The GroES homolog of Helicobacter pylori confers protective immunity against mucosal infection in mice.

Helicobacter pylori is an important etiologic agent of gastroduodenal disease. In common with other organisms, H. pylori bacteria express heat shock proteins that share homologies with the GroES-GroEL class of proteins from Escherichia coli. We have assessed the heat shock proteins of H. pylori as potential protective antigens in a murine model of gastric Helicobacter infection. Orogastric immunization of mice with recombinant H. pylori GroES- and GroEL-like proteins protected 80% (n = 20) and 70% (n = 10) of animals, respectively, from a challenge dose of 10(4) Helicobacter felis bacteria (compared to control mice, P = 0.0042 and P = 0.0904, respectively). All mice (n = 19) that were immunized with a dual antigen preparation, consisting of H. pylori GroES-like protein and the B subunit of H. pylori urease, were protected against infection. This represented a level of protection equivalent to that provided by a sonicated Helicobacter extract (P = 0.955). Antibodies directed against the recombinant H. pylori antigens were predominantly of the IgG1 class, suggesting that a type 2 T-helper cell response was involved in protection. This work reports a protein belonging to the GroES class of heat shock proteins that was shown to induce protective immunity. In conclusion, GroES-like and urease B-subunit proteins have been identified as potential components of a future H. pylori subunit vaccine.

ABO, Lewis, secretor and non-secretor phenotypes in patients infected or uninfected by the Helicobacter pylori bacillus

CONTEXT: Epidemiological studies have demonstrated higher frequencies of the O blood group and the non-secretor phenotype of ABH antigens among patients suffering from peptic ulcers. Since Helicobacter pylori has been established as the main etiological factor in this disease, controversies about the associations of the ABO and Lewis blood group phenotypes and secretor and non-secretor phenotypes in relation to susceptibility towards infection by this bacillus have been presented. OBJECTIVE: To verify the frequencies of ABO, Lewis blood group phenotypes, secretor and non-secretor phenotypes in patients infected or uninfected by H. pylori. DESIGN: Cross-sectional study. SETTING: Outpatient clinic. PARTICIPANTS: One hundred and twenty patients with dyspeptic symptoms who underwent endoscopy. MAIN MEASUREMENTS: ABO and Lewis blood group phenotypes were determined by a standard hemagglutination test and the secretor and non-secretor phenotypes were evaluated by saliva samples using the inhibitor hemagglutination test. RESULTS: The diagnosis of infection, made via breath and urea tests and confirmed using polymerase chain reaction (PCR) in gastric biopsy fragments, showed the presence of H. pylori in 61.7% of the patients and absence in 38.3%. The differences between the frequencies of the ABO blood group phenotypes among infected (A 27.0%; B 12.2%; AB 4.0% and O 56.8%) and uninfected patients (A 58.7%; B 13.0%; AB 4.3% and O 24.0%) were significant. The Lewis blood type, secretor and non-secretor phenotypes showed homogeneous distribution between the groups of patients analyzed. CONCLUSIONS: Our results suggest that the infection of H. pylori can be related to ABO blood groups but not to the Lewis blood group nor to secretor and non-secretor phenotypes. Copyright©2002, Associação Paulista de Medicina.

