Association of Helicobacter pylori infection with atrophic gastritis and intestinal metaplasia

Prevalence of Gastric Precursor Lesions in Countries With Differential Gastric Cancer Burden: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The prevalence of precursor lesions for gastric cancer (GC) and the differential burden between countries of varying GC risk is not well-understood. We conducted a systematic review and meta-analysis to estimate the global prevalence of precursor lesions.

METHODS

We estimated the prevalence of atrophic gastritis (AG), gastric intestinal metaplasia (IM), and dysplasia in regions with low, medium, and high GC incidence. Because IM is an advanced manifestation of AG, we assessed the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. Prevalence was sub-stratified by Helicobacter pylori infection, symptomatology, and period (<2000, 2000-2010, and >2010).

RESULTS

Among the 582 articles that underwent full-text review, 166 studies met inclusion criteria. The global prevalence estimates of AG, IM, and dysplasia were 25.4%, 16.2%, and 2.0%, respectively, on the basis of 126 studies that reported the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. The prevalence of all precursor lesions was higher in high and medium compared with low GC incidence countries (P < .01). Prevalence of AG and IM was significantly higher among H pylori-infected individuals (P < .01) but not statistically different between symptomatic and asymptomatic individuals (P > .17). All precursors demonstrated a secular decrease in prevalence over time.

CONCLUSIONS

Gastric precursor lesions have differences in prevalence in regions with differential GC incidence and are associated with H pylori infection. Because of the substantial prevalence of precursor lesions in both symptomatic and asymptomatic individuals, symptomatic evaluation may not be sufficient to identify individuals at risk. These estimates provide important insights for tailoring GC prevention strategies.

Prevalence and factors associated with atrophic gastritis and intestinal metaplasia: A multivariate, hospital-based, statistical analysis

BACKGROUND

Atrophic gastritis (AG) and intestinal metaplasia (IM) play an essential role in gastric carcinogenesis. This study aimed to determine the prevalence of AG and IM and their associated factors.

METHODS

Subjects who underwent upper endoscopy at Chiang Mai University Hospital from January 2018 to Dec 2021 were included. All participants were interviewed using a structured questionnaire to collect their personal histories. In addition, clinical and histological data and associated factors of AG and IM were analyzed.

RESULTS

A total of 947 subjects (mean age, 53.61 ± 9.73 years; 60% male) were included. The prevalence of AG and IM, diagnosed by histopathology, was 39% and 19%. Prevalence of AG and IM increased from 28% and 9% in those under 50 years to 43% and 30% in those above 60 (p < 0.05). In a multivariate analysis, Helicobacter pylori (H. pylori) infection, age 50-59 and over 60 years were significantly associated with higher odds of AG (odds ratio (OR), 2.07, 2.06, and 1.98) and IM (OR, 2.07, 2.18, and 4.46), respectively. Conversely, ingestion of spicy food was significantly associated with lower odds of AG and IM (OR, 0.75, and 0.62).

CONCLUSIONS

This study confirms that age and H. pylori infection are risk factors, whereas spicy food intake is a protective factor against AG and IM, which are common in patients over 50. Therefore, upper endoscopy and gastric mapping sampling are recommended for patients with chronic dyspepsia older than 50 to reduce gastric cancer risk.

Involvement of Helicobacter pylori in Preoperative Gastric Findings on a Bariatric Population

The prevalence of Helicobacter pylori (Hp) in bariatric patients is common and related to gastric pathology. With preoperative upper gastrointestinal endoscopy (UGE), these pathologies and the presence of Hp are diagnosed. The histopathological study of the UGE biopsies is classified based on the Sydney System, a scoring system that stages chronic gastritis (CG) and precancerous gastric lesions. The objective is to assess the histological findings of gastric biopsies during routine UGE and to determine the involvement of Hp in gastric disorders in patients undergoing bariatric surgery. A multicenter retrospective review of prospectively collected databases was performed. The presence of CG, gastric atrophy (GA), and gastric intestinal metaplasia (GIM) in the study of the biopsies was assessed and correlated with Hp infection. The incidence of Hp among our bariatric population was 36.1%, and it increases with age. The percentage of patients with severe Hp infection is higher in patients with GA or GIM. The Hp eradication rate is also reduced when GA and GIM are present. A histological examination of all the biopsies did not show features of malignancy in any of the cases. Hp is not the only factor involved in the development of gastric pathology in bariatric patients.

Lifetime incidence risk for gastric cancer in the Helicobacter pylori-infected and uninfected population in Japan: A Monte Carlo simulation study

Helicobacter pylori (H. pylori) infection is considered the leading cause of gastric cancer. Gastric cancer is currently a common cancer with high incidence and mortality rates, but it is expected that the incidence rate will gradually decrease as the H. pylori infection prevalence decreases in the future. When evaluating the effectiveness of gastric cancer prevention strategies, it is essential to note the differences in long‐term cumulative risks between H. pylori‐infected and uninfected populations, but this has not yet been precisely evaluated. In our study, we aimed to estimate the cumulative incidence risks of developing gastric cancer from birth to 85 years among H. pylori‐infected and uninfected populations by using population‐based cancer registry data and birth year‐specific H. pylori infection prevalence rates. Death from gastric cancer and other causes of death were considered in the estimations of the adjusted cumulative incidence risks stratified by sex and H. pylori infection status. After performing 5000 Monte Carlo simulations with repeated random sampling using observed cancer incidence in selected three prefectures (Fukui, Nagasaki, Yamagata) of prefectural population‐based cancer registry in Japan, the mean adjusted cumulative incidence risk for gastric cancer in the H. pylori‐infected population was 17.0% for males and 7.7% for females and 1.0% for males and 0.5% for females in the uninfected population. These results calculated with Japanese cancer registry data may be useful in considering and evaluating future prevention strategies for gastric cancer in Japan.

What's new?

Helicobacter pylori infection is considered the leading cause of gastric cancer. This study estimated the cumulative incidence risk for gastric cancer from birth to 85 years of age, stratified by H. pylori infection status, for the first time in Japan. The cumulative risk among H. pylori‐infected individuals was 17.0% in males and 7.7% in females, after adjusting for gastric cancer incidence and other causes of death. The cumulative risk in the population without H. pylori infection was low. These results offer essential information for future cost‐effectiveness and cost‐benefit analyses and new gastric cancer prevention programs in Japan.

Endoscopic findings of Helicobacter pylori gastritis in children and young adults based on the Kyoto classification of gastritis and age-associated changes

Background and Aim

We aimed to evaluate endoscopic findings of Helicobacter pylori (H. pylori)-positive children and young adults based on the Kyoto classification, and to examine if there are age-associated changes in H. pylori-positive gastritis.

Methods

H. pylori-positive patients under 40 years old who underwent upper gastrointestinal endoscopy from 1 April 2009 to 15 February 2017 were included. Subjects were classified into the Pediatric (<20 years) and Young adult groups (20-39 years). The patients' endoscopic photographs were retrospectively re-evaluated based on the Kyoto classification. We compared endoscopic findings between the two groups and examined alterations in the findings of H. pylori-associated gastritis in 5-year age groups.

Results

Forty-three and 163 subjects were classified into the Pediatric and Young adult groups, respectively. In the Pediatric group, nodularity was seen in the majority (93.0%); other endoscopic findings in order of decreasing frequency included mucosal swelling (32.6%), spotty redness (25.6%), diffuse redness (18.6%), and atrophy (9.3%). In the Young adult group, endoscopic findings included atrophy (66.9%), mucosal swelling (49.7%), spotty redness (39.3%), nodularity (31.9%), and diffuse redness (30.3%). The difference in prevalence of nodularity or atrophy between the two groups reached statistical significance (P < 0.0001 each). The rate of nodularity decreased with increasing age in the Young adult group. The rate of atrophy was 33% in young adult patients aged 20-24, and the rate increased to >65% in patients over age 25.

Conclusion

H. pylori-positive children had endoscopic findings besides nodularity based on the Kyoto classification. The prevalence of atrophy increased in patients over age 20.

The relationship between gastric microbiota and gastric disease

Traditionally, the stomach was believed to be a sterile organ unsuitable for microbiota growth. However, the discovery of H. pylori subverted this conception. With the development of molecular techniques, an abundance of microbiota of great diversity was found in the stomach. In addition, various lines of evidence suggest that the gastric microbiota plays a critical role in the development and progression of the gastric disease.The gastrointestinal microbiome plays an important role in various physiologic and pathologic processes.

Accuracy of Endoscopic Diagnosis for Mild Atrophic Gastritis Infected with Helicobacter pylori

Background/Aims

This study examined the accuracy of endoscopic evaluation for determining the Helicobacter pylori infection status in patients with mild atrophy who might not exhibit characteristic endoscopic findings.

Methods

Forty endoscopists determined the H. pylori infection status of 50 randomly presented H. pylori-positive and H. pylori-negative cases on the basis of a list of established findings.

Results

The median clinical endoscopy experience was 7 years (range, 1–35 years), including 22 board-certified endoscopists (55%) of the Japan Gastroenterological Endoscopy Society. The mean accuracy rate of endoscopic diagnosis was 67% and was unrelated to experience status (experienced vs. trainee: 69% vs. 65%, p=0.089) and total years of experience (R² =0.022). The most frequently selected endoscopic findings were regular arrangement of collecting venules (59%), atrophy (45%), and red streak (22%), which had fair accuracy rates of 67%, 65%, and 73%, respectively. By contrast, the accuracy rates of nodularity (89%) and mucosal swelling (77%) were highest. The 20 endoscopists who more frequently identified these findings diagnosed H. pylori infection significantly more accurately than did the other endoscopists (71% vs. 64%, p=0.008).

Conclusions

Careful attention to nodularity and mucosal swelling in patients with mild atrophy may enhance diagnosis, enable prompt treatment, and avoid possible long-term carcinogenesis.

Histopathological Changes in Laparoscopic Sleeve Gastrectomy Specimens: Prevalence, Risk Factors, and Value of Routine Histopathologic Examination

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is a common surgical therapeutic option for obese patients, with debate about the value of routine histopathologic examination of LSG specimens. We assessed the following: prevalence of different histopathologic changes in LSG specimens, risk factors associated with premalignant and with frequent histopathologic changes, and whether routine histopathologic examination is warranted for LSG patients with nonsignificant clinical history.

METHODS

Retrospective review of records of all LSG patients operated upon at Hamad General Hospital, Qatar (February 2011-July 2014, n = 1555), was conducted. Risk factors (age, BMI, gender, and Helicobacter pylori) were assessed in relation to specific abnormal histopathologic changes.

RESULTS

Mean age and BMI of our sample were 35.5 years and 46.8, respectively. Females comprised 69.7% of the sample. Normal histopathologic specimens comprised 52% of the sample. The most common histopathologic changes were chronic inactive gastritis (33%), chronic active gastritis (6.8%), follicular gastritis (2.7%), and lymphoid aggregates (2.2%). We observed rare histopathology in 3.3% of the sample [e.g., intestinal metaplasia and gastrointestinal stromal tumor (GIST)]. Older age was associated with GIST and intestinal metaplasia (P = 0.001 for both). Females were associated with chronic active gastritis (P = 0.003). H. pylori infection was associated with follicular gastritis, lymphoid aggregates, GIST, intestinal metaplasia, and chronic active gastritis (P < 0.001 for each).

CONCLUSION

Older age, H. pylori, and female gender are risk factors for several abnormal histopathologic changes. Histopathologic examination of LSG specimens might harbor significant findings; however, routine histopathologic examination of all LSG specimens, particularly in the absence of suggestive clinical symptoms, is questionable. The association between female gender and chronic active gastritis; and the association between H. pylori infection and GIST are both novel findings that have not been previously reported in the published literature.

Tobacco smoking and intestinal metaplasia: Systematic review and meta-analysis

BACKGROUND

The evaluation of specific risk factors for early endpoints in the gastric carcinogenesis pathway may further contribute to the understanding of gastric cancer aetiology.

AIMS

To quantify the relation between smoking and intestinal metaplasia through systematic review and meta-analysis.

METHODS

Articles providing data on the association between smoking and intestinal metaplasia were identified in PubMed(®), Scopus(®) and Web of Science™, searched until April 2014, and through backward citation tracking. Summary odds ratio estimates and 95% confidence intervals were computed using the DerSimonian and Laird method. Heterogeneity was quantitatively assessed using the I(2) statistic.

RESULTS

A total of 32 articles were included in this systematic review and 19 provided data for meta-analysis. Smoking was defined as ever vs. never (crude estimates, six studies, summary odds ratio=1.54, 95% confidence interval: 1.12-2.12, I(2)=67.4%; adjusted estimates, seven studies, summary odds ratio=1.26, 95% confidence interval: 0.98-1.61, I(2)=65.0%) and current vs. non-smokers (crude estimates, seven studies, summary odds ratio=1.27, 95% confidence interval: 0.88-1.84, I(2)=73.4%; adjusted estimates, two studies, summary odds ratio 1.49, 95% confidence interval: 0.99-2.25, I(2)=0.0%).

CONCLUSION

The weak and non-statistically significant association found through meta-analysis of the available evidence does not confirm smoking as an independent risk factor for intestinal metaplasia.

Legionella pneumophila type IV effectors hijack the transcription and translation machinery of the host cell

Intracellular bacterial pathogens modulate the host response to persist and replicate inside a eukaryotic cell and cause disease. Legionella pneumophila, the causative agent of Legionnaires' disease, is present in freshwater environments and represents one of these pathogens. During coevolution with protozoan cells, L. pneumophila has acquired highly sophisticated and diverse strategies to hijack host cell processes. It secretes hundreds of effectors into the host cell, and these manipulate host signaling pathways and key cellular processes. Recently it has been shown that L. pneumophila is also able to alter the transcription and translation machinery of the host and to exploit epigenetic mechanisms in the cells it resides in to counteract host responses.

OLGA and OLGIM stage distribution according to age and Helicobacter pylori status in the Korean population

BACKGROUND

The Operative Link for Gastritis Assessment (OLGA) and the Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) staging systems have been suggested to provide risk assessment for gastric cancer. This study aimed to evaluate the distribution of OLGA and OLGIM staging by age and Helicobacter pylori status.

MATERIALS AND METHODS

We studied 632 subjects who underwent esophagogastroduodenoscopy for gastric cancer screening. Helicobacter pylori status and histologic changes were assessed using the updated Sydney system. Stage III and IV OLGA or OLGIM stages were considered as high-risk stages.

RESULTS

The rate of H. pylori infection was 59.0% (373/632). Overall, the proportion of high OLGA and OLGIM stages was significantly increased with older age (p < .001 for both). Old age (OR = 5.17, 6.97, and 12.23 for ages in the 40's, 50's, and 60's, respectively), smoking (OR = 2.54), and H. pylori infection (OR = 8.46) were independent risk factors for high-risk OLGA stages. These risk factors were the same for high-risk OLGIM stages. In the H. pylori-positive subgroup, the proportion of high-risk OLGA stages was low (6.9%) before the age of 40, but increased to 23.0%, 29.1%, and 41.1% for those in their 40s, 50s, and 60s, respectively (p < .001). High-risk OLGIM stages showed a similar trend of 2.8% before the age of 40 and up to 30.1% for those in their 60s. High-risk OLGA and OLGIM stages were uncommon in the H. pylori-negative group, with a respective prevalence of 10.3% and 3.4% even among those in their 60s.

CONCLUSIONS

Because high-risk OLGA and OLGIM stages are uncommon under the age of 40, H. pylori treatment before that age may reduce the need for endoscopic surveillance for gastric cancer.

Helicobacter pylori infection affects mitochondrial function and DNA repair, thus, mediating genetic instability in gastric cells

Helicobacter pylori infection is an important factor for the development of atrophic gastritis and gastric carcinogenesis. However, the mechanisms explaining the effects of H. pylori infection are not fully elucidated. H. pylori infection is known to induce genetic instability in both nuclear and mitochondrial DNA of gastric epithelial cells. The mutagenic effect of H. pylori infection on nuclear DNA is known to be a consequence, in part, of a down-regulation of expression and activity of major DNA repair pathways. In this study, we demonstrate that H. pylori infection of gastric adenocarcinoma cells causes mtDNA mutations and a decrease of mtDNA content. Consequently, we show a decrease of respiration coupled ATP turnover and respiratory capacity and accordingly a lower level and activity of complex I of the electron transport chain. We wanted to investigate if the increased mutational load in the mitochondrial genome was caused by down-regulation of mitochondrial DNA repair pathways. We lowered the expression of APE-1 and YB-1, which are believed to be involved in mitochondrial base excision repair and mismatch repair. Our results suggest that both APE-1 and YB-1 are involved in mtDNA repair during H. pylori infection, furthermore, the results demonstrate that multiple DNA repair activities are involved in protecting mtDNA during infection.

Helicobacter pylori infection in clinical practice: probiotics and a combination of probiotics + lactoferrin improve compliance, but not eradication, in sequential therapy

BACKGROUND

Sequential therapy (ST) seems to offer higher success rates than triple therapy (TT) in the eradication of Helicobacter pylori (H. pylori) infection. However, from the standpoint of therapeutic compliance, there is no difference between the two treatments. Adjuvant treatment (especially with probiotics (PB) and lactoferrin (LF)) has often improved compliance and eradication rates in patients subjected to TT, while ST had never been used in association with adjuvants.

METHODS

Over a period of 2 years, we randomized and divided 227 consecutive adult patients with H. pylori infection into three groups. The patients were given ST with the addition of adjuvants, as follows: group A (ST + placebo), group B (ST + LF + PB), and group C (ST + PB). Our goal was to assess therapeutic compliance, so we prepared a questionnaire to help determine the severity of the side effects. We also determined the eradication rates for the groups.

RESULTS

Patients with ST + placebo had the worst compliance as compared with the other two groups in terms of the absence of symptoms (p < .001 between B and A; p = .001 between C and A) and the presence of intolerable symptoms (p = .016 between B and A; p = .046 between C and A). The differences between the values for the treated groups and those for the placebo group were statistically significant. On the other hand, there was no statistically significant difference in compliance between groups B and C. The eradication rate was similar for the three groups.

CONCLUSIONS

Probiotics associated with ST provide optimum therapeutic compliance compared with the placebo and, despite the need to take a larger number of tablets, they should be taken into consideration as an adjuvant to therapy for H. pylori infection. The addition of LF to the PB did not bring about any further improvements in compliance. As compared with the placebo, the eradication rate of ST did not improve by adding LF + PB or by using PB alone.

A novel model might predict the risk of chronic atrophic gastritis: a multicenter prospective study in China

OBJECTIVE

To find a new way to predict the risk of chronic atrophic gastritis (CAG).

MATERIAL AND METHODS

All the participants received endoscopy and histological examination as well as a standard questionnaire. Multivariate analysis was performed by logistic regression to build the CAG risk model. The accuracy was evaluated by 1418 subjects recruited from six medical centers. 63 subjects received another endoscopy after 1-year follow-up and divided into three groups according to the comparison of the histological results (improved, no change and worse).

RESULTS

The model showed relatively good discrimination, with an AUROC of 0.888 (95% CI 0.852-0.925). A final probability cut-off score of 0.73 was used to predict the presence (>0.73) or absence of CAG (≤0.73). Sensitivity, specificity, PPV and NPV were 82.8%, 74.7%, 91.8% and 56%, respectively. The predicted results of 1418 subjects compared with the histological results were quite similar. There was a significant difference of the scores between three groups who were followed-up for 1 year (F = 3.248, p = 0.046). In multiple comparisons, a significant difference existed between Group A (the histological results had improved after 1-year follow-up) and Group C (the results were worse) (p = 0.019).

CONCLUSIONS

This is the first demonstration of the use of a mathematical model for CAG risk screening. Endoscopy should be recommended to those who are positive according to the model, to detect CAG early and conserve medical resources. In those who have a high-risk score, closer follow-up is needed.

Gastric cancer risk according to the distribution of intestinal metaplasia and neutrophil infiltration

BACKGROUND AND AIM

Gastritis and intestinal metaplasia (IM) have long been known to be risk factors for and precursors of gastric cancer. We aimed to elucidate the association between gastric cancer risk and the distribution of precancerous lesions in the stomach by histological analyses.

METHODS

We analyzed patients from whom two biopsy specimens (one from the antrum and one from the corpus) were obtained by upper gastrointestinal endoscopy. Specimens were assessed for Helicobacter pylori, IM, and neutrophil infiltration (NI). Patients were classified into three groups based on the presence of IM. Patients were also classified into four groups based on the presence of NI. The prevalence of gastric cancer was compared between groups.

RESULTS

A total of 1395 patients were analyzed. Of these, 54 had gastric cancer (34 intestinal and 20 diffuse type). A multivariate analysis showed that male sex and the distribution of IM were independent risk factors for intestinal-type cancer. Compared with patients without IM (n = 1005), the odds ratio (OR) for patients with IM in the antrum only (n = 240) was 2.34 (95% confidence interval: 1.08-4.96), and that for patients with IM in the corpus (n = 150) was 5.84 (2.92-11.8). However, NI was related to diffuse-type cancer. Compared with patients without NI (n = 899), the OR for patients with NI in the corpus only (n = 122) was 3.66 (1.02-12.2).

CONCLUSIONS

The histological pattern and distribution of gastric mucosal change assessed by two biopsy specimens were related to gastric cancer.

Analysis of DNA copy number aberrations by multiple ligation-dependent probe amplification on 50 intestinal type gastric cancers

BACKGROUND AND OBJECTIVES

The molecular genetic alterations leading to gastric malignancy are largely unknown. This study aimed to unravel the genomic DNA copy number aberrations (CNAs) profile during gastric tumorigenesis.

METHODS

In this study, we performed genomic profiling in a set of 50 intestinal type gastric carcinomas by a PCR-based relative quantification method, multiple ligation-dependent probe amplification (MLPA) with 112 cancer-related gene loci selected throughout each human chromosome as probes of MLPA assay.

RESULTS

Numerous chromosomal DNA CNAs, including gains of 3p22, 4q25, 8q24, 11p13, and 20q13, and losses of 1p36 and 9p21, were identified by MLPA assay as recurrent DNA CNAs in gastric cancer. Moreover, we found the median numbers of gains, losses, and total CNAs were significantly higher in lymph node metastasis positive patients than in cases without metastasis. And gain of 11p13 and losses of 9p21.3, 11q13.3, 17q25.3, and 22q11.23 were associated with lymph node metastasis (P < 0.05). Finally, two major groups, including G1 + 2 with a large number of CNAs and G3 + 4 with a small number of CNAs, can be successfully distinguished by hierarchical cluster analysis.

CONCLUSIONS

Our results proved MLPA is a reliable and efficient method to evaluate DNA copy number changes in gastric cancers.

Epigenetic reprogramming of host genes in viral and microbial pathogenesis

One of the key questions in the study of mammalian gene regulation is how epigenetic methylation patterns on histones and DNA are initiated and established. These stable, heritable, covalent modifications are largely associated with the repression or silencing of gene transcription, and when deregulated can be involved in the development of human diseases such as cancer. This article reviews examples of viruses and bacteria known or thought to induce epigenetic changes in host cells, and how this might contribute to disease. The heritable nature of these processes in gene regulation suggests that they could play important roles in chronic diseases associated with microbial persistence; they might also explain so-called ‘hit-and-run’ phenomena in infectious disease pathogenesis.

Alcohol consumption and chronic atrophic gastritis: population-based study among 9,444 older adults from Germany

Moderate alcohol consumption has been suggested to facilitate elimination of Helicobacter pylori infection which is a key risk factor for chronic atrophic gastritis (CAG) and gastric cancer. The aim of our study was to assess the association of alcohol consumption with CAG among older adults from Germany. In the baseline examination of ESTHER, a population-based study conducted in Saarland, serological measurements of pepsinogen I and II (for CAG definition) and H. pylori antibodies were taken in 9,444 subjects aged 50-74 years. Moderate current (<60 g/week) and lifetime (<or=51,376 g, lowest quartile) alcohol consumption were found to be associated with significantly reduced CAG risk compared to alcohol abstinence with adjusted odds ratios of 0.71 (0.55-0.90) and 0.73 (0.55-0.96), respectively. Inverse associations with CAG were observed for moderate alcohol consumption from both beer and wine, and were slightly attenuated after additional adjustment for H. pylori infection. Our results are consistent with the hypothesis that moderate alcohol consumption may be inversely related to CAG, partly through facilitating the elimination of H. pylori. However, the observed patterns suggest that other mechanisms are likely to contribute to the association as well.

Polymorphism in COX-2 modifies the inverse association between Helicobacter pylori seropositivity and esophageal squamous cell carcinoma risk in Taiwan: a case control study

Background

Overexpression of Cyclooxygenase-2 (COX-2) was observed in many types of cancers, including esophageal squamous cell carcinoma (ESCC). One functional SNP, COX-2 -1195G/A, has been reported to mediate susceptibility of ESCC in Chinese populations. In our previous study, the presence of Helicobacter pylori (H. pylori) was found to play a protective role in development of ESCC. The interaction of COX-2 and H. pylori in gastric cancer was well investigated. However, literature on their interaction in ESCC risk is scarce. The purpose of this study was to evaluate the association and interaction between COX-2 single nucleotide polymorphism (SNP), H. pylori infection and the risk of developing ESCC.

Methods

One hundred and eighty patients with ESCC and 194 controls were enrolled in this study. Personal data regarding related risk factors, including alcohol consumption, smoking habits and betel quid chewing, were collected via questionnaire. Genotypes of the COX-2 -1195 polymorphism were determined by PCR-based restriction fragment length polymorphism. H. pylori seropositivity was defined by immunochromatographic screening test. Data was analyzed by chi-squared tests and polytomous logistics regression.

Results

In analysis adjusting for the covariates and confounders, H. pylori seropositivity was found to be inversely association with the ESCC development (adjusted OR: 0.5, 95% CI: 0.3 – 0.9). COX-2 -1195 AA homozygous was associated with an increased risk of contracting ESCC in comparison with the non-AA group, especially among patients with H. pylori seronegative (adjusted OR ratio: 2.9, 95% CI: 1.2 – 7.3). The effect was strengthened among patients with lower third ESCC (adjusted OR ratio: 6.9, 95% CI 2.1 – 22.5). Besides, H. pylori seropositivity conveyed a notably inverse effect among patients with COX-2 AA polymorphism (AOR ratio: 0.3, 95% CI: 0.1 – 0.9), and the effect was observed to be enhanced for the lower third ESCC patients (AOR ratio: 0.09, 95% CI: 0.02 – 0.47, p for multiplicative interaction 0.008)

Conclusion

H. pylori seropositivity is inversely associated with the risk of ESCC in Taiwan, and COX-2 -1195 polymorphism plays a role in modifying the influence between H. pylori and ESCC, especially in lower third esophagus.

Effect of smoking on gastric histology in Helicobacter pylori-positive gastritis

OBJECTIVE

Smoking and Helicobacter pylori are both deleterious to the gastric and duodenal mucosa. Smoking also seems to modify inflammation in H. pylori infection. The aim of this study was to investigate the relationship between smoking and H. pylori in the Finnish population.

MATERIAL AND METHODS

We analysed the effect of smoking on gastric inflammation, humoral response to H. pylori and peptic ulcer disease among 318 Finnish H. pylori-positive patients (age 18-75 years; 73 smokers). Gastric histology was evaluated according to the updated Sydney system.

RESULTS

Smoking affected neither antral inflammation nor atrophy. In the gastric body, smokers showed milder chronic and neutrophilic inflammation and less atrophy (4% versus 17%, p=0.004). In smokers, H. pylori infiltration was denser in the atrium (mean 2.14 versus 1.87, p=0.02) but less dense in the body (mean 1.55 versus 1.84, p=0.003). Smoking thus seems to decrease inflammation in the gastric body and to delay atrophic changes in the gastric body. Subsequently, the prevalence of duodenal ulcers increased (32% versus 11%, p<0.001), but not the prevalence of gastric ulcers. Smoking also reduced serum IgG antibody titres against H. pylori (mean 8535 versus 5587, p=0.002) and their percentage decrease after successful eradication, possibly affecting serological diagnostic efficacy. Smokers were younger than non-smokers, but when age was taken into account, the differences remained the same.

CONCLUSIONS

In H. pylori-positive gastritis, smoking reduced inflammation and atrophy in the gastric body as well as humoral response to H. pylori.

Prevalence of Helicobacter pylori seropositivity among patients undergoing bariatric surgery: a preliminary study

BACKGROUND

The objective of this study was to compare the prevalence of Helicobacter pylori (HP) seropositivity in patients undergoing bariatric surgery with that of the general population.

METHODS

H. pylori serologies, tested by ELISA, were collected on 240 morbidly obese patients seen at the Cleveland Clinic Florida and on 2444 randomly selected patients seen at the Cleveland Clinic Health System from 2003-2005.

RESULTS

H. pylori prevalence was 61.3% in the bariatric surgery group versus 48.2% in the general population control group (p < 0.001). Bariatric patients had a 1.7-fold increased likelihood of having HP when compared with controls (95% CI = 1.3-2.2). Age over 35 years was an independent risk factor for HP seropositivity (p < 0.01) in both the bariatric and control groups. There was no association found between body mass index and seropositivity within the bariatric group. There was no significant association between seropositivity and gender (p = 0.776). However, there was a significant association between seropositivity and race (p < 0.01). African-Americans had four times more (OR = 4.05) probability of having HP seropositivity than Caucasians (p < 0.01). Hispanics had almost three times (OR = 2.6) more probability of having HP seropositivity than Caucasians (p < 0.01).

CONCLUSION

The prevalence of HP seropositivity among bariatric patients is significantly higher than the general population control group.

Helicobacter pylori infection: a clinical overview

BACKGROUND

Helicobcater pylori colonizes the stomach of more than half of the world's population, and the infection continues to play a key role in the pathogenesis of a number of gastroduodenal diseases. Colonization of the gastric mucosa with Helicobcater pylori results in the development of chronic gastritis in all infected individuals and in a subset of patients chronic gastritis progresses to complications (i.e. ulcer disease, gastric neoplasias, some distinct extragastric disorders). The clinical outcome of the disease is dependent on many variables, including Helicobcater pylori genotype, innate host physiology, genetic predisposition and environmental factors. Helicobcater pylori eradication decreases the incidence of gastroduodenal ulcer and prevents its recurrence. Helicobcater pylori eradication for gastric cancer prevention has been suggested by preclinical research and clinical trials, showing even reversibility of precancerous lesions (atrophic gastritis and intestinal metaplasia) after Helicobcater pylori eradication.

AIMS

To review the current literature about H. pylori and its related pathologies.

CONCLUSION

At present, several clinical manifestations are recognized to be causally linked to Helicobcater pylori infection, and most of them can be cured by Helicobcater pylori eradication. Besides the relationship of Helicobcater pylori and gastroduodenal diseases, it has been well established that Helicobcater pylori infection is also involved in some extragastrointestinal diseases.

Association of Helicobacter pylori infection with chronic atrophic gastritis: Meta-analyses according to type of disease definition

Helicobacter pylori is a major risk factor for chronic atrophic gastritis (CAG). A large variety of definitions of CAG have been used in epidemiologic studies in the past. The aim of this work was to systematically review and summarize estimates of the association between H. pylori infection and CAG according to the various definitions of CAG. Articles on the association between H. pylori infection and CAG published until July 2007 were identified. Separate meta-analyses were carried out for studies defining CAG based on gastroscopy with biopsy, serum pepsinogen I (PG I) only, the pepsinogen I/pepsinogen II ratio (PG I/PG II ratio) only, or a combination of PG I and the PG I/PG II ratio. Numbers of identified studies and summary odds ratios (OR) (95% confidence intervals) were as follows: gastroscopy with biopsy: n = 34, OR = 6.4 (4.0-10.1); PG I only: n = 13, OR = 0.9 (0.7-1.2); PG I/PG II ratio: n = 8, OR = 7.2 (3.1-16.8); combination of PG I and the PG I/PG II ratio: n = 20, OR = 5.7 (4.4-7.5). Studies with CAG definitions based on gastroscopy with biopsy or the PG I/PG II ratio (alone or in combination with PG I) yield similarly strong associations of H. pylori with CAG. The association is missed entirely in studies where CAG is defined by PG I only.

Correlation of Helicobacter pylori virulence genotypes vacA and cagA with histological parameters of gastritis and patient's age

The histological parameters of Helicobacter pylori (H. pylori) gastritis are dependent on the virulence factor profile of the microbe, which includes the cytotoxins vacA (vacuolating cytotoxin A) and cagA (cytotoxin-associated gene A) as well as the duration of infection. The virulence factor genotypes vacA and cagA were assessed by the line probe reverse hybridization assay INNO-LiPA and correlated with the histological parameters of H. pylori infection, in particular intestinal metaplasia (IM) as well as with the patient's age. A total of 120 patients were analyzed; 47 patients with IM in the antrum and 73 control patients without this alteration. The vacA s1 cagA+ genotype (high virulence) correlated with the presence of antral IM, a more intense acute inflammation in both antrum and corpus and the formation of ulcer. The vacA m1 genotype (high virulence) correlated with a more intense acute inflammation in only the corpus as well as more prominent Russell bodies in the antrum. H. pylori strains with the vacA s2 m2 cagA- genotype (low virulence) were rarely found in these conditions (all P <0.05). No correlation with the virulence status was found for the type and extent of IM, the intensity of chronic inflammation, the formation of lymphoid follicles and the microbial density. Furthermore, patients with IM were 7 years older than their counterparts without (P<0.05). Finally, there was a trend for more virulent vacA s1 m1 cagA+ strains to be found in younger individuals (P>0.05). The virulence genotype of the microbe is an important determinant for the severity of the gastritis and the formation of antral IM. Age is an additional factor for the development of IM.

Protective effects of heat shock protein70 induced by geranylgeranylacetone in atrophic gastritis in rats

AIM

To investigate the effect of geranylgeranylacetone (GGA) on the progression of atrophic gastritis in rats and its potential mechanism.

METHODS

Atrophic gastritis was induced in Sprague-Dawley rats with 0.1% ammonia solution, 60% ethanol, and 20 mmol/L deoxycholic acid for 24 weeks. Accompanied by the induction of atrophic gastritis, 200 mg/kg GGA was administered by oral gavage for 8 weeks (weeks 17-24). The histological changes in gastric mucosa were quantitated by the index of inflammation, the gastric mucosal thickness, and the amount of glands of 1 mm horizontal length in antrum. Endogenous heat shock protein (HSP)70 levels and distribution were determined by immunoblotting and immunohistochemistry in gastric mucosa.

RESULTS

GGA alleviated the pathological progression of atrophic gastritis with inflammation relief (inflammation index: 1.40 in the GGA group and 1.65 in the atrophic gastritis group) and glandular restoration (mucosal thickness and quantity of glands: 194.3 microm and 38.7 mm in the GGA group; 123.3 microm and 32.7 mm in the atrophic gastritis group; P<0.05). GGA significantly induced HSP70 synthesis (P<0.05). Moreover, quercetin, an inhibitor of HSP70 expression, aggravated the infiltration of inflammatory cells and glandular loss in the antrum.

CONCLUSION

GGA prevented the progression of atrophic gastritis in rats via the induction of HSP70 expression.

Comparison of prevalence of chronic atrophic gastritis in Japan, China, Tanzania, and the Dominican Republic

PURPOSE

To compare the prevalence of chronic atrophic gastritis (CAG) in Japan, China, Tanzania, and the Dominican Republic and to assess the usefulness of Helicobacter pylori infection and serum gastrin level as markers of CAG.

METHODS

The subjects were volunteers from local communities in Japan (n=859), China (n=1741), Tanzania (n=573), and the Dominican Republic (n=1215). Each individual underwent a health checkup and blood sampling for measurement of serum pepsinogen I and II, pepsinogen I /II ratio, serum gastrin, and H. pylori antibodies, and responded to a questionnaire on upper digestive tract diseases.

RESULTS

The prevalences of H. pylori infection (23.5-96.1%), CAG (5.6-60.4%), and serum gastrin (62.0-136.5 pg/ml) varied by age, sex, and country. Serum gastrin level for men differed in each country according to age. In Tanzanian men, the median gastrin level (101.0 pg/ml) was the highest in the 40 to 49 years age group (p < 0.01) while there was no significant difference among different age groups in Tanzanian women. Serum gastrin level in subjects > or = 70 years was higher than in other age groups in both sexes in the Dominican Republic (males, 92.5, females, 136.5 pg/ml). The prevalence of H. pylori infection increased (p < 0.01) with advancing age in Japan (only for women) and the Dominican Republic but was high in all age groups of both sexes in China and Tanzania. The prevalence of CAG increased (p < 0.01) with age in both sexes in Japan, China (women only), and the Dominican Republic, but not in Tanzania. The odds ratio of CAG in H. pylori infected subjects was 5.3 times that in H. pylori-negative subjects. The odds ratio of CAG increased by 0.6%/1 pg/ml increase in serum gastrin.

CONCLUSIONS

Our results indicated that H. pylori infection, serum gastrin, and advancing age are good markers of CAG and that the prevalence of CAG is the highest in Japan.

Association between cag-pathogenicity island in Helicobacter pylori isolates from peptic ulcer, gastric carcinoma, and non-ulcer dyspepsia subjects with histological changes

AIM

To investigate the presence of the cag-pathogenicity island and the associated histological damage caused by strains with complete cag-PAI and with partial deletions in correlation to the disease status.

METHODS

We analyzed the complete cag-PAI of 174 representative Helicobacter pylori (H pylori ) clinical isolates obtained from patients with duodenal ulcer, gastric ulcer, gastric cancer, and non-ulcer dyspepsia using eight different oligonucleotide primers viz cagA1, cagA2, cagAP1, cagAP2, cagE, cagT, LEC-1, LEC-2 spanning five different loci of the whole cag-PAI by polymerase chain reaction (PCR).

RESULTS

The complete screening of the genes comprising the cag-PAI showed that larger proportions of subjects with gastric ulcer (97.8%) inhabited strains with complete cag-PAI, followed by gastric cancer (85.7%), non-ulcer dyspepsia (7.1%), and duodenal ulcer (6.9%), significant differences were found in the percentage distribution of the genes in all the clinical groups studied. It was found that strains with complete cag-PAI were able to cause severe histological damage than with the partially deleted ones.

CONCLUSION

The cag-PAI is a strong virulent marker in the disease pathogenesis as it is shown that a large number of those infected with strain with complete cag-PAI had one or the other of the irreversible gastric pathologies and interestingly 18.5% of them developed gastric carcinoma. The presence of an intact cag-PAI correlates with the development of more severe pathology, and such strains were found more frequently in patients with severe gastroduodenal disease. Partial deletions of the cag-PAI appear to be sufficient to render the organism less pathogenic.

Dynamic expression of pepsinogen C in gastric cancer, precancerous lesions and Helicobacter pylori associated gastric diseases

AIM

To investigate the relationship between the expression of pepsinogen C (PGC) and gastric cancer, precancerous diseases, and Helicobacter pylori (H pylori) infection.

METHODS

The expression of PGC was determined by immunohistochemistry method in 430 cases of gastric mucosa. H pylori infection was determined by HE staining, PCR and ELISA in 318 specimens.

RESULTS

The positive rate of PGC expression in 54 cases of normal gastric mucosa was 100%. The positive rates of PGC expression in superficial gastritis or gastric ulcer or erosion, atrophic gastritis or gastric dysplasia and gastric cancer decreased significantly in sequence (P<0.05; 100%/89.2% vs 14.3%/15.2% vs 2.4%). The over-expression rate of PGC in group of superficial gastritis with H pylori infection was higher than that in group without H pylori infection (P<0.05; chi2= 0.032 28/33 vs 15/25). The positive rate of PGC expression in group of atrophic gastritis with H pylori infection was lower than that in group without H pylori infection (P<0.01; chi2= 0.003 4/61 vs 9/30), and in dysplasia and gastric cancer.

CONCLUSION

The level of PGC expression has a close relationship with the degree of malignancy of gastric mucosa and development of gastric lesions. There is a relationship between H pylori infection and expression of antigen PGC in gastric mucosa, the positive rate of PGC expression increases in early stage of gastric lesions with H pylori infection such as gastric inflammation and decreases during the late stage such as precancerous diseases and gastric cancer. PGC-negative cases with H pylori-positive gastric lesions should be given special attention.

Influence of various proton pump inhibitors on intestinal metaplasia in noneradicated Helicobacter pylori patients

AIM: Intestinal metaplasia (IM) is more often found in patients with Helicobacter pylori (H pylori) infection, while eradication of H pylori results in significant reduction in the severity and activity of chronic gastritis. We aimed to determine in patients with unsuccessful eradication of H pylori the role of various proton pump inhibitors (PPIs) having different mechanisms in the resolution of IM.

METHODS: We confirmed endoscopically and pathohistol-ogically (Sydney classification) the IM in 335 patients with gastritis before and after medication for eradication of H pylori (Maastricht Protocol 2002). H pylori infection was determined by using histology, urease test and culture. Control endoscopy and histology were done after 30 d and thereafter (within 1 year). Unsuccessful eