Influence of anti-Helicobacter triple-therapy with metronidazole, omeprazole and clarithromycin on intestinal microflora

BACKGROUND

Proton pump inhibitor-based therapy including two antibiotics is the treatment of choice for Helicobacter pylori infection. Oral antibiotic treatment can lead to intestinal overgrowth of potentially pathogenic bacteria.

AIM

To investigate the intestinal microflora before and at different times after H. pylori treatment with omeprazole, clarithromycin and metronidazole.

METHODS

Bacterial growth in faecal samples from 51 patients infected with H. pylori was determined qualitatively and quantitatively. During the same period of time, stool samples from 27 H. pylori-negative controls were taken and investigated at the same intervals.

RESULTS

The microflora of H. pylori-infected patients was different from that in H. pylori negative controls. It was characterized by a high concentration of lactobacilli, mainly Lactobacillus acidophilus. Immediately after therapy there was an increased colonization with yeasts, while the growth of lactobacilli and other species was inhibited. Clostridium difficile was cultured from three cases, but without clinical manifestations of pseudomembranous colitis. After 4 weeks of therapy, the microflora returned to normal and was not different from that of the H. pylori-negative control group.

CONCLUSIONS

In H. pylori-positive patients the intestinal flora is characterized by an increase in growth of acid-tolerant L. acidophilus. Eradication therapy exerts only a short-term influence on intestinal flora, whereas in the long term, the intestinal microflora is restored to a pattern similar to that of the control group.

Review article: managing the dyspeptic patient--an interactive discussion

Dyspepsia, a common disorder, can present some difficult clinical dilemmas. Physicians should explore some of the more challenging cases of dyspepsia in a setting that fosters interactive dialogue among colleagues, as was the case at the interactive discussion reported below. A panel of experts presented and discussed three case histories. The audience was able to choose from among several options for diagnosis or treatment and recorded their votes by means of an electronic handset. The first case concerned the relationship between continued non-steroidal anti-inflammatory drug (NSAID) use and recurrent upper gastrointestinal (GI) symptoms without ulcer or Helicobacter pylori infection. The second was a woman with complex upper GI symptoms including heartburn. The last featured a young man with dyspepsia and no alarm symptoms. The first case showed that a standard dose of proton pump inhibitor (PPI) is the best treatment for patients with gastritis who continue to use NSAIDs. The second case revealed that 24-h pH monitoring can be used to establish a relationship between symptoms and reflux episodes. The third case demonstrated that it can be difficult to make a definitive diagnosis based on clinical symptoms, and that patients with endoscopy-negative reflux disease usually respond well to PPI therapy.

Effect of Helicobacter pylori eradication on expression of cyclin D2 and p27 in gastric intestinal metaplasia

BACKGROUND AND AIMS

Cyclins and cyclin-dependent kinase inhibitors play a crucial role in the control of cell cycle transitions. Enhanced expression of cyclin D2 and reduced expression of p27kip1 (p27) have been implicated in the pathogenesis of cancer. Because intestinal metaplasia has been regarded as a pre-malignant lesion, we investigated the expression of cyclin D2 and p27 in Helicobacter pylori-associated chronic gastritis with and without intestinal metaplasia, and followed the changes after H. pylori eradication.

METHODS

Expression of cyclin D2 and p27 was studied by immunohistochemistry in 59 patients (including 35 patients with intestinal metaplasia) and in 10 gastric cancer patients. Among them, 29 H. pylori-infected patients had serial gastric biopsies taken before and at 1-year after eradication of H. pylori.

RESULTS

Expression of cyclin D2 was significantly higher in gastric cancers when compared to their adjacent non-tumour tissues (median score 3 vs. 1, P=0.015). Over-expression of cyclin D2 was detected in H. pylori-associated chronic gastritis and intestinal metaplasia, which was reduced after eradication of the organism (median score 2 vs. 1, P=0.037 in chronic gastritis; median score 2 vs. 0, P=0.008 in intestinal metaplasia). While the normal gastric mucosa showed strong p27 expression, five of the 10 gastric cancer tissues exhibited reduced p27 expression (P=0.039). Diminished p27 expression was also seen in intestinal metaplasia, which was restored 1-year after H. pylori eradication (eight out of 16 vs. one out of 16, P=0.018). Reduced expression of p27 was frequently associated with increased cyclin D2 expression in H. pylori-associated intestinal metaplasia (P=0.02).

CONCLUSION

Over-expression of cyclin D2 and reduced expression of p27 are closely linked to H. pylori-associated intestinal metaplasia. Eradication of H. pylori infection reverses the aberrant expression of cyclin D2 and p27 in intestinal metaplasia.

Human cathepsin W, a cysteine protease predominantly expressed in NK cells, is mainly localized in the endoplasmic reticulum

Human cathepsin W (also called lymphopain) is a recently described papain-like cysteine protease of unknown function whose gene expression was found to be restricted to cytotoxic cells. Here we demonstrate that cathepsin W is expressed predominantly in NK cells and, to a lesser extent, in CTLs. Quantitative RT-PCR revealed that NK cells contained approximately 21 times more cathepsin W transcript than CTLs. The predominant expression of cathepsin W in NK cells was further confirmed by Western blot analysis and immunohistochemistry. IL-2-mediated stimulation of NK cells and CTLs revealed a stronger up-regulation of the cathepsin W gene and protein expression in NK cells (7-fold) than in CTLs (2-fold). Transfection experiments of HeLa cells and biochemical analyses revealed that cathepsin W is exclusively "high mannose-type" glycosylated and is mainly targeted to the endoplasmic reticulum (ER). Interestingly, the ER localization of cathepsin W was also found in NK cells, in which colocalization studies revealed an overlapping staining of cathepsin W and Con A, an ER-specific lectin. Furthermore, subcellular fractionation of cathepsin W-expressing cells confirmed the ER localization and showed that cathepsin W is membrane associated. Based on the results of this study, cathepsin W might represent a putative component of the ER-resident proteolytic machinery. The constitutive expression in NK cells and the stronger up-regulation of cathepsin W by IL-2 in NK cells than CTLs suggest that cathepsin W is not just a marker of cytotoxic cells but is, rather, specifically expressed in NK cells.

Prognostic parameters determining survival in pancreatic carcinoma and, in particular, after palliative treatment

Prognosis and outcome of patients with pancreatic carcinoma is poor. The aim of the study was to investigate (1) which factors of medical history and clinical status as well as which laboratory parameters determine survival in pancreatic carcinoma and (2) whether specific data can be used as prognostic parameters or for early diagnosis of pancreatic carcinoma. In total, 287 patients with pancreatic carcinoma were enrolled in the study. In 193 subjects, only palliative treatment was possible. Survival was assessed using univariate survival probability curves by Kaplan-Meier. Comparison of patient groups with regard to survival was achieved using the log-rank test. Multivariate analysis was carried out using the Cox regression model. Overall, 22 factors, showing a significant impact on survival in pancreatic carcinoma were found, e.g., tumor-associated factors such as (1) tumor stage according to the UICC classification including TNM-based staging, grading, tumor site, and vascular infiltration; (2) preoperative habits and signs and symptoms (physical condition, pain, loss of appetite, ethanol consumption); (3) change of laboratory parameters (CA 19-9, bilirubin, prothrombin time, urea, C-reactive protein), and (4) type of intervention (surgical approach, R0/1/2 resection). Using multivariate analysis, seven factors (UICC tumor stage and site, surgical intervention including number of resected lymph nodes, chemotherapy, occurence of a carcinoma in relatives, preoperative physical condition, night sweat) were determined. In the 193 patients with palliative treatment, only ten factors (among them UICC tumor stage including the presence of metastases; data from the medical history such as physical condition, loss of appetite, and carcinoma in relatives, and laboratory parameters including prothrombin time, protein content, and aspartate aminotransferase levels) were found to be important. Chemotherapy had the strongest impact on survival which was confirmed by multivariate analysis, followed by tumor stage (UICC) and preoperative appetite. Besides tumor-associated determinants, data from the medical history, and pathological laboratory parameters, the prognosis in pancreatic carcinoma is considerably determined by the treatment such as interventional and/or using antineoplastic agents.

A novel immunoassay based on monoclonal antibodies for the detection of Helicobacter pylori antigens in human stool

BACKGROUND AND AIM

With the Premier Platinum HpSA EIAtrade mark a new enzyme immunoassay was developed for diagnosis of H. pylori infection, using polyclonal antibodies against H. pylori antigens in human stool. Here we evaluated FemtoLab H. pyloritrade mark based on the use of monoclonal antibodies in comparison to established reference methods.

METHODS

53 consecutive patients (27male, 26 female, age: 17-85 years) undergoing routine upper gastrointestinal endoscopy were enrolled in this study. The H. pylori status was determined by 4 reference methods: Histology, rapid urease test (HUT), (13)C-urea breath test ((13)C-UBT) and serology. Patients were considered to be infected with H. pylori if at least 2 of the 4 reference tests were positive. Stool samples were aliquoted after reception and stored frozen (-20 degrees C) until tested. The FemtoLab H. pyloritrade mark (Connex GmbH, Germany) and the Premier Platinum HpSA EIAtrade mark (Meridian, Connecticut, Ohio, USA) were performed according to the manufacturers protocols.

RESULTS

26 of the 53 patients were H. pylori infected. 3 were false-negative by the FemtoLab H. pyloritrade mark and one false-positive result was obtained (sensitivity 88,5 %, specificity 96,3 %). The concordance between the 2 stool tests was 94,3 % (50/53 cases).

CONCLUSION

The diagnostic quality of the novel FemtoLab H. pyloritrade mark Enzyme Immunoassay is comparable with the established Premier Platinum HpSA EIAtrade mark. The differences between positive and negative results obtained with the FemtoLab H. pyloritrade mark are greater in comparison to the Premier Platinum HpSA EIAtrade mark and therefore this test system allows a better distinction.

Helicobacter pylori eradication in functional dyspepsia: new evidence for symptomatic benefit

Several large studies investigating the benefit of eradicating Helicobacter pylori in patients with functional dyspepsia have reported varying results, and therefore questions about the clinical management of H. pylori infection remain. The ELAN study, a recent large multicentre, randomized study, compared eradication of H. pylori (with lansoprazole and antibiotics) with acid-suppressant treatment alone (lansoprazole) in H. pylori-associated functional dyspepsia. Investigators found that eradication led to improvement of dyspeptic symptoms. Although the symptomatic benefit was limited to a small subset of patients (approximately 9%) with H. pylori-positive functional dyspepsia, cure of chronic gastritis can be offered to the majority of patients (approximately 80%) and thus, in addition to the elimination of symptoms in some, the key risk factor for gastroduodenal pathology is eliminated. This study provides support for the recommendations of Maastricht 2, which found that H. pylori eradication is an appropriate therapeutic option for functional dyspepsia.

Induction and expression of cyclin D3 in human pancreatic cancer

PURPOSE

Cyclins play a key role in the control and regulation of the cell cycle. The role of cyclins in the pathogenesis of pancreatic cancer is largely unknown.

METHODS

Using Northern blot analysis, polymerase chain reaction (PCR) and immunohistochemistry, we examined the expression of cyclins D1, D2, and D3 in human pancreatic cancer and studied the induction of these cyclins by growth factors in pancreatic cancer cell lines.

RESULTS

We now report that cyclin D1 and D3 mRNAs are expressed in human pancreatic cancer cell lines, and that the expression of cyclin D3 is enhanced in pancreatic cancer cells by amphiregulin, a member of the epidermal growth factor family. Cyclins D1 and D3 are also expressed in normal and malignant pancreatic tissues. However, while the normal pancreas and pancreatic cancers express cyclin D2 as determined by reverse-transcriptase PCR, we could not detect cyclin D2 mRNA by either Northern blot analysis or reverse transcriptase PCR in the two pancreatic cancer cell lines. Immunohistochemical analysis revealed the expression of cyclin D3 in pancreatic cancer cells.

CONCLUSIONS

These findings suggest that D-type cyclins are differentially expressed in pancreatic cancer and that the aberrant activation of the EGF receptor in human pancreatic cancer by amphiregulin may lead to the progression of the cell cycle via induction of cyclin D3 expression, thus contributing to the growth advantage of these transformed cells.

Phase III of the migrating motor complex: associated with endogenous xenin plasma peaks and induced by exogenous xenin

Xenin, a recently discovered peptide produced by specific endocrine cells of the duodenal mucosa, has shown exocrine, endocrine and motility effects in the gastroenteropancreatic system in animal experiments. The aim of the present investigation was to study the role of xenin in the regulation of duodenojejunal motility of humans. Twenty-nine healthy volunteers from the hospital staff gave informed consent to participate in this investigation. In 20 volunteers, we determined plasma concentrations of immunoreactive xenin at 15 min intervals over a mean time period of 8 h fasting and recorded the interdigestive motor activity of the duodenojejunum. In a double-blind randomized crossover study on other nine subjects, synthetic xenin in a dose of 4 pmol kg-1 min-1 or placebo was infused for 10 min intravenously in the interdigestive period and postprandially after a liquid meal. Duodenojejunal motility was recorded simultaneously. Predefined interdigestive xenin plasma peaks were found to be significantly associated with the phases III of the migrating motor complex. In the interdigestive period, xenin induced a premature phase III activity in each volunteer; this was followed by a second phase III in five out of nine subjects. In the postprandial state, xenin significantly increased contraction frequency and the percentage of aborally propagated contractions. These findings suggest a role of the peptide hormone xenin in modulating interdigestive and postprandial duodenojejunal motility in humans.

