Randomized trial of rifabutin-based triple therapy and high-dose dual therapy for rescue treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin

BACKGROUND

The clinical management of Helicobacter pylori infected patients who failed standard eradication therapies remains a challenge.

AIM

To investigate the efficacy of rifabutin-based triple therapy and high-dose dual therapy for rescue treatment of H. pylori, and the correlation between cytochrome P450 2C19 (CYP2C19) polymorphisms and treatment outcome.

METHODS

Patients infected with H. pylori resistant to both metronidazole and clarithromycin (n = 145) were randomized to either esomeprazole 20 mg, rifabutin 150 mg and amoxicillin 1 g, each given b.d. for 7 days (ERA), or to omeprazole 40 mg and amoxicillin 1000 mg, each given t.d.s. for 14 days (OA). Crossover therapy was offered in cases of persistent infection. CYP2C19 polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism.

RESULTS

Intention-to-treat and per-protocol eradication rates were: ERA 74% (62.4-83.6) and 78% (66.7-87.3); high-dose OA 70% (57.5-79.7) and 75% (62.5-84.5). Crossover therapy was successful in seven of 10 patients with ERA and in eight of 10 patients with OA. Premature discontinuation of treatment occurred in 2% and 5% of patients, respectively. There was only a non-significant trend to lower eradication rates in homozygous extensive metabolizers.

CONCLUSIONS

Triple therapy with esomeprazole, rifabutin and amoxicillin and high-dose omeprazole/amoxicillin are comparable and effective and safe for rescue therapy of H. pylori regardless of the patient's CYP2C19 genotype.

Healing of lymphocytic gastritis after Helicobacter pylori eradication therapy--a randomized, double-blind, placebo-controlled multicentre trial

BACKGROUND

An association between Helicobacter pylori infection and lymphocytic gastritis has been postulated.

AIM

To assess the long-term effect of H. pylori eradication therapy on lymphocytic gastritis in a double-blind, placebo-controlled, multicentre trial.

METHODS

Patients with lymphocytic gastritis were randomized to receive either 1-week triple therapy for eradication of H. pylori or omeprazole plus placebo. Endoscopy and histology was performed at baseline and after 3 and 12 months. Patients of the omeprazole/placebo group with persistent lymphocytic gastritis after 12 months received crossover open-label triple therapy.

RESULTS

Fifty-one patients were randomized. Intention-to-treat analysis revealed a trend to a higher healing rate of lymphocytic gastritis 3 months after triple therapy compared with omeprazole/placebo (83.3% vs. 57.7%, 95% CI for RR: 0.8-2.8, P = 0.06). After 12 months, the healing rate of lymphocytic gastritis was significantly higher after triple therapy compared with omeprazole/placebo (intention-to-treat 95.8% vs. 53.8%, 95% CI for RR: 1.1-3.5, P = 0.01). All patients (n = 5) who received crossover triple therapy, showed healing of lymphocytic gastritis after further 12 months.

CONCLUSION

Our study demonstrates that 1-week triple therapy aiming at eradication of H. pylori leads to a complete and long-lasting resolution of lymphocytic gastritis in the majority of patients.

Impact of reflux disease on general and disease-related quality of life - evidence from a recent comparative methodological study in Germany

BACKGROUND

The clinical and socioeconomic burden of gastro-esophageal reflux disease (GERD) is considerable. The primary symptom of GERD is heartburn, but it may also be associated with extraesophageal manifestations, such as asthma, chest pain and otolaryngologic disorders.

AIM

To describe the impact of heartburn on patients' Health-Related Quality of Life (HRQL) in Germany, using validated generic and disease-specific instruments to measure patient-reported outcomes.

METHOD

Patients with symptoms of heartburn completed the German versions of the Gastrointestinal Symptom Rating Scale (GSRS), the Quality of Life in Reflux and Dyspepsia questionnaire (QOLRAD), the Short Form-36 (SF-36) and the Hospital Anxiety and Depression (HAD) scale. Frequency and severity of heartburn during the previous 7 days were also recorded.

RESULTS

142 consecutive patients completed the assessments (mean age of 47.5 years, SD = 14.6; 55.6 % female). 70 % of patients had moderate symptoms. Over half (68 %) had symptoms on more than 4 days in the previous week. Patients were most bothered by symptoms of reflux with a mean GSRS score, (ranges from 1 [not bothered] to 7 [very bothered]), of 3.9, indigestion of 3.3 and abdominal pain of 3.0, respectively. As a result of their symptoms, patients experienced problems with food and drink. The mean QOLRAD score (ranges from 1 to 7; the lower the value the more severe the impact on quality of life) of daily functioning was 4.4, impaired vitality 4.6, emotional distress 5.0 and sleep disturbance 5.1, respectively. This led to impaired overall HRQL across all domains (mean SF-36 score of this heartburn population compared to a general population in Germany). Using HAD, 25 % of patients were anxious and 8 % were depressed.

CONCLUSION

There is consistent evidence that heartburn substantially impairs all aspects of health-related quality of life.

Esomeprazole-based one-week triple therapy with clarithromycin and metronidazole is effective in eradicating Helicobacter pylori in the absence of antimicrobial resistance

AIM

This study aimed to investigate the effectiveness of a one-week triple therapy with esomeprazole, clarithromycin and metronidazole for eradication of Helicobacter pylori infection in the absence of antimicrobial resistance.

METHODS

Patients testing positive for H. pylori susceptible to metronidazole and clarithromycin (E-test) were randomized to receive a one-week regimen with either esomeprazole 2 x 20 mg or omeprazole 2 x 20 mg in combination with clarithromycin 2 x 250 mg and metronidazole 2 x 400 mg. Follow-up endoscopy with histology and culture and/or rapid urease test was performed 4-8 weeks after the end of treatment.

RESULTS

Eighty patients were randomized. Helicobacter pylori infection was cured in 38/39 patients of the esomeprazole group and 31/33 patients of the omeprazole group (per protocol 97.4% (95% confidence interval [CI], 86.2-99.9), 93.7% (95% CI, 79.2-99.2), P=0.59); intention-to-treat 90.4% (95% CI: 77.4-97.3), 81.6% (95% CI: 65.7-92.3), respectively. No major side effects occurred. Minor side effects occurred in eight (20%) and six (23%) patients during esomeprazole and omeprazole therapy, respectively. Post-treatment susceptibility testing revealed resistance to both metronidazole and clarithromycin in two of the three patients who failed.

CONCLUSION

We conclude that esomeprazole, clarithromycin and metronidazole as one-week triple therapy is effective for eradication of H. pylori in the absence of antimicrobial resistance.

Esomeprazole 20 mg and lansoprazole 15 mg in maintaining healed reflux oesophagitis: Metropole study results

INTRODUCTION

Esomeprazole, the first proton pump inhibitor to be developed as an optical isomer, has demonstrated more effective healing vs. omeprazole and lansoprazole in patients with reflux oesophagitis (RO). However, RO recurs in a high proportion (approximately 80%) of these patients within 12 months of initial therapy, highlighting the importance of maintenance treatment. Previous studies have shown esomeprazole to be effective as maintenance therapy in healed RO patients.

AIM

This study was conducted to compare esomeprazole 20 mg once daily (o.d.) with lansoprazole 15 mg o.d. for the prevention of recurrence of RO.

METHODS

1391 patients with endoscopically verified RO (LA classification) were enrolled in this randomized, double-blind, parallel-group, multicentre trial. During the initial healing phase of the study, all patients received 4-8 weeks' open treatment with esomeprazole 40 mg: 1236 healed (identified by endoscopy at 4 and 8 weeks) and symptom-free (i.e. no heartburn or acid regurgitation) patients were randomized to 6 months' maintenance treatment with esomeprazole 20 mg o.d. or lansoprazole 15 mg o.d. Time to relapse (relapse of RO and/or discontinuation due to symptom recurrence) was analysed using a log-rank test.

RESULTS

Esomeprazole maintained a significantly higher proportion of patients in remission than lansoprazole over the 6-month course of treatment (P < 0.0001, intention-to-treat analysis). After 6 months' treatment, 83% of esomeprazole recipients were in remission compared with 74% of lansoprazole recipients (life-table estimates). Esomeprazole gave a longer time to relapse than lansoprazole irrespective of baseline LA Grade, significantly so for baseline LA Grades B, C and D (P < 0.05 for each comparison). Significantly more patients were free from heartburn in the esomeprazole group compared with the lansoprazole group at 1, 3 and 6 months (P < 0.05). Significant differences at 6 months between esomeprazole 20 mg o.d. and lansoprazole 15 mg o.d. were also observed for control of epigastric pain and acid regurgitation (P < 0.05 and P < 0.001, respectively). Both treatment regimens were well tolerated.

CONCLUSION

Esomeprazole 20 mg o.d. is a more effective maintenance treatment than lansoprazole 15 mg o.d. for symptom-free patients with healed RO.

Esomeprazole 20 mg and lansoprazole 15 mg in maintaining healed reflux oesophagitis: Metropole study results

AIM

To compare the efficacy of esomeprazole, 20 mg once daily, vs. lansoprazole, 15 mg once daily, for the maintenance treatment of patients with healed reflux oesophagitis.

METHODS

During the initial open healing phase, 1391 patients with endoscopically verified reflux oesophagitis and a history of heartburn, with or without acid regurgitation, received esomeprazole 40 mg for 4-8 weeks. Patients who were healed (identified by endoscopy at 4 or 8 weeks) and symptom free were then randomized to receive 6 months of treatment with esomeprazole, 20 mg once daily, or lansoprazole, 15 mg once daily.

RESULTS

Esomeprazole, 20 mg once daily, maintained a significantly higher proportion of patients in remission than lansoprazole, 15 mg once daily, over 6 months [83% (95% CI, 80-86%) of esomeprazole recipients compared with 74% (95% CI, 70-78%) of lansoprazole recipients; P < 0.0001; life table estimates]. When data were analysed according to baseline Los Angeles grade classification, esomeprazole, 20 mg once daily, achieved consistently higher remission rates across all grades of disease severity, whereas the efficacy of lansoprazole decreased to a greater extent with increasing severity of reflux oesophagitis.

CONCLUSION

Esomeprazole, 20 mg once daily, is more effective than lansoprazole, 15 mg once daily, in maintaining remission in patients with healed reflux oesophagitis.

Healing of active, non-atrophic autoimmune gastritis by H. pylori eradication

BACKGROUND AND AIMS

The antigastric antibodies present in Helicobacter pylori infection act as a marker for an ongoing antigastric autoimmune process in the gastric mucosa, which can already be diagnosed in the non-atrophic stage. In a retrospective, uncontrolled study, therefore, we investigated the question as to whether this type of gastritis can be healed by the eradication of H. pylori.

PATIENTS AND METHODS

In 80 patients with an active, not yet atrophic autoimmune gastritis, we analysed a maximum of four investigations per patient over a period of up to 39.5 months. The following parameters were graded in the antral and corpus mucosa prior to and after H. pylori eradication treatment: grade and activity of the gastritis, H. pylori colonization, atrophy, parietal cell hypertrophy, and incidence of intestinal metaplasia. In addition, the typical parameters for this type of gastritis, such as grade of the periglandular lymphocytic infiltration, grade of glandular destruction and incidence of nodular ECL cell proliferates in the corpus mucosa were determined.

RESULTS

In 64 patients (80%), H. pylori eradication treatment was followed by healing of the active autoimmune corpus gastritis, that is, the activity of the gastritis disappeared, and lymphocytic infiltration of the glands, glandular destruction and parietal cell hypertrophy was found to be significantly reduced.

CONCLUSIONS

Our uncontrolled, retrospective study confirms the existence of an active, not yet atrophic autoimmune gastritis as a sequela of H. pylori infection.

Prevalence of H. pylori-infection in family members of H. pylori positive and its influence on the reinfection rate after successful eradication therapy: a two-year follow-up

INTRODUCTION

Living conditions (e. g. domestic crowding) may influence the infection rate. Some studies suggested that the reappearance of H. pylori in H. pylori positive patients after successful eradication therapy might be a result of transmission by H. pylori positive spouses. Therefore this study has been performed to evaluate the effect of the H. pylori status of family members on the reinfection rate of H. pylori positive patients after successful eradication therapy.

METHODS

108 H. pylori positive patients (64 male, 44 female, aged 48.7 years, range 18-76 years) who presented with dyspeptic symptoms for upper GI-endoscopy have been included into this study. H. pylori status has been defined by culture and/or histology, rapid urease test and serology. For eradication therapy patients received omeprazole 20 mg bd, clarithromycine 250 mg bd and metronidazole 400 mg bd. H. pylori status was controlled by (13)C-urea breath test 28 days (n = 96), 6 (n = 35), 12 (n = 28) and 24 months (n = 25) after eradication therapy. Additionally H. pylori status of 170 family members (82 spouses, 68 children, 20 siblings/parents, aged 3-83 years) was defined by (13)C-urea breath test (n = 167), upper GI-endoscopy (n = 2) or serology (n = 1).

RESULTS

The eradication rate was 98 % (94/96). H. pylori prevalence in all family members was 40 % (56 % in spouses, 20 % in children). No reinfection has been found in successful eradicated patients within the two-years follow-up.

DISCUSSION

These results suggest that reinfection is not dependent on the H. pylori prevalence in family members and that H. pylori reinfection after successful eradication therapy is an unlikely event.

Helicobacter and gastric MALT lymphoma

Helicobacter pylori infection is a pre-MALT lymphoma condition. H pylori eradication leads to complete remission in 80% of low grade stage E1 lymphomas, with a yearly recurrence rate of approximately 5%. The possibility for complete remission in high grade lymphomas needs to be investigated in prospective studies. In addition, the significance of persistent B cell monoclonality (stable disease? danger of relapse? regression of monoclonality?) needs to be investigated in follow up studies.

Atrophy-metaplasia-dysplasia-carcinoma sequence in the stomach: a reality or merely an hypothesis?

The results of recent investigations have suggested that the old hypothesis of an atrophy-metaplasia-dysplasia-carcinoma sequence in the stomach needs to be qualified. The most common cause of intestinal metaplasia is Helicobacter pylori gastritis. The consequence of this intestinal metaplasia is focal atrophy. Helicobacter pylori infection may also trigger an autoimmune gastritis of the corpus mucosa, with atrophy and intestinal metaplasia. Most intestinal metaplasias are only 'paracancerous' but not 'precancerous' lesions. Diffuse gastric carcinomas, such as the signet ring cell carcinoma, arise independently of intestinal metaplasia. Histogenetically, numerous carcinomas of the stomach are primarily of the gastric type, and may secondarily change into the intestinal type.High-grade intra-epithelial neoplasias (dysplasias) detected during the biopsy-based diagnostic work-up appear to be a marker for carcinoma and must, therefore, be removed endoscopically. The detection of intestinal metaplasia in routinely obtained biopsy material is subject to sampling error and is, therefore, not a suitable marker for an increased risk of a gastric carcinoma developing. As an alternative, the concept of gastritis of the carcinoma phenotype, which is more frequently found in early gastric carcinomas and in the relatives of gastric carcinoma patients, has been developed. In this concept, the diffuse parameters of grade and activity of the gastritis in the antrum and corpus, which are independent of sampling error, are subjected to a comparative analysis. A risk gastritis of the carcinoma phenotype is diagnosed when the grade and activity of the gastritis in the corpus are at least equally as pronounced as in the antrum. Currently, this concept is being tested in a prospective ongoing study. Future studies must show whether, and if so which, immunohistochemical or molecular-genetically detectable changes can be applied as risk markers in the diagnostic work-up. Helicobacter pylori eradication probably does not lead to complete regression of the intestinal metaplasia and ensuing focal atrophy. However, eradication of H. pylori does lead to the normalization of changes that can lead to mutations of the stem cells of the gastric mucosa (free radicals, nitric oxide, cell proliferation and vitamin C secretion).

Long-term follow-up of gastric MALT lymphoma after H. pylori eradication

For almost 10 years, we have been familiar with the concept of mucosa-associated lymphoid tissue (MALT)-type lymphoma of the stomach caused by chronic Helicobacter pylori infection. Many epidemiologic, biologic, and molecular genetic studies have implicated H. pylori for its role in lymphoma genesis. Since the first reports on complete remission of gastric MALT lymphomas after cure of bacterial infection, many clinical studies have investigated the effect of eradicating H. pylori on the course of MALT lymphoma, and indeed were able to confirm remission of the lymphoma. To date, more than 650 patients worldwide have been treated for gastric MALT lymphoma with antibiotics, and we have gained many new insights concerning the biologic behavior of this disease, especially from the deepened knowledge of cytogenetics. Furthermore, factors relevant for the prediction of treatment outcome have been identified, which has helped to stratify patients into risk groups.

Molecular diagnostics in low-grade gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type after Helicobacter pylori eradication therapy

The primary gastric lymphomas are extranodal non-Hodgkin's lymphomas that likely originate from the mucosa-associated lymphoid tissue (MALT). Data suggest that chronic infection with Helicobacter pylori (H pylori) is significantly associated with the pathogenesis of low-grade gastric MALT lymphomas. This is in keeping with the observation that many patients with early low-grade MALT lymphomas have complete remissions after H pylori eradication therapy. However, the stability of these remissions remains unclear and relapses have been reported. It can be difficult to distinguish between early malignant and benign disorders of the gastric mucosa. A polymerase chain reaction (PCR) assay can detect rearrangements of the variable region of immunoglobulin heavy chains. This assay can be used to distinguish the clonality of B lymphocytes and has been investigated as a test for differential diagnosis of MALT lymphomas. Monoclonality is observed in the majority of MALT-lymphoma samples at diagnosis but has been found in gastritis samples as well. Whether the presence of monoclonal B cells is associated with the risk of lymphoma progression remains unclear. As many as 50% of patients who have complete histologic remissions of MALT lymphoma after H pylori eradication therapy have persisting monoclonal bands in follow-up PCR monitoring. Although it is unclear as to whether monoclonality indicates the presence of minimal residual disease, patients who have persistent monoclonal bands during follow-up should be considered at risk for relapse. The PCR assay for rearrangements of the variable region of the immunoglobulin heavy-chain gene appears to be of low value in the diagnosis of B-cell malignancies but could provide a useful tool in the follow-up of patients who achieve remissions after H pylori eradication.

Treatment of Helicobacter pylori infection

Helicobacter pylori is a serious, chronic, progressive, and transmissible infection associated with a significant morbidity and mortality, which alone emphasizes the priority of developing adequate prophylactic or therapeutic measures. What was previously termed "asymptomatic H. pylori infection" is now recognized as a latent infection, and it is now accepted that the presence of an H. pylori infection is an indication for eradication therapy. Successful cure of H. pylori infection requires 2 or more antibiotics. Antibiotic resistance is the major impediment of cure. The ideal duration of therapy is unknown, but in general, 1 week therapy is less effective than longer durations. Compliance is important for the success of treatment; therefore, the favored regimen should have the least side effects. At present, a proton pump inhibitor (or ranitidine bismuth citrate)-clarithromycin triple therapy with either amoxicillin or metronidazole, for at least 10 days is considered first-line therapy. The alternative is quadruple therapy containing a proton pump inhibitor, bismuth, tetracycline, and a higher dose of metronidazole. Quadruple therapy is the best choice after failure of proton pump inhibitor-clarithromycin triple therapy. Confirmation of successful therapy with a urea breath test or a stool antigen test is now the standard of practice.

Development of early gastric cancer 4 and 5 years after complete remission of Helicobacter pylori associated gastric low grade marginal zone B cell lymphoma of MALT type

AIM: To report 3 of 120 patients on the German MALT lymphoma trial with H. pylori associated gastric MALT lymphoma who developed early gastric cancer 4 and 5 years, after complete lymphoma remission following cure of H. pylori infection.

PATIENTS AND RESULTS: Three patients (two men, 74 and 70 years; one women, 77 years) with H. pylori-associated low-grade MALT lymphoma achieved complete lymphoma remission after being cured. Surveillance endoscopies were performed twice a year in accordance to the protocol. Four years after complete lymphoma remission in two patients, and after 5 years in the other, early gastric adenocarcinoma of the mucosa-type, type II a and type II c, respectively, was detetcted, which were completely removed by endoscopic mucosa resection. In one patient, the gastric cancer was diagnosed at the same location as the previous MALT lymphoma, in the other patients it was detected at different sites of the stomach distant from location of the previous MALT lymphoma. The patients were H. pylori negative during the whole follow-up time.

CONCLUSION: These findings strengthen the importance of regular Long term follow-up endoscopies in patients with complete remission of gastric MALT lymphoma after cure of H. pylori infection. Furthermore, gastric adenocarcinoma may develop despite eradication of H. pylori.

Helicobacter pylori and gastric cancer: current status of the Austrain-Czech-German gastric cancer prevention trial (PRISMA-Study)

AIM: To test the hypothesis that Helicobacter pylori eradication alone can reduce the incidence of gastric cancer in a subgroup of individuals with an increased risk for this fatal disease.

METHODS: It is a prospective, randomized, double blind, placebo controlled multinational multicenter trial. Men between 55 and 65 years of age with a gastric cancer phenotype of Helicobacter pylori gastritis are randomized to receive a 7 day course of omeprazole 2 × 20 mg, clarithromycin 2 × 500 mg, and amoxicillin 2 × 1 g for 7 days, or omeprazole 2 × 20 mg plus placebo. Follow-up endoscopy is scheduled 3 months after therapy, and thereafter in one-year intervals. Predefined study endpoints are gastric cancer, precancerous lesions (dysplasia, adenoma), other cancers, and death.

RESULTS: Since March 1998, 1524 target patients have been screened, 279 patients (18.3%) had a corpus dominant type of H. pylori gastritis, and 167 of those were randomized (58.8%). In the active treatment group (n = 86), H. pylori infection infection was cured in 88.9% of patients. Currently, the cumulative follow-up time is 3046 months (253. 38 patient years, median follow up 16 months). So far, none of the patients developed gastric cancer or any precancerous lesion. Three (1.8%) patients reached study endpoints other than gastric cancer.

CONCLUSION: Among men between 55 and 65 years of age, the gastric cancer phenotype of H. pylori gastritis appears to be more common than expected. Further follow up and continuing recruitment are necessary to fulfil the main aim of the study.

Complete remission of primary high-grade B-cell gastric lymphoma after cure of Helicobacter pylori infection

PURPOSE

Treatment of low-grade gastric mucosa-associated lymphoid tissue lymphoma by eradication of Helicobacter pylori is reported to result in complete lymphoma remission in approximately 75% of cases. The effect that cure of the infection has on the course of a primary high-grade gastric lymphoma is largely uncertain. The aim of this study was to report the effect of cure of H pylori infection exerted in patients with high-grade B-cell gastric lymphoma.

PATIENTS AND METHODS

Eight patients (4 males and 4 females; age range, 26 to 85 years) with H pylori infection and high-grade lymphoma received eradication therapy before planned treatment. The effect of H pylori eradication on the course of high-grade lymphoma was assessed by analysis of surgical specimens (n = 2) or endoscopic biopsies (n = 6).

RESULTS

H pylori eradication was successful in all patients and led to complete remission of the lymphoma in seven patients. One patient has experienced partial remission. Two patients were referred to surgery, one of whom (stage II(1E)) had lymph node involvement, and the histologic work-up of the resected stomach revealed residual infiltrates of a low-grade lymphoma, which prompted consolidation chemotherapy. In one patient (initially stage I(1E)), abdominal lymphoma developed 6 months after eradication therapy, which regressed completely after chemotherapy. In four patients, no further treatment was given. Six patients continue in complete remission (range, 6 to 66 months).

CONCLUSION

Primary high-grade B-cell gastric lymphoma in stages I(E) through II(E1) associated with H pylori may regress completely after successful cure of the infection. Prospective trials are needed to investigate this treatment in larger numbers of patients.

Helicobacter pylori vacA, iceA, and cagA status and pattern of gastritis in patients with malignant and benign gastroduodenal disease

OBJECTIVE

Both bacterial virulence factors and the pattern of Helicobacter pylori (H. pylori) gastritis may contribute to the development of clinically relevant gastroduodenal disease. The aim of our study was to investigate the frequency of H. pylori vacA alleles, iceA, and cagA, and the pattern of gastritis in patients with gastric cancer (GC), gastric lymphoma (MALT), duodenal ulcer (DU), and functional dyspepsia (FD).

METHODS

H. pylori was cultured from 141 patients (34 GC, 26 MALT, 49 DU, 32 FD). Allelic variants of vacA and iceA, and cagA were identified by polymerase chain reaction. Antrum and corpus biopsies were obtained for assessment of gastritis according to the updated Sydney System.

RESULTS

The vacA sl,ml genotype was more frequently detected in H. pylori from GC patients (70.6%) than from MALT, DU, and FD patients (p < 0.05). The frequency of iceA1 and cagA did not differ among the groups. The proportion of patients with severe gastritis in the corpus was significantly higher in patients with GC and MALT compared with patients with DU (p < 0.001).

CONCLUSIONS

In a German patient population, only the vacA s1,m1 genotype of H. pylori is associated with GC, and therefore may be useful to identify infected patients being at an increased risk for GC.