MGMT and MLH1 methylation in Helicobacter pylori-infected children and adults

AIM: To evaluate the association between Helicobacter pylori(H. pylori) infection and MLH1 and MGMT methylation and its relationship with microsatellite instability (MSI). METHODS: The methylation status of the MLH1 and MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction (MSPPCR) in gastric biopsy samples from uninfected or H. pylori -infected children (n = 50), from adults with chronic gastritis (n = 97) and from adults with gastric cancer (n = 92). MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene (β actin). MSI analysis was performed by screening MSI markers at 4 loci (Bat-25, Bat-26, D17S250 and D2S123) with PCR; PCR products were analysed by single strand conformation polymorphism followed by silver staining. Statistical analyses were performed with either the χ 2 test with Yates continuity correction or Fisher's exact test, and statistical significance for expression analysis was assessed using an unpaired Student's t -test. RESULTS: Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children, regardless of H. pylori infection status. The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H. pylori infection (P < 0.05); this region was methylated in 66% of gastric cancer patients, and the difference in the percentage of methylated samples between these patients and those from H. pylori -infected chronic gastritis patients was statistically significant (P < 0.05). MLH1 methylation frequencies among H. pylori -infected and non-infected chronic gastritis adult patients were 13% and 7%, respectively. We observed methylation of the MLH1 promoter (39%) and increased MSI levels (68%) in samples from gastric cancer patients in comparison to samples from H. pylori -infected adult chronic gastritis patients (P < 0.001 and P < 0.01, respectively). The frequency of promoter methylation for both genes was higher in gastric cancer samples than in H. pylori -positive chronic gastritis samples (P < 0.05). The levels of MLH1 and MGMT mRNA were significantly reduced in chronic gastritis samples that were also hypermethylated (P < 0.01). MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction (MSPPCR) in gastric biopsy samples from uninfected or H. pylori -infected children (n = 50), from adults with chronic gastritis (n = 97) and from adults with gastric cancer (n = 92). MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene (β actin). MSI analysis was performed by screening MSI markers at 4 loci (Bat-25, Bat-26, D17S250 and D2S123) with PCR; PCR products were analysed by single strand conformation polymorphism followed by silver staining. Statistical analyses were performed with either the χ 2 test with Yates continuity correction or Fisher's exact test, and statistical significance for expression analysis was assessed using an unpaired Student's t -test. RESULTS: Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children, regardless of H. pylori infection status. The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H. pylori infection (P < 0.05); this region was methylated in 66% of gastric cancer patients, and the difference in the percentage of methylated samples between these patients and those from H. pylori -infected chronic gastritis patients was statistically significant (P < 0.05). MLH1 methylation frequencies among H. pylori -infected and non-infected chronic gastritis adult patients were 13% and 7%, respectively. We observed methylation of the MLH1 promoter (39%) and increased MSI levels (68%) in samples from gastric cancer patients in comparison to samples from H. pylori -infected adult chronic gastritis patients (P < 0.001 and P < 0.01, respectively). The frequency of promoter methylation for both genes was higher in gastric cancer samples than in H. pylori -positive chronic gastritis samples (P < 0.05). The levels of MLH1 and MGMT mRNA were significantly reduced in chronic gastritis samples that were also hypermethylated (P < 0.01). CONCLUSION: In summary, MGMT and MLH1 methylation did not occur in earlier-stage H. pylori infections and thus might depend on the duration of infection. © 2013 Baishideng. All rights reserved.

Marked increase in proton pump inhibitors use in Australia

Objectives: To examine the trends in the prescribing of subsidised proton pump inhibitors (PPIs) and histamine receptor antagonists (H2RAs), in the Australian population from 1995 to 2006 to encourage discussion regarding appropriate clinical use. PPIs and H2RAs are the second highest drug cost to the publicly subsidised Pharmaceutical Benefits Scheme (PBS). Design: Government data on numbers of subsidised scripts, quantity and doses for PPIs and H2RAs were analysed by gender and age, dose and indication. Main outcome measure: Drug utilisation as DDD [defined daily dose]/1000 population/day. Results: The use of combined PPIs increased by 1318%. Utilisation increased substantially after the relaxation of the subsidised indications for PPIs in 2001. Omeprazole had the largest market share but was substituted by its S-enantiomer esomeprazole after its introduction in 2002. There was considerable use in the elderly with the peak use being in those aged 80 years and over. The utilisation of H2RAs declined 72% over 12 years. Conclusions: PPI use has increased substantially, not only due to substitution of H2RAs but to expansion in the overall market. Utilisation does not appear to be commensurate with prevalence of gastro-oesophageal reflux disease (GORD) nor with prescribing guidelines for PPIs, with significant financial costs to patients and PBS. This study encourages clinical discussion regarding quality use of these medicines. © 2010 John Wiley & Sons, Ltd.

Role of mast cells in inflammatory bowel disease and inflammation-associated colorectal neoplasia in IL-10-deficient mice.

