Histological classification of gastritis and Helicobacter pylori infection: an agreement at last? The International Workshop on the Histopathology of Gastritis

[Impact of primary duodenogastric reflux and Helicobacter pylori infection on gastritis and antibiotic resistance in children]

OBJECTIVES

To investigate the risk factors for Helicobacter pylori (HP) infection in children with primary duodenogastric reflux (DGR) and its impact on gastritis and antibioticresistance.

METHODS

A retrospective analysis was performed on the clinical data of 2 190 children who underwent upper gastrointestinal endoscopy in Wuxi Children's Hospital from January 2019 to February 2022, among whom 308 children were diagnosed with primary DGR. According to the presence or absence of HP infection, the children were classified to HP infection group (53 children) and non-HP infection group (255 children). The risk factors for HP infection and its impact on the incidence rate and severity of gastritis were analyzed. According to the presence or absence of primary DGR, 331 children with HP infection were classified to primary DGR group (29 children) and non-primary DGR group (302 children), and then the impact of primary DGR with HP infection on antibiotic resistance was analyzed.

RESULTS

The HP infection group had a significantly higher age than the non-HP infection group (P<0.05), and there was a significant difference in the age distribution between the two groups (P<0.05), while there were no significant differences in the incidence rate and severity of gastritis between the two groups (P>0.05). The multivariate logistic regression analysis showed that older age was a risk factor for HP infection in children with DGR (P<0.05). Drug sensitivity test showed that there were no significant differences in the single and combined resistance rates of metronidazole, clarithromycin, and levofloxacin between the primary DGR group and the non-primary DGR group (P>0.05).

CONCLUSIONS

Older age is closely associated with HP infection in children with DGR. Primary DGR with HP infection has no significant impact on gastritis and antibiotic resistance in children.

Effect of gastric helicobacter pylori colonization in the development of erosive esophagitis in patients with hiatal hernia

Background/Aims

There may be various factors that determine gastroesophageal reflux disease (GERD) as a result of hiatal hernia (HH) (such as the size of the hernia, age, other host and environmental factors) and the presence of protective factors to explain the absence of reflux disease should not be ignored. Helicobacter pylori (Hp) infection can prevent the development of GERD or cause it. This study aimed to determine whether Hp colonized in the stomach and hernia affects the development of erosive esophagitis (EE) in patients with HH.

Materials and Methods

In this case-controlled study, 111 patients with HH were eligible for the study. Study group with EE (n = 61, 55%) and control group without EE (n = 50, 45%) were formed. Groups were compared for gastric Hp and Hp in the hernia.

Results

While the frequency of Hp in the antrum was 55.7% in the group with EE, it was 30% in the control group (p = 0.01, OR: 2.94 in 95% CI 1.34-6.46). The rates in terms of HP frequency in the corpus were 43.6% and 32.1%, respectively, (p = 0.45). Hp colonization in HH was detected in 18 cases (29.50%) and 14 cases (28%), respectively, (p = 0.86). In regression analysis, antral Hp was found to be effective in the development of EE (p = 0.01).

Conclusion

As a result of this study, we think that antral Hp may have a causative role in the development of reflux esophagitis, but the presence of Hp in HH does not have an effective role in reflux esophagitis formation.

Correlations between Endoscopic and Histopathological Assessment of Helicobacter pylori-Induced Gastric Pathology-A Cross-Sectional Retrospective Study

Helicobacter pylori (H. pylori) infects about half of the world’s population and can lead to premalignant lesions and gastric cancer. Updated data about the correlation of histopathological diagnostics with endoscopic diagnostics are scarce. The objective of this study was to identify the concordance between endoscopic and histopathologic findings, with a focus on premalignant lesions. We performed a cross sectional, retrospective study over a 4-year period (2017−2021) on adult patients with dyspeptic symptoms and positive RUT (rapid urease test) in a single hospital centre, with a total of 133 patients infected with H. pylori being included in the study. Statistical associations between endoscopic appearance and histopathological results were found for atrophic antral gastritis (p = 0.001), intestinal metaplasia of the antrum (p = 0.018), gastric polyps (p < 0.001) and gastric corpus cancer (p = 0.012). Females were more likely to be diagnosed through endoscopy with gastric atrophy or intestinal metaplasia (p = 0.031), while chronic atrophic gastritis in corpus was more prevalent in patients older than 65 (p = 0.024). Overall, our study reveals only 21% concordance between Giemsa stain and RUT, highlighting the importance of combining rapid testing with endoscopic and histopathological diagnostic methods for a more accurate early diagnosis and prevention of gastric cancer.

Assessment of Efficacy and Adverse Effects of Bismuth-Based Treatment Combined with Bifidobacterium Lactis for Eradication of Helicobacter Pylori in Turkish Children

Objective There are many adverse effects of drugs used to eradicate Helicobacter pylori, and reconstructing the microbiota by external ingestion of probiotics seems to have good effects on H. pylori eradication and prevents side effects.

Methods The study included 161 outpatients aged between 8 and 18 years diagnosed with H. pylori gastritis in the Gülhane Training and Research Hospital Pediatric Gastroenterology unit from June 1, 2018, through March 31, 2020, and patients were randomized into two groups. Eighty patients in the probiotic group (first group) received H. pylori eradication therapy for 14 days; additionally, Bifidobacterium lactis B94 was administered for 14 days for eradication of H. pylori. Eighty-one patients in the standard therapy group (second group) received the same eradication therapy but no probiotics. All patients were asked to complete a detailed questionnaire regularly, including changes in symptoms and side effects of drugs on days 0, 7, and 14 of treatment. The eradication success was checked with the H. pylori stool antigen test kit 8 weeks after completion of the treatment regimen.

Results The mean age of the patients was 14.2 ± 2.9 years, and 88 (64.7%) were female. The eradication rates were similar between the standard therapy and the probiotic groups by intention-to-treat analysis (p = 0.930). In order of frequency, the most common eradication treatment–related side effects were abdominal pain, taste abnormalities, and anorexia. In addition, therapy-related epigastric pain and flatulence were similar initially (p > 0.05) but seemed to be significantly lower in the probiotic group than in the standard therapy group on days 7 and 14 (p < 0.05).

Conclusions Our results suggest that additional probiotic supplementation has not changed the eradication rates but seems to reduce some specific gastrointestinal adverse events in children with H. pylori infections treated with a bismuth-based quadruple eradication regimen. More extensive randomized controlled trials are needed to explain probiotics' effects on H. pylori eradication and drug side effects.

Brazilian Red Propolis Presents Promising Anti-H. pylori Activity in In Vitro and In Vivo Assays with the Ability to Modulate the Immune Response

Helicobacter pylori is a Gram-negative, microaerophilic, curved-rod, flagellated bacterium commonly found in the stomach mucosa and associated with different gastrointestinal diseases. With high levels of prevalence worldwide, it has developed resistance to the antibiotics used in its therapy. Brazilian red propolis has been studied due to its biological properties, and in the literature, it has shown promising antibacterial activities. The aim of this study was to evaluate anti-H. pylori from the crude hydroalcoholic extract of Brazilian red propolis (CHEBRP). For this, in vitro determination of the minimum inhibitory and bactericidal concentration (MIC/MBC) and synergistic activity and in vivo, microbiological, and histopathological analyses using Wistar rats were carried out using CHEBRP against H. pylori strains (ATCC 46523 and clinical isolate). CHEBRP presented MIC/MBC of 50 and 100 μg/mL against H. pylori strains (ATCC 43526 and clinical isolate, respectively) and tetracycline MIC/MBC of 0.74 µg/mL. The association of CHEBRP with tetracycline had an indifferent effect. In the stomach mucosa of rats, all treatments performed significantly decreased the number of H. pylori, and a concentration of 300 mg/kg was able to modulate the inflammatory response in the tissue. Therefore, CHEBRP showed promising anti-H. pylori in in vitro and in vivo assays.

Differential Expression of Tissular miRNA-155 in Pediatric Gastritis

BACKGROUND

MicroRNA molecules, among them the intensely studied miRNA-155 (miR-155), are regarded as potential biomarkers of chronic gastric inflammation and premalignant lesion progression. However, literature data are scarce in terms of pediatric studies and in the evaluation of the predictive role of miRNA in early gastric inflammation. This study aims to assess the differential expression of miR-155 in relation to pediatric gastritis.

METHODS

The present research was conducted on 192 patients with chronic dyspeptic symptoms who underwent upper digestive endoscopy. Bioptic samples were harvested for histopathological analysis and tissue miR-155 depiction. MiR-155 expression analysis was carried out through quantitative real-time polymerase chain reaction (qRT-PCR). The study population was divided into two groups: controls (93 patients) and study group (99 patients) with inflammatory modifications.

RESULTS

MiR-155 expression was augmented in patients with gastritis but did not differ significantly from controls (p = 0.16). An increase in miR-155 expression was noted in relation to chronic gastritis, H. pylori infection, or increase in gastritis severity, but these variations were not important (p = 0.30, p = 0.44, and p = 0.45, respectively).

CONCLUSIONS

According to our study, pediatric gastritis increases, but does not greatly influence, miR-155 expression. Dynamic evaluation of miR-155 might enlighten its prognostic role in pediatric gastritis.

Epidemiology Helicobacter pylori infection in children in the Tyva Republic (Russia)

BACKGROUND

Tyva Republic is a small mountainous area at the geographical center of Asia in southern Siberia, with a high incidence of gastric cancer.

AIM

We examined the prevalence of H. pylori and associated risk factors among children in Tyva.

METHODS

Cross-sectional study was conducted among Tuvan children who had upper gastrointestinal symptoms and underwent upper gastroscopy with gastric biopsies. Informed consent was obtained from the parents and assent from the children. Demographic information, ethnicity, parents' education and employment status, and family size were collected. H. pylori infection was diagnosed by histologic examination.