Long-term persistence of monoclonal B cells after cure of Helicobacter pylori infection and complete histologic remission in gastric mucosa-associated lymphoid tissue B-cell lymphoma

PURPOSE

Cure of Helicobacter pylori infection is associated with remission induction in the majority of patients with low-grade gastric mucosa associated lymphoid tissue (MALT) lymphoma in localized stages; however, limited data exist as to whether these patients may be cured of their lymphoma. The present study was performed to investigate whether the polymerase chain reaction (PCR) for the rearranged immunoglobulin heavy chain region may be used to define "molecular" remission.

PATIENTS AND METHODS

Ninety-seven patients who suffered from low-grade gastric MALT lymphoma stage I(E) were observed with central pathology and molecular biology after cure of H pylori infection. PCR was performed with the use of consensus primers for the framework regions 1, 2, and 3 and monoclonality was corroborated by sequence analysis. In selected cases, microdissection was performed to study the origin of the monoclonal B cells.

RESULTS

Of the 97 patients, 77 obtained complete endoscopic and histologic remission (CR). Twenty of 44 patients with PCR monoclonality at diagnosis and with sufficient molecular follow-up displayed monoclonal bands for a median time of 20.5 months after CR (range, 0 to 50.4 months). These B cells were related to the original lymphoma clone by sequence analysis. Microdissection analysis identified basal lymphoid aggregates as the source of these monoclonal B cells. Local relapse occurred in and was observed by PCR in four patients. All four patients displayed monoclonal PCR before relapse, and three of these four showed ongoing PCR monoclonality throughout their course, indicating the persistence of malignant cells.

CONCLUSION

Half of all patients with gastric MALT lymphoma show long-term PCR monoclonality up to several years after cure of H pylori infection and CR. Patients with monoclonal PCR should be observed closely, whereas long-term PCR negativity may indicate cure of the disease.

Inducible nitric oxide synthase expression before and after eradication of Helicobacter pylori in different forms of gastritis

An increased expression of inducible nitric oxide synthase (iNOS) has been observed in the inflamed human gastric mucosa as well as in some tumors. This observation suggests a pathobiological role of elevated NO production. The purpose of this study was to compare the immunohistochemical iNOS expression in the different kinds of gastritis before and after the eradication of Helicobacter pylori. We performed iNOS and H. pylori immunohistochemical staining and counted iNOS positive cells. We detected elevated expression of iNOS around sites infected with H. pylori. iNOS expression in chemical gastritis was strongly elevated in mucosal glands. After treatment, we found a significant difference in iNOS expression in patients with classical H. pylori-induced antrum predominant gastritis and in patients with active autoimmune gastritis. In the special case of progressed gastritis with intestinal metaplasia we found persistence of intestinal metaplasia, and we could not find a significant difference in the number of positive iNOS cells before and after treatment. The persistence of IM as a possibly precancerous lesion is probably at least in the antrum a source of continuous iNOS induction even after H. pylori eradication.

[Extent, topography and symptoms of Helicobacter pylori gastrtitis. Phenotyping for accurate diagnosis and therapy?]

Helicobacter pylori gastritis, a very common condition, may lead to serious sequelae such as peptic ulcer, gastric carcinoma, and mucosa-associated lymphoid tissue lymphoma. Histological grading of the various gastritis parameters can help to identify the risk of these sequelae and thus improve the indication for prophylactic treatment of the H. pylori infection. This applies in particular to two types of "risk gastritis": gastritis of the duodenal ulcer phenotype and gastritis of the carcinoma phenotype. In the former the antrum shows pronounced inflammatory changes while only low-grade gastritis is seen in the corpus. In the latter, by contrast, the gastritis in the corpus is at least equally as severe as that in the antrum; in addition, intestinal metaplasia and focal atrophy is also frequently found in this phenotype. By establishing topographic grading of the gastritis in antrum and corpus the pathologist can therefore play the role of a "litmus test" for prophylactic H. pylori eradication treatment.

[Precancerous risk markers in Helicobacter pylori gastritis]

Primarily on the basis of epidemiological evidence, Helicobacter pylori was classified as a definite human carcinogen in 1994. Although several pathophysiological consequences of chronic H. pylori gastritis have been identified which may contribute to the development of gastric carcinoma, it is still largely unknown why only a minority of individuals infected with H. pylori (approximately 1/1000) develop this fatal disease. In recent years many studies have examined potential risk factors of H. pylori gastritis to improve our understanding of the early events in gastric carcinogenesis. The present paper summarizes research data supporting the following hypotheses: (a) Some H. pylori possess virulence factors which may contribute to the pathogenicity of the organism and may increase the risk for subsequent severe gastroduodenal diseases such as gastric cancer. However, the associations between these virulence factors and disease is not specific, and may vary considerably among different geographic regions. (b) Chronic H. pylori gastritis induces several pathophysiological alterations which may promote cancer development. In particular, the corpus-dominant phenotype of H. pylori gastritis is strongly associated with gastric cancer. (c) A family history of gastric cancer per se, but also in combination with H. pylori infection, is associated with histopathological and molecular alterations that are considered relevant in gastric carcinogenesis.

The HOMER Study: the effect of increasing the dose of metronidazole when given with omeprazole and amoxicillin to cure Helicobacter pylori infection

BACKGROUND

Helicobacter pylori eradication with omeprazole, amoxycillin, and metronidazole is both effective and inexpensive. However, eradication rates with different dosages and dosing vary, and data on the impact of resistance are sparse. In this study, three different dosages of omeprazole, amoxycillin, and metronidazole were compared, and the influence of metronidazole resistance on eradication was assessed.

METHODS

Patients (n = 394) with a positive H. pylori screening test result and endoscopy-proven duodenal ulcer in the past were enrolled into a multicenter study performed in four European countries and Canada. After baseline endoscopy, patients were randomly assigned to treatment for 1 week with either omeprazole, 20 mg twice daily, plus amoxycillin, 1,000 mg twice daily, plus metronidazole, 400 mg twice daily (low M); or omeprazole, 40 mg once daily, plus amoxycillin, 500 mg three times daily, plus metronidazole, 400 mg three times daily (medium M); or omeprazole, 20 mg twice daily, plus amoxycillin, 1,000 mg twice daily, plus metronidazole, 800 mg twice daily (high M). H. pylori status at entry was assessed by a 13C urea breath test and a culture. Eradication was defined as two negative 13C-urea breath test results 4 and 8 weeks after therapy. Susceptibility testing using the agar dilution method was performed at entry and in patients with persistent infection after therapy.

RESULTS

The eradication rates, in terms of intention to treat (ITT) (population n = 379) (and 95% confidence interval [CI]) were as follows: low M 76% (68%, 84%), medium M 76% (68%, 84%), and high M 83% (75%, 89%). By per-protocol analysis (population n = 348), the corresponding eradication rates were: low M 81%, medium M 80%, and high M 85%. No H. pylori strains were found to be resistant to amoxycillin. Prestudy resistance of H. pylori strains to metronidazole was found in 72 of 348 (21%) of the cultures at entry (range, 10%-39% in the five countries). The overall eradication rate in prestudy metronidazole-susceptible strains was 232 of 266 (87%) and, for resistant strains, it was 41 of 70 (57%; p <.001). Within each group, the results were as follows (susceptible/resistant): low M, 85%/54%; medium M, 86%/50%; and high M, 90%/75%. There were no statistically significant differences among the treatment groups. 23 strains susceptible to metronidazole before treatment were recultured after therapy failed; 20 of these had now developed resistance.

CONCLUSIONS

H. pylori eradication rates were similar (approximately 80%) with all three regimens. Metronidazole resistance reduced efficacy; increasing the dose of metronidazole appeared not to overcome the problem or significantly improve the outcome. Treatment failure was generally associated with either prestudy or acquired metronidazole resistance. These findings are of importance when attempting H. pylori eradication in communities with high levels of metronidazole resistance.

The Helicobacter pylori vacA s1, m1 genotype and cagA is associated with gastric carcinoma in Germany

BACKGROUND

The H. pylori vacuolating cytotoxin encoded by vacA and the cytotoxin-associated protein encoded by cagA are considered to be important virulence determinants that have been implicated in the development of peptic ulcers and gastric carcinoma. However, conflicting results regarding the association between these virulence factors and clinical disease have been reported from different geographic regions.

AIMS

To determine the frequency of vacA genotypes, vacuolating cytotoxin activity, and cagA in H. pylori isolates obtained from patients with gastric cancer in Germany.

METHODS

H. pylori isolates were obtained from 34 patients with gastric cancer and from 35 subjects with asymptomatic H. pylori gastritis. vacA genotypes and cagA were identified by PCR. Cytotoxic activity was determined by HeLa cell assays. Gastritis was assessed according to the updated Sydney System.