Effect of cisapride on gastric sensitivity to distension, gastric compliance and duodeno-gastric reflexes in healthy humans

BACKGROUND AND AIMS

Visceral hypersensitivity and impaired gastric relaxation after the ingestion of a meal are frequent features in patients with functional dyspepsia. Cisapride improves dyspeptic symptoms. The study aims to evaluate whether cisapride influences gastric sensitivity to distension as well as gastric compliance and duodenogastric reflexes.

PATIENTS AND METHODS

Eight healthy males were studied on two different days, each after 7 days' treatment either with placebo or cisapride 10 mg qid in randomized order. A spherical bag connected to a barostat was placed in the gastric fundus and an 8-lumen manometric catheter was positioned with 4 side holes in antrum and 4 in duodenum. During a phase II of the migrating motor complex, the intragastric bag was inflated at a constant pressure 1 mm Hg above the intra-abdominal pressure and the gastric volume was measured during intraduodenal infusion of lipids and citric acid at different rates. Once the stomach returned to the basal volume, the bag was distended according to two different protocols until subjects reported discomfort. Antroduodenal motility was measured throughout the study.

RESULTS

Intraduodenal infusion of lipids and citric acid caused relaxation of gastric fundus. Relaxation was similar for lipids and acid (203 +/- 30 vs 199 +/- 43 ml), and was not influenced by cisapride and infusion rate. Cisapride did not influence gastric sensitivity to distension (10 +/- 1.5 vs 9.7 +/- 1.3 mm Hg) and gastric compliance (52.7 +/- 1.2 vs 49.8 +/- 1.8 ml/mm Hg). The antral motor index significantly decreased following infusion of acid and lipids with placebo but not with cisapride.

CONCLUSIONS

Cisapride inhibits the physiological duodenoantral reflexes but does not influence either the mechanical properties of the gastric fundus nor the gastric sensitivity to distension.

Validity of a Helicobacter pylori stool antigen assay for the assessment of H. pylori status following eradication therapy

BACKGROUND

A Helicobacter pylori stool antigen (HpSA) test has been proposed as a valid alternative to the 13C-urea breath test (13C-UBT) for the non-invasive detection of H. pylori infection in primary diagnosis. Published reports show conflicting results with regard to the test's diagnostic accuracy after eradication therapy. The aim of the present study was to assess the diagnostic value of the HpSA test and to determine the optimal discriminating cut-off value in patients following H. pylori eradication therapy.

METHOD

Stool samples were collected and the 13C-UBT was performed in 113 patients 4-6 weeks after eradication therapy. A validated test protocol for the 13C-UBT was used. Stool specimens were analysed with the Premier Platinum HpSA enzyme immunoassay (EIA). A receiver operator characteristics (ROC) analysis was performed to define the optimal cut-off value on the basis of the results of the 13C-UBT.

RESULTS

The results of the 13C-UBT showed that H. pylori eradication was successful in 83/113 (73%) patients. According to the manufacturer, the cut-off value for the HpSA test is 0.14 optical density, but this does not appear to be valid after eradication therapy (sensitivity 76.7%, specificity 98.8%). On the basis of ROC analysis, the optimal cut-off value after therapy was determined to be 0.11 optical density, giving a sensitivity of 93.3% and a specificity of 93.9%.

CONCLUSION

The HpSA test is a valid test for the assessment of H. pylori status after eradication therapy, provided an adjusted cut-off value is applied.

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.

[Reflux esophagitis--a community-wide increase in incidence]

Gastroesophageal reflux disease (GERD) is a common disease increasing in incidence and prevalence in the industrialised countries. It is a chronic disease with a large spectrum of clinical manifestations. The leading symptom is heartburn, however the disease may also present with extraesophageal symptoms or stay asymptomatic. Motility disorders of the upper GI tract with the key feature of impaired LES are the cause for pathologic gastroesophageal reflux in the terminal esophagus. The relationship of H. pylori infection with GERD is part of the current discussion. The Savary Miller classification for grading of refluxesophagitis is now proposed for substitution by the Los Angeles classification for the assessment of erosive lesions. Besides complications such as bleeding or strictures the main risk is the development of Barrett esophagus and adenocarcinoma. Proton pump inhibitors are the therapy of choice for healing as well as in longterm therapy and prophylaxis. New endoscopic interventional therapies for treatment of GERD and related diseases should be used only in controlled studies.

Expression of thrombospondin-1 in pancreatic carcinoma: correlation with microvessel density

Thrombospondin-1 (TSP-1) is a multifunctional platelet and extracellular matrix protein that is involved in angiogenesis. Under certain pathological conditions, e.g., malignant tumors, high concentrations of TSP-1 work as an angiogenic agonist. Here we examined 98 pancreatic carcinomas with respect to TSP-1 immunoreactivity and its correlation to intratumoral microvessel density (MVD), a representation of the overall degree of angiogenesis in carcinomas. Northern blot analysis for TSP-1 mRNA was performed in seven additional cases. Eighty-seven tumors showed strong TSP-1 immunoreactivity, nine carcinomas were only weakly positive, and two lesions were negative for TSP-1. TSP-1 immunoreactivity was detected in the extracellular matrix, mostly at the invasion front of the tumor. Using Northern blot analysis, we observed high levels of TSP-1 mRNA in three out of seven pancreatic carcinomas. The mean MVD in pancreatic carcinoma was 38.8 vessels per mm2. Tumors with a high expression of TSP-1 showed a higher MVD and the correlation between TSP-1 immunoreactivity and microvessel density was highly significant (P=0.003). As a modulator of angiogenesis, TSP-1 is strongly expressed in most pancreatic adenocarcinomas and is likely to contribute to the extensive neovascularization and spread of this highly aggressive tumor.

Comparison of two tubeless function tests in the assessment of mild-to-moderate exocrine pancreatic insufficiency

BACKGROUND

Faecal elastase 1 (FE1) and the pancreolauryl test (PLT) are widely used for the non-invasive diagnosis of exocrine pancreatic insufficiency (EPI). Whether one of these two tests is superior for the detection of mild-to-moderate EPI is the subject of controversy. The aim of this study was to compare the diagnostic performance of the PLT and FE1 for the detection of EPI in patients with chronic pancreatitis.

METHODS

Forty consecutive patients (27 males, 13 females, 23-72 years) with chronic pancreatitis based on imaging procedures (computed tomography, endoscopic retrograde pancreatography and endoscopic ultrasound) were admitted to the study. A secretin-caerulein test (SCT) was performed after an overnight fast by giving secretin (1 U/kg/h) and caerulein (100 ng/kg/h) intravenously over 90 min. Duodenal contents were aspirated at 15 min intervals and analysed for pH, bicarbonate, amylase, lipase and elastase. EPI was graded on the basis of the results of the SCT as absent, mild, moderate or severe. A serum PLT was performed in accordance with a modified protocol previously described. A commercial ELISA was used for determination of FE1. The cut-off values were > or = 4.5 mg/l for PLT and > or = 200 microg/g for FE1. and 13 severe) on the basis of the results of the SCT. The sensitivity of the PLT for diagnosing EPI of all degrees of severity was 82% (27/33), compared with 50% for FE1 (16/ 33). In patients with severe EPI, the PLT was abnormal in 100% (13/13) and FE1 was abnormal in 85% (11/13) of the cases. The sensitivity decreases for both tests in the group of mild/moderate EPI (PLT 70% (14/20), FE1 35% (7/20)). In all seven patients with normal exocrine pancreatic function, both PLT and FE1 were also normal.

CONCLUSIONS

The PLT is more sensitive than FE1 for the diagnosis of mild-to-moderate EPI, and is therefore more appropriate for completing the staging of chronic pancreatitis.

Helicobacter pylori infection and gastro-oesophageal reflux disease: coincidence or association?

Concerning the relationship between Helicobacter pylori infection and gastro-oesophageal reflux disease (GORD), the debate is ongoing whether the infection confers protection, is harmful or whether both entities are independent. Epidemiological evidence is given for an increased prevalence of GORD and a decreased prevalence of H. pylori infection in the western world. The assumpton derived from it is that H. pylori protects from GORD. Pathophysiological aspects need to consider the type and expression of gastritis which is associated with varying changes of gastric function. Depending on the type of gastritis, acid secretion may either increase or decrease and thereby impact on acid exposure of the oesophagus. Other changes related to the role of H. pylori in pathophysiology of GORD are still hypothetical. Clinical data are controversial whether or not GORD increases after H. pylori eradication. Prospective studies including characterization of strains and gastric physiology will clarify this issue. An accelerated induction of gastric mucosal atrophy in patients on long-term proton pump inhibitors is reported in most available studies. An increase of inflammatory activity in fundic and corpus mucosa is a consistent phenomenon. Therefore, in the authors' opinion, eradication appears advisable.

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.