BACKGROUND: Inflammatory bowel disease (IBD) is hypothesized to result from stimulation of immune responses against resident intestinal bacteria within a genetically susceptible host. Mast cells may play a critical role in IBD pathogenesis, since they are typically located just beneath the intestinal mucosal barrier and can be activated by bacterial antigens. METHODOLOGY/PRINCIPAL FINDINGS: This study investigated effects of mast cells on inflammation and associated neoplasia in IBD-susceptible interleukin (IL)-10-deficient mice with and without mast cells. IL-10-deficient mast cells produced more pro-inflammatory cytokines in vitro both constitutively and when triggered, compared with wild type mast cells. However despite this enhanced in vitro response, mast cell-sufficient Il10(-/-) mice actually had decreased cecal expression of tumor necrosis factor (TNF) and interferon (IFN)-gamma mRNA, suggesting that mast cells regulate inflammation in vivo. Mast cell deficiency predisposed Il10(-/-) mice to the development of spontaneous colitis and resulted in increased intestinal permeability in vivo that preceded the development of colon inflammation. However, mast cell deficiency did not affect the severity of IBD triggered by non-steroidal anti-inflammatory agents (NSAID) exposure or helicobacter infection that also affect intestinal permeability. CONCLUSIONS/SIGNIFICANCE: Mast cells thus appear to have a primarily protective role within the colonic microenvironment by enhancing the efficacy of the mucosal barrier. In addition, although mast cells were previously implicated in progression of sporadic colon cancers, mast cells did not affect the incidence or severity of colonic neoplasia in this inflammation-associated model.

GSTT1, GSTM1 and CYP2E1 genetic polymorphisms in gastric cancer and chronic gastritis in a Brazilian population

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polymorphisms of DNA repair genes XRCC1 and XRCC3, interaction with environmental exposure and risk of chronic gastritis and grastic cancer

Aim: To evaluate the association between polymorphisms XRCC1 Arg194Trp and Arg399Gln and XRCC3 Thr241Met and the risk for chronic gastritis and gastric cancer, in a Southeastern Brazilian population. Methods: Genotyping by PCR-RFLP was carried out on 202 patients with chronic gastritis (CG) and 160 patients with gastric cancer (GC), matched to 202 (C1) and 150 (C2) controls, respectively. Results: No differences were observed among the studied groups with regard to the genotype distribution of XRCC1 codons 194 and 399 and of XRCC3 codon 241. However, the combined analyses of the three variant alleles (194Trp, 399Gln and 241Met) showed an increased risk for chronic gastritis when compared to the GC group. Moreover, an interaction between the polymorphic alleles and demographic and environmental factors was observed in the CG and GC groups. XRCC1 194Trp was associated with smoking in the CG group, while the variant alleles XRCC1 399Gln and XRCC3 241Met were related with gender, smoking, drinking and H pylori infection in the CG and GC groups. Conclusion: Our results showed no evidence of a rela-tionship between the polymorphisms XRCC1 Arg194Trp and Arg399Gln and XRCC3 Thr241Met and the risk of chronic gastritis and gastric cancer in the Brazilian population, but the combined effect of these variants may interact to increase the risk for chronic gastritis, considered a premalignant lesion. Our data also indicate a gene-environment interaction in the susceptibility to chronic gastritis and gastric cancer. © 2005 The WJG Press and Elsevier Inc. All rights reserved.

Genetic alterations in benign lesions: Chronic gastritis and gastric ulcer

Aim: To investigate the occurrence of chromosome 3, 7, 8, 9, and 17 aneuploidies, TP53 gene deletion and p53 protein expression in chronic gastritis, atrophic gastritis and gastric ulcer, and their association with H pylori infection. Methods: Gastric biopsies from normal mucosa (NM, n = 10), chronic gastritis (CG, n = 38), atrophic gastritis (CAG, n = 13) and gastric ulcer (GU, n = 21) were studied using fluorescence in situ hybridization (FISH) and immunohistochemical assay. A modified Giemsa staining technique and PCR were used to detect H pylori. An association of the gastric pathologies and aneuploidies with H pylori infection was assessed. Results: Aneuploidies were increasingly found from CG (21%) to CAG (31%) and to GU (62%), involving mainly monosomy and trisomy 7, trisomies 7 and 8, and trisomies 7, 8 and 17, respectively. A significant association was found between H pylori infection and aneuploidies in CAG (P = 0.0143) and GU (P = 0.0498). No TP53 deletion was found in these gastric lesions, but p53-positive immunoreactivity was detected in 45% (5/11) and 12% (2/17) of CG and GU cases, respectively. However, there was no significant association between p53 expression and H pylori infection. Conclusion: The occurrence of aneuploidies in benign lesions evidences chromosomal instability in early stages of gastric carcinogenesis associated with H pylori infection, which may confer proliferative advantage. The increase of p53 protein expression in CG and GU may be due to overproduction of the wild-type protein related to an inflammatory response in mucosa. © 2006 The WJG Press. All rights reserved.

Expression of annexin-A1 and galectin-1 anti-inflammatory proteins and mRNA in chronic gastritis and gastric cancer

Objective. The anti-inflammatory proteins annexin-A1 and galectin-1 have been associated with tumor progression. This scenario prompted us to investigate the relationship between the gene and protein expression of annexin-A1 (ANXA1/AnxA1) and galectin-1 (LGALS1/Gal-1) in an inflammatory gastric lesion as chronic gastritis (CG) and gastric adenocarcinoma (GA) and its association with H. pylori infection. Methods. We analyzed 40 samples of CG, 20 of GA, and 10 of normal mucosa (C) by the quantitative real-time PCR (qPCR) technique and the immunohistochemistry assay. Results. High ANXA1 mRNA expression levels were observed in 90% (36/40) of CG cases (mean relative quantification RQ = 4.26 ± 2.03) and in 80% (16/20) of GA cases (mean RQ = 4.38 ± 4.77). However, LGALS1 mRNA levels were high (mean RQ = 2.44 ± 3.26) in 60% (12/20) of the GA cases, while low expression was found in CG (mean RQ = 0.43 ± 3.13; P < 0.01). Normal mucosa showed modest immunoreactivity in stroma but not in epithelium, while stroma and epithelium displayed an intense immunostaining in CG and GA for both proteins. Conclusion. These results have provided evidence that galectin-1 and mainly annexin-A1 are overexpressed in both gastritis and gastric cancer, suggesting a strong association of these proteins with chronic gastric inflammation and carcinogenesis. © 2013 Yvana Cristina Jorge et al.

Transcutaneous immunization with novel lipid-based adjuvants induces protection against gastric Helicobacter pylori infection

The development of vaccines to combat pathogens that infect across mucosal surfaces has been a major goal of vaccine research. Successful mucosal vaccination requires the co-administration of adjuvants that can overcome the state of immune tolerance normally associated with mucosal application of proteins. In the case of oral immunization, delivery systems are also required to protect vaccine antigens against destruction by gastric pH and digestive enzymes. Furthermore, adjuvants used for mucosal delivery must be free of neurotoxic effects like those induced by the commonly used experimental mucosal adjuvant cholera toxin. Maintenance of the "cold chain" is also essential for the effectiveness of any vaccine and adjuvants/delivery systems that enhance the stability of a vaccine would offer a significant advantage. Needle-free methods of vaccination that induce protective immunity at multiple mucosal surfaces are also desirable for rapid vaccination of large populations. In the present study we show that transcutaneous immunization (TCI) using Lipid C, a novel lipid-based matrix originally developed for oral immunization, containing soluble Helicobacter sonicate significantly reduces the gastric bacterial burden in mice following gastric challenge with live Helicobacter pylori. Protection is associated with the production of splenic gamma interferon and gastric IgA and was achieved without the co-administration of potent and potentially toxic adjuvants, although protection was further enhanced by inclusion of CpG-ODN and cholera toxin in the lipid delivery system.