RESULTS

The H. pylori vacA s1,m1 genotype was significantly more frequent in patients with gastric cancer (24/34, 70.6%) as compared with controls (12/35, 34. 3%) (p = 0.005). Cytotoxic activity was detected in 24 (70.6%) and 15 (42.9%) H. pylori isolates from gastric cancer patients and controls, respectively (p = 0.03). The cagA gene was identified in 30 (88.2%) and 21 (60%) H. pylori isolates in the respective groups (p = 0.01).

CONCLUSIONS

Our study suggests a significant association between the H. pylori vacA s1,m1 genotype, cytotoxic activity, cagA, and gastric cancer. Detection of H. pylori possessing these virulence determinants may help to identify patients being at an increased risk to develop gastric cancer in our population.

The Helicobacter pylori vacA s1, m1 genotype and cagA is associated with gastric carcinoma in Germany

BACKGROUND

The H. pylori vacuolating cytotoxin encoded by vacA and the cytotoxin-associated protein encoded by cagA are considered to be important virulence determinants that have been implicated in the development of peptic ulcers and gastric carcinoma. However, conflicting results regarding the association between these virulence factors and clinical disease have been reported from different geographic regions.

AIMS

To determine the frequency of vacA genotypes, vacuolating cytotoxin activity, and cagA in H. pylori isolates obtained from patients with gastric cancer in Germany.

METHODS

H. pylori isolates were obtained from 34 patients with gastric cancer and from 35 subjects with asymptomatic H. pylori gastritis. vacA genotypes and cagA were identified by PCR. Cytotoxic activity was determined by HeLa cell assays. Gastritis was assessed according to the updated Sydney System.

RESULTS

The H. pylori vacA s1,m1 genotype was significantly more frequent in patients with gastric cancer (24/34, 70.6%) as compared with controls (12/35, 34. 3%) (p = 0.005). Cytotoxic activity was detected in 24 (70.6%) and 15 (42.9%) H. pylori isolates from gastric cancer patients and controls, respectively (p = 0.03). The cagA gene was identified in 30 (88.2%) and 21 (60%) H. pylori isolates in the respective groups (p = 0.01).

CONCLUSIONS

Our study suggests a significant association between the H. pylori vacA s1,m1 genotype, cytotoxic activity, cagA, and gastric cancer. Detection of H. pylori possessing these virulence determinants may help to identify patients being at an increased risk to develop gastric cancer in our population.

The Helicobacter pylori vacA s1, m1 genotype and cagA is associated with gastric carcinoma in Germany

BACKGROUND

The H. pylori vacuolating cytotoxin encoded by vacA and the cytotoxin-associated protein encoded by cagA are considered to be important virulence determinants that have been implicated in the development of peptic ulcers and gastric carcinoma. However, conflicting results regarding the association between these virulence factors and clinical disease have been reported from different geographic regions.

AIMS

To determine the frequency of vacA genotypes, vacuolating cytotoxin activity, and cagA in H. pylori isolates obtained from patients with gastric cancer in Germany.

METHODS

H. pylori isolates were obtained from 34 patients with gastric cancer and from 35 subjects with asymptomatic H. pylori gastritis. vacA genotypes and cagA were identified by PCR. Cytotoxic activity was determined by HeLa cell assays. Gastritis was assessed according to the updated Sydney System.

RESULTS

The H. pylori vacA s1,m1 genotype was significantly more frequent in patients with gastric cancer (24/34, 70.6%) as compared with controls (12/35, 34. 3%) (p = 0.005). Cytotoxic activity was detected in 24 (70.6%) and 15 (42.9%) H. pylori isolates from gastric cancer patients and controls, respectively (p = 0.03). The cagA gene was identified in 30 (88.2%) and 21 (60%) H. pylori isolates in the respective groups (p = 0.01).

CONCLUSIONS

Our study suggests a significant association between the H. pylori vacA s1,m1 genotype, cytotoxic activity, cagA, and gastric cancer. Detection of H. pylori possessing these virulence determinants may help to identify patients being at an increased risk to develop gastric cancer in our population.

The Helicobacter pylori vacA s1, m1 genotype and cagA is associated with gastric carcinoma in Germany

BACKGROUND

The H. pylori vacuolating cytotoxin encoded by vacA and the cytotoxin-associated protein encoded by cagA are considered to be important virulence determinants that have been implicated in the development of peptic ulcers and gastric carcinoma. However, conflicting results regarding the association between these virulence factors and clinical disease have been reported from different geographic regions.

AIMS

To determine the frequency of vacA genotypes, vacuolating cytotoxin activity, and cagA in H. pylori isolates obtained from patients with gastric cancer in Germany.

METHODS

H. pylori isolates were obtained from 34 patients with gastric cancer and from 35 subjects with asymptomatic H. pylori gastritis. vacA genotypes and cagA were identified by PCR. Cytotoxic activity was determined by HeLa cell assays. Gastritis was assessed according to the updated Sydney System.

RESULTS

The H. pylori vacA s1,m1 genotype was significantly more frequent in patients with gastric cancer (24/34, 70.6%) as compared with controls (12/35, 34. 3%) (p = 0.005). Cytotoxic activity was detected in 24 (70.6%) and 15 (42.9%) H. pylori isolates from gastric cancer patients and controls, respectively (p = 0.03). The cagA gene was identified in 30 (88.2%) and 21 (60%) H. pylori isolates in the respective groups (p = 0.01).

CONCLUSIONS

Our study suggests a significant association between the H. pylori vacA s1,m1 genotype, cytotoxic activity, cagA, and gastric cancer. Detection of H. pylori possessing these virulence determinants may help to identify patients being at an increased risk to develop gastric cancer in our population.

Malignant tumors of the stomach. Gastric mucosa-associated lymphoid tissue lymphoma and Helicobacter pylori

With the help of many clinical studies, the diagnosis and therapy of gastric MALT lymphoma have evolved. Major progress has been seen in this area, including improvement of biopsy diagnosis, better histologic classification, new information concerning pathogenesis, and, especially, the start of a revolution in the treatment of low-grade gastric MALT lymphomas by eradicating H. pylori. About 12 clinical studies with almost 400 patients and case reports have shown that cure of H. pylori infection is associated with complete remission in approximately 80% of patients with low-grade MALT lymphoma in an early clinical stage. To establish H. pylori eradication as the primary choice in low-grade gastric MALT lymphoma further, it is necessary to select patients before therapy who are most likely to benefit from this single treatment modality. An excellent histologic workup of obtained biopsy specimens and comprehensive clinical staging are necessary. Because of the supposition that H. pylori-related growth support may play a role only in the early stages of low-grade gastric MALT lymphoma, the importance of determining the depth of lymphoma infiltration in the gastric wall is evident. Examinations by endosonographic ultrasonography have been shown to be the most reliable method to differentiate the layers of the gastric wall and to determine the infiltration depth of lymphomas. Eradication of H. pylori has to be considered as a first-line and single treatment modality in patients with low-grade gastric MALT lymphoma in clinical stage EI1. As a therapy with fewer side effects than radiation, surgery, or chemotherapy and as a stomach-conserving treatment, eradication of H. pylori in patients with low-grade gastric MALT lymphoma should be the treatment of the choice within clinical trials because there are no long-term results available thus far. Besides pretreatment patient selection, careful follow-up with endoscopy, biopsies, and clinical staging including endoscopic ultrasonography is necessary. A 5- to 10-year follow-up is necessary before the definitive value of H. pylori eradication can be established, but long-term results are excellent thus far. There are many questions to be addressed: What are the exact mechanisms that lead to the malignant transformation of a reactive infiltrate? Why do approximately 20% of low-grade MALT lymphomas not regress after H. pylori eradication? Is there a molecular-genetic or immunologic point of no return? What is the biologic significance of the immunoglobulin rearrangement detected with PCR? What will be the 5- and 10-year relapse-free survival rates of patients suffering from low-grade MALT lymphoma treated with H. pylori eradication alone as first and only treatment? The wave of new data each year about the role of H. pylori in gastric MALT lymphoma may help many of these questions to be answered.

Eradication of Helicobacter pylori and stability of remissions in low-grade gastric B-cell lymphomas of the mucosa-associated lymphoid tissue: results of an ongoing multicenter trial

The normal human stomach is devoid of any organized lymphatic tissue. Acquisition of mucosa-associated lymphatoid tissue (MALT) in the stomach is considered to be a direct consequence of chronic infection with Helicobacter pylori. Thus, MALT appears to be part of the host defense against the pathogen H. pylori. Consequently, lymphomas arising from gastric MALT may be seen as an end point of a clonal evolution starting from the infection. Cumulative data from several studies show that eradication of H. pylori induces complete histologic remissions in about 70%-80% of the patients. Here we present data of an extended analysis of an ongoing multicenter trial. Eighty-four patients with low-grade gastric MALT lymphoma in stage EI were treated using a dual regimen to eradicate H. pylori. Complete remission was observed in 68 (81%) patients; a partial remission was found in seven (8%) patients. In contrast, nine (11%) patients revealed "no change" and were referred for alternative treatment strategies. The majority of these cases were found to harbor high-grade lymphomas in deeper mucosal areas. Polymerase chain reaction (PCR) performed on the VDJ rearrangements of the immunoglobulin heavy chain yielded monoclonal bands in 50 of 65 analyzed patients (77%) at diagnosis. Interestingly, in patients analyzed during follow up after achieving complete histologic remission, ongoing PCR monoclonality was found in 19 of 39 eligible patients (49%). Several patients who developed local relapse of the lymphoma were found in the group with ongoing PCR monoclonality. Together with data from the literature, these results suggest that the majority of low-grade gastric MALT lymphomas in stage EI respond to eradication of H. pylori. Longer follow-up investigations are necessary to determine whether remissions really indicate a cure from the disease and to elucidate whether PCR monoclonality after complete histological remission is predictive of increased relapse rate.

Expression of transforming growth factor beta-1 in gastric cancer and in the gastric mucosa of first-degree relatives of patients with gastric cancer

Transforming growth factors beta (TGF-beta) constitute a family of polypeptide growth factors that control cell growth, cell differentiation and migration, as well as the formation of the extracellular matrix. Recent analyses revealed the overexpression of TGF-beta1 in human gastric cancers and demonstrated increased cell proliferation in the stomach of patients with gastric cancer and their first-degree relatives. Using human gastric tissues obtained from patients with gastric cancer (n = 19), biopsies from healthy first-degree relatives of gastric cancer patients (n = 18) and healthy individuals (n = 19), we analysed the expression of TGF-beta1 using the reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. Fifteen of 19 patients with gastric cancer expressed TGF-beta1 in the tumour. In 11 of these 15 cases TGF-beta1 mRNA was also detectable in the non-tumourous stomach. Interestingly, all but two individuals with a first-degree relative diagnosed with gastric cancer exhibited TGF-beta1 expression in either the antrum or corpus biopsy or both. In contrast, only one of 19 individuals without a family history of gastric cancer expressed TGF-beta1 in the stomach (P< 0.0001). TGF-beta1 expression is detectable in a large proportion of gastric cancers and in the stomach of healthy first-degree relatives of gastric cancer patients. Since individuals without gastric cancers in their family express TGF-beta1 only in one of 19 cases, the induction of TGF-beta1 expression in first-degree relatives of patients with gastric cancer points to the presence of specific molecular alterations in a subgroup of individuals with an increased risk of developing gastric cancer that may precede the development of gastric cancers.

Ablation of Barrett's epithelium by endoscopic argon plasma coagulation in combination with high-dose omeprazole

BACKGROUND

Barrett's esophagus is a premalignant condition induced by gastroesophageal reflux. The aim of this prospective study was to assess the efficacy of argon plasma coagulation in combination with high-dose omeprazole therapy to ablate nondysplastic Barrett's epithelium.

METHODS

In 73 patients with histologically confirmed Barrett's epithelium, argon plasma coagulation was used in combination with maximal acid suppression (omeprazole 40 mg three times a day). Histologic and endoscopic changes were evaluated at 6- and 12-month intervals.

RESULTS

In 69 of 70 patients (98.6%) complete squamous regeneration was achieved after a median of 2 argon plasma coagulation sessions (range 1 to 5). During a median follow-up of 12 months (range 2 to 51 months) there has been no relapse or evidence of the development of dysplasia under continuous acid suppression. Three patients (4.3%) developed a mild stricture of the distal esophagus that resolved after a single session of bougie dilation.

CONCLUSIONS

In our experience, argon plasma coagulation in combination with high-dose omeprazole treatment is an effective and safe technique for complete ablation of nondysplastic Barrett's epithelium. Restoration of squamous mucosa after argon plasma coagulation appears to be long-lasting.

Frequency of TPR-MET rearrangement in patients with gastric carcinoma and in first-degree relatives

BACKGROUND

The activation of the c-met protooncogene through a rearrangement has been detected previously in gastric carcinoma tissue and precancerous lesions. In the current study the authors analyzed the rearrangement of TPR-MET in gastric carcinoma patients and in first-degree relatives to evaluate the potential role and timepoint of this genetic alteration in the process of gastric carcinogenesis and its potential value in identifying those individuals with an increased risk of developing gastric carcinoma.

METHODS

The presence of TPR-MET mRNA was determined in gastric tissue from 19 patients with gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. A 205-base pair (bp) cDNA fragment and a 70-bp cDNA fragment spanning the breakpoint were amplified by nested PCR. Amplification products were hybridized with an oligonucleotide labeled at the 3'-end with DIG-11-dUTP spanning the breakpoint using Southern blot analysis. The MNNG-HOS cell line served as a positive control.

RESULTS

TPR-MET mRNA was detected in nine gastric carcinoma patients (47%). Among these patients, TPR-MET mRNA was present in the both tumor and tumor free tissues in 5 patients (26%), in the tumor tissue only in 2 patients (11%), and in the tumor free gastric mucosa only in 2 patients (11%). It is interesting to note that TPR-MET rearrangement also was detected in the gastric corpus mucosa of 1 first-degree relative (6%), but in none of the control subjects.

CONCLUSIONS

The data from the current study indicate that TPR-MET activation may be an early event in gastric carcinogenesis and may be useful for the identification of individuals with an increased risk of developing gastric carcinoma.

Frequency of TPR-MET rearrangement in patients with gastric carcinoma and in first-degree relatives

BACKGROUND

The activation of the c-met protooncogene through a rearrangement has been detected previously in gastric carcinoma tissue and precancerous lesions. In the current study the authors analyzed the rearrangement of TPR-MET in gastric carcinoma patients and in first-degree relatives to evaluate the potential role and timepoint of this genetic alteration in the process of gastric carcinogenesis and its potential value in identifying those individuals with an increased risk of developing gastric carcinoma.

METHODS

The presence of TPR-MET mRNA was determined in gastric tissue from 19 patients with gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. A 205-base pair (bp) cDNA fragment and a 70-bp cDNA fragment spanning the breakpoint were amplified by nested PCR. Amplification products were hybridized with an oligonucleotide labeled at the 3'-end with DIG-11-dUTP spanning the breakpoint using Southern blot analysis. The MNNG-HOS cell line served as a positive control.

RESULTS

TPR-MET mRNA was detected in nine gastric carcinoma patients (47%). Among these patients, TPR-MET mRNA was present in the both tumor and tumor free tissues in 5 patients (26%), in the tumor tissue only in 2 patients (11%), and in the tumor free gastric mucosa only in 2 patients (11%). It is interesting to note that TPR-MET rearrangement also was detected in the gastric corpus mucosa of 1 first-degree relative (6%), but in none of the control subjects.

CONCLUSIONS

The data from the current study indicate that TPR-MET activation may be an early event in gastric carcinogenesis and may be useful for the identification of individuals with an increased risk of developing gastric carcinoma.

Frequency of TPR-MET rearrangement in patients with gastric carcinoma and in first-degree relatives

BACKGROUND

The activation of the c-met protooncogene through a rearrangement has been detected previously in gastric carcinoma tissue and precancerous lesions. In the current study the authors analyzed the rearrangement of TPR-MET in gastric carcinoma patients and in first-degree relatives to evaluate the potential role and timepoint of this genetic alteration in the process of gastric carcinogenesis and its potential value in identifying those individuals with an increased risk of developing gastric carcinoma.

METHODS

The presence of TPR-MET mRNA was determined in gastric tissue from 19 patients with gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. A 205-base pair (bp) cDNA fragment and a 70-bp cDNA fragment spanning the breakpoint were amplified by nested PCR. Amplification products were hybridized with an oligonucleotide labeled at the 3'-end with DIG-11-dUTP spanning the breakpoint using Southern blot analysis. The MNNG-HOS cell line served as a positive control.

RESULTS

TPR-MET mRNA was detected in nine gastric carcinoma patients (47%). Among these patients, TPR-MET mRNA was present in the both tumor and tumor free tissues in 5 patients (26%), in the tumor tissue only in 2 patients (11%), and in the tumor free gastric mucosa only in 2 patients (11%). It is interesting to note that TPR-MET rearrangement also was detected in the gastric corpus mucosa of 1 first-degree relative (6%), but in none of the control subjects.

