Histologic changes in the gastroduodenal mucosa after long-term medical treatment with cimetidine or parietal cell vagotomy in patients with juxtapyloric ulcer disease

Different Pathophysiology of Gastritis in East and West? A Western Perspective

Background

Gastritis results from multifactorial gastric mucosal injury. Helicobacter pylori (Hp) is the main cause, and associated diseases have typical underlying patterns of gastritis. Gastric ulcer and gastric cancer (GC) develop from chronic atrophic corpus gastritis (CAG) which therefore represents the most important pattern. GC incidences in East Asia are substantially higher than elsewhere, and this should be also reflected by higher prevalences of CAG and characteristic differences in pathophysiology compared to the West.

Summary

The few available comparative studies of gastritis in Eastern and Western patients are summarized. The main pathogenic factors of gastritis are discussed together with their limitations to explain local differences in disease outcome. Emphasis was put to also include less well-established pathogenic host and environmental factors of possible impact.

Conclusions

CAG is more prevalent in East Asian areas with high GC incidences than the West. Geographic heterogeneity of associated diseases is due to differences in Hp prevalence and virulence as well as modulating host and environmental factors. The following may contribute to the higher burden of CAG in the East: ABD type of CagA with vacA s1 and babA2 alleles of Hp, host Lewis(b) expression in sej/sej nonsecretors, H. heilmannii, low parietal cell mass, high sodium and nitrate intake, preferences in vegetable and fruit consumption, cigarette smoking, air pollution, alcohol. Conversely, green tea, nonfermented soy products and rice may confer protective effects. Hp is on the decline, but also in a world cleared from this bacterium, differences in host genetics will continue to modify gastric disease outcome together with maintained customs as part of cultural diversity.

Review of atrophic gastritis and intestinal metaplasia as a premalignant lesion of gastric cancer

Atrophic gastritis (AG) and intestinal metaplasia (IM) are the main precursor lesions of gastric cancer as the incidence of gastric cancer increases in the gastric mucosa involved with AG and IM. The prevalence of AG and IM vary depending on countries, even it represents diverse results in the same nation. Usually AG is antecedent of IM but the etiologies of AG and IM are not always the same. The sensitivity and specificity of diagnostic methods to detect AG and IM are different. Furthermore, the management strategy of AG and IM has not been established, yet. Helicobacter pylori infection has been proved as the most important cause of AG and IM. Thus the eradication of H. pylori is very important to prevent the progression to gastric cancer which is still placed in the high rank in morbidity and mortality among cancers. However, the reversibility of AG and IM by eradication of H. pylori which was assumed to be certain by meta-analysis is; however, controversial now. Therefore, the understanding and early diagnosis of AG and IM are very important, especially, in high incidence area of gastric cancer such as Republic of Korea.

Current concepts in the diagnosis and management of type 1 gastric neuroendocrine neoplasms

The vast majority of gastrin-related gastrointestinal neuroendocrine neoplasms (GI-NENs) develop in the context of chronic atrophic gastritis (type 1), a condition closely related to autoimmune thyroid diseases. These neoplasms are defined as gastric NENs type 1 (GNEN1) and have recently been shown to constitute the commonest GI-NENs in a prospective study. GNEN1s are usually multiple and follow a relative indolent course, raising questions regarding the extent that such patients should be investigated and the appropriate therapeutic interventions needed. Recently, a number of consensus statements and guidelines have been published from various societies dealing with the diagnosis and management of GI-NENs. Endocrinologists are among the many different medical specialties involved in GNEN1s diagnosis and management. However, despite recent advances, few randomized trials are available, and thus existing evidence remains relatively weak compared to other malignancies. The purpose of this review is to provide recent evidence along with currently employed modalities addressing the diagnosis, management, long-term follow-up and potential comorbidities of GNEN1s.

Risk for gastric neoplasias in patients with chronic atrophic gastritis: A critical reappraisal

Chronic atrophic gastritis (CAG) is an inflammatory condition characterized by the loss of gastric glandular structures which are replaced by connective tissue (non-metaplastic atrophy) or by glandular structures inappropriate for location (metaplastic atrophy). Epidemiological data suggest that CAG is associated with two different types of tumors: Intestinal-type gastric cancer (GC) and type I gastric carcinoid (TIGC). The pathophysiological mechanisms which lead to the development of these gastric tumors are different. It is accepted that a multistep process initiating from Helicobacter pylori-related chronic inflammation of the gastric mucosa progresses to CAG, intestinal metaplasia, dysplasia and, finally, leads to the development of GC. The TIGC is a gastrin-dependent tumor and the chronic elevation of gastrin, which is associated with CAG, stimulates the growth of enterochromaffin-like cells with their hyperplasia leading to the development of TIGC. Thus, several events occur in the gastric mucosa before the development of intestinal-type GC and/or TIGC and these take several years. Knowledge of CAG incidence from superficial gastritis, its prevalence in different clinical settings and possible risk factors associated with the progression of this condition to gastric neoplasias are important issues. This editorial intends to provide a brief review of the main studies regarding incidence and prevalence of CAG and risk factors for the development of gastric neoplasias.

Incidence of chronic atrophic gastritis: systematic review and meta-analysis of follow-up studies

Chronic atrophic gastritis (CAG) is an important precursor lesion of intestinal gastric cancer. As it is typically asymptomatic, epidemiological data on the incidence of CAG are sparse. We aimed to provide an overview of published data on CAG incidence (overall and according to risk factors) from follow-up studies. Articles with information on incidence of CAG published in English until 26th of July 2009 were identified through a systematic MEDLINE and EMBASE search. Data extracted include study characteristics and key findings regarding the incidence of CAG. A meta-analysis was performed on the association between Helicobacter pylori infection and CAG incidence. Overall, data on CAG incidence were available from 14 studies, in 7 studies incidence could be estimated according to H. pylori infection. Most studies were conducted in symptomatic or high risk populations and the maximum number of incident cases was 284. Incidence estimates ranged from 0 to 11% per year and were consistently below 1% in patients not infected with H. pylori. The highest incidence was observed in a special study conducted on ulcer patients treated by proximal gastric vagotomy. Rate ratios for the association between H. pylori infection and CAG incidence ranged from 2.4 to 7.6 with a summary estimate of 5.0 (95% confidence interval: 3.1-8.3). Incidence of CAG is very low in the absence of H. pylori infection. There is a need for more population-based studies to provide comparable estimates of incidence and the impact of risk factors in the development of CAG.

Incidence and risk factors for the development of chronic atrophic gastritis: five year follow-up of a population-based cohort study

Chronic atrophic gastritis (CAG) is a well-established precursor of intestinal gastric cancer. However, data on incidence of CAG are rare, especially from population-based studies. The aim of this analysis was to estimate the incidence of CAG in a large population-based study among older adults from Germany and to identify major risk factors associated with its development. In the baseline and 5-year follow-up examinations of the ESTHER study, serological measurements of pepsinogen (PG) I and II and Helicobacter pylori antibodies were performed in 5,229 women and men, aged 50-74 years at baseline. Information on additional potential risk factors was obtained by questionnaire. CAG was defined by PGI < 70 ng/mL and PGI/PGII < 3. In total, there were 58 (1.1%) incident CAG cases. CAG incidence increased with increasing age from 0.5% in age group 50-54 years to 2.1% in age group 70-74 years. Seropositivity with H. pylori was strongly associated with CAG incidence, with adjusted odds ratios of 5.0 [95% confidence interval (CI): 1.6-15.8] and 11.3 (95% CI: 4.2-30.0) for participants with cytotoxin associated gene A (cagA) negative and cagA positive H. pylori infection at both baseline and follow-up compared to those without H. pylori infection, respectively. Gender, education, smoking, alcohol consumption and family history of gastric cancer were not significantly associated with CAG incidence. Incidence of CAG is rather low in the German population. Older age and infection with H. pylori are key risk factors for the development of CAG.

Helicobacter pylori-induced damage to the gastric mucosa is not modulated by previous vagotomy or medical treatment of peptic ulcer disease: a comparative study of vagotomized patients, medically treated peptic ulcer patients and community control subjects

BACKGROUND

An increase in the prevalence of precancerous lesions and atrophic changes in the gastric mucosa has been reported as long-term consequences of vagotomy-induced acid suppression. This study was designed to describe the long-term changes in the gastric mucosa caused by vagotomy and Helicobacter pylori infection.

METHODS

Seventy-nine patients with vagotomized peptic ulcers, 70 nonoperated patients with peptic ulcers, and 85 matched community control subjects were randomly selected to participate in an upper endoscopic study. Biopsy specimens were taken from predestined locations of the gastric mucosa.

RESULTS

Mean follow-up time for the vagotomized patients was 17.3 (range, 6-28) years and 12.7 (range, 10-17) years for the medically treated peptic ulcer patients. In H. pylori-positive subjects, severe atrophic changes in the distal gastric mucosa (prepylorus and angulus) was found in 30% (95% confidence interval (CI), 19-43) of the vagotomized patients and in 43% (95% CI, 29-58) of medically treated patients with peptic ulcers, and in 32% (95% CI, 20-46) of the community control subjects. Severe intestinal metaplasia was not found more frequently in vagotomized peptic ulcer patients compared with medically treated patients with peptic ulcers (p = 0.5). The histological picture of the age-matched community control subjects did not differ significantly from the patients with peptic ulcers when corrected for presence of H. pylori infection.

CONCLUSIONS

This study lends no support to theories of increased premalignant changes in the gastric mucosa of vagotomized patients. H. pylori infection rather than long-term acid suppression seems to be the explanation of the gastric mucosal changes seen after vagotomy.

Clinical significance of widespread gastric metaplasia in the duodenal bulb

BACKGROUND

All the risk factors of peptic ulcer disease are not thoroughly understood.

GOALS

To assess duodenal gastric metaplasia (DGM) in relation to Helicobacter pylori status and endoscopy findings with special reference to the effects of highly selective vagotomy.

STUDY

The study population consisted of 1056 adult patients and an additional 154 patients who had had a highly selective vagotomy. Their clinical and endoscopy records as well as the histology of gastric and duodenal biopsies were evaluated retrospectively. H. pylori infection had been determined by serology and culture.

RESULTS

Widespread (more than 20%) DGM was strongly associated with H. pylori positive duodenal ulcer disease (in 59.7% of patients). The prevalence of DGM diminished progressively the more proximally the ulcer was located in the stomach, and was 2.5% in proximal gastric ulcers patients. In vagotomized patients, the prevalence of widespread DGM (8.4% of patients, median 14 years after operation and the majority still H. pylori positive) was close to that of patients with H. pylori gastritis without peptic ulcer disease (4.5%).

CONCLUSIONS

Widespread DGM is an indicator for an increased risk of duodenal ulcer among H. pylori positive patients and it could be used to select patients for eradication therapy.

Effect of long-term half-dose famotidine therapy on corpus gastritis in peptic ulcer disease

BACKGROUND

Recent studies showed that acid-suppressive therapy aggravates corpus gastritis in patients with Helicobacter pylori infection.

AIM

The aim of this study was to evaluate the effect of famotidine, a histamine receptor antagonist on corpus gastritis in patients with peptic ulcer disease.

METHODS

We enrolled 287 patients, 173 with duodenal ulcer and 114 with gastric ulcer and 100 patients with H. pylori-positive gastritis as control subjects. Patients with peptic ulcer were classified according to whether or not they received famotidine-maintenance therapy (20 mg/day) after primary treatment. At the time of endoscopy, biopsy specimens were obtained from the antrum and the corpus. The degrees of neutrophil and lymphocyte infiltration, atrophy and intestinal metaplasia were scored according to the updated Sydney System.

RESULTS

The degrees of neutrophil infiltration and atrophy in the corpus were significantly less in patients with gastric ulcer or duodenal ulcer than in patients with H. pylori-positive gastritis (P < 0.01). Differences in the degrees of neutrophil infiltration and atrophy in the corpus between the non-maintenance group and the maintenance group were not significant.

CONCLUSION

Long-term therapy with famotidine does not appear to lead to an increase in the incidence of corpus gastritis or corpus atrophy in patients with peptic ulcer disease.

Topical application of benzalkonium chloride to the stomach serosa increases gastric emptying time, acid secretion, serum gastrin and size of the mucosa

AIM

In the present study we evaluated the effects of gastric myenteric denervation using benzalkonium chloride (BAC) on the time for gastric emptying, as well as gastric secretion, and mucosal epithelial cell size and population in rats.

METHODS AND RESULTS

Wistar rats were treated with topical serosal application of BAC to the stomach. Control animals received saline. Ninety days after surgery, gastric emptying time, gastric acid secretion and serum gastrin levels were studied. Next, the animals were sacrificed and the stomachs were removed, fixed in formalin and histologically processed for histomorphometry of the height, area and volume of the glandular portion, and volume and population of mucous, chief, parietal, G- and labelled cells. BAC animals showed a significant delay in gastric emptying and an increase in gastric acid secretion and serum gastrin levels. These animals also presented a significant reduction of myenteric neuron number, hypertrophy of parietal and chief cells, hyperplasia of G cells and an increase in the gastric mucosa area.

CONCLUSION

The absence of the myenteric plexus seems to protect the stomach from the hyperplastic effects of hypergastrinemia. Gastric food stasis may act as a factor triggering morphological and functional alterations of the gastric epithelium. Although gastric food stasis is a common finding in medical practice, its physiopathological consequences are poorly understood and have not been frequently discussed in the literature.

Changes in gastric mucosa and luminal environment during acid-suppressive therapy: a review in depth

Acid-suppressive therapy and subsequent changes in gastric mucosa and luminal environment rank highly amongst the investigated issues in gastroenterology over the past two to three decades. Herewith, we present an overview of these intragastric changes, particularly during long-term administration of acid-suppresive medication and concurrent infection with Helicobacter pylori. Current evidence indicates that: i) Long-term acid suppression facilitates the development of fundic ECL cell hyperplasia, especially in the presence of Helicobacter pylori. No neoplastic changes directly attributable to acid suppression have so far been demonstrated in humans. ii) Acid-suppressive therapy increases the risk of enteric infections. iii) Acid-suppressive therapy does not alter fat and mineral bioavailability, but may decrease the absorption of protein-bound vitamin B12. iv) Acid suppression invariably results in intragastric overgrowth of non-Helicobacter pylori bacterial species. The concurrent infection with Helicobacter pylori may promote this bacterial overgrowth and the intragastric formation of N-nitrosamines. v) Acid-suppressive therapy alters the natural course of Helicobacter pylori gastritis, transforming the antral-predominant pattern into a body-predominant pattern, which in turn may progress to body gland atrophy. The pathophysiology of this phenomenon is currently under investigation. vi) In view of the potential adverse effects of acid suppression in the presence of Helicobacter pylori, the screen-and-treat strategy is advocated for Helicobacter pylori in subjects considered for long-term treatment.

Non-Helicobacter pylori bacterial flora during acid-suppressive therapy: differential findings in gastric juice and gastric mucosa

BACKGROUND

Intragastric growth of non-Helicobacter pylori bacteria commonly occurs during acid-suppressive therapy. The long-term clinical consequences are still unclear.