Irregular meal timing is associated with helicobacter pylori infection and gastritis

Background Helicobacter pylori (HP) is associated with chronic gastritis and gastric cancer, and more than half of the world’s population is chronically infected. The aim of this retrospective study was to investigate whether an irregular meal pattern is associated with increased risk of gastritis and HP infection. Methods The study involved 323 subjects, divided into three groups: subjects with HP infection and gastritis, with gastritis, and a control group. Subjects were interviewed on eating habits and meal timing. Multivariate logistic regression was used to compare groups. Adjusted odds ratios (OR) were derived controlling for gender, age, stress and probiotic consumption. Results Subjects who deviated from their regular meals by 2 hours or more had a significantly higher incidence of HP infection with gastritis (adjusted OR= 13.3, 95% CI 5.3–33.3, p<0.001) and gastritis (adjusted OR=6.1, 95% CI 2.5–15.0, p<0.001). Subjects who deviated their meals by 2 hours or more, twice or more per week, had an adjusted OR of 6.3 and 3.5 of acquiring HP infection with gastritis (95% CI 2.6–15.2, p<0.001) and gastritis (95% CI 1.5–8.5, p<0.001) respectively. Conclusion Frequent deviation in meal timing over a prolonged period appears associated with increased risk of developing HP infection and gastritis.

Current treatment of Helicobacter pylori infection and peptic ulcer disease

Since the initial report by Warren and Marshall in 1984, Helicobacter pylori has assumed an increasingly important role in the pathogenesis of peptic ulcer disease and gastric carcinoma in all ages. A recent National Institutes of Health Consensus Development conference acknowledges the relationship between H. pylori infection and peptic ulcer disease and recommends that the medical community treat H. pylori infection in all patients with Helicobacter pylori and peptic ulcer. Although the same organism, the response to Helicobacter pylori infection in childhood differs somewhat from that seen in adults. The paediatric patient mounts a different inflammatory response, has different macroscopic appearances and has a markedly diminished peptic ulcer disease frequency compared with their adult counterparts. The appearances of antral nodularity appear to be characteristic of Helicobacter pylori infections. The appearances, however, are unrelated to symptoms and the underlying cause for this nodularity remains obscure. Younger children with peptic ulcer diseases are more likely to be Helicobacter pylori negative. This may suggest an increased susceptibility to gastric acid or possibly a very transient Helicobacter pylori infection rather than the well described lifelong infection without treatment. It is well known that the epidemiology of Helicobacter pylori would suggest that the incidence of infection increases with age. There is also geographical variations with the incidence being higher in countries of a third world background. These epidemiological observations fly in the face of all other infections where the major period of acquisition is in childhood. There has been recent evidence to suggest that in fact the incidence in childhood is decreasing in developed countries which could support the observation that there is a decreasing positive serology with successive decades in some countries. It is felt that the most likely mode of transmission of Helicobacter pylori is faecal to oral or oral to oral route. These are similar modes of transmission to Hepatitis A infections. It is obvious that most infections in childhood remain asymptomatic. It is also clear that there is no relationship between chronic recurrent abdominal pain of childhood syndrome and the presence of Helicobacter pylori infections. It remains to be seen as to who should be treated, what with and when. All of these issues will be discussed in the paper.

The role of probiotics in Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is a major cause of chronic gastritis and peptic ulcer disease, and it is also designated as a class-I carcinogen for stomach cancer. The role of probiotics in the treatment of gastrointestinal infections is increasingly documented as an alternative or complement to antibiotics, with the potential to decrease the use of antibiotics or reduce their adverse effects. These studies were conducted to investigate the role of probiotics in the treatment of H. pylori infection. Various aspects included: an investigation of the effects of a probiotic combination consisting of Lactobacillus rhamnosus GG, L. rhamnosus LC705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium breve Bb99 or B. lactis Bb12 as a supplementation to H. pylori eradication therapy, with special reference to tolerability, effectiveness, and microbiota alterations following the treatment; discovering the role of probiotics in vivo with H. pylori infected and uninfected patients, as well as with an in vitro model of H. pylori infection. The probiotic combination therapy was able to reduce significantly the total symptom score, which takes into account both the frequency and the severity of the adverse effects, during the eradication treatment. The supplementation did not improve the success of the eradication treatment significantly, though some difference was seen in the eradication percentages (91% vs. 79%). The quantities of predominant bacterial groups were altered significantly following the triple treatment. Probiotics slightly counteracted the effects of anti-H. pylori treatment, monitored as significantly less alterations in the total numbers of aerobes and lactobacilli/enterococci group bacteria. After probiotic intervention, L. rhamnosus GG adhered to a minority of the patients upper gastrointestinal mucosa, but all of the probiotics survived well through the gastrointestinal tract transit with and without antimicrobial treatment. Probiotic intervention decreased gastrin-17 levels in H. pylori infected patients and appeared to decrease the 13C-urea breath test values. In in vitro Caco-2 cell line experiments, probiotics inhibited H. pylori adhesion to intestinal epithelial cells. Both L. rhamnosus strains, P. freudenreichii ssp. shermanii JS and the combination inhibited the H. pylori-induced acute cell leakage. Simultaneously, both L.rhamnosus strains and the combination transiently improved the epithelial barrier function. The pro-inflammatory effects prevailed when the probiotics were used in combination. According to this series of studies, probiotic combination could have some potential in reducing adverse effects induced by H. pylori eradication treatment and beneficial effects on H. pylori infected subjects.

New aspects of the diagnosis of Helicobacter pylori infection

Aims: Helicobacter pylori infection, although the prevalence is declining in Western world, is still responsible for several clinically important diseases. None of the diagnostic tests is perfect and in this study, the performance of three stool antigen tests was assessed. In areas of high H. pylori prevalence, the definition of patients with the greatest benefit from eradication therapy may be a problem; the role of duodenal gastric metaplasia in categorizing patients at risk for duodenal ulcer was evaluated in this respect. Whether persistent chronic inflammation and elevated H. pylori antibodies after successful eradication are associated with each other or with atrophic gastritis, a long term sequelae of H. pylori infection, were also studied. Patients and methods: The three stool antigen tests were assessed in pre- and post-eradication settings among 364 subjects in two studies as compared to the rapid urease test (RUT), histology, culture, the 13C-urea breath test (UBT) and enzyme immunoassay (EIA) based H. pylori serology. The association between duodenal gastric metaplasia with duodenal ulcer was evaluated in a retrospective study including 1054 patients gastroscopied due to clinical indications and 154 patients previously operated for duodenal ulcer. The extent of duodenal gastric metaplasia was assessed from histological specimens in different patient groups formed on the basis of gastroscopy findings and H. pylori infection. Chronic gastric inflammation (108 patients) and H. pylori antibodies and serum markers for atrophy (77 patients) were assessed in patients earlier treated for H. pylori. Results: Of the stool antigen tests studied, the monoclonal antibody-based EIA-test showed the highest sensitivity and specificity both in the pre-treatment setting (96.9% and 95.9%) and after therapy (96.9% and 97.8%). The polyclonal stool antigen test and the in-office test had at baseline a sensitivity of 91% and 94%, and a specificity of 96% and 89%, respectively and in a post-treatment setting, a sensitivity of 78% and 91%, and a specificity of 97%, respectively. Duodenal gastric metaplasia was strongly associated with H. pylori positive duodenal ulcer (odds ratio 42). Although common still five years after eradication, persistent chronic gastric inflammation (21%) and elevated H. pylori antibodies (33%) were neither associated with each other nor with atrophic gastritis. Conclusions: Current H. pylori infection can feasibly be diagnosed by a monoclonal antibody-based EIA test with the accuracy comparable to that of reference methods. The performance of the polyclonal test as compared to the monoclonal test was inferior especially in the post-treatment setting. The in-office test had a low specificity for primary diagnosis and hence positive test results should probably be confirmed with another test before eradication therapy is prescribed. The presence of widespread duodenal gastric metaplasia showed promising results in detecting patients who should be treated for H. pylori due to an increased risk of duodenal ulcer. If serology is used later on in patients with earlier successfully treated for H. pylori, it should be taken into account that H. pylori antibodies may persist elevated for years for unknown reason. However, this phenomenon was not found to be associated with persistent chronic inflammation or atrophic changes.