CONCLUSIONS

The data from the current study indicate that TPR-MET activation may be an early event in gastric carcinogenesis and may be useful for the identification of individuals with an increased risk of developing gastric carcinoma.

Gastric MALT lymphoma and its relationship to Helicobacter pylori infection: management and pathogenesis of the disease

Chronic Helicobacter pylori infection is strongly associated with the development of primary gastric B cell lymphoma of MALT-type. Therapeutic decisions in primary gastric MALT lymphomas, e.g., the choice for gastric surgery or stomach-conserving treatments in the form of radio-, chemo-, or eradication therapy, should be based on an accurate histopathological diagnosis, grading and clinical staging. Primary gastric low-grade MALT-NHLs in an early clinical stage associated with H. pylori infection were shown to respond with complete remission in approximately 77% of cases upon successful cure of the infection as only treatment modality. The effect of curing H. pylori infection on the course of a high-grade gastric MALT lymphoma is largely uncertain but preliminary results indicate a possible benefit for patients with high-grade MALT lymphoma upon eradication therapy. Concerning the pathogenetic mechanisms of lymphomagenesis, there are many questions to be addressed in the near future. In general, it is still unclear what the exact mechanisms are which lead to the malignant transformation of a reactive infiltrate. Is there a molecular-genetic or immunological point of no return? What is the biological significance of the immunoglobulin rearrangement detected with PCR? The wave of new data each year about the role of H. pylori in gastric MALT lymphoma might help that many of these questions addressed above might be answered within the next years.

Helicobacter heilmannii-associated primary gastric low-grade MALT lymphoma: complete remission after curing the infection

BACKGROUND & AIMS

Cure of Helicobacter pylori infection may lead to complete remission of associated low-grade mucosa-associated lymphoid tissue (MALT) lymphoma in stage EI. This study investigated whether Helicobacter heilmannii infection-associated primary gastric MALT lymphoma will regress after cure of the infection.

METHODS

H. heilmannii-induced gastritis was diagnosed histologically, by a new specific immunoglobulin G enzyme-linked immunosorbent assay, and with 16S ribosomal RNA amplification and sequencing in 5 consecutive patients with primary gastric MALT lymphoma clinical stage EI. Patients received 40 mg omeprazole and 750 mg amoxicillin 3 times per day for 14 days. Polymerase chain reaction (PCR) was used to detect rearrangement of immunoglobulin heavy-chain genes before treatment and during follow-up.

RESULTS

Five patients (3 men, 2 women; mean age, 65 years; range, 42-79 years) were studied. H. pylori was not detected by culture, histology, serology, or PCR. Treatment resulted in the cure of H. heilmannii infection in each case and complete histological and endoscopic remission of the tumors. Three of 5 patients showed monoclonal B cells before treatment, 2 of whom remained PCR positive. Within a median follow-up period of 24 months, no relapse of the lymphoma or reinfection with H. heilmannii occurred.

CONCLUSIONS

These data suggest that gastric MALT lymphoma may arise in patients with H. heilmannii infection. Cure of this infection may lead to complete remission of the MALT lymphoma.

alpha-catenin expression is decreased in human gastric cancers and in the gastric mucosa of first degree relatives

BACKGROUND AND AIMS

The role of altered cell adhesion is critical for the development of epithelial cancers. E-cadherin plays an important role in the maintenance of cell-cell adhesion and its function is thought to be regulated by its associated cytoplasmic proteins, such as alpha-catenin and beta-catenin. To determine the role of alpha-catenin expression in gastric carcinogenesis, we studied its expression in human gastric cancer and in the gastric mucosa of first degree relatives with no clinical disease.

METHODS

alpha-Catenin expression was assessed by immunohistochemical analysis and reverse transcriptase-polymerase chain reaction (RT-PCR) using gastric tissue specimens from patients with gastric cancer and from the gastric mucosa of first degree relatives of gastric cancer patients and healthy controls.

RESULTS

mRNA levels of alpha-catenin were reduced or absent in 13 of 19 gastric cancer tissues, which differed significantly from levels found in the tumour free gastric mucosa of cancer patients (p<0.05). Of the cancer samples with altered alpha-catenin mRNA levels, alpha-catenin expression was negative in seven and decreased in six cases. Interestingly, decreased alpha-catenin mRNA expression also occurred in the mucosa of the corpus (11/18) and antrum (4/18) of first degree relatives. In the corpus biopsies alpha-catenin expression was more often decreased or lost compared with the antrum biopsies in first degree relatives and healthy controls (p<0.05). Immunohistochemical analysis revealed membranous expression of alpha-catenin in gastric cancer cells and the non-malignant gastric epithelium. However, some cancers also exhibited loss of membranous staining. Generally, loss or downregulation of alpha-catenin mRNA in the gastric mucosa was associated with Helicobacter pylori infection (p<0.05).

CONCLUSION

Our findings suggest that loss or downregulation of alpha-catenin expression may be an early event in gastric carcinogenesis and may be associated with H pylori infection.

Gastric MALT lymphoma and its relationship to Helicobacter pylori infection: management and pathogenesis of the disease

Chronic Helicobacter pylori infection is strongly associated with the development of primary gastric B cell lymphoma of MALT-type. Therapeutic decisions in primary gastric MALT lymphomas, e.g., the choice for gastric surgery or stomach-conserving treatments in the form of radio-, chemo-, or eradication therapy, should be based on an accurate histopathological diagnosis, grading and clinical staging. Primary gastric low-grade MALT-NHLs in an early clinical stage associated with H. pylori infection were shown to respond with complete remission in approximately 77% of cases upon successful cure of the infection as only treatment modality. The effect of curing H. pylori infection on the course of a high-grade gastric MALT lymphoma is largely uncertain but preliminary results indicate a possible benefit for patients with high-grade MALT lymphoma upon eradication therapy. Concerning the pathogenetic mechanisms of lymphomagenesis, there are many questions to be addressed in the near future. In general, it is still unclear what the exact mechanisms are which lead to the malignant transformation of a reactive infiltrate. Is there a molecular-genetic or immunological point of no return? What is the biological significance of the immunoglobulin rearrangement detected with PCR? The wave of new data each year about the role of H. pylori in gastric MALT lymphoma might help that many of these questions addressed above might be answered within the next years.

Efficacy of two different dosage regimens of omeprazole, amoxycillin and metronidazole for the cure of Helicobacter pylori infection

BACKGROUND

While addition of metronidazole to the omeprazole-amoxycillin combination has been shown to be advantageous, the optimal dosage and drug distribution of the antimicrobials has not been sufficiently evaluated.

AIM

To investigate the efficacy of two different regimens of omeprazole, amoxycillin and metronidazole for the cure of Helicobacter pylori infection.

METHODS

Two hundred and fifty-five patients with H. pylori associated duodenal ulcers were randomly treated with either a 1-week regimen of omeprazole 20 mg b.d., amoxycillin 1000 mg b.d. and metronidazole 800 mg b.d. (OAM b.d.) or a combination of omeprazole 40 mg o.d., amoxycillin 500 mg t.d.s. and metronidazole 400 mg t.d.s. (OAM t.d.s.). All patients subsequently received omeprazole 20 mg o.d. for an additional 3 weeks. H. pylori status was assessed by histology and 13C-UBT prior to treatment and 8 weeks after randomization. Additional biopsies were obtained for H. pylori culture to determine primary and secondary resistance to metronidazole by agar dilution.

RESULTS

Two hundred and thirty-seven patients were included in the intention-to-treat analysis and 198 patients in the per protocol analysis. With intention-to-treat analysis, the cure rate was 77% after treatment with OAM b.d. (95% CI, 69%-85%) and 76% after OAM t. d.s. therapy (95% CI, 67%-83%). Ulcer healing (intention-to-treat analysis) was documented in 95% of patients in the OAM b.d. group (n=122) and in 97% of patients in the OAM t.d.s. group (n=115). Adverse events were reported in 26 (20%) and in 18 (14%) patients in the OAM b.d. and OAM t.d.s. groups, respectively. None resulted in discontinuation of treatment. Overall primary resistance of H. pylori against metronidazole was found in 22 of 116 strains (19%).

CONCLUSIONS

The combination of omeprazole, amoxycillin and metronidazole achieves about an 80% cure rate of H. pylori infection even in active ulcers. The total daily dose, and the choice of twice or three times daily dosing does not seem critical with this regimen.

