication), the measurement of serum pepsinogens is useful for predicting the individual gastric acid secretion level not only in H. pylori-infected subjects, but also in subjects with histories of eradication of the infection.

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.

Inflammation, atrophy, and gastric cancer

The association between chronic inflammation and cancer is now well established. This association has recently received renewed interest with the recognition that microbial pathogens can be responsible for the chronic inflammation observed in many cancers, particularly those originating in the gastrointestinal system. A prime example is Helicobacter pylori, which infects 50% of the world's population and is now known to be responsible for inducing chronic gastric inflammation that progresses to atrophy, metaplasia, dysplasia, and gastric cancer. This Review provides an overview of recent progress in elucidating the bacterial properties responsible for colonization of the stomach, persistence in the stomach, and triggering of inflammation, as well as the host factors that have a role in determining whether gastritis progresses to gastric cancer. We also discuss how the increased understanding of the relationship between inflammation and gastric cancer still leaves many questions unanswered regarding recommendations for prevention and treatment.

Patterns of gastritis and the effect of eradicating Helicobacter pylori on gastro-oesophageal reflux disease in Western patients with non-ulcer dyspepsia

BACKGROUND

The effect of Helicobacter pylori eradication on the development of gastro-oesophageal reflux disease is controversial. Aim To determine the incidence of symptoms of reflux disease and of erosive oesophagitis, and the relationship to changes in histological gastritis, in patients with non-ulcer dyspepsia over 12 months.

METHODS

Six hundred and ninety-three patients in two similar randomized placebo controlled trials of H. pylori eradication in non-ulcer dyspepsia were studied. Symptoms were assessed using the validated Gastrointestinal Symptom Rating Scale during a 1-week run-in period, at 6 months and 12 months. Endoscopy was performed at baseline to exclude patients with pathology and at 3 months and 12 months to determine if oesophagitis was present. Gastric biopsies were scored using the modified Sydney Classification.

RESULTS

Patients without predominant heartburn, oesophagitis or ulcers at endoscopy were randomized to active (n = 297, omeprazole, amoxicillin and clarithromycin) treatment or to placebo/omeprazole (n = 306) for 1 week. The eradication rate was 82% in the active treatment group. Antrum-predominant gastritis (55%) was more frequently found than corpus-predominant gastritis (6%). In patients with antrum-predominant gastritis, heartburn and regurgitation scores improved significantly 12 months after eradication. Erosive oesophagitis developed in 15/232 patients in the eradication group (7%) compared with 2/227 (2%) in the control group, but there was no significant difference when adjusted for oesophagitis present at baseline.

CONCLUSIONS

Antrum-predominant gastritis is the most common pattern of gastritis seen in non-ulcer dyspepsia in Western populations. Heartburn and regurgitation improve after eradication therapy or placebo in patients with non-ulcer dyspepsia; the development of oesophagitis is uncommon.

Gastrointestinal pain in functional bowel disorders: sensory neurons as novel drug targets

Functional bowel disorders (FBDs) are defined by symptoms of gastrointestinal (GI) dysfunction, discomfort and pain in the absence of a demonstrable organic cause. Since the prevalence of FBDs, particularly functional dyspepsia and irritable bowel syndrome, can be as high as 20%, FBDs represent a significant burden in terms of direct healthcare and productivity costs. There is emerging evidence that the discomfort and pain experienced by many FBD patients is due to persistent hypersensitivity of primary afferent neurons, which may develop in response to infection, inflammation or other insults. This concept identifies vagal and spinal sensory neurons as important targets for novel therapies of GI hyperalgesia. Sensory neuron-specific targets can be grouped into three categories: receptors and sensors at the peripheral nerve terminals, ion channels relevant to nerve excitability and conduction and transmitter receptors. Particular therapeutic potential is attributed to targets that are selectively expressed by afferent neurons, such as the transient receptor potential channel TRPV1, acid-sensing ion channels and tetrodotoxin-resistant Na + channels.

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.