RESULTS

There were 270 children between the ages 7 and 17 years (mean 13.4 ± 2.7); 64% girls; 147e Tuvan and 123 Caucasians. The overall prevalence of H. pylori was high and similar between boys and girls (55 vs. 57%, respectively, p = 0.42). The infection was highest in Tuvan children (67%. vs. 43%, respectively (OR = 2.4; 95%CI = 1.9.4-3), p = 0.05. H. pylori prevalence increased with age from 44% among 7 to 10 years and 64% among those 14 to 17 (OR = 3.0; 95%CI = 1.6-5.8), p = 0.0.005; the pattern was consistent among both ethnic groups. The prevalence of the infection among Caucasian children was inversely correlated with the level of mother's education (44%, vs. 61%) (i.e., for with and without a college education the OR = 2.3; 95%CI = 1.2-3.7), p = 0.02. Neither the total number of children nor adults living in the same household correlated with H. pylori prevalence.

CONCLUSIONS

Strategies to reduce the incidence of gastric cancer in Tyva will need to start in childhood.

A Comparison of Tumor-Associated and Non-Tumor-Associated Gastric Microbiota in Gastric Cancer Patients

BACKGROUND

How gastric cancer (GC) incidence is associated with changes in the gastric microbiome has not been firmly established. The present study therefore aims to investigate the microbial communities present within the gastric mucosa of patients with superficial gastritis (SG) or GC.

METHODS

Paired tumor and paracancerous samples of the gastric mucosa were collected from 18 patients being surgically treated for GC and from 32 patients with SG being treated via gastroscopy. The gastric microbiome in these samples was then profiled via 16S rRNA sequencing, with a linear discriminant analysis effect size (LEfSe) approach used to identify and compare different bacteria, and with PICRUSt used for predictive functional analyses.

RESULTS

GC patients exhibited a distinct gastric microbiota profile from that observed in SG patients. These changes were evident in both tumor and paracancerous tissues from GC patients. Specifically, we found that 6 bacterial genera were specifically enriched in GC tissue samples relative to SG samples, while 18 genera were depleted in these same samples. Based on the differential abundance of these bacteria, we were able to calculate microbial dysbiosis index (MDI) values, which were significantly higher in GC patients than in SG patients. In addition, MDI values were negatively correlated with gastric Shannon index and were positively correlated with relative Helicobacter spp. abundance. Importantly, these MDI values were readily able to discriminate between GC and SG patient samples. Functional analysis suggested that GC patients were more likely to harbor a nitrosating microbial community.

CONCLUSIONS

GC patients exhibited a gastric microbiome profile distinct from that observed in SG patients, with these differences being evident in both tumor and paracancerous tissues. Differences in the relative abundance of Helicobacter spp. may be the primary driver of gastric dysbiosis in GC patients.

Helicobacter pylori infection is associated with the co-occurrence of bacteria in the oral cavity and the gastric mucosa

BACKGROUND

Pathogens capable of impacting gastrointestinal tract tumor development are located in the oral cavity, but whether these oral bacteria are able to colonize the gastric mucosa in gastric cancer (GC) patients and whether Helicobacter pylori infection can influence this process remains to be established.

METHODS

Microbial 16S rDNA deep sequencing was conducted to characterize bacteria present in paired gastric mucosa and tongue coating samples in 27 patients with superficial gastritis (SG) and 11 GC patients.

RESULTS

While the overall composition of the gastric mucosa and tongue coating microbiomes differed substantially, certain bacteria were present in both of these communities. The co-occurrence of bacteria between the tongue coating and gastric mucosa differed significantly between SG and GC patients. Of the 15 most abundant shared oral bacteria genera (the core shared oral bacteria), which were associated with differences in microbiota composition between these tongue coating and gastric mucosa, three were enriched in the gastric mucosa of GC patients relative to SG patients, whereas, 12 were depleted in GC patient samples. Furthermore, the prevalence and relative abundance of these core shared oral bacteria in the gastric mucosa were also linked to H. pylori infection status, and the core shared oral bacteria were also associated with the overall composition of the gastric mucosal microbiome.

CONCLUSIONS

Helicobacter pylori infections are linked to the co-occurrence of bacteria in the oral microbiome and the gastric mucosal microbiome. Ectopic colonization of oral microbes may be a primary driver of H. pylori-induced gastric microbial dysbiosis in patients with GC.

Efficacy of a novel sequential treatment regimen containing bismuth for Helicobacter pylori eradication in Turkish children

BACKGROUND

Eradication rates of Helicobacter pylori (H pylori) with standard triple therapy are gradually decreasing all over the world, including in children, due to the development of strains resistant to antimicrobials. Sequential therapy can be used as an alternative method to increase eradication rates.

MATERIALS AND METHODS

A total of 75 patients ≥ 8 years of age with H pylori gastritis were included in the study. According to Rome IV criteria, 38 patients had functional abdominal pain and dyspepsia, and 37 patients had alarm findings suggesting organic disease. Patients were treated with a novel sequential therapy consisting of the proton pump inhibitor (PPI)-lansoprazole (1 mg/kg/day, maximum 30 mg daily), amoxicillin (50 mg/kg/d in two doses, maximum 2 × 1000 mg) for 7 days followed by PPI-lansoprazole (1 mg/kg/d, maximum 30 mg daily), metronidazole (20 mg/kg/day in two doses, maximum 2 x 500 mg), tetracycline (50 mg/kg/d divided into four equal doses, maximum 4 x 500 mg), and bismuth subsalicylate (262 mg QID in patients ≤ 10 years of age, 524 mg QID in patients > 10 years of age in days 8-14). Eradication status was evaluated by H pylori stool antigen test 8 weeks after the completion of treatment.

RESULTS

The mean age of the patients was 15.1 ± 2.4 years and 51 (68%) were female. No patient discontinued therapy due to side effects. All patients had antral gastritis (76.0%) or pangastritis (24.0%). The peptic ulcer rate was 6.6%. Eradication therapy was given to all patients with or without peptic ulcer. H pylori eradication was achieved in 69 (92.0%) patients and symptoms improved in 61 of those eradicated.

CONCLUSIONS

As a first-line treatment for H pylori eradication in children, administering a novel sequential therapy including bismuth for 14 days provides a high rate of eradication.

Helicobacter pylori Prevalence and Impact: A Histology-Based Report About Children from an Endemic Country

Background

Helicobacter pylori is spreading worldwide with a high prevalence rate in the developing countries. Our primary goal was to measure the histology-based prevalence of Helicobacter pylori infection in children and to quantify its impact on the gastric inflammation and anemia. Our secondary goal was to study possible predictors for the presence of Helicobacter pylori in this cohort.

Methods

A retrospective chart review was performed for children who underwent Esophago-gastro-duodenoscopy at Jordan university hospital in Jordan from 2008 to 2016. Data collected included epidemiological data, indication for endoscopy, endoscopic findings, and laboratory data. The gastric biopsies were re-examined by a pathologist to check for the presence of Helicobacter pylori, the presence of gastritis, and to grade gastritis according to the updated Sydney criteria.

Results

A total of 98 children (53 girls-54%) underwent Esophago-gastro-duodenoscopy. The average age was 11.7 years ± 4.7 years. Of them, 53 patients (29 boys-55%) had Helicobacter pylori identified in the gastric biopsy. The histology-based prevalence rate of Helicobacter pylori was 54%. The most common indication for endoscopy was abdominal pain (53%) followed by vomiting (18%). Nodular gastric mucosa was present in 43% of the Helicobacter pylori-positive group, and in only 11% of the Helicobacter pylori-negative group (P-value <0.0.5). Moderate to severe chronic gastritis was seen in 59% of the biopsies of Helicobacter pylori-positive group, compared to 31% in the Helicobacter pylori-negative group (p value <0.05). Presence of anemia was not different between the two groups (p value > 0.05). Presence of endoscopic nodularity, active gastritis by histology, and moderate to severe gastritis by histology were positive predicators for the presence of Helicobacter pylori. (p value <0.05).

Conclusion

Helicobacter pylori infection in this study cohort of Jordanian children is common, with a histology-based prevalence rate of 54%. Nodularity of the stomach is the most common positive endoscopic feature, and its presence predicts the presence of Helicobacter pylori. Moderate to severe active gastritis is associated with Helicobacter pylori. The presence of Helicobacter pylori does not affect anemia status in this cohort of Jordanian children.

The Effect of Primary Duodenogastric Bile Reflux on the Presence and Density of Helicobacter pylori and on Gastritis in Childhood

Background and Objectives: Although there are many studies that investigate the relationship between duodenogastric reflux (DGR) and Helicobacter pylori in adult patients, the reported data are contradictory. In addition, there are very few studies in the literature investigating the relationship between DGR and H. pylori in the pediatric age group. In the present study, we investigated the effect of primary DGR on H. pylori and gastritis. Materials and Methods: A total of 361 patients who were referred to the clinic of our hospital with dyspeptic complaints who had an upper gastrointestinal system endoscopy and a gastric biopsy were included in the study. Results: DGR was detected in 45 cases, and 316 cases that did not have DGR were considered as the control group. Comparisons were made between the DGR cases and the control group in terms of risk factors (age, gender), the presence and density of H. pylori, and the presence and severity of gastritis. The average age of the patients who were included in the study was 11.6 ± 4.6 years. A total of 128 (36%) of the cases were male and 233 (64%) were female. DGR was present in 45 (13%) of the cases. The average age of the patients with DGR was 13.9 ± 3.1 years, the average age of the control group was 11.3 ± 4.7, and there were statistically significant differences (p < 0.001). No significant differences were detected in terms of gender between DGR and the control group (p > 0.05). H. pylori (+) was detected in 29 (64%) of patients with DGR, and in 202 (64%) of the control group. No significant differences were detected between H. pylori prevalence (p = 0.947). Gastritis was detected in 37 (82%) of the patients with DGR, and in 245 (77%) of the control group (p = 0.476). No significant differences were detected between the presence and density of H. pylori, gastritis presence, severity and DGR (p > 0.05). Conclusions: The ages of patients with DGR were significantly higher than in the control group, and advanced age was shown to be a risk factor for primary DGR. It was found that the presence of DGR has no effect on the presence and severity of H. pylori. Given this situation, we consider it is important to eradicate H. pylori infection, especially in the case where H. pylori is present together with DGR.

Fermented milk containing Lactobacillus paracasei and Glycyrrhiza glabra has a beneficial effect in patients with Helicobacter pylori infection: A randomized, double-blind, placebo-controlled study

BACKGROUND

Lactobacillus paracasei and Glycyrrhiza glabra have been reported as having beneficial effects on Helicobacter pylori infection. We aimed to assess the efficacy and safety of fermented milk containing L paracasei HP7 and G glabra in patients with H pylori infection.

METHODS

This multicenter, prospective, randomized, double-blind, placebo-controlled clinical trial was conducted in 2 hospitals from April to December 2017. Patients with H pylori infection were randomized into either the treatment group (fermented milk with L paracasei HP7 and G glabra) or placebo group (fermented milk only) once daily for 8 weeks. The primary endpoint was the gastric load of H pylori measured by C-urea breath test (UBT). Secondary endpoints were histologic and clinical improvement.

RESULTS

A total of 142 patients were randomly allocated to the treatment (n = 71) or placebo groups (n = 71). Compared to baseline data, the quantitative value of C-UBT at 8 weeks was significantly reduced in the treatment group (from 20.8 ± 13.2% to 16.9 ± 10.8%, P = .035), but not in the placebo group (P = .130). Chronic inflammation improved significantly only in the treatment group (P = .013), whereas the neutrophil activity deteriorated significantly only in the placebo group (P = .003). Moreover, the treatment group had significant improvement in gastrointestinal symptoms (P = .049) and quality of life (P = .029). No serious adverse events were observed.

CONCLUSION

The combination of fermented milk containing L paracasei and G glabra reduced H pylori density and improved histologic inflammation. However, their mechanisms of action should be elucidated in further studies.

Expression of tryptophan hydroxylase in gastric mucosa in symptomatic and asymptomatic Helicobacter pylori infection

INTRODUCTION

Helicobacter pylori infection induces clinical symptoms in 15-20% of subjects, and the reason for this variation is still not clear. The aim of the present study is to evaluate the expression of tryptophan hydroxylase (TpH-1) in gastric mucosa of patients with symptomatic and asymptomatic H. pylori infection in relation to the intensity of bacterial colonization and severity of dyspeptic symptoms.

MATERIAL AND METHODS

Ninety subjects (aged 35-49 years) were enrolled in the study and separated into 3 groups of 30 subjects each. Group I - healthy volunteers without H. pylori infection, group II - subjects with asymptomatic H. pylori infection, group III - H. pylori-infected patients with dyspeptic symptoms, mainly fasting and nocturnal epigastric pain. To diagnose H. pylori infection the urea breath test (UBT-13C) and histological analysis were performed. The level of mRNA expression of tryptophan hydroxylase (TpH-1) was estimated in gastric mucosa with RT-PCR.

RESULTS

The expression of this enzyme in antral mucosa was 2.69 ±0.97 in group I, 2.28 ±0.69 in group II (p > 0.05) and 4.40 ±1.64 in group III (p < 0.001). The levels of expression of TpH-1 in gastric body mucosa were 2.16 ±0.70, 1.57 ±0.52 (p > 0.05) and 3.40 ±1.51 (p < 0.001), respectively. In group III a positive correlation was found between intensity of H. pylori colonization and TpH-1 expression as well as between TpH-1 expression and severity of dyspeptic symptoms.

CONCLUSIONS

Increased expression of TpH-1 in gastric mucosa plays a role in pathogenesis of chronic dyspepsia.

HELICOBACTER PYLORI INFECTION AND IMMUNE PROFILE OF PATIENTS WITH DIFFERENT GASTRODUODENAL DISEASES

BACKGROUND

The association between infection with Helicobacter pylori and different gastroduodenal diseases is related to bacterial, host and environmental factors. Studies have demonstrated an association between the genetic diversity of H. pylori, especially in the vacA and cagA genes, and the development of digestive diseases such as peptic ulcer and gastric cancer. In addition, the nature of the host inflammatory response may explain these different manifestations of infection caused by this microorganism. In this respect, host factors that regulate the immune and inflammatory responses involving the functional interaction of H. pylori infection with different components of the immune system, particularly T cells, in gastroduodenal diseases still need further investigation.

OBJECTIVE

To characterize the immune response, including immunity induced by infection with H. pylori, especially virulent strains (vacA alleles and cagA gene), by analyzing the cytokine profile and T-cell population present in gastroduodenal diseases in a Brazilian population.

METHODS

In a prospective study, gastric biopsies were collected from 554 patients with different gastroduodenal diseases for histological analysis and for the determination of bacterial genotype and cytokine production (IL-4, IL-10, IFN-γ and IL-12) by ELISA.

RESULTS

The predominant genotype of the H. pylori strains isolated from the patients studied was s1m1cagA+, which was more common among patients with gastric ulcer, duodenal ulcer and gastric cancer. A significant association was observed between the s1m1cagA+ genotype and a higher degree of inflammation, higher neutrophil activity and the development of intestinal metaplasia. The gastric concentrations of IFN-γ and IL-12 were significantly higher in patients infected with H. pylori than in uninfected individuals. Higher levels of these cytokines were detected in patients with gastric ulcer and cancer, while the levels of IL-4 and IL-10 in the gastric mucosa were lower in these patients. In addition, IFN-γ and IL-12 concentrations in gastric biopsies were higher in patients infected with the virulent s1m1cagA+ genotype. In contrast, IL-4 and IL-10 levels were higher in tissue infected with s2m2cagA in gastric biopsies.

CONCLUSION

Our study shows that the interaction between the type of infectious strain and the Th1 immune response can influence and perpetuate gastric inflammation, and thus contributes to the development of the different clinical manifestations of H. pylori infection.

Serum Cytokine Signature That Discriminates Helicobacter pylori Positive and Negative Juvenile Gastroduodenitis

Gastroduodenitis caused by H. pylori, often acquired in early childhood, is found in about 50% of the adult population. Although H. pylori infections can remain asymptomatic, its virulence factors usually trigger epithelial vacuolization and degeneration, loss of microvilli, disintegration of cytoplasm, and leukocyte accumulation. It is believed that leukocyte infiltration is driven by cytokines produced locally in infected tissue. However, so far little is known about changes in serum cytokines in juvenile patients infected with H. pylori. Serum cytokine profiles were analyzed in 62 juvenile patients diagnosed with gastroduodenitis using the Bio-Plex multiplex assay. H. pylori infection was confirmed in 32 patients, while 30 patients were H. pylori-free. Cytokines CXCL5 and CXCL6, potent neutrophil chemoattractants, were upregulated in all patients diagnosed with gastroduodenitis. Serum levels of IL8, a prototype neutrophil attractant, remained unchanged in subjects with gastroduodenitis relative to controls. Therefore, our data suggest that CXCL5 and CXCL6 play a role in directing neutrophil trafficking into inflamed gastroduodenal tissue. In addition, the CCL25/GM-CSF ratio differed significantly between H. pylori-positive and -negative juveniles. Further, study is needed to evaluate the role of CCL25 and GM-CSF in the pathogenesis of the different etiologies of gastroduodenitis.

Strategies for a Successful Anatomic Pathology Subspecialty Workgroup: The 26-Year Collaboration of "The Elves"

From 1990 to present, 14 liver pathologists and 2 clinical hepatologists from 9 countries have met annually to hold thematic 2.5-day meetings centered on case-based discussion. The goal of these meetings has been to identify gaps in knowledge in our field and fuel scholarly effort to address these gaps. The founding principles were worldwide representation, good representation of women, compatibility of participants, commitment to stable membership and regular attendance, mutual education and friendship, and free exchange of ideas. A summary report of the 2.5-day meeting constituted an enduring document that captured the free flow of ideas discussed. These ideas were open to all participants for the pursuit of scholarship back at their home institutions. However, any idea borne out of an Elves meeting merits open invitation for other Elves to participate in, using established standards for meaningful coauthorship. Over 26 consecutive meetings (1990-2015), themes covered the breadth of liver pathology. With retirement of 2 individuals, resignation of 3, and death of 1, six new members were nominated and voted into membership. Over these same 26 years, active members published 2025 articles indexed in PubMEd Central under the topic "liver;" 3% of these articles represented collaborations between members. This international group represents a successful model in a subspecialty of anatomic pathology for open exchange of ideas, mutual education, and generation of topics worthy of scholarly investigation. We conclude that a self-selected group of subspecialty pathologists can meet successfully over 26 years, maintain a high state of engagement through each annual meeting, self-renew as a result of retirement or resignation, and provide a creative stimulus for highly productive academic careers.

Clarithromycin resistance and prevalence of Helicobacter pylori virulent genotypes in patients from Southern México with chronic gastritis

In developing countries, clarithromycin resistance and frequency of re-infection are factors that contribute to high prevalence of Helicobacter pylori infection. The aim of this research was determine the prevalence of clarithromycin resistance and its relation with A2142G, A2142C and A2143G mutations in the domain V of the 23S rRNA gene of H. pylori isolates in patients from Southern Mexico with chronic gastritis. Another purpose of this work was to study the prevalence of virulent genotypes and distribution of resistant strains according to the vacA/cagA/babA2 H. pylori genotypes. One hundred forty-four patients with chronic gastritis were studied. Forty-five H. pylori strains were isolated and clarithromycin susceptibility was determined by the disk-diffusion method. The 82.2% of the strains had the combination of alleles vacA s1 m1 and the cagA gene was detected in 77.8% and 40% of the strains were babA2 positive. The vacA s1 m1 genotype was detected more frequently in cagA(+) strains, vacA s1m1/cagA(+)/babA2(-) genotype was more frequent than vacA s1m1/cagA(+)/babA2(+), 37.8% and 33.3%, respectively. Eight strains were clarithromycin resistant, in three of these, point mutations were identified, but only in one strain the A2143G mutation associated with clarithromycin resistance was found. Other point mutations (A1821G, G1826A, T1830C, A2089G, T1600C, C1601T, C1602T, T1610C, A1611C and T1633G) that have not been associated with clarithromycin resistance were identified. The highest proportion of resistant strains was vacA s1m1/cagA(+) (62.5%). In patients from southern Mexico with chronic gastritis, the prevalence of clarithromycin resistance is within internationally accepted range (17.8%) and allows continued use of triple therapy for H. pylori eradication. However, it is necessary to monitor the evolution of clarithromycin resistance in this area. The largest proportion of resistant H. pylori strains is not harboring the A2142G, A2142C and A2143G mutations in the 23S rRNA gene (87.5%). The vacA s1m1/cagA(+) genotype was the most prevalent and among clarithromycin-resistant strains, this was the predominant.

Helicobacter pylori chronic gastritis updated Sydney grading in relation to endoscopic findings and H. pylori IgG antibody: diagnostic methods

Helicobacter pylori (Hp) inhabits the stomach of > 50% of humans and has been established as a major etiological factor in the pathogenesis of chronic gastritis, gastric atrophy, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. The aim of this study was to provide unequivocal information about Hp-associated gastritis grading according to the Sydney grading system and to compare the histopathological features with the endoscopic findings and anti-Hp immunoglobulin (Ig)G serological status. This analytical study was conducted on 157 patients with dyspeptic gastritis. All patients underwent esophagogastroduodenoscopy, and antrum and corpus biopsies were taken. Blood samples were obtained from all participants. Different stains were performed on formalin-fixed, paraffin-embedded tissue blocks that included hematoxylin and eosin and Giemsa stain for histopathological interpretation. The endoscopic findings of gastritis were observed in 120 patients and most of them showed hyperemia (80 patients), whereas seven patients had normal appearing gastric mucosa. Histologically variable numbers of mononuclear inflammatory cellular infiltrates were seen in 150 cases (95.5%). Most of them showed Grade 1 gastritis (80 patients), whereas Grades 2 and 3 were found in 43 and 27 biopsies, respectively. Hp colonization was observed in most of the examined biopsies (93.7%). Hp-IgG seropositivity was found in 80.9% of cases and 19.1% were seronegative. The relationship between endoscopic and histological findings was significant (p < 0.001).

[Indicators of apoptosis in the gastric mucosa in patients with atrophic gastritis among the indigenous and nonindigenous dwellers of Evenkia]

AIM

To study the indicators of apoptosis in the gastric mucosa (GM) in relation to atrophy and the presence of CagA gene- containing Helicobacter pylori strains in the indigenous and nonindigenous dwellers of Evenkia.

SUBJECTS AND METHODS

Clinical and morphological examinations and fibrogastroscopy of GM were performed in 159 Caucasians and 136 Mongoloids (Evenks). The TUNEL assay was used to determine GM apoptosis in 24 Caucasians and 22 Evenks and the H. pylori strains containing the CagA gene were detected in all the 295 patients.

RESULTS

The extent of atrophic gastritis in the gastric antrum and body was higher in the Caucasians than in the Evenks. The total indicator of GM apoptosis in the gastric antrum was 5.19 ± 0.26% in the newcomers and 4.04 ± 0.28% in the aboriginals (p = 0.01). Apoptosis in both populations was associated with GM atrophy and the presence of H. pylori strains containing CagA gene.

CONCLUSION

There were ethnic differences in the extent of atrophic gastritis, which may be attributable to differences in the rate of GM apoptosis and the spread of H. pylori strains containing CagA gene in the indigenous and non-indigenous dwellers of Evenkia.

Differences in gastric mucosal microbiota profiling in patients with chronic gastritis, intestinal metaplasia, and gastric cancer using pyrosequencing methods

BACKGROUND

Helicobacter pylori (H. pylori) infection plays an important role in the early stage of cancer development. However, various bacteria that promote the synthesis of reactive oxygen and nitrogen species may be involved in the later stages. We aimed to determine the microbial composition of gastric mucosa from the patients with chronic gastritis, intestinal metaplasia, and gastric cancer using 454 GS FLX Titanium.

METHODS

Gastric mucosal biopsy samples were collected from 31 patients during endoscopy. After the extraction of genomic DNA, variable region V5 of the 16S rRNA gene was amplified. PCR products were sequenced using 454 high-throughput sequencer. The composition, diversity, and richness of microbial communities were compared between three groups.

RESULTS

The composition of H. pylori-containing Epsilonproteobacteria class appeared to be the most prevalent, but the relative increase in the Bacilli class in the gastric cancer group was noticed, resulting in a significant difference compared with the chronic gastritis group. By analyzing the Helicobacter-dominant group at a family level, the relative abundance of Helicobacteraceae family was significantly lower in the gastric cancer group compared with chronic gastritis and intestinal metaplasia groups, while the relative abundance of Streptococcaceae family significantly increased. In a UPGMA clustering of Helicobacter-dominant group based on UniFrac distance, the chronic gastritis group and gastric cancer group were clearly separated, while the intestinal metaplasia group was distributed in between the two groups. The evenness and diversity of gastric microbiota in the gastric cancer group was increased compared with other groups.

CONCLUSIONS

In Helicobacter predominant patients, the microbial compositions of gastric mucosa from gastric cancer patients are significantly different to chronic gastritis and intestinal metaplasia patients. These alterations of gastric microbial composition may play an important, as-yet-undetermined role in gastric carcinogenesis of Helicobacter predominant patients.

Association of genetic variants of membrane receptors related to recognition and induction of immune response with Helicobacter pylori infection in Ecuadorian individuals

Helicobacter pylori (Hp) has a worldwide distribution showing its higher prevalence of infection in developing countries. Toll-like receptors (TLRs) and C-type lectin receptors (CLRs) are proteins that recognize pathogen-associated molecular patterns (PAMPs) and initiate an innate immune response by promoting growth and differentiation of specialized hematopoietic cells for host defense. Gastric infections led by Hp induce a Th-1 cellular immune response, regulated mainly by the expression of IFN-γ. In this retrospective case-control study, we evaluated the TLR1 1805T/G, TLR2 2029C/T, TLR4 896A/G, CD209 -336A/G and IFNGR1 -56C/T polymorphisms and their relationship with susceptibility to Hp infection. TLR1 1805T/G showed statistical differences when the control (Hp-) and infected (Hp+) groups (P = 0.041*) were compared; the TLR1 1805G allele had a protective effect towards infection (OR = 0.1; 95% CI = 0.01-0.88, P = 0.033*). Similarly, the IFNGR1 -56C/T polymorphism showed statistical differences between Hp+ and Hp- (P = 0.018*), and the IFNGR1 -56TT genotype exhibited significant risk to Hp infection (OR = 2.9, 95% CI = 1.27-6.54, P = 0.018*). In conclusion, the pro-inflammatory TLR1 1805T and IFNGR1 -56T alleles are related with susceptibility to Hp infection in Ecuadorian individuals. The presence of these polymorphisms in individuals with chronic infection increases the risk of cellular damage and diminishes the cellular immune response efficiency towards colonizing agents.

DC-LAMP+ dendritic cells are recruited to gastric lymphoid follicles in Helicobacter pylori-infected individuals

Infection with Helicobacter pylori is associated with development of ulcer disease and gastrointestinal adenocarcinoma. The infection leads to a large infiltration of immune cells and the formation of organized lymphoid follicles in the human gastric mucosa. Still, the immune system fails to eradicate the bacteria, and the substantial regulatory T cell (Treg) response elicited is probably a major factor permitting bacterial persistence. Dendritic cells (DCs) are professional antigen-presenting cells that can activate naive T cells, and maturation of DCs is crucial for the initiation of primary immune responses. The aim of this study was to investigate the presence and localization of mature human DCs in H. pylori-infected gastric mucosa. Gastric antral biopsy specimens were collected from patients with H. pylori-associated gastritis and healthy volunteers, and antrum tissue was collected from patients undergoing gastric resection. Immunohistochemistry and flow cytometry showed that DCs expressing the maturation marker dendritic cell lysosome-associated membrane glycoprotein (DC-LAMP; CD208) are enriched in the H. pylori-infected gastric mucosa and that these DCs are specifically localized within or close to lymphoid follicles. Gastric DC-LAMP-positive (DC-LAMP(+)) DCs express CD11c and high levels of HLA-DR but little CD80, CD83, and CD86. Furthermore, immunofluorescence analyses demonstrated that DC-LAMP(+) DCs are in the same location as FoxP3-positive putative Tregs in the follicles. In conclusion, we show that DC-LAMP(+) DCs with low costimulatory capacity accumulate in the lymphoid follicles in human H. pylori-infected gastric tissue, and our results suggest that Treg-DC interactions may promote chronic infection by rendering gastric DCs tolerogenic.

Antibiotic treatment decreases microbial burden associated with pseudomyxoma peritonei and affects β-catenin distribution

PURPOSE

Pseudomyxoma peritonei is an understudied cancer in which an appendiceal neoplasm invades the peritoneum and forms tumor foci on abdominal organs. Previous studies have shown that bacteria reside within pseudomyxoma peritonei tumors and mucin. Thus, we sought to analyze the effect of antibiotics on bacterial density and β-catenin expression within pseudomyxoma peritonei samples.

EXPERIMENTAL DESIGN

The study included 48 patients: 19 with disseminated peritoneal adenomucinosis (DPAM) and 29 with peritoneal mucinous carcinomatosis (PMCA). Fourteen patients were given antibiotics (30 mg lansoprazole, 1 g amoxicillin, and 500 mg clarithromycin) twice a day for 14 days. One week after completion of therapy, surgery was conducted and specimens were harvested for pathology, bacterial culture, ISH, and immunohistochemistry.

RESULTS

ISH showed the presence of bacteria in 83% of the patient samples, with a higher Helicobacter pylori density observed in PMCA versus DPAM. PMCA patients treated with antibiotics had a significantly lower bacterial density and decreased β-catenin levels in the cytoplasm, the cell nuclei, and mucin-associated cells. Although not significant, similar trends were observed in DPAM patients. Cell membrane β-catenin was significantly increased in both DPAM and PMCA patients receiving antibiotics.

CONCLUSIONS

Bacteria play an important role in pseudomyxoma peritonei. Antibiotic treatment improved the histopathology of tissue, particularly in PMCA patients. In PMCA, antibiotics decreased bacterial density and were associated with a significant β-catenin decrease in the cytoplasm, cell nuclei, and mucin along with a small membrane increase. These results suggest that antibiotics offer potential protection against cell detachment, cellular invasion, and metastasis.

Caveolin-1 protects B6129 mice against Helicobacter pylori gastritis

Caveolin-1 (Cav1) is a scaffold protein and pathogen receptor in the mucosa of the gastrointestinal tract. Chronic infection of gastric epithelial cells by Helicobacter pylori (H. pylori) is a major risk factor for human gastric cancer (GC) where Cav1 is frequently down-regulated. However, the function of Cav1 in H. pylori infection and pathogenesis of GC remained unknown. We show here that Cav1-deficient mice, infected for 11 months with the CagA-delivery deficient H. pylori strain SS1, developed more severe gastritis and tissue damage, including loss of parietal cells and foveolar hyperplasia, and displayed lower colonisation of the gastric mucosa than wild-type B6129 littermates. Cav1-null mice showed enhanced infiltration of macrophages and B-cells and secretion of chemokines (RANTES) but had reduced levels of CD25⁺ regulatory T-cells. Cav1-deficient human GC cells (AGS), infected with the CagA-delivery proficient H. pylori strain G27, were more sensitive to CagA-related cytoskeletal stress morphologies (“humming bird”) compared to AGS cells stably transfected with Cav1 (AGS/Cav1). Infection of AGS/Cav1 cells triggered the recruitment of p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1) to Cav1 and counteracted CagA-induced cytoskeletal rearrangements. In human GC cell lines (MKN45, N87) and mouse stomach tissue, H. pylori down-regulated endogenous expression of Cav1 independently of CagA. Mechanistically, H. pylori activated sterol-responsive element-binding protein-1 (SREBP1) to repress transcription of the human Cav1 gene from sterol-responsive elements (SREs) in the proximal Cav1 promoter. These data suggested a protective role of Cav1 against H. pylori-induced inflammation and tissue damage. We propose that H. pylori exploits down-regulation of Cav1 to subvert the host's immune response and to promote signalling of its virulence factors in host cells.

Infection with the bacterium Helicobacter pylori (H. pylori) mainly affects children in the developing countries who are at risk to progress to gastric cancer (GC) as adults after many years of persistent infection, especially with strains which are positive for the oncogenic virulence factor CagA. Eradication of H. pylori by antibiotics is a treatment of choice but may also alter the susceptibility to allergies and other tumor types. Thus, novel diagnostic or prognostic markers are needed which detect early molecular changes in the stomach mucosa during the transition of chronic inflammation to cancer. In our study, we found that the tumor suppressor caveolin-1 (Cav1) is reduced upon infection with H. pylori, and CagA was sufficient but not necessary for this down-regulation. Loss of Cav1 was caused by H. pylori-dependent activation of sterol-responsive element-binding protein-1 (SREBP1), and this event abolished the interaction of Cav1 with p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1), a second bona fide tumor suppressor in gastric tissue. Conclusively, Cav1 and DLC1 may constitute novel molecular markers in the H. pylori-infected gastric mucosa before neoplastic transformation of the epithelium.

Nucleotide oligomerization domain 1 enhances IFN-γ signaling in gastric epithelial cells during Helicobacter pylori infection and exacerbates disease severity

Virulent Helicobacter pylori strains that specifically activate signaling in epithelial cells via the innate immune molecule, nucleotide oligomerization domain 1 (NOD1), are more frequently associated with IFN-γ-dependent inflammation and with severe clinical outcomes (i.e., gastric cancer and peptic ulceration). In cell culture models, we showed that H. pylori activation of the NOD1 pathway caused enhanced proinflammatory signaling in epithelial cells in response to IFN-γ stimulation through the direct effects of H. pylori on two components of the IFN-γ signaling pathway, STAT1 and IFN regulatory factor 1 (IRF1). Specifically, H. pylori activation of the NOD1 pathway was shown to increase the levels of STAT1-Tyr(701)/Ser(727) phosphorylation and IRF1 expression/synthesis in cells, resulting in enhanced production of the NOD1- and IFN-γ-regulated chemokines, IL-8- and IFN-γ-induced protein 10, respectively. Consistent with the notion that heightened proinflammatory signaling in epithelial cells may have an impact on disease severity, we observed significantly increased expression levels of NOD1, CXCL8, IRF1, and CXCL10 in human gastric biopsies displaying severe gastritis, when compared with those without gastritis (p < 0.05, p < 0.001, p < 0.01, and p < 0.05, respectively). Interestingly, NOD1, CXCL8, and IRF1 expression levels were also significantly upregulated in gastric tumor tissues, when compared with paired nontumor samples (p < 0.0001, p < 0.05, and p < 0.05, respectively). Thus, we propose that cross-talk between NOD1 and IFN-γ signaling pathways contribute to H. pylori-induced inflammatory responses, potentially revealing a novel mechanism whereby virulent H. pylori strains promote more severe disease.

Protease-activated receptor-2 (PAR2) in human gastric mucosa as mediator of proinflammatory effects in Helicobacter pylori infection

INTRODUCTION

Protease-activated receptors (PAR) are seven transmembrane receptors that are expressed throughout the gastrointestinal tract. In vitro experiments using gastric tumor cell lines, murine models and one clinical study provided evidence for a potential role of PAR2 in Helicobacter pylori-induced gastritis.

AIM

To investigate PAR2 expression in H. pylori-infected patients and correlation with proinflammatory IL-8, IL-1β as well as histologic changes of the mucosa. Furthermore, PAR2 expression was studied in context to mucosal amounts of secretory leukocyte protease inhibitor (SLPI), a putative regulator of PAR2.

METHODS

Twenty-two H. pylori-infected patients and 72 H. pylori-negative subjects underwent upper GI endoscopy. In antrum-derived mucosal biopsies, PAR2, IL-1β, IL-8, and SLPI expression was analyzed by quantitative RT-PCR, and in part by ELISA and immunohistochemistry. Histopathologic evaluation of gastritis was performed according to the updated Sydney classification.

RESULTS

IL-8 gene expression was 5-fold increased in the mucosa of H. pylori-infected patients compared with non-infected (p < .0001), whereas no differences for PAR2 and IL-1β mRNA amounts were observed between both groups. PAR2 gene expression correlated positively with transcript levels of IL-8, IL-1β as well mucosal SLPI levels in H. pylori-infected patients (r: 0.47-0.84; p < .0001), whereas no correlation was found with the degree of gastritis.

CONCLUSIONS

PAR2 represents an additive pathway of IL-8 secretion and proinflammatory effects in H. pylori-induced gastritis. Reduced SLPI levels leading to higher serine protease activities in the mucosa of infected subjects might regulate PAR2 activation.

Determination of strains of Helicobacter pylori and of polymorphism in the interleukin-8 gene in patients with stomach cancer

CONTEXT

Gastric neoplasia is the second most common cause of death by cancer in the world and H. pylori is classified as a type I human carcinogen by the World Health Organization. However, despite the high prevalence of infection by H. pylori around the world, less than 3% of individuals carrying the bacteria develop gastric neoplasias. Such a fact indicates that evolution towards malignancy may be associated with bacterial factors in the host and the environment.

OBJECTIVES

To investigate the association between polymorphism in the region promoting the IL-8 (-251) gene and the H. pylori genotype, based on the vacA alleles and the presence of the cagA gene, using clinical and histopathological data.

METHODS

In a prospective study, a total of 102 patients with stomach cancer and 103 healthy volunteers were analysed. Polymorphism in interleukin 8 (-251) was determined by the PCR-restriction fragment length polymorphism reaction and sequencing. PCR was used for genotyping the vacA alleles and the cagA in the bacterial strains PCR. Gastric biopsies were histologically assessed.

RESULTS

The H. pylori serology was positive for 101 (99%) of all patients analysed, and 98 (97%) of them were colonized by only one strain. In patients with monoinfection, 82 (84%) of the bacterial strains observed had the s1b/m1 genotype. The cagA gene was detected in 74 (73%) of patients infected by H. pylori. The presence of the cagA gene was demonstrated as associated with the presence of the s1b/m1 genotype of the vacA gene (P = 0.002). As for polymorphism in the interleukin 8 (-251) gene we observed that the AA (P = 0.026) and AT (P = 0.005) genotypes were most frequent in the group of patients with gastric adenocarcinoma. By comparing the different types of isolated bacterial strains with the interleukin -8 (-251) and the histopathological data we observed that carriers of the A allele (AT and AA) infected by virulent strains (m1s1 cagA+) demonstrated a greater risk of presenting a degree of inflammation (OR = 24.75 CI 95% 2.29-267.20 P = 0.004) and increased neutrophilic activity (OR = 28.71 CI 95% 2.62-314 P = 0.002) in the gastric mucosa.

CONCLUSION

Our results demonstrate that the interaction between polymorphism in the interleukin -8 (-251) gene, particularly with carriers of the A allele and the infecting type of H. pylori strain (s1m1 cagA positive) performs an important function in development of gastric adenocarcinoma.

Gastric phenotype in children with Helicobacter pylori infection undergoing upper endoscopy

INTRODUCTION

Helicobacter pylori is a definite risk factor for the development of gastric cancer, especially in the context of corpus-predominant gastritis. The infection is usually acquired in early childhood, implying lifelong exposure to this carcinogen if untreated. Our objective was to analyze the prevalence of H. pylori induced corpus-predominant gastritis in children.

MATERIAL AND METHODS

We analyzed the results of 265 esophagogastroduodenoscopies (EGD) in children performed between February 2006 and August 2008; 34 endoscopies were excluded (24 with follow-up investigations, 5 with incomplete data, 5 adults). H. pylori gastritis was defined by the presence of H. pylori in histology or by a positive rapid urease test. Grade of inflammation was rated according to the updated Sydney Scoring System. Gastritis was classified as corpus-predominant when the degree of chronic inflammation was higher in the corpus than in the antrum and vice versa for antrum-predominant gastritis.

RESULTS

Two hundred thirty-one patients (128 female; mean age ± SEM: 10.5 ± 3.5 years) were analyzed. Eighty-four (36%) were H. pylori positive, 147 (64%) patients were negative for H. pylori. In H. pylori positive patients, 39 (46%) patients had pangastritis (one patient with mucosal atrophy, which is regarded as precancerous lesion), 42 (50%) had antrum-predominant gastritis and 3 (4%) had corpus-predominant gastritis. One female patient (15.6 years old) with severe (grade 3) pangastritis had focal mucosal atrophy in both antrum and corpus, but no patient had intestinal metaplasia.

CONCLUSIONS

Corpus-predominant gastritis develops in H. pylori infected children, while mucosal atrophy and intestinal metaplasia develop later in the course of the infection.

Gastritis: the histology report

Gastritis is defined as inflammation of the gastric mucosa. In histological terms, it is distinguishable into two main categories, i.e. non-atrophic and atrophic. In the gastric mucosa, atrophy is defined as the loss of appropriate glands. There are several etiological types of gastritis, their different etiology being related to different clinical manifestations and pathological features. Atrophic gastritis (resulting mainly from long-standing Helicobacter pylori infection) is a major risk factor for the onset of (intestinal type) gastric cancer. The extent and site of the atrophic changes correlate significantly with the cancer risk. The current format for histology reporting in cases of gastritis fails to establish an immediate link between gastritis phenotype and risk of malignancy. Building on current knowledge of the biology of gastritis, an international group of pathologists [Operative Link for Gastritis Assessment (OLGA)] has proposed a system for reporting gastritis in terms of its stage (the OLGA Staging System): this system places the histological phenotypes of gastritis on a scale of progressively increasing gastric cancer risk, from the lowest (Stage 0) to the highest (Stage IV). The aim of this tutorial is to provide unequivocal information on how to standardize histology reports on gastritis in diagnostic practice.

The Sydney System for classification of gastritis 20 years ago

The roots of research into gastritis go back into the early decades of the 20th century. Modern aspects of its classification and knowledge of its biological course and consequences were relatively well known even at the time that Helicobcter pylori was discovered by Robin Warren and Barry Marshall in 1982. This discovery, however, significantly changed the field, establishing that the commonest form of gastritis is simply an infectious disease, a finding that raised enormous interest in the subject amongst gastroenterologists, microbiologists, pathologists and basic researchers. However, many of these "new" players in the field often had a limited knowledge of the morphological aspects of gastric inflammations and chronic gastritis. As a consequence in the late 1980's a Working Party was set up to review the biology and natural course of chronic gastritis, to propose a new classification for gastritis, and to provide simple guidelines for reporting the pathology of gastritis in endoscopic biopsies in an attempt to bring uniformity to the subject and facilitate comparative studies in what was to be an era of high research activity. These guidelines, The Sydney System: A New Classification of Gastritis was presented to the World Congress of Gastroenterology in Sydney in 1990, and was later published as six papers in the Journal of Gastroenterology and Hepatology. Now, twenty years on, this review looks back on the birth of Sydney System and why it is still important and successful.

Enhanced M1 macrophage polarization in human helicobacter pylori-associated atrophic gastritis and in vaccinated mice

Background

Infection with Helicobacter pylori triggers a chronic gastric inflammation that can progress to atrophy and gastric adenocarcinoma. Polarization of macrophages is a characteristic of both cancer and infection, and may promote progression or resolution of disease. However, the role of macrophages and their polarization during H. pylori infection has not been well defined.

Methodology/Principal Findings

By using a mouse model of infection and gastric biopsies from 29 individuals, we have analyzed macrophage recruitment and polarization during H. pylori infection by flow cytometry and real-time PCR. We found a sequential recruitment of neutrophils, eosinophils and macrophages to the gastric mucosa of infected mice. Gene expression analysis of stomach tissue and sorted macrophages revealed that gastric macrophages were polarized to M1 after H. pylori infection, and this process was substantially accelerated by prior vaccination. Human H. pylori infection was characterized by a mixed M1/M2 polarization of macrophages. However, in H. pylori-associated atrophic gastritis, the expression of inducible nitric oxide synthase was markedly increased compared to uncomplicated gastritis, indicative of an enhanced M1 macrophage polarization in this pre-malignant lesion.

Conclusions/Significance

These results show that vaccination of mice against H. pylori amplifies M1 polarization of gastric macrophages, and that a similar enhanced M1 polarization is present in human H. pylori-induced atrophic gastritis.

Helicobacter pylori in dental plaque and stomach of patients from Northern Brazil

AIM: To establish whether virulence factor genes vacA and cagA are present in Helicobacter pylori (H. pylori) retrieved from gastric mucosa and dental plaque in patients with dyspepsia.

METHODS: Cumulative dental plaque specimens and gastric biopsies were submitted to histological examination, rapid urease test and polymerase chain reaction (PCR) assays to detect the presence of cagA and vacA polymorphisms.

RESULTS: Detection of H. pylori from dental plaque and gastric biopsy samples was greater by PCR compared to histological examination and the rapid urease test. DNA from H. pylori was detected in 96% of gastric mucosa samples and in 72% of dental plaque samples. Sixty-three (89%) of 71 dental plaque samples that were H. pylori-positive also exhibited identical vacA and cagA genotypes in gastric mucosa. The most common genotype was vacAs1bm1 and cagA positive, either in dental plaque or gastric mucosa. These virulent H. pylori isolates were involved in the severity of clinical outcome.

CONCLUSION: These pathogenic strains were found simultaneously in dental plaque and gastric mucosa, which suggests that gastric infection is correlated with the presence of H. pylori in the mouth.

Diet synergistically affects helicobacter pylori-induced gastric carcinogenesis in nonhuman primates

BACKGROUND & AIMS

Gastric cancer results from a combination of Helicobacter pylori (H pylori) infection, exposure to dietary carcinogens, and predisposing genetic make-up. Because the role of these factors in gastric carcinogenesis cannot be determined readily in human beings, the present study examined the role of an oral carcinogen and H pylori infection in rhesus monkeys.

METHODS

Gastroscopies were performed in 23 monkeys assigned to 4 groups: controls; nitrosating carcinogen ethyl-nitro-nitrosoguanidine administration alone; inoculation of a virulent H pylori strain alone (H); and ethyl-nitro-nitrosoguanidine in combination with H pylori (EH). Follow-up gastroscopies and biopsies were performed at 3-month intervals for 5 years for pathologic and molecular studies.

RESULTS

Postinoculation, H and EH groups showed persistent infection and antral gastritis. Starting at 2 and 5 years, respectively, gastric intestinal metaplasia and intraepithelial neoplasia developed in 3 EH monkeys but in no other groups. Transcriptional analysis of biopsy specimens at 5 years revealed group-specific expression profiles, with striking changes in EH monkeys, plus a neoplasia-specific expression profile characterized by changes in multiple cancer-associated genes. Importantly, this neoplastic profile was evident in nonneoplastic mucosa, suggesting that the identified genes may represent markers preceding cancer.

CONCLUSIONS

Gastric intraglandular neoplasia is induced in primates when H pylori infection is associated with consumption of a carcinogen similar to the nitrosamines found in pickled vegetables, suggesting that H pylori and the carcinogen synergistically induce gastric neoplasia in primates.

Interleukin-1 and TNF-alpha polymorphisms and Helicobacter pylori in a Brazilian Amazon population

AIM

To study the association between Interleukin-1 (IL-1) and tumor necrosis factor (TNF)-alpha polymorphisms, infection by Helicobacter pylori (H pylori) and the development of gastrointestinal diseases.

METHODS

Genomic DNA was extracted from the peripheral blood of 177 patients with various gastrointestinal diseases and from 100 healthy volunteers. The polymorphisms in IL-1beta and TNF-alpha genes were analyzed using the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) and those from IL-1RN with PCR. The presence of infection due to H pylori and the presence of the CagA toxin were detected by serology. The histopathological parameters in the gastric biopsies of the patients were according to the Sydney classification.

RESULTS

A comparison of the frequencies of the different polymorphisms studied among the patients and the control group demonstrated that the allele IL-1RN*2 was more frequent among patients with gastric ulcers and adenocarcinoma. Carriers of the allele IL-RN*2 and those with reactive serology for anti-CagA IgG had a greater risk of developing peptic ulcer and gastric adenocarcinoma, as well as a higher degree of inflammation and neutrophilic activity in the gastric mucosa.

CONCLUSION

Our results indicate a positive association between IL-1RN gene polymorphism and infection by positive H pylori CagA strains and the development of gastric ulcers and adenocarcinoma.

Selective upregulation of endothelial E-selectin in response to Helicobacter pylori-induced gastritis

Helicobacter pylori is one of the most common bacterial pathogens, infecting up to 50% of the world's population. The host is not able to clear the infection, leading to life-long chronic inflammation with continuous infiltration of lymphocytes and granulocytes. The migration of leukocytes from the blood into inflamed tissue is dependent on adhesion molecules expressed on the vascular endothelium. The aim of this study was to characterize the effect of H. pylori-induced gastritis with regard to the expression of endothelial adhesion molecules in the gastric mucosa and compare this to other types of chronic mucosal inflammations. Our results demonstrate an increased level of expression of the adhesion molecule E-selectin, but not of intracellular adhesion molecule 1, vascular adhesion molecule 1, or vascular adhesion protein 1, in H. pylori-induced gastritis but not in gastritis induced by acetylsalicylic acid or pouchitis. The upregulated E-selectin expression was determined to be localized to the gastric mucosa rather than being a systemic response to the infection. Moreover, the H. pylori type IV secretion system encoded by the cag pathogenicity island (cagPAI) was found to be an important determinant for the upregulation of human endothelial E-selectin expression in vitro, and this process is probably dependent on the CagL protein, mediating binding to alpha5beta1 integrins. Thus, endothelial E-selectin expression induced by H. pylori probably contributes to the large influx of neutrophils and macrophages seen in infected individuals, and our results suggest that this process may be more pronounced in patients infected with cagPAI-positive H. pylori strains and may thereby contribute to tissue damage in these individuals.

Interleukin-1 and TNF-α polymorphisms and Helicobacter pylori in a Brazilian Amazon population

AIM: To study the association between Interleukin-1 (IL-1) and tumor necrosis factor (TNF)-α polymorphisms, infection by Helicobacter pylori (H pylori) and the development of gastrointestinal diseases.

METHODS: Genomic DNA was extracted from the peripheral blood of 177 patients with various gastrointestinal diseases and from 100 healthy volunteers. The polymorphisms in IL-1β and TNF-α genes were analyzed using the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) and those from IL-1RN with PCR. The presence of infection due to H pylori and the presence of the CagA toxin were detected by serology. The histopathological parameters in the gastric biopsies of the patients were according to the Sydney classification.

RESULTS: A comparison of the frequencies of the different polymorphisms studied among the patients and the control group demonstrated that the allele IL-1RN*2 was more frequent among patients with gastric ulcers and adenocarcinoma. Carriers of the allele IL-RN*2 and those with reactive serology for anti-CagA IgG had a greater risk of developing peptic ulcer and gastric adenocarcinoma, as well as a higher degree of inflammation and neutrophilic activity in the gastric mucosa.

CONCLUSION: Our results indicate a positive association between IL-1RN gene polymorphism and infection by positive H pylori CagA strains and the development of gastric ulcers and adenocarcinoma.

A randomized, open trial evaluating the effect of Saccharomyces boulardii on the eradication rate of Helicobacter pylori infection in children

AIM

The failure rate of Helicobacter pylori (H. pylori) eradication imposes the assessment of new options.

SUBJECTS AND METHODS

A prospective open study was performed in 90 symptomatic children (range 3-18 years) with H. pylori infection, randomized in two groups: control (42 patients) and intervention group (48 patients). Both groups were treated with the standard triple eradication therapy (omeprazole/esomeprazole, amoxicillin and clarithromycin) for 7-10 days. The intervention group was also treated with Saccharomyces boulardii (S. boulardii), 250 mg b.i.d., for 4 weeks. The eradication rate of H. pylori was assessed by the same methods (urease test and histology) 4-6 weeks after treatment. Adverse events and compliance were evaluated after 7 and 28 days of treatment. The Chi-square test was used for statistical evaluation (p < 0.05).

RESULTS

H. pylori infection was identified in 90 of 145 children (62%) and it correlated positively with age (p < 0.002) and inversely with socioeconomic status (p < 0.005). All infected children had chronic gastritis, with antral nodularity in 76.7%. Overall, H. pylori eradication rate was 87.7% (control 80.9%, S. boulardii group 93.3%) (p = 0.750). The incidence of side effects was reduced in the S. boulardii group: 30.9% in the control versus 8.3% in the probiotic group (p = 0.047).

CONCLUSION

The addition of S. boulardii to the standard eradication treatment confers a 12% nonsignificant enhanced therapeutic benefit on H. pylori eradication and reduces significantly the incidence of side effects.

OLGA staging for gastritis: a tutorial

Atrophic gastritis (resulting mainly from long-standing Helicobacter pylori infection) is a major risk factor for (intestinal-type) gastric cancer development and the extent/topography of the atrophic changes significantly correlates with the degree of cancer risk. The current format for histology reporting in cases of gastritis fails to establish an immediate link between gastritis phenotype and risk of malignancy. The histology report consequently does not give clinical practitioners and gastroenterologists an explicit message of use in orienting an individual patient's clinical management. Building on current knowledge of the biology of gastritis and incorporating experience gained worldwide by applying the Sydney System for more than 15 years, an international group of pathologists (Operative Link for Gastritis Assessment) has proposed a system for reporting gastritis in terms of stage (the OLGA staging system). Gastritis staging arranges the histological phenotypes of gastritis along a scale of progressively increasing gastric cancer risk, from the lowest (stage 0) to the highest (stage IV). This tutorial aims to provide unequivocal information on how to consistently apply the OLGA staging system in routine diagnostic histology practice.

CCL28 is increased in human Helicobacter pylori-induced gastritis and mediates recruitment of gastric immunoglobulin A-secreting cells

Human Helicobacter pylori infection gives rise to an active chronic gastritis and is a major risk factor for the development of duodenal ulcer disease and gastric adenocarcinoma. The infection is accompanied by a large accumulation of immunoglobulin A (IgA)-secreting cells in the gastric mucosa, and following mucosal immunization only H. pylori-infected volunteers mounted a B-cell response in the gastric mucosa. To identify the signals for recruitment of gastric IgA-secreting cells, we investigated the gastric production of CCL28 (mucosa-associated epithelial chemokine) and CCL25 (thymus-expressed chemokine) in H. pylori-infected and uninfected individuals and the potential of gastric B-cell populations to migrate toward these chemokines. Gastric tissue from H. pylori-infected individuals contained significantly more CCL28 protein and mRNA than that from uninfected individuals, while CCL25 levels remained unchanged. Chemokine-induced migration of gastric lamina propria lymphocytes isolated from patients undergoing gastric resection was then assessed using the Transwell system. IgA-secreting cells and IgA(+) memory B cells from H. pylori-infected tissues migrated toward CCL28 but not CCL25, while the corresponding cells from uninfected patients did not. Furthermore, IgG-secreting cells from H. pylori-infected patients did not migrate to CCL28 but instead to CXCL12 (SDF-1alpha). However, chemokine receptor expression did not correlate to the migratory pattern of the different B-cell populations. These studies are the first to show increased CCL28 production during gastrointestinal infection in humans and provide an explanation for the large influx of IgA-secreting cells to the gastric mucosa in H. pylori-infected individuals.

Leptin receptor signaling is required for vaccine-induced protection against Helicobacter pylori

BACKGROUND

A vaccine against Helicobacter pylori would be a desirable alternative to antibiotic therapy. Vaccination has been shown to be effective in animal models but the mechanism of protection is poorly understood. Previous studies investigating the gene expression in stomachs of vaccinated mice showed changes in adipokine expression correlated to a protective response. In this study, we investigate a well-characterized adipokine-leptin, and reveal an important role for leptin receptor signaling in vaccine-induced protection.

MATERIALS AND METHODS

Leptin receptor signaling-deficient (C57BL/Ks Lepr(db)), wild-type C57BL/Ks m littermates and C57BL/6 mice were vaccinated, and then challenged with H. pylori. Levels of bacterial colonization, antibody levels, and gastric infiltrates were compared. The local gene expression pattern in the stomach of leptin receptor signaling-deficient and wild-type mice was also compared using microarrays.

RESULTS

Interestingly, while vaccinated wild-type lean C57BL/6 and C57BL/Ks m mice were able to significantly reduce colonization compared to controls, vaccinated obese C57BL/Ks Lepr(db) were not. All mice responded to vaccination, i.e. developed infiltrates predominantly of T lymphocytes in the gastric mucosa, and made H. pylori-specific antibodies. A comparison of expression profiles in protected C57BL/6 and nonprotected C57BL/Ks Lepr(db) mice revealed a subset of inflammation-related genes that were more strongly expressed in nonprotected mice.

CONCLUSIONS

Our data suggest that functional leptin receptor signaling is required for mediating an effective protective response against H. pylori.

Chronic gastritis in former times and now

The roots of gastritis research stretch far back into the 19th century, and into early decades of the 20th century. Modern aspects in classification of gastritis and knowledge of the biologic course of chronic gastric inflammation, and of the links of chronic gastritis with many important gastric disorders were well known even at time of discovery of Helicobacter pylori in 1982. This discovery, however, significantly changed the field and raised the interest of gastroenterologists in gastritis. Chronic gastritis became a curable disease with known etiology and well-established links to main gastric diseases including gastric cancer. The personal view of the author into this history is presented. Some events and observations which were, in his opinion, noteworthy and important in the story of chronic gastritis have been emphasized.

Association between Helicobacter pylori concentration and the combining frequency of histopathological findings in gastric biopsies specimens

BACKGROUND: Helicobacter pylori is the most prevalent infectious agent worldwide. About 90% of patients with chronic gastritis are infected with this bacterium. Some studies have shown a association between the H. pylori concentration and the scores of gastritis activity and severity. AIM: To evaluate the association between H. pylori concentration and the combining frequency of findings on histopathological examination. METHODS: Two hundred consecutive gastric endoscopic biopsies diagnosed as chronic gastritis were retrospectively investigated. The Warthin-Starry silver stain was used to study H. pylori and the following parameters were assessed (according to the Sydney system): 1. infiltration by polymorphonuclear cells in chorio and epithelium (activity) graded as mild, moderate and marked; 2. presence of lymphoid follicles; 3. presence of intestinal metaplasia; 4. presence of regenerative cell atypias, graded as mild, moderate and marked; and 5. H. pylori concentration on the mucous covering the foveolar epithelium. RESULTS: The most frequent association was chronic gastritis and activity, regardless of H. pylori concentration. The association of five histopathological findings in the same biopsy has not occurred in the cases of higher concentration of H. pylori. CONCLUSION: Our study has not revealed any association between H. pylori concentration and an increasing in the number of histopathological findings found in the gastric mucosa. Since referring to its presence is much more important than to its concentration.

Low concentrations of zinc in gastric mucosa are associated with increased severity of Helicobacter pylori-induced inflammation

BACKGROUND

Chronic Helicobacter pylori infection is the most common cause of gastric cancer. H. pylori induces oxidative stress while zinc deficiency results in increased sensitivity to it. In Ecuador, the prevalence of gastric cancer and zinc deficiency are high. We hypothesized that zinc deficiency in Ecuadorian people would cause increased H. pylori-induced inflammation in the gastric mucosa associated with lower tissue zinc concentrations.

METHODS

Three hundred and fifty-two patients with dyspepsia underwent endoscopy to obtain gastric mucosa biopsies. Diagnosis of H. pylori infection and its severity, histopathology, mucosal zinc concentration, and inflammation intensity were determined.

RESULTS

H. pylori-infected patients with non-atrophic chronic gastritis had lower concentrations of zinc in gastric mucosa than uninfected patients with the same type of gastritis (251.3 +/- 225.3 vs. 426.2 +/- 279.9 ng/mg of protein; p = .016). Considering all patients, the more severe the H. pylori infection, the higher the percentage of subjects with infiltration by polymorphonuclear (PMN) cells (p = .0001). Patients with high PMN infiltration had lower mucosal zinc concentrations than patients with low PMN infiltration (35.2 +/- 20.7 vs. 242.9 +/- 191.8 ng/mg of protein; p = .021).

CONCLUSIONS

The degree of inflammation in H. pylori-induced gastritis appears to be modulated by gastric tissue zinc concentrations.

Sensitivity and specificity of various tests for the diagnosis of Helicobacter pylori in Egyptian children

OBJECTIVES

Many noninvasive methods (using breath, blood, and stool samples) are available to diagnose Helicobacter pylori. However, because the noninvasive tests are proxy measures of the infection, they need validation before use. Factors that may affect test validity include patient age, gender, and geographic location. Because no data were available on the validation of noninvasive tests for the diagnosis of H. pylori among children in the Middle East, this study was performed.

METHODS

Children between 2 and 17 years of age evaluated at the Cairo University School of Medicine pediatric gastroenterology clinic who were already scheduled for upper endoscopy were eligible for enrollment in the study. At the time of endoscopy, 3 biopsies were collected and used for rapid urease, histology, and culture, respectively. All children also donated a sample of stool and blood and had a urea breath test performed. Stool and serum samples were tested for the presence of H. pylori by using commercially available enzyme-linked immunosorbent assay-based technology. The sensitivity, specificity, and positive and negative predictive values were calculated for each noninvasive test used in the study. Receiver operating curves also were charted to determine optimal cut points for the various tests when used in the current study cohort.

RESULTS

One hundred eight children were enrolled in the study, with 52 children being under 6 years of age. The urea breath test and HpStar (DakoCytomation, Norden, Denmark) stool enzyme-linked immunosorbent assay kit had the highest sensitivity and specificity (sensitivity and specificity: 98 and 89 [urea breath test] and 94 and 81 [HpStar], respectively), whereas the serologic kit had an unacceptably low sensitivity (50%). The sensitivity of neither the urea breath test nor the HpStar tests was affected by subject age, but specificity of the HpStar test, although still high, was significantly lower among children under 6 years. Receiver operating curves found optimal cut points of the urea breath test at 6.2 delta over baseline and of the HpStar at 0.25 enzyme-linked immunosorbent assay units.

CONCLUSION

The urea breath test and HpSTAR stool antigen kit are reliable tests for the noninvasive diagnosis of H. pylori among children living in the Middle East.

Cholesterol glucosylation promotes immune evasion by Helicobacter pylori

Helicobacter pylori infection causes gastric pathology such as ulcer and carcinoma. Because H. pylori is auxotrophic for cholesterol, we have explored the assimilation of cholesterol by H. pylori in infection. Here we show that H. pylori follows a cholesterol gradient and extracts the lipid from plasma membranes of epithelial cells for subsequent glucosylation. Excessive cholesterol promotes phagocytosis of H. pylori by antigen-presenting cells, such as macrophages and dendritic cells, and enhances antigen-specific T cell responses. A cholesterol-rich diet during bacterial challenge leads to T cell-dependent reduction of the H. pylori burden in the stomach. Intrinsic alpha-glucosylation of cholesterol abrogates phagocytosis of H. pylori and subsequent T cell activation. We identify the gene hp0421 as encoding the enzyme cholesterol-alpha-glucosyltransferase responsible for cholesterol glucosylation. Generation of knockout mutants lacking hp0421 corroborates the importance of cholesteryl glucosides for escaping phagocytosis, T cell activation and bacterial clearance in vivo. Thus, we propose a mechanism regulating the host-pathogen interaction whereby glucosylation of a lipid tips the scales towards immune evasion or response.

Helicobacter pylori and infantile hypertrophic pyloric stenosis: is there a possible relationship?

BACKGROUND

Recently, it has been suggested that Helicobacter pylori might be a cause of some cases of infantile hypertrophic pyloric stenosis (IHPS) in infancy on the basis of its epidemiologic and clinical features. We performed this study to evaluate the possible relationship between IHPS and H. pylori.

DESIGN

In consecutive infants with IHPS, we performed upper gastrointestinal endoscopy with biopsy before pyloromyotomy. The endoscopic appearance of the pylorus was noted to validate endoscopic features of IHPS.

RESULTS

Sixteen infants, 15 male, 14 white, mean age 42 days, range 21 to 104 days, were studied. The index case had chronic active gastritis on biopsy with organisms suspicious for H. pylori. Four others had chronic active gastritis, six more had focal or mild chronic gastritis, five were normal, and none had H. pylori on histology or immune histochemical staining in selected cases. All patients had negative rapid urease test. Most common endoscopic findings of IHPS were thickened prominent asymmetric pyloric folds and pin-hole pylorus that could not be intubated by the pediatric endoscope.

CONCLUSION

H. pylori was not specifically identified in our patients with IHPS. The presence of H. pylori-like organisms in the gastric mucosa in our index case and finding of chronic active gastritis in several others may indicate the possibility of an acquired infectious etiology for IHPS.

Clinical and pathological importance of vacA allele heterogeneity and cagA status in peptic ulcer disease in patients from North Brazil

We have examined the prevalence of gene cagA and vacA alleles in 129 patients, 69 with gastritis and 60 with peptic ulcer diseases from North Brazil and their relation with histopathological data. vacA and cagA genotype were determined by polymerase chain reaction. Hematoxylin-eosin staining was used for histological diagnosis. 96.6% of the patients were colonized by Helicobacter pylori strains harboring single vacA genotype (nont-mixed infection). Among them, 11.8% had subtype s1a, 67.8% had subtype s1b, and 17% subtype s2. In regard to the middle region analysis, m1 alleles were found in 75.4% and m2 in 21.2% of patients. The cagA gene was detected in 78% patients infected with H. pylori and was associated with the s1-m1 vacA genotype. The H. pylori strains, vacA s1b m1/cagA-positive, were associated with increased risk of peptic ulcer disease and higher amounts of lymphocytic and neutrophilic infiltrates and the presence of intestinal metaplasia. These findings show that cagA and vacA genotyping may have clinical relevance in Brazil.

Helicobacter pylori adhesion to carbohydrates

Adherence of bacterial pathogens to host tissues contributes to colonization and virulence and typically involves specific interactions between bacterial proteins called adhesins and cognate oligosaccharide (glycan) or protein motifs in the host that are used as receptors. A given pathogen may have multiple adhesins, each specific for a different set of receptors and, potentially, with different roles in infection and disease. This chapter provides strategies for identifying and analyzing host glycan receptors and the bacterial adhesins that exploit them as receptors, with particular reference to adherence of the gastric pathogen Helicobacter pylori.