Antimicrobial susceptibility testing of Helicobacter pylori in a large multicenter trial: the MACH 2 study

Culture and susceptibility testing of Helicobacter pylori strains was performed in a large multinational, multicenter randomized clinical trial. Culture was carried out on gastric biopsy samples obtained from 516 patients at entry and had a sensitivity of 99% when the [(13)C]urea breath test was used as a reference. Susceptibility testing was performed for clarithromycin and metronidazole on 485 strains by an agar dilution method and the epsilometer test (Etest) and for amoxicillin by an agar dilution method only. Resistance to clarithromycin (>1 microgram/ml) was found in 3% of the H. pylori strains, with a perfect correlation between Etest and agar dilution methods. Resistance to metronidazole (>8 microliter/ml) was found in 27% of the strains by agar dilution, but there were important discrepancies between it and the Etest method. No resistance to amoxicillin was found. The logarithms of the MICs of the three antibiotics against susceptible strains had a distribution close to normal. The impact of resistance was tested in the four arms of the trial. There were not enough clarithromycin-resistant strains to evaluate the impact of resistance on the cure rate of clarithromycin-based regimens. For metronidazole-resistant strains, the impact noted in the clarithromycin-metronidazole arm was partially overcome when omeprazole was added (76% eradication for resistant strains versus 95% for susceptible strains). Secondary resistance to clarithromycin occurred in strains from 12 of 105 patients (11.4%) after the failure of a clarithromycin-based regimen to effect eradication. The detection of point mutations in clarithromycin-resistant strains was performed by a combination of PCR and restriction fragment length polymorphism. Mutations (A2142G and 2143G) were found in all strains tested except one. This study stresses the importance of performing susceptibility tests in clinical trials in order to explain the results of different treatments.

Leptin and its receptor in normal human gastric mucosa and in Helicobacter pylori-associated gastritis

BACKGROUND

Leptin, a newly discovered weight-reducing hormone, is mainly produced in fat cells. Recently, this hormone has been reported to be produced in rat gastric mucosa cells. In the present study we analyzed the localization and expression of leptin and its receptors in normal human gastric mucosa and in patients with Helicobacter pylori-associated gastritis.

METHODS

Plasma leptin levels and gastric mucosa leptin content were determined in 39 patients with dyspepsia. Cellular localization of leptin and of the signaling receptor (Ob-RL) were assessed by immunohistochemistry. Reverse transcriptase polymerase chain reaction (RT-PCR) for leptin receptor isoforms was performed on gastric epithelial cells isolated by laser-capture-microdissection.

RESULTS

Leptin content of the corpus gastric mucosa in H. pylori-positive patients was significantly increased (4.6+/-1.2. n = 15) as compared with the H. pylori-negative group (27.5+/-0.5 pg/mg, n = 24, P = 0.006). The presence of leptin immunoreactivity was shown in the lower half of corpus epithelial glands. By RT-PCR no leptin mRNA was detectable in human gastric tissue. In contrast, expression of both Ob-R(L) and the leptin receptor isoforms could be detected in gastric epithelial cells. Leptin receptor protein was detected throughout the mucosa.

CONCLUSIONS

Leptin itself is stored and secreted but not produced in human gastric mucosa. The functional receptor and all isoforms are present in human gastric mucosa. H. pylori-associated gastritis leads to significant increases in local leptin concentration in the gastric corpus.

Omeprazole, amoxycillin and metronidazole for the cure of Helicobacter pylori infection

OBJECTIVE

In two studies, different regimens of omeprazole-amoxycillin-metronidazole were assessed for the eradication of Helicobacter pylori.

DESIGN

Randomized, international, multicentre studies with parallel groups.

SETTING

The studies were performed at centres in Canada, Czech Republic, France, Germany, Hungary, Sweden and UK.

PARTICIPANTS AND INTERVENTIONS

H. pylori-positive patients with duodenal ulcer disease (active or in remission) were randomized to 7-day treatment with: omeprazole 40 mg once daily, amoxycillin 500 mg three times daily and metronidazole 400 mg three times daily (OAMtid; n = 242); omeprazole 20 mg twice daily, amoxycillin 1000 mg twice daily and metronidazole 800 mg twice daily (OAM800; n = 247); or omeprazole 20 mg twice daily, amoxycillin 1000 mg twice daily and metronidazole 400 mg twice daily (OAM400; n = 127).

MAIN OUTCOME MEASURES

Eradication of H. pylori.

RESULTS

Intention-to-treat analysis revealed H. pylori eradication rates of 76% (184/242) with OAMtid, 80% (198/247) with OAM800, and 76% (97/127) with OAM400. There was considerable variation in the levels of primary resistance to metronidazole in different countries. The overall eradication rate in patients infected with metronidazole-sensitive H. pylori strains was 85% (313/370), compared with 60% (56/94) in patients harbouring metronidazole-resistant strains (P<0.001). All regimens were generally well tolerated, with mild adverse events occurring in 4-26% of patients (mainly diarrhoea, reversible increase in liver enzymes and headache).

CONCLUSION

The OAM combination is effective in curing H. pylori infection. Primary metronidazole resistance may reduce its effectiveness, but an increased daily dosing of metronidazole may partly overcome this problem.

Helicobacter pylori gastritis of the gastric cancer phenotype in relatives of gastric carcinoma patients

OBJECTIVE

Infection with Helicobacter pylori is associated with gastric cancer. However, a hereditary risk of gastric cancer has also been reported. Hence, we decided to evaluate H. pylori gastritis in relatives of gastric cancer patients in comparison with matched controls.

DESIGN

Case-controlled study.

METHODS

A total of 237 patients with merely H. pylori gastritis (i.e. not associated with either peptic ulcer or gastric malignancy), and either first-degree (93.7%) or second-degree (6.3%) relatives with gastric cancer, were age- and sex-matched with 237 patients with H. pylori gastritis unassociated with a family history of gastric cancer. From each patient, antral and corpus biopsy specimens were obtained and investigated for degree (lymphocyte/plasma cell infiltration) and activity (polymorph infiltration) of gastritis (score: 0-4). Intestinal metaplasia was recorded as present or absent.

RESULTS

The results show that relatives of gastric cancer patients have a significantly greater expression of gastritis due to a higher grade of gastritis in the antrum and corpus (P < 0.0001) and a greater activity of gastritis in the corpus (P < 0.0001). Intestinal metaplasia occurs more often in relatives of gastric cancer patients (antrum: P < 0.0001; corpus: P = 0.0237).

CONCLUSION

Since the grade of H. pylori gastritis in relatives of gastric cancer patients is significantly higher than in controls, there appears to be a genetic susceptibility influencing the expression of H. pylori gastritis.

The GU-MACH study: the effect of 1-week omeprazole triple therapy on Helicobacter pylori infection in patients with gastric ulcer

AIMS

To study the efficacy of omeprazole triple therapy in the eradication of Helicobacter pylori in patients with active gastric ulcer, and to assess healing and relapse of gastric ulcer.

METHODS

A double-blind, randomized study was carried out in 18 centres in Germany, Hungary and Poland. Patients (n = 160) with gastric ulcer and a positive H. pylori screening test were randomized to a 7-day twice daily treatment with omeprazole 20 mg, clarithromycin 500 mg and amoxycillin 1000 mg (OAC) or omeprazole 20 mg, clarithromycin 250 mg and metronidazole 400 mg (OMC), or with omeprazole 20 mg once daily (O). After completion of this 1-week treatment, patients were treated with omeprazole until healing (maximum 12 weeks), and followed for 6 months. H. pylori was assessed by urea breath test (UBT) and histology.

RESULTS

Eradication rates ITT were OAC 79% (95% CI: 65-90%), OMC 86% (95% CI: 73-94%) and O 4% (95% CI: 0-14%). Eradication rates PP were OAC 83% (95% CI: 68-93%), OMC 93% (95% CI: 80-98%) and O 3% (95% CI: 0-13%). Gastric ulcer relapses occurred in 5, 0 and 11 patients in the groups, respectively.

CONCLUSIONS

The results from the study demonstrate that OMC and OAC 1-week regimens are safe and effective for eradication of H. pylori in gastric ulcer patients, and that ulcer relapse is infrequent after successful eradication.

Rifampin and rifabutin resistance mechanism in Helicobacter pylori

Eighty-one clinical isolates of Helicobacter pylori showed no resistance to rifampin (MIC range, 0.032 to 2 microg/ml; MIC at which 50% of isolates are inhibited [MIC50], 0.25 microg/ml). The MIC50 of rifabutin was 0.008 microg/ml (n = 16). All resistant laboratory mutants of H. pylori ATCC 43504 showed amino acid exchanges in codons 524 to 545 or codon 585 of the rpoB gene, corresponding to the gene sequences from Mycobacterium tuberculosis and Escherichia coli.