Rifaximin, a poorly absorbed antibiotic: pharmacology and clinical potential

Rifaximin (4-deoxy-4'-methylpyrido[1',2'-1,2]imidazo- [5,4-c]-rifamycin SV) is a synthetic antibiotic designed to modify the parent compound, rifamycin, in order to achieve low gastrointestinal (GI) absorption while retaining good antibacterial activity. Both experimental and clinical pharmacology clearly show that this compound is a nonsystemic antibiotic with a broad spectrum of antibacterial action covering Gram-positive and Gram-negative organisms, both aerobes and anaerobes. Being virtually nonabsorbed, its bioavailability within the GI tract is rather high with intraluminal and fecal drug concentrations that largely exceed the minimal inhibitory concentration values observed in vitro against a wide range of pathogenic organisms. The GI tract represents, therefore, the primary therapeutic target and GI infections the main indication. The appreciation of the pathogenic role of gut bacteria in several organic and functional GI diseases has increasingly broadened its clinical use, which is now extended to hepatic encephalopathy, small intestine bacterial overgrowth, inflammatory bowel disease and colonic diverticular disease. Potential indications include the irritable bowel syndrome and chronic constipation, Clostridium difficile infection and bowel preparation before colorectal surgery. Because of its antibacterial activity against the microorganism and the lack of strains with primary resistance, some preliminary studies have explored the rifaximin potential for Helicobacter pylori eradication. Oral administration of this drug, by getting rid of enteric bacteria, could also be employed to achieve selective bowel decontamination in acute pancreatitis, liver cirrhosis (thus preventing spontaneous bacterial peritonitis) and nonsteroidal anti-inflammatory drug (NSAID) use (lessening in that way NSAID enteropathy). This antibiotic has, therefore, little value outside the enteric area and this will minimize both antimicrobial resistance and systemic adverse events. Indeed, the drug proved to be safe in all patient populations, including young children. Although rifaximin has stood the test of time, it still attracts the attention of both basic scientists and clinicians. As a matter of fact, with the advancement of the knowledge on microbial-gut interactions in health and disease novel indications and new drug regimens are being explored. Besides widening the clinical use, the research on rifaximin is also focused on the synthesis of new derivatives and on the development of original formulations designed to expand the spectrum of its clinical use.

Indicaciones y consecuencias de la erradicación de Helicobacter pylori en la enfermedad por reflujo gastroesofágico

Several epidemiological data indicate that H. pylori infection prevalence in patients with gastroesophageal reflux disease (GERD) is lower than that reported in respective controls, which would suggest that the organism plays a protective role against this disease. On the other hand, most studies demonstrate that the presence of the infection in patients with GERD does not negatively affect the therapeutic efficacy of proton pump inhibitors (PPIs), and, in case of negatively influencing it, the effects are not clinically relevant and are easily controllable with standard antisecretory treatment. Therefore, the decision to administer H. pylori eradication treatment to a patient should not be influenced by the concomitant presence of GERD. In most cases, H. pylori eradication does not seem to induce GERD development, and it does not seem to worsen GERD when it was already present. Nevertheless, when the gastritis pattern is unknown before the antibiotic administration, the effect of H. pylori eradication on gastric acid secretion and the incidence of GERD is unpredictable. In the exceptional cases in which H. pylori eradication could have negative effects on GERD, its clinical relevance will be limited, and reflux symptoms or endoscopic esophagitis will favourably respond to the standard PPI antisecretory treatment. Therefore, again, when H. pylori eradication is indicated in a particular patient, the concomitant diagnosis of GERD should not change our attitude. Finally, is has recently been recommended to eradicate H. pylori infection in those patients with GERD needing long-term treatment with PPI, as some studies have reported that these drugs induce, in presence of the organism, an atrophic gastritis, with the consequent risk of gastric cancer. However, most of these studies have important methodological defects, and several authors have reported contrary results. In any case, the appearance in the gastric mucosa of clinically relevant lesions, such as intestinal metaplasia, dysplasia or adenocarcinoma, in patients treated with PPI for several years, has not yet been demonstrated, although this could simply be a problem of time. This question seems to be too controversial to be answered with the available data, and we should wait until new studies clarify this topic. In the meantime, as it occurs with any controversial indication, the decision of the doctor facing a patient infected by H. pylori and needing maintenance therapy with PPIs should be assessed on a case by case basis.

Peptic ulcer disease

PURPOSE OF REVIEW

This review reports and attempts to place in some context current key observations in the literature, as they relate to peptic ulcer disease.

RECENT FINDINGS

Focus areas in this review are general, the usefulness of symptom-based triage in management decision making and critical review of current practice as it relates to foregut malignancy; Helicobacter pylori, important observations regarding gastric cancer prevention are presented, the role of the organism in "acid rebound" is discussed, and further evidence to support the role of H. pylori eradication in peptic ulcer disease is provided; medication, a number of studies comparing steady state and onset of action efficacy of current proton pump inhibitors at a gastric pH level are reviewed and a new agent is introduced. Problems with and strategies for the safe use of antithrombotic agents are reviewed, and exciting data with regard to a new class of nonsteroidal antiinflammatory drug are provided, now at the "proof of concept" stage.

SUMMARY

The review period's main "new" information relates to the nonsteroidal antiinflammatory drugs in which a number of exciting agents are being developed. Although inconclusive, the observations with regard to the effect of H. pylori eradication on gastric carcinogenesis is likely to lead to more work in this field.

Serological markers for gastric atrophy in asymptomatic patients infected with Helicobacter pylori

OBJECTIVE

Atrophic gastritis is a precancerous condition that is commonly caused by chronic Helicobacter pylori (H. pylori) infection. This blinded, controlled study was designed to determine if serum gastrin and pepsinogens were reliable markers of atrophy in asymptomatic patients.

METHODS

One hundred and forty-seven asymptomatic patients underwent endoscopy with multiple gastric biopsies obtained for histology, culture, and rapid urease test. Fasting serum gastrin (total and G-17) and serum pepsinogens (I-II) were determined by standard immunoassays. Gastric atrophy was histologically assessed in accordance with internationally accepted criteria; three main patterns of gastritis were distinguished: (a) nonatrophic gastritis, (b) atrophic antrum-restricted and antrum-predominant gastritis, and (c) corpus-restricted gastritis. Receiving operating characteristic (ROC) analysis was used to determine the best cut-off for each serum test in nonatrophic gastritis versus antrum-restricted/antrum-predominant atrophic gastritis.

RESULTS

No significant differences in serum gastrin and pepsinogens I-II were detected in nonatrophic gastritis versus patients with antrum-restricted/antrum-predominant atrophic gastritis. The positive likelihood ratios for an abnormal serum test to detect antrum-restricted/antrum-predominant atrophy in the gastric body were total serum gastrin 2.13 (95% CI 0.99, 4.6), gastrin-17: 1.55 (95% CI 0.75, 36.17), pepsinogen I: 2.74 (1.4, 5.4), pepsinogen II: 1.74 (1.27, 2.39), and the ratio of pepsinogen I and II: 1.8 (1.2-2.8). Negative likelihood ratios ranged from 0.20 to 0.65.

CONCLUSION

In an asymptomatic population, serum gastrin (total and G-17) and pepsinogens I-II (and their ratio) do not discriminate nonatrophic versus antrum-restricted/predominant atrophic gastritis.

Helicobacter pylori and nonmalignant diseases

This paper reviews the new literature from the past year on the association between colonization with Helicobacter pylori and non-malignant disease of the upper gastrointestinal tract. This issue has, in the past year, remained a topic of wide research interest yielding many important new data. These data show that H. pylori eradication is the most effective therapy for peptic ulcer disease, but that a considerable proportion of ulcer patients remain to have dyspeptic symptoms. The discussion on the interaction between H. pylori and NSAID use in the etiology of ulcer disease has not yet been settled. Several studies, both from Asia and Europe, now reported that H. pylori eradication has a minimal effect on the primary prevention of ulcer disease in NSAID users, but eradication appears of relevance for the secondary prevention of ulcer disease in addition to proton pump inhibitor maintenance therapy. Various studies brought further support for the hypothesis that H. pylori eradication is of some benefit for patients with non-ulcer dyspepsia, although the effects are limited. The prevalence of H. pylori is lower among GERD patients than among controls, but H. pylori eradication has not been consistently shown to increase the risk for the newly development of GERD in an individual subject undergoing H. pylori eradication. The discussion on H. pylori and GERD should not preclude us from treating H. pylori-infected patients for accepted clinical indications. In patients using proton pump inhibitors for GERD, H. pylori eradication leads to a resolution of their corpus-predominant pangastritis, without impairing the efficacy of PPI therapy.

Helicobacter pylori infection: anything new should we know?

Over the past year, 2003-4, there have been a number of studies consolidating previous work in relation to pathogenesis of disease, diagnosis and management of Helicobacter pylori. Studies into the pathogenesis of disease have identified the main adhesin of H. pylori as an important virulence marker and as a potential target for therapy. Molecular investigations of both the strain and host variations have identified the action of several of the virulence factors, e.g. cagA, vacA, on disrupting host cell signalling and the consequences in respect of the release of chemokines from the damaged gastric epithelium and the effect on apoptosis. Over the past year, there have been further diagnostic kits developed based on modifications of current technology. Two promising areas of research for diagnosis are the use of host/strain genome polymorphisms as a means of identifying high-risk patients who may develop severe disease and the use of proteomics to identify potential antigens of diagnostic (or therapeutic) use. The three main antibiotics that are used in first-line eradication regimens are clarithromycin, metronidazole and amoxycillin. Of these, metronidazole has the highest prevalence of resistance, followed by clarithromycin; amoxycillin resistance is only rarely reported. The decreasing success of current first-line therapy is the driving force for the development of new antibiotic combinations and a search for novel sources for chemotherapeutic agents and novel therapeutic targets.