AIM

To investigate the luminal and mucosal bacterial growth during gastric acid inhibition, in relation to the type and duration of acid-inhibitory treatment, as well as to concomitant H. pylori infection.

METHODS

A total of 145 patients on continuous acid inhibition with either proton pump inhibitors (n=109) or histamine2-receptor antagonists (H(2)RAs, n=36) for gastro-oesophageal reflux disease, and 75 dyspeptic patients without acid inhibition (control group) were included. At endoscopy, fasting gastric juice was obtained for pH measurement and bacteriological culture. Gastric biopsy specimens were examined for detection of H. pylori (immunohistochemistry) and of non-H. pylori bacteria (modified Giemsa stain-positive and immunohistochemistry-negative at the same location).

RESULTS

Non-H. pylori flora was detected in the gastric juice of 92 (41.8%) patients and in the gastric mucosa of 109 (49.6%) patients. In gastric juice, prevalence rate for non-H. pylori bacteria was higher in patients taking proton pump inhibitors than controls and those taking H(2)RAs (58.7% vs. 22.6% and vs. 30.6%, P < 0.0001 and P < 0.003, respectively), but did not differ statistically between H(2)RAs and controls. In gastric mucosa, prevalence rates for non-H. pylori bacteria were higher in patients taking proton pump inhibitors and H(2)RAs than in the controls (antrum: 46.9% and 48.6% vs. 25%, P < 0.05 for both; corpus: 52.2% and 56.8% vs. 23.7%, P < 0.001 for both), but did not differ between proton pump inhibitors and H(2)RAs. Both luminal and mucosal growth of non-H. pylori bacteria were significantly greater in H. pylori-positive than -negative patients taking proton pump inhibitors (P < 0.05 for both). Luminal growth of non-H. pylori flora increased with the intragastric pH level, whilst mucosal bacterial growth increased with the duration of acid inhibition.

CONCLUSIONS

Non-H. pylori flora not only contaminates the gastric juice but also colonizes the gastric mucosa of a large proportion of patients treated long-term with acid inhibition. The relationship between H. pylori and non-H. pylori bacteria in the pathogenesis of atrophic gastritis and gastric cancer needs further elucidation.

Proton pump inhibitors in the treatment of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) is the most common peptic acid disease in the western world and is the commonest indication for acid suppression therapy. Major advances have been made over the past 30 years in the understanding of lower oesophageal sphincter function and the mechanism of acid secretion. Developments in surgical and pharmacological therapy have paralleled these advances. Pharmacotherapy for GERD has evolved from antacids to H2-receptor antagonists (H2RAs) to prokinetics to proton pump inhibitors (PPIs). The H2RAs, while modestly effective in symptom relief and healing of GERD, are limited by pharmacological tolerance. The prokinetics (metoclopramide and cisapride) are limited by low efficacy, pharmacological tolerance and toxicity. The PPIs have emerged as the most effective therapy for symptom relief, healing and long-term maintenance. They have also proved to be remarkably safe and cost-effective in long-term therapy. This review evaluates the pharmacology, efficacy, tolerability, safety and cost-effectiveness of the four currently available PPIs, lansoprazole, omeprazole, pantoprazole and rabeprazole, in the treatment of GERD.

Lack of effect of acid suppression therapy on gastric atrophy. Nordic Gerd Study Group

BACKGROUND & AIMS

A hypothesis suggesting that profound acid inhibition therapy facilitates and hastens the development of gastric glandular atrophy in patients infected with Helicobacter pylori was investigated in this randomized study comparing omeprazole therapy with antireflux surgery (ARS) for chronic gastroesophageal reflux disease (GERD).

METHODS

Patients with esophagitis and/or chronic GERD were enrolled; 155 patients were randomized to ARS and 155 to long-term omeprazole therapy. Baseline data were obtained and repeated after 3 years in 131 ARS patients and in 139 omeprazole-treated patients. Histopathologic status of the oxyntic mucosa was assessed according to the Sydney system.

RESULTS

Forty omeprazole-treated patients were infected with H. pylori compared with 53 in the ARS group. Basal gastrin levels were significantly higher in H. pylori-infected patients, particularly in the omeprazole group. No further increases in serum gastrin levels were observed during 3 years. Despite 3 years of therapy, only slight changes were found in the prevalence of inflammation in the corpus mucosa of H. pylori-infected subjects. A slow progression of gastric glandular atrophy was observed in these patients irrespective of therapy with no obvious difference between treatment regimens. Intestinal metaplasia (all of type I) was only exceptionally observed with no difference between the treatment arms.

CONCLUSIONS

Acid-suppressive therapy in the form of omeprazole maintained for 3 years facilitates neither the development of gastric glandular atrophy of the corpus mucosa nor the occurrence of intestinal metaplasia in H. pylori-infected GERD patients.

The gastric transitional zones: neglected links between gastroduodenal pathology and helicobacter ecology

The gastric transitional zones are the junctional zones between the different types of mucosa: antral-body, body-cardia, and antrum-duodenum. In this article, the importance of the transitional zone in determining disease outcome, specifically duodenal ulcer, gastric ulcer, and possibly gastric cancer, is reviewed. Both gastric ulcers and duodenal ulcers are located immediately adjacent to the transitional zones. The transitional zones are dynamic rather than static areas. Local acid levels determine the behavior of Helicobacter pylori at the antral-body transitional zone and, as a consequence, the geographic distribution of gastritis in the stomach and the formation of duodenal ulcer and gastric ulcer. This review also explains that diffuse antral gastritis and multifocal atrophic gastritis are part of the same disease and not separate entities.

Long-term effect of Helicobacter pylori eradication on gastric metaplasia in patients with duodenal ulcer

There have been conflicting reports on the effect of Helicobacter pylori eradication on gastric metaplasia in the duodenal bulb (DGM). In the present study, we have investigated the relationships between DGM and H. pylori by examining whether or not H. pylori-positive patients had more DGM than H. pylori-negative patients with nonulcer dyspepsia (NUD) or duodenal ulcer (DU), and by examining the effect of eradication of H. pylori on the prevalence and the extent of DGM during the long-term up to 4 years. Fifty H. pylori-positive and seven H. pylori-negative patients with DU and 23 H. pylori-positive and 23 H. pylori-negative NUD subjects were studied. Two duodenal bulb biopsy specimens were taken for histologic evaluation and the presence and the extent of DGM were evaluated. The extent of DGM was classified as none (grade 0), focal (grade 1), multifocal (grade 2), and diffuse type (grade 4). In H. pylori-positive patients with DU, follow-up gastroscopy was conducted 4 weeks, 1 year, and 4 years after H. pylori eradication. DGM was significantly (p < 0.001) more common (DU: 93%, NUD: 22%) and significantly (p < 0.001) greater in extent for patients with DU than for NUD subjects (DU: 1.89, NUD: 0.28). Neither the prevalence nor the extent of DGM was affected by H. pylori status in patients with DU or NUD; the prevalence (extent) of DGM of H. pylori-positive and -negative patients with DU were 96% (1.94) and 71% (1.57), respectively. In the 43 "H. pylori-eradicated" group, initial prevalence of DGM was 95% and those of 4 weeks, 1 year, and 4 years after eradication were 91%, 96%, and 79%, respectively. The initial extent of DGM was 1.93, and those of 4 weeks, 1 year, and 4 years after eradication were 1.90, 1.88, and 1.57, respectively. In conclusion, the prevalence and the extent of DGM were not related to H. pylori in patients with DU or NUD. In addition, the prevalence and the extent of DGM did not change until 1 year after H. pylori eradication in patients with DU, and decreased to the initial level of the H. pylori-negative DU group but without statistical significance after 4-year follow-up.

Changes in Helicobacter pylori-induced gastritis in the antrum and corpus during and after 12 months of treatment with ranitidine and lansoprazole in patients with duodenal ulcer disease

BACKGROUND

Several studies have shown that acid-suppressing treatment leads to aggravation of Helicobacter pylori gastritis in the corpus. It remains unclear whether this augmentation of the inflammation reverts to baseline after termination of treatment.

METHODS

In 114 H. pylori-infected duodenal ulcer patients we investigated the gastritis parameters in antral and corpus mucosa before treatment, after 6 and 12 months of therapy, and 6 months after termination of treatment with 15 mg lansoprazole or 150 mg ranitidine/day.

RESULTS

Lansoprazole and ranitidine led to a significant aggravation of gastritis in the corpus after 6 and 12 months of treatment. However, while there was no change in gastritis in the antrum with ranitidine, treatment with lansoprazole led to partial elimination of H. pylori with improvement of the inflammation in this part of the stomach. Following termination of therapy, the observed changes reverted to baseline. No increase in intestinal metaplasia and/or atrophy in the antrum or corpus was observed.

CONCLUSION

Both substances are associated with an aggravation of H. pylori gastritis in the corpus. However, only lansoprazole leads to a partial elimination of H. pylori with improvement of the inflammation in the antrum. The changes provoked by acid-suppressing treatment revert to baseline after termination of therapy.

Changes in Helicobacter pylori-induced gastritis in the antrum and corpus during 12 months of treatment with omeprazole and lansoprazole in patients with gastro-oesophageal reflux disease

BACKGROUND

Several studies have shown that treatment with omeprazole leads to aggravation of Helicobacter pylori gastritis in the corpus. Whether this also applies to lansoprazole, and whether, in comparison with omeprazole, there are differences in therapy-induced gastritis parameter changes remains unclear.

METHODS

In 111 patients infected with H. pylori and with gastro-oesophageal reflux disease we investigated the gastritis parameters in antral and corpus mucosa before and after 2, 6 and 12 months of treatment with 15 or 30 mg lansoprazole or 20 mg omeprazole/day.

RESULTS

In all groups the different treatments had a similar effect: in both regions of the stomach, suppression or partial elimination of H. pylori was seen. However, improvement in the inflammation was observed only in the antrum, while in the corpus most gastritis parameters worsened significantly. There was no increase in intestinal metaplasia or atrophy.

CONCLUSION

In common with omeprazole, lansoprazole aggravates the gastritis parameters in the corpus but improves them in the antrum. Treatment with proton pump inhibitors does not result in any increase in the incidence of atrophy/intestinal metaplasia. However, as gastritis predominating in the corpus seems to be associated with an elevated carcinogenic risk, consideration should be given to prophylactic H. pylori eradication therapy before initiating proton pump inhibitor treatment.

Helicobacter pylori infection, reflux esophagitis, and atrophic gastritis: an unexplored triangle

OBJECTIVE

H. pylori causes chronic gastritis, which may progress to peptic ulcer, gastric atrophy, or gastric cancer. However, little is known about the role of H. pylori infection in reflux esophagitis and the relationship between reflux esophagitis and atrophic gastritis needs to be clarified. We sought to identify the possible interrelationships among Helicobacter pylori infection, reflux esophagitis, and atrophic gastritis, to signal areas in which researchers should consider focusing their attention.

METHODS

A broad-based Medline search was performed to identify all related publications addressing H. pylori infection, atrophic gastritis, gastroesophageal reflux disease (GERD), secretion of gastric acid, and gastric motility published between 1966 and July 1997.

RESULTS

Whereas some studies have shown no significant association between H. pylori infection and reflux esophagitis, others have observed that the prevalence of H. pylori infection was lower in patients with GERD, implying a protective role. Eradication of H. pylori leads to occurrence of reflux esophagitis in some cases, but the mechanisms inducing posteradication reflux esophagitis are unknown. H. pylori infection may lead to atrophic gastritis (and hence hypochlorhydia) through both bacterial and host factors, although gastric atrophy and subsequent intestinal metaplasia are hostile to H. pylori because of hypochlorhydria. Although it has been reported that long-term proton pump inhibitor therapy for refractory reflux esophagitis may induce or enhance the development of gastric atrophy in H. pylori-infected patients, this relationship has been disputed.

CONCLUSIONS

H. pylori infection may be negatively associated with reflux esophagitis, but this requires confirmation. Research then needs to focus on whether this is explained through motility- or acid-related mechanisms. The potential costs of maintenance antireflux therapy may need to be taken into account when evaluating the cost effectiveness of anti-H. pylori therapy.

H2-receptor antagonists and antacids have an aggravating effect on Helicobacter pylori gastritis in duodenal ulcer patients

BACKGROUND

Antacids, such as aluminium-magnesium hydroxide (AIMg(OH)3), or H2-receptor antagonists, such as ranitidine, are common drugs used for treating peptic ulcer disease and acid-related symptoms.

METHODS

In a prospective double-blind controlled study, 174 patients were randomized to a 4-week course of treatment with either AIMg(OH)3 (acid-binding capacity: 280 mval/day) or ranitidine 300 mg for active Helicobacter pylori-associated duodenal ulcers (as determined by histology and the urease test). Before and after treatment, two biopsy specimens each were obtained from the antrum and corpus, and the grade and activity of gastritis, as well as H. pylori density, were determined using a score ranging from 0 = none to 4 = severe.

RESULTS

Pre- and post-treatment histology were available for 138 patients (AIMg(OH)3: 67, ranitidine; 71). Treatment with AIMg(OH)3 significantly increased the activity of corpus gastritis (Wilcoxon signed-rank: P = 0.0014), while ranitidine treatment significantly increased both the grade and activity of corpus gastritis (P = 0.0002 and P = 0.0001 respectively). In the antrum, both regimens provoked a significant increase in the frequency of intestinal metaplasia, but this may be a consequence of sampling error.

CONCLUSIONS

Ranitidine and AIMg(OH)3 have an aggravating effect on H. pylori gastritis in duodenal ulcer patients. This should be considered a side-effect of the respective drugs and is more pronounced with ranitidine.

Helicobacter pylori and atrophic gastritis

Infection with Helicobacter pylori plays a crucial role in the etiology of atrophic gastritis and gastric cancer. Studies suggest a nine-fold increased risk for both conditions in the presence of infection. The risk of atrophic gastritis in the presence of infection is dependent upon the severity of the gastritis. Gastritis is increased in subjects infected with a cytotoxic H pylori strain and in those with a decreased acid production. The development of atrophy may be related to the induction of cross-reacting antibodies recognizing Lewis epitopes on H pylori lipopolysaccharide and gastric mucosa. Future studies have to demonstrate whether atrophic gastritis and gastric cancer can be prevented by early H pylori eradication.

Relation between gastric acid output, Helicobacter pylori, and gastric metaplasia in the duodenal bulb

BACKGROUND

Factors that determine gastric metaplasia in the duodenal bulb are ill defined. It is more common and extensive in the presence of high acid output and possibly in the presence of Helicobacter pylori. However, no quantitative relation between acid output and the extent of gastric metaplasia has been demonstrated and its relation to H pylori is uncertain.

AIM

To determine the relation between H pylori infection and acid output and the presence and extent of gastric metaplasia in the duodenal bulb. subjects: H pylori positive and negative patients with duodenal ulcer and healthy controls were studied.

METHODS

Quadrantic duodenal bulb biopsy specimens were taken and the presence and extent of gastric metaplasia determined using a computer enhanced image intensifier. Basal and stimulated acid outputs were measured.

RESULTS

gastric metaplasia was significantly (p < 0.05 more common and significantly (p < 0.05) greater in extent in patients with duodenal ulcer than in controls. Neither the prevalence or extent of gastric metaplasia was affected by H pylori status. There were significant (p < 0.01) direct correlations between acid output and extent of gastric metaplasia.

CONCLUSIONS

Prevalence and extent of gastric metaplasia are not related to H pylori in controls, or in patients with duodenal ulcer. Rather, high acid response to gastrin may be more important.

Atrophic gastritis and Helicobacter pylori infection in patients with reflux esophagitis treated with omeprazole or fundoplication

BACKGROUND

Helicobacter pylori infection plays an important part in the development of atrophic gastritis and intestinal metaplasia, conditions that predispose patients gastric cancer. Profound suppression of gastric acid is associated with increased severity of gastritis caused by H. pylori, but it is not known whether acid suppression increases the risk of atrophic gastritis.

METHODS

We studied patients from two separate cohorts who were being treated for reflux esophagitis: 72 patients treated with fundoplication in Sweden and 105 treated with omeprazole (20 to 40 mg once daily) in the Netherlands. In both cohorts, the patients were followed for an average of five years (range, three to eight). After fundoplication, the patients did not receive acid-suppressive therapy. The presence of H. pylori was assessed at the first visit by histologic evaluation in the fundoplication group and by histologic and serologic evaluation in the omeprazole group. The patients were not treated for H. pylori infection. Before treatment and during follow-up, the patients underwent repeated gastroscopy, with biopsy sampling for histologic evaluation.

RESULTS

Among the patients treated with fundoplication, atrophic gastritis did not develop in any of the 31 who were infected with H. pylori at base line or the 41 who were not infected; 1 patient infected with H. pylori had atrophic gastritis before treatment that persisted after treatment. Among the patients treated with omeprazole, none of whom had atrophic gastritis at base line, atrophic gastritis developed in 18 of the 59 infected with H. pylori(P<0.001) and 2 of the 46 who were not infected (P=0.62).

CONCLUSIONS

Patients with reflux esophagitis and H. pylori infection who are treated with omeprazole are at increased risk of atrophic gastritis.

Effects of ranitidine on gastric vesicles containing H+,K(+)-adenosine triphosphatase in rats

BACKGROUND

To ascertain the mechanism for rebound acid hypersecretion after treatment with an H2-receptor blocker, we investigated the effects of ranitidine on gastric H+,K(+)-adenosine triphosphatase (ATPase) in rats.

METHODS

Male Wistar rats received ranitidine (1-50 mg/kg body weight intraperitoneally twice a day for 5 days). The rats were starved for 15 h after the last treatment and then killed, and gastric vesicles containing H+,K(+)-ATPase were prepared.

RESULTS

Treatment with ranitidine dose-dependently increased protein content in the gastric vesicular fraction purified from the gastric mucosa without changing total protein content. Ranitidine also increased the content of a 94,000-dalton protein, the catalytic subunit of H+,K(+)-ATPase. On the other hand, ranitidine did not affect the specific activity of the enzyme (mumol/min/mg of the gastric vesicular protein). Since gastric vesicles in the fasting state mainly consist of the tubulovesicular membrane, these results suggest that ranidine administration increases total tubulovesicular H+,K(+)-ATPase content (mumol/min/rat) by increasing the number of tubulovesicles per parietal cell. The ranitidine-induced increase in total tubulovesicular H+,K(+)-ATPase activity was still evident 1 week after treatment and returned to control level 1 month later.

CONCLUSIONS

All these findings suggest that the increased content and total activity of tubulovesicular H+,K(+)-ATPase after ranitidine treatment may contribute to the mechanism for acid rebound after H2-blocker therapy.

Review article: the development of atrophic gastritis--Helicobacter pylori and the effects of acid suppressive therapy

Helicobacter pylori is uniquely adapted to survival in the strongly acidic gastric lumen. In vitro, both acid and certain acid suppressors affect bacterial growth. In vivo, there is little evidence that acid suppressors have any effect on bacterial survival. In contrast, decrease of acid secretion quickly leads to a spreading of the bacterial infection throughout the body and fundus of the stomach, which is accompanied by an increase of the associated gastritis. Helicobacter pylori gastritis may, in a substantial number of infected subjects, ultimately lead to atrophy and intestinal metaplasia, conditions with an increased risk for gastric cancer. This review summarizes the data on the interrelation between Helicobacter pylori, gastric acid secretion and development of atrophic gastritis.

Effect of Helicobacter pylori eradication on gastric metaplasia of the duodenum

Helicobacter pylori associated duodenal ulcers occur in patches of gastric metaplasia. The pathogenesis of gastric metaplasia is unclear, but it has been produced in experimental animals by acute injury and has been shown to be present to a greater extent of H pylori positive subjects. This study aimed to discover if gastric metaplasia regressed with eradication of H pylori or healing of duodenal ulcers, or both. Thirty two duodenal ulcer patients with H pylori infection confirmed by biopsy urease test and by antral histological examination were studied. Patients were treated with triple therapy (deNol 240 mg twice daily, amoxycillin 500 mg three times daily, and metronidazole 400 mg three times daily) for two weeks after the first endoscopy and were subsequently re-endoscoped. Three duodenal bulb biopsy specimens were obtained per patient at each endoscopy. Biopsy sections were stained with haematoxylin and eosin to determine the severity of duodenitis, and with diastase periodic acid-Schiff/alcian blue to assess the extent of gastric metaplasia. Slides were assessed by two histopathologists unaware of treatment status. H pylori was eradicated in 63% of subjects and all ulcers were healed at follow up. The median extent of gastric metaplasia at the start of treatment and 6-18 months (median 10) after treatment was compared in the two groups. Gastric metaplasia declined in eradicators from 16% to 8% (p < 0.05) while in non-eradicators there was no significant change (25% initially and at follow up). A positive relation between extent of gastric metaplasia and duodenal inflammation score was present before treatment (r(s) = 0.74, p < 0.001) and was unchanged after treatment in the non-eradicator group (r(s) = 0.89, p < 0.001). In the eradicator group, however, the inflammation score had significantly declined (p < 0.02) and the close relation with gastric metaplasia was no longer present. These results suggest that H pylori itself is at least in part responsible for producing gastric metaplasia of the duodenum.

Future research in peptic ulcer disease

For the past 10 years, research into peptic ulcer disease has focused on the surprising suggestion that gastritis and peptic ulcers may be caused by the bacterium Helicobacter pylori. However, the time has now come to reappraise research directions, as a causal link has been established, and even the most ardent sceptics now accept that H. pylori infection is the major factor in most cases of peptic ulcer disease. As with any established microbial disease, we need to understand the epidemiology and mechanisms of pathogenesis, but the major focus should be towards improving therapies and defining the long-term outcome of H. pylori eradication. To devise novel therapeutic agents effectively, we must increase our knowledge of the basic physiology of H. pylori and its ecology in the stomach. This has been a surprisingly neglected area of research and major questions remain. Why does the organism flourish in different areas of the gastric mucosa when gastric pH is increased? Is a change in pH the reason for the potentiating effects of acid-inhibitory agents on anti-H. pylori activity? Will knowledge of the host and bacterial factors that initiate ulcerogenesis allow us to better predict H. pylori-associated ulcers by using non-invasive methods? As H. pylori is a major gastroduodenal pathogen, can we eliminate the infection from selected populations? What are the criteria that will allow therapeutic intervention? The first steps have been taken in the development of an effective vaccine, but who should be immunized?(ABSTRACT TRUNCATED AT 250 WORDS)

Cumulative 10-year risk of symptomatic duodenal and gastric ulcer in patients with or without chronic gastritis. A clinical follow-up study of 454 outpatients

The cumulative rate of symptomatic peptic ulcer (PU) was examined in a 10-year clinical follow-up study of 454 consecutive outpatients who had undergone diagnostic gastroscopy, from whom routine biopsy specimens were taken from the antral and corpus mucosa, and who were found to be ulcer-free before and at the time of this initial gastroscopy. During the follow-up period 34 (11%) of 321 patients who showed gastritis in the biopsy specimens at the initial gastroscopy had contracted symptomatic PU (18, 5, 7, and 4 cases of duodenal, pyloric, antral, and angular or corpus ulcer, respectively), which was verified by endoscopy. Only 1 (0.8%) of 133 patients with normal antral and corpus mucosa had contracted PU. It was calculated that the 10-year cumulative probability of PU was 10.6% (95% confidence interval (CI95), 7.2-14.0%) in the patients with gastritis, whereas this probability was only 0.8% (0-2.2%) in the patients who had normal antral and corpus mucosa in the initial specimens. The cumulative probability of PU was found to be highest, 27.3% (1.0-53.6%), in middle-aged men (41-60 years of age) who had chronic antral gastritis or chronic pangastritis (gastritis in both antrum and corpus). It is concluded that chronic gastritis precedes the appearance of PU and that the cumulative 10-year risk of PU is very low when both antral and corpus mucosa are normal but may be high if chronic gastritis is present.

Gastric histology and plasma gastrin response to a meal in patients with duodenal ulcer disease after five years treatment with ranitidine

Fifty asymptomatic patients with duodenal ulcer disease, aged 31-82 years, who had received ranitidine maintenance therapy continuously for five or more years without a symptomatic recurrence, were studied. Fasting plasma gastrin concentrations were normal (mean 24 pmol/L, S.D. +/- 22) while the post-prandial gastrin response was variable with maximum plasma concentrations ranging from 16 to 309 pmol/L. Endoscopy revealed six asymptomatic peptic ulcers. Histological examination of gastric biopsies showed mild, superficial inflammatory cell infiltration of the fundic mucosa, but more extensive inflammatory cell infiltration with some atrophy of the mucosal glands in the antral mucosa. Patchy intestinal metaplasia was evident in the antral mucosa of 18 patients. No fundic ECL cell hyperplasia was seen. Helicobacter pylori were detected in the corpus and antrum of most patients. These results suggest that maintenance treatment with ranitidine for 5 years is not associated with either significant hypergastrinaemia or with changes in the fundic mucosa which could be interpreted as pre-malignant.