Effects of 5 years of treatment with rabeprazole or omeprazole on the gastric mucosa

Whether long-term use of proton pump inhibitor increases the risk of precancerous lesions in the stomach: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

To evaluate through meta-analysis whether long-term use of proton pump inhibitor (PPI) increases the risk of precancerous lesions in the stomach.

METHODS

Randomized controlled trials that compared the occurrence and progression of precancerous lesions in patients receiving PPI treatment versus non-PPI treatment were retrieved from CNKI, VIP, Wanfang, CBM, Pubmed, Embase, Web of Science, and Cochrane Library databases (from database inception to May 1, 2023). The Revman 5.3 and STATA 17.0 software were used for analysis, and subgroup analysis was conducted based on follow-up time (≤12 months and > 12 months) and lesion type (atrophic gastritis, intestinal metaplasia, and epithelial dysplasia).

RESULTS

Six randomized controlled trials with a total of 1623 cases were included, including 1015 cases in the experimental group and 608 cases in the control group. The meta-analysis results showed that the overall abnormal lesion rate combined with statistical relative risk (RR) = 1.31 (0.85-2.02), P = .23. Subgroup analysis showed that the follow-up time > 12 months combined result was RR = 2.21 (1.47-3.33), P = .0001, the intestinal metaplasia group combined result was RR = 1.96 (0.91-2.47), P = .04.

CONCLUSION SUBSECTIONS

During long-term follow-up, patients using PPI exhibited a significantly higher incidence of overall abnormal lesions compared to the control group, particularly with a higher risk observed for intestinal metaplasia. However, there were no statistically significant differences between the 2 groups in terms of short-term follow-up and other types of lesions. It is important to exercise caution when interpreting these findings due to the limited number of nominated investigations included in the meta-analysis.

Outcomes associated with proton pump inhibitors and distal radius fractures: A post-hoc comparative analysis

Long-term, high-dose, daily proton pump inhibitors (PPI) may impact outcomes associated with distal radius fractures (DRF). The hypothesis was that differences existed in patient demographics, but there existed no differences in injury patterns, interventions, post-operative complications, and patient-reported outcomes between patients not on a PPI and patients on a PPI with a DRF. METHODS: An IRB-approved, post-hoc analysis of patients with DRF from 2012 through 2018 was performed. Patients included were age ≥18 years, sustained a DRF, had completed medical and medication records, Quick Disabilities of the Arm, Shoulder and Hand (DASH) scores, Global Assessment of Functioning (GAF) scores, visual analogue scale (VAS) pain scores, and a minimum of 1-year follow-up. Patients were stratified into two cohorts. Cohort one patients had no prescription or over-the-counter PPI use (no PPI cohort). Cohort two patients had adherence to a long-term, high-dose, daily PPI (PPI cohort). RESULTS: Two hundred and eighty-one DRF patients were included. Of these 281 patients, 240 were in the no PPI cohort and 41 were in the PPI cohort. Patients in the PPI cohort had more median nerve injuries (12% versus 3%, p = 0.025) and radial shaft fractures (5% versus 0%, p = 0.020), less contralateral upper extremity injuries (0% versus 4%, p = 0.001), and more post-operative nonunions (7% versus 1%, p = 0.029) compared to patients in the no PPI cohort. The results obtained suggest that a CONCLUSIONS: Long-term, high-dose, daily PPI's may be associated with more median nerve injuries and radial shaft fractures, less contralateral upper extremity injuries, and more post-operative nonunions compared to DRF patients not on a PPI.

Influence of hypergastrinemia secondary to long-term proton pump inhibitor treatment on ECL cell tumorigenesis in human gastric mucosa

Proton pump inhibitor (PPI) therapy causes hypergastrinemia, which could promote the development and progression of neuroendocrine tumors (NETs). Concerns have been raised about the safety of long-term PPI use due to a possible increased risk of NETs. This study aimed to investigate the association between hypergastrinemia and the risk of NETs. Twenty outpatients presenting with serum gastrin levels greater than 400 pg/mL after long-term PPI treatment were registered in this study. Immunohistochemical analyses for chromogranin A (CgA), Ki67, gastrin and CCK/B gastrin receptor (CCKBR) were performed, and positive cell numbers were counted. There were no NET or gastric epithelial neoplasia cases observed among any of the 20 patients examined throughout the PPI treatment period. Histologically, ECL cell hyperplasia were shown in all patients. However, no relationship was found between serum gastrin levels and the number of CgA positive ECL cells. There was also no relationship between serum gastrin levels and the proportion of Ki67 positive cells or the density of CCKBR positive cells. The data indicate no relationship may exist between NETs and hypergastrinemia secondary to PPI treatment in patients having no, or mild, atrophic gastritis.

Proton Pump Inhibitors and Fracture Risk: A Review of Current Evidence and Mechanisms Involved

The number of patients with gastroesophageal problems taking proton pump inhibitors (PPIs) is increasing. Several studies suggested a possible association between PPIs and fracture risk, especially hip fractures, but the relationship remains contentious. This review aimed to investigate the longitudinal studies published in the last five years on the relationship between PPIs and fracture risk. The mechanism underlying this relationship was also explored. Overall, PPIs were positively associated with elevated fracture risk in multiple studies (n = 14), although some studies reported no significant relationship (n = 4). Increased gastrin production and hypochlorhydria are the two main mechanisms that affect bone remodeling, mineral absorption, and muscle strength, contributing to increased fracture risk among PPI users. As a conclusion, there is a potential relationship between PPIs and fracture risks. Therefore, patients on long-term PPI treatment should pay attention to bone health status and consider prophylaxis to decrease fracture risk.

Mid- and Deep-Zone Gastritis: A Histologic Pattern Associated With Autoimmune Disease but Distinct From Autoimmune Atrophic Gastritis

OBJECTIVES

We sought to characterize a histologic pattern of mid- and deep-zone gastritis, distinct from the typical pattern of Helicobacter pylori or autoimmune gastritis and to see if it had any clinicopathologic association(s).

METHODS

We analyzed inflammatory patterns and composition, excluded autoimmune gastritis using immunohistochemistry, and reviewed the medical record for demographics, medical/surgical history, presenting symptoms, endoscopic findings, and medications for 28 cases.

RESULTS

All cases had inflammation in the middle and/or deep mucosal zones with sparing of the superficial/pit compartment. Subfeatures included corpus or antral predominance, pangastric involvement, prominence of a subset(s) of inflammatory cells, and degree of epithelial injury. Of 28 patients, 13 had autoimmune disease(s), autoantibodies, or both. There was no other unifying clinical feature.

CONCLUSIONS

This unique pattern of gastritis should be distinguished from other entities such as H pylori and autoimmune gastritis. At least a subset may be an autoimmune condition different from classic autoimmune gastritis.

Autoimmune metaplastic atrophic gastritis in chinese: a study of 320 patients at a large tertiary medical center

OBJECTIVES

Autoimmune metaplastic atrophic gastritis (AMAG) is an uncommon disease worldwide and may predispose to gastric carcinoid tumors or adenocarcinomas. The aims of this study were to outline the clinical characteristics of Chinese AMAG patients, including demographic pattern, hematologic features, and gastroscopic and histopathologic findings.

PATIENTS AND METHODS

A total of 320 Chinese patients with AMAG, from January 2007 to December 2014, were reviewed in a regional hospital of China.

RESULTS

Of the 320 AMAG patients, the mean age was 60.6 ± 12.3 years [range 26-86; 206 (64.4%) women]. The coarse annual detection rate was 0.9%. Anemia was present in only 19.3% patients (53/275) and 3.5% (11/315) AMAG patients also had primary biliary cirrhosis. One hundred and thirty-six had endoscopically identifiable lesions. These lesions consisted of 130 polypoid lesions (63 hyperplastic polyps, 2 oxyntic mucosa pseudopolyps, 2 intestinal-type gastric adenomas, 2 fundic gland polyps, 5 concurrent polyps, 14 well-differentiated neuroendocrine neoplasms, 7 submucosal tumors and 35 chronic gastritis), 6 adenocarcinomas. The detection rate of atrophy and intestinal metaplasia in antral mucosa were 47.2 and 37.5%, respectively.

CONCLUSIONS

AMAG is more frequent than expected in China and display a female predominance, accompanied with other autoimmune disorders. AMAG should be paid more attention by clinicians through a multidisciplinary team approach.

Effect of netazepide, a gastrin/CCK2 receptor antagonist, on gastric acid secretion and rabeprazole-induced hypergastrinaemia in healthy subjects

AIMS

To compare gastric acid suppression by netazepide, a gastrin/CCK2 receptor antagonist, with that by a proton pump inhibitor (PPI), and to determine if netazepide can prevent the trophic effects of PPI-induced hypergastrinaemia.

METHODS

Thirty healthy subjects completed a double-blind, randomized, parallel group trial of oral netazepide and rabeprazole, alone and combined, once daily for 6 weeks. Primary end points were: basal and pentagastrin-stimulated gastric acid and 24 h circulating gastrin and chromogranin A (CgA) at baseline, start and end of treatment, gastric biopsies at baseline and end of treatment and basal and pentagastrin-stimulated gastric acid and dyspepsia questionnaire after treatment withdrawal.

RESULTS

All treatments similarly inhibited pentagastrin-stimulated gastric acid secretion. All treatments increased serum gastrin, but the combination and rabeprazole did so more than netazepide alone. The combination also reduced basal acid secretion. Rabeprazole increased plasma CgA, whereas netazepide and the combination reduced it. None of the biopsies showed enterochromaffin-like (ECL) cell hyperplasia. Withdrawal of treatments led neither to rebound hyperacidity nor dyspepsia.

CONCLUSIONS

Netazepide suppressed pentagastrin-stimulated gastric acid secretion as effectively as did rabeprazole. The reduction in basal acid secretion and greater increase in serum gastrin by the combination is consistent with more effective acid suppression. Despite our failure to show rabeprazole-induced ECL cell hyperplasia and rebound hyperacidity, the increase in plasma CgA after rabeprazole is consistent with a trophic effect on ECL cells, which netazepide prevented. Thus, netazepide is a potential treatment for the trophic effects of hypergastrinaemia and, with or without a PPI, is a potential treatment for acid-related conditions.

Systematic review: the effects of long-term proton pump inhibitor use on serum gastrin levels and gastric histology

BACKGROUND

Proton pump inhibitors (PPIs) have a well-established safety profile. However, concerns have been raised about a potential relationship between PPI-induced hypergastrinaemia and the development of enterochromaffin-like (ECL) cell hyperplasia, neuroendocrine tumours and gastric cancer during long-term therapy.

AIM

To review the effects of long-term PPI use on serum gastrin levels and gastric histopathology.

METHODS

A systematic literature search was conducted in PubMed on 21 April 2015 to identify studies reporting the effects of long-term (defined as >3 years) PPI use on gastrin levels and gastric histopathology.

RESULTS

A total of 16 studies (1920 patients) met the inclusion criteria. During long-term PPI therapy, mean gastrin levels rose to one to three times the upper limit of the normal range (~100 pg/mL), and an increased prevalence of ECL cell hyperplasia was observed (+7.8-52.0%). Helicobacter pylori-positive patients had a significantly increased risk of developing ECL linear/micronodular hyperplasia compared with H. pylori-negative patients [OR: 2.45 (95% CI: 1.47-4.10), P = 0.0006]; however, no evidence of neoplastic changes was found. The risk of corpus atrophy was markedly higher in H. pylori-positive patients than in H. pylori-negative patients [OR: 11.45 (95% CI: 6.25-20.99), P < 0.00001]. Not a single case of gastric adenocarcinoma was found.

CONCLUSIONS

Long-term PPI therapy induced moderate hypergastrinaemia in most patients and an increased prevalence of ECL cell hyperplasia. H. pylori-positive patients receiving long-term PPI therapy were exposed to a higher risk of corpus atrophy than H. pylori-negative patients. No neuroendocrine tumours or gastric cancers were found.

Gastric neuroendocrine tumors: prevalence in Europe, USA, and Japan, and rationale for treatment with a gastrin/CCK2 receptor antagonist

OBJECTIVE

Gastric carcinoids (neuroendocrine tumors) arise from enterochromaffin-like cells in the gastric mucosa. Most are caused by hypergastrinemia. The objectives were to determine if their prevalence in Europe, USA and Japan meets the criteria for an orphan disease and to justify treatment with a gastrin/CCK2 receptor antagonist.

METHODS

We obtained data from European and USA cancer registries, and searched PubMed.

RESULTS

Prevalence per 10,000 population obtained from cancer registries was: median 0.32 (range 0.09-0.92) for Europe; and 0.17 for the USA, equivalent to 4812 for the whole population. A PubMed search for gastric carcinoids yielded prevalence for Japan only, which was 0.05 per 10,000 population, equivalent to 665 for the entire population. A further search for gastric carcinoids in patients with pernicious anemia (PA) or autoimmune chronic atrophic gastritis (CAG), two presentations of about 80% of gastric carcinoids, produced prevalence rates of 5.2-11%. Prevalence of PA itself was 0.12-1.9%. Data on CAG epidemiology were sparse.

CONCLUSION

Prevalence of gastric carcinoids varied widely. All sources probably underestimate prevalence. However, prevalence was below the limits required for recognition by drug regulatory authorities as an orphan disease: 5 per 10,000 population of Europe; 200,000 for the whole population of the USA; and 50,000 for the whole population of Japan. Because gastric carcinoids are an orphan disease, and nonclinical and healthy volunteer studies support treatment with netazepide, a gastrin/CCK2 antagonist, netazepide has been designated an orphan medicinal product in Europe and the USA for development as targeted treatment for gastric carcinoids.

Long-term proton pump inhibitor (PPI) use and the development of gastric pre-malignant lesions

BACKGROUND

Proton pump inhibitors (PPIs) are the most effective drugs to reduce gastric acid secretion. PPIs are one of the most commonly prescribed classes of medications worldwide. Apart from short-term application, maintenance therapy with PPIs is recommended and increasingly used in certain diseases, such as Zollinger-Ellison syndrome and gastro-oesophageal reflux disease, especially for people with erosive oesophagitis or Barrett's oesophagus. Although PPIs are generally safe, their efficacy and safety of long-term use remains unclear. The question of whether the long-term use of PPIs could promote the development of gastric pre-malignant lesions has been widely investigated, but results are inconsistent. Limited insight on this problem leads to a dilemma in decision making for long-term PPI prescription.

OBJECTIVES

To compare the development or progression of gastric pre-malignant lesions, such as atrophic gastritis, intestinal metaplasia, enterochromaffin-like (ECL) cell hyperplasia, and dysplasia, in people taking long-term (six months or greater) PPI maintenance therapy.

SEARCH METHODS

We searched the following databases (from inception to 6 August 2013): the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL. In addition, we searched the reference lists of included trials and contacted experts in the field.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in adults (aged 18 years or greater) concerning the effects of long-term (six months or greater) PPI use on gastric mucosa changes, confirmed by endoscopy or biopsy sampling (or both).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed selection of eligible trials, assessment of trial quality, and data extraction. We calculated odds ratios (OR) for analysis of dichotomous data and mean differences for continuous data, with 95% confidence intervals (CI).

MAIN RESULTS

We included seven trials (1789 participants). Four studies had high risk of bias and the risk of bias in the other three trials was unclear. In addition, it was difficult to assess possible reporting bias. We pooled 1070 participants from four RCTs to evaluate corporal atrophy development revealing an insignificantly increased OR of 1.50 (95% CI 0.59 to 3.80; P value = 0.39; low-quality evidence) for long-term PPI users relative to non-PPI users. In five eligible trials, corporal intestinal metaplasia was assessed among 1408 participants, also with uncertain results (OR 1.46; 95% CI 0.43 to 5.03; P value = 0.55; low-quality evidence). However, by pooling data of 1705 participants from six RCTs, our meta-analysis showed that participants with PPI maintenance treatment were more likely to experience either diffuse (simple) (OR 5.01; 95% CI 1.54 to 16.26; P value = 0.007; very-low-quality evidence) or linear/micronodular (focal) ECL hyperplasia (OR 3.98; 95% CI 1.31 to 12.16; P value = 0.02; low-quality evidence) than controls. No participant showed any dysplastic or neoplastic change in any included studies.

AUTHORS' CONCLUSIONS

There is presently no clear evidence that the long-term use of PPIs can cause or accelerate the progression of corpus gastric atrophy or intestinal metaplasia, although results were imprecise. People with PPI maintenance treatment may have a higher possibility of experiencing either diffuse (simple) or linear/micronodular (focal) ECL cell hyperplasia. However, the clinical importance of this outcome is currently uncertain.

Acid peptic diseases: pharmacological approach to treatment

Acid peptic disorders are the result of distinctive, but overlapping pathogenic mechanisms leading to either excessive acid secretion or diminished mucosal defense. They are common entities present in daily clinical practice that, owing to their chronicity, represent a significant cost to healthcare. Key elements in the success of controlling these entities have been the development of potent and safe drugs based on physiological targets. The histamine-2 receptor antagonists revolutionized the treatment of acid peptic disorders owing to their safety and efficacy profile. The proton-pump inhibitors (PPIs) represent a further therapeutic advance due to more potent inhibition of acid secretion. Ample data from clinical trials and observational experience have confirmed the utility of these agents in the treatment of acid peptic diseases, with differential efficacy and safety characteristics between and within drug classes. Paradigms in their speed and duration of action have underscored the need for new chemical entities that, from a single dose, would provide reliable duration of acid control, particularly at night. Moreover, PPIs reduce, but do not eliminate, the risk of ulcers in patients taking NSAIDs, reflecting untargeted physiopathologic pathways and a breach in the ability to sustain an intragastric pH of more than 4. This review provides an assessment of the current understanding of the physiology of acid production, a discussion of medications targeting gastric acid production and a review of efficacy in specific acid peptic diseases, as well as current challenges and future directions in the treatment of acid-mediated diseases.

Qualitative analysis of anatomopathological changes of gastric mucosa due to long term therapy with proton pump inhibitors: experimental studies x clinical studies

INTRODUCTION

For a few decades the long-term use of proton pump inhibitors has had wide application in the treatment of several gastrointestinal diseases. Since then, however, several studies have called attention to the possible development of anatomical and pathological changes of gastric mucosa, resulting from the long term use of this therapeutic modality. Recent experimental and clinical studies suggest that these changes have connection not only to the development of precancerous lesions, but also of gastric tumors.

OBJECTIVE

To present a qualitative analysis of anatomical and pathological changes of gastric mucosa resulting from the long-term use of proton pump inhibitors.

METHOD

The headings used were: proton pump inhibitors, precancerous lesions and gastric neoplasms for a non systematic review of the literature, based on Medline, Lillacs and Scielo. Twelve articles were selected from clinical (9) and experimental (3) studies, for qualitative analysis of the results.

RESULTS

The gastric acid suppression by high doses of proton pump inhibitors induces hypergastrinemia and the consequent emergence of neuroendocrine tumors in animal models. Morphological changes most often found in these experimental studies were: enterochromaffin-like cell hyperplasia, neuroendocrine tumor, atrophy, metaplasia and adenocarcinoma. In the studies in humans, however, despite enterochromaffin-like cell hyperplasia, the other effects, neuroendocrine tumor and gastric atrophy, gastric metaplasia and or adenocarcinoma, were not identified.

CONCLUSION

Although it is not possible to say that the long-term treatment with proton pump inhibitors induces the appearance or accelerates the development of gastric cancer in humans, several authors have suggested that prolonged administration of this drug could provoke the development of gastric cancer. Thus, the evidence demonstrated in the animal model as well as the large number of patients who do or will do a long-term treatment with proton pump inhibitors, justifies the maintenance of this important line of research.

Acid suppressive drugs and gastric cancer: A meta-analysis of observational studies

AIM: To evaluate the association between acid suppressive drug use and the development of gastric cancer.

METHODS: A systematic search of relevant studies that were published through June 2012 was conducted using the MEDLINE (PubMed), EMBASE, and Cochrane Library databases. The search included observational studies on the use of histamine 2-receptor antagonists (H₂RAs) or proton pump inhibitors and the associated risk of gastric cancer, which was measured using the adjusted odds ratio (OR) or the relative risk and 95%CI. An independent extraction was performed by two of the authors, and a consensus was reached.

RESULTS: Of 4595 screened articles, 11 observational studies (n = 94558) with 5980 gastric cancer patients were included in the final analyses. When all the studies were pooled, acid suppressive drug use was associated with an increased risk of gastric cancer risk (adjusted OR = 1.42; 95%CI: 1.29-1.56, I² = 48.9%, P = 0.034). The overall risk of gastric cancer increased among H₂RA users (adjusted OR = 1.40; 95%CI: 1.24-1.59, I² = 59.5%, P = 0.008) and PPI users (adjusted OR = 1.39; 95%CI: 1.19-1.64, I² = 0.0%, P = 0.377).

CONCLUSION: Acid suppressive drugs are associated with an increased risk of gastric cancer. Further studies are needed to test the effect of acid suppressive drugs on gastric cancer.

Rabeprazole for the treatment of acid-related disorders

Proton pump inhibitors are widely used for the treatment of acid-related disorders. Rabeprazole is a potent and irreversible inhibitor of H(+)/K(+)-ATPase gastric pump, and it is indicated for the treatment of gastroesophageal reflux disease, Zollinger Ellison syndrome, duodenal and gastric ulcers and for the eradication of Helicobacter pylori in combination with antibiotics. Pharmacokinetic and pharmacodynamic data show that rabeprazole achieves a pronounced acid suppression from the first administration that is maintained with repeated use; this may translate into faster onset of symptom relief for patients, particularly suitable when the indication is for the on-demand long-term maintenance of gastroesophageal reflux disease. Due to its predominantly nonenzymatic metabolism, rabeprazole has a lower potential for drug-drug interactions. The objective of this article is to update efficacy and safety data of rabeprazole in the treatment of acid-related disorders, following a previous review dated 2008.

Safety and efficacy of long-term maintenance therapy with oral dose of rabeprazole 10 mg once daily in Japanese patients with reflux esophagitis

OBJECTIVE

The aim of this prospective clinical study was to evaluate the efficacy and safety of long-term proton pump inhibitor (PPI) treatment for two years in Japanese patients with reflux esophagitis (RE).

METHODS

The efficacy and safety of two-year (104-week) treatment with rabeprazole (RPZ) 10 mg were studied in patients confirmed to have been cured of RE by PPI and who required long-term maintenance therapy with PPI. We performed serial endoscopy, checked gastroesophageal reflux disease (GERD) symptoms, adverse events, laboratory values and serum gastrin. We also monitored gastric mucosal histology, atrophy and polyps.

RESULTS

The endoscopic non-relapse rate for RE was 87.3% for the 104-week period. GERD symptoms improved based on the fact that the mean change from baseline in GERD symptom score after treatment was a negative value. Treatment was safe; and atrophy was found to have developed in virtually no cases. A few new benign fundic gland or hyperplastic polyps developed throughout the study, but no ECL carcinoids were found to have developed. Serum gastrin levels tended to increase up to 24 weeks, but there were no subsequent changes thereafter up to 104 weeks.

CONCLUSION

The results confirmed oral RPZ 10 mg to be effective for maintenance therapy in Japanese patients with RE. Although effects on the gastric mucosa were not ruled out, long-term use of RPZ was confirmed to be safe overall.

Guidelines for the diagnosis and management of gastroesophageal reflux disease: an evidence-based consensus

Gastroesophageal reflux disease (GERD) is one of the most common disorders in medical practice. A number of guidelines and recommendations for the diagnosis and management of GERD have been published in different countries, but a Brazilian accepted directive by the standards of evidence-based medicine is still lacking. As such, the aim of the Brazilian GERD Consensus Group was to develop guidelines for the diagnosis and management of GERD, strictly using evidence-based medicine methodology that could be clinically used by primary care physicians and specialists and would encompass the needs of physicians, investigators, insurance and regulatory bodies. A total of 30 questions were proposed. Systematic literature reviews, which defined inclusion and/or exclusion criteria, were conducted to identify and grade the available evidence to support each statement. A total of 11,069 papers on GERD were selected, of which 6,474 addressed the diagnosis and 4,595, therapeutics. Regarding diagnosis, 51 met the requirements for the analysis of evidence-based medicine: 19 of them were classified as grade A and 32 as grade B. As for therapeutics, 158 met the evidence-based medicine criteria; 89 were classified as grade A and 69 as grade B. In the topic Diagnosis, answers supported by publications grade A and B were accepted. In the topic Treatment only publications grade A were accepted: answers supported by publications grade B were submitted to the voting by the Consensus Group. The present publication presents the most representative studies that responded to the proposed questions, followed by pertinent comments. Follow examples. In patients with atypical manifestations, the conventional esophageal pH-metry contributes little to the diagnosis of GERD. The sensitivity, however, increases with the use of double-channel pH-metry. In patients with atypical manifestations, the impedance-pHmetry substantially contributes to the diagnosis of GERD. The examination, however, is costly and scarcely available in our country. The evaluation of the histological signs of esophagitis increases the diagnostic probability of GERD; hence, the observation of the dimensions of the intercellular space of the esophageal mucosa increases the probability of diagnostic certainty and also allows the analysis of the therapeutic response. There is no difference in the clinical response to the treatment with PPI in two separate daily doses when compared to a single daily dose. In the long term (>1 year), the eradication of H. pylori in patients with GERD does not decrease the presence of symptoms or the high recurrence rates of the disease, although it decreases the histological signs of gastric inflammation. It seems very likely that there is no association between the eradication of the H. pylori and the manifestations of GERD. The presence of a hiatal hernia requires larger doses of proton-pump inhibitor for the clinical treatment. The presence of permanent migration from the esophagogastric junction and the hernia dimensions (>2 cm) are factors of worse prognosis in GERD. In this case, hiatal hernias associated to GERD, especially the fixed ones and larger than 2 cm, must be considered for surgical treatment. The outcomes of the laparoscopic fundoplication are adequate.

Rabeprazole: a review of its use in the management of gastric acid-related diseases in adults

Rabeprazole (Aciphex, Alfence, Pariet) is a proton pump inhibitor (PPI) used for the treatment of adults with conditions requiring a reduction of gastric acid secretion such as erosive or ulcerative gastro-oesophageal reflux disease (GORD), non-erosive reflux disease (NERD), duodenal and gastric ulcers, and pathological hypersecretory conditions including Zollinger-Ellison syndrome (ZES). It is also used as part of combination therapy for the eradication of Helicobacter pylori, a pathogen frequently implicated in the development of gastric and duodenal ulcers. Rabeprazole has a well established efficacy and safety profile in the treatment of gastric acid-related diseases. Rabeprazole is a useful, well tolerated and cost-effective option for the treatment of GORD, NERD, peptic ulcer and other gastric acid-related diseases (including ZES), and provides an appropriate alternative to other currently available PPIs, with the added benefits of having a consistent efficacy profile and low drug interaction potential due to its predominantly nonenzymatic metabolism.

Transmucosal gastric leak induced by proton pump inhibitors

Despite their remarkable safety profile and lack of clinical side effects, proton pump inhibitors (PPIs) induce a transmucosal gastric leak to non-electrolyte probes of various sizes. The ex vivo addition of PPIs to isolated rat gastric corpus increases transmucosal permeability in a dose-dependent manner, which corresponds with PPIs' dose-dependent inhibition of acid secretion. Upon the addition of omeprazole, lansoprazole, or esomeprazole, a small decrease in transepithelial resistance and the concomitant stimulation of short circuit current was observed. Additionally, transepithelial flux of (14)C-[D]-mannitol (MW 182.17) across the gastric mucosa increased by a mean of 68% immediately following the addition of 200 microM omeprazole. This flux increase was bidirectional. Omeprazole also increased the paracellular permeability to larger radiolabeled probes, including (14)C-sucrose (MW 342.3) and (14)C-polyethylene glycol (MW 4,000) by 118% and 350%, respectively. However, the flux of still larger probes, 10,000 and 70,000 MW dextrans, was not increased. Because PPIs are so widely used and are assumed to be innocuous, this transmucosal gastric leak must be further investigated, as it may carry considerable biomedical implications.

Rabeprazole: a second-generation proton pump inhibitor in the treatment of acid-related disease

Rabeprazole is a proton pump inhibitor (PPI) presenting a very advantageous pharmacodynamic and pharmacokinetic profile over older PPIs. In particular, this drug has a very fast onset of action, due to a short activation time and a very high pKa, and may therefore be defined as a 'second generation' PPI. The aim of this article is to provide an update on the pharmacology and clinical profile of rabeprazole and its use in acid-related disorders, with a particular focus on its role in gastroesophageal reflux disease; in the treatment and prevention of duodenal and gastric ulcers and Zollinger-Ellison syndrome; in the therapy of the extraesophageal manifestations of gastroesophageal reflux disease (in particular the respiratory and ear, nose and throat ones); and in the eradication of Helicobacter pylori.

Gastric cancer: Animal studies on the risk of hypoacidity and hypergastrinemia

Gastric hypoacidity and hypergastrinaemia are seen in several conditions associated with an increased risk of gastric malignancy. Hypoacidity and hypergastrinaemia are closely related and their long-term effects are difficult to study separately in patients. Studies using animal models can provide valuable information about risk factors and mechanisms in gastric cancer development as the models allow a high degree of intervention when introducing or eliminating factors possibly affecting carcinogenesis. In this report, we briefly review findings from relevant animal studies on this topic. Animal models of gastric hypoacidity and hypergastrinaemia provide evidence hypergastrinaemia is a common causative factor in many otherwise diverse settings. In all species where sufficient hypoacidity and hypergastrinaemia have been induced, a proportion of the animals develop malignant lesions in the gastric oxyntic mucosa.

Prognostic significance of gastrin expression in patients undergoing R0 gastrectomy for adenocarcinoma

BACKGROUND

Gastrointestinal (GI) hormones regulate several GI functions, including the proliferation and repair of normal mucosa, and hormone receptors may therefore be implicated in the growth, invasion, and metastasis of cancers of the GI tract. The aim of this study was to determine the cellular distribution of gastrin in intestinal-type gastric cancers, and to determine its relationship to outcomes after R0 gastrectomy.

METHODS

Eighty-six consecutive patients undergoing R0 gastrectomy for adenocarcinoma were studied. Normal gastric mucosa and tumor were stained for gastrin and their specific cellular distribution was determined.

RESULTS

The duration of survival of patients whose tumors exhibited well-differentiated gastrin-positive tumor (GPT) cells (n = 12) was significantly poorer than that of patients whose tumors were GPT-negative (5-year survival, 30% vs 54%; P = 0.037). Patients with GPT-positive intestinal-type gastric cancer (5 of 47 patients) had the poorest survival of all (median, 14 months; 5-year survival, 0%; P = 0.006). In a multivariate analysis, only lymph node metastases (hazard ratio [HR], 2.13; 95% confidence interval [CI], 1.2 to 3.79; P = 0.01) and the presence of GPT cells (HR, 6.61; 95% CI, 1.74 to 25.09; P = 0.01) were independently and significantly associated with durations of survival in patients with intestinal-type gastric cancer.

CONCLUSION

The presence of GPT cells in patients with gastric adenocarcinoma is a significant and independent prognostic indicator.

Drug-induced injury in the gastrointestinal tract: clinical and pathologic considerations

Drug toxicity in the gastrointestinal tract is a common and serious medical problem; the number of drugs that can harm the gastrointestinal tract is impressive. The morbidity, mortality, and medical costs associated with drug toxicity, even when restricted to the gastrointestinal tract, are probably underestimated. Drug-induced gastrointestinal tract pathology is very diverse and can mimic many non-drug-related conditions. Drug toxicity, whether direct or indirect, can be restricted to a segment of the gastrointestinal tract or affect the entire gastrointestinal tract. The consequences of drug toxicity are also quite variable and can range from unimportant pathology (e.g. the relatively common and usually benign drug-induced diarrhea) at one end of the spectrum, to fatal gastrointestinal tract hemorrhage or perforation at the other end of the spectrum. Better awareness of the possibility of drug-induced gastrointestinal tract pathology, by both gastroenterologists and pathologists, and better communication between gastroenterologists, pathologists and other specialists will improve the recognition of drug-induced gastrointestinal tract pathology, and, ultimately, improve patient care. This Review focuses on the most common and well-described drug-related clinicopathologic conditions of the gastrointestinal tract. Much discussion is, therefore, dedicated to NSAIDs--the most commonly prescribed drugs and consequently the drugs most commonly associated with gastrointestinal tract toxicity.

Attack and defence in the gastric epithelium - a delicate balance

The gastric epithelium is a complex structure formed into tubular branched gastric glands. The glands contain a wide variety of cell types concerned with the secretion of hydrochloric acid, proteases, mucus and a range of signalling molecules. All cell types originate from stem cells in the neck region of the gland, before migrating and differentiating to assume their characteristic positions and functions. Endocrine and local paracrine mediators are of crucial importance for maintaining structural and functional integrity of the epithelium, in the face of a hostile luminal environment. The first such mediator to be recognized, the hormone gastrin, was identified over a century ago and is now established as the major physiological stimulant of gastric acid secretion. Recent studies, including those using mice that overexpress or lack the gastrin gene, suggest a number of previously unrecognized roles for this hormone in the regulation of cellular proliferation, migration and differentiation. This review focuses on the identification of hitherto unsuspected gastrin-regulated genes and discusses the paracrine cascades that contribute to the maintenance of gastric epithelial architecture and secretory function. Helicobacter infection is also considered in cases where it shares targets and signalling mechanisms with gastrin.

Proton pump inhibitors and Helicobacter pylori gastritis: friends or foes?

H. pylori gastritis and gastric acid closely interact. In H. pylori-positive patients, profound acid suppressive therapy induces a corpus-predominant pangastritis, which is associated with accelerated corpus gland loss and development of atrophic gastritis. Both corpus-predominant and atrophic gastritis have been associated with an increased risk of development of gastric cancer. H. pylori eradication leads to resolution of gastritis and may induce partial regression of pre-existent gland loss. H. pylori eradication does not aggravate GERD nor does it impair the efficacy of proton pump inhibitor maintenance therapy for this condition. This is the background of the advise within the European guidelines for the management of H. pylori infection to offer an H. pylori test and treat policy to patients who require proton pump inhibitor maintenance therapy for GERD. As such a policy fully reverses H. pylori pangastritis even in patients who have been treated for years with proton pump inhibitors, there is no need to eradicate H. pylori before the start of proton pump inhibitors. In fact, the somewhat slower initial response of H. pylori-negative GERD patients to proton pump inhibitor therapy and the fact that many GERD patients will only require short-term therapy suggests to first start the proton pump inhibitor, and only test and treat when maintenance therapy needs to be prescribed. Such considerations prevent the persistent presence of active corpus-predominant gastritis in proton pump inhibitor-treated reflux patients without impairing the clinical efficacy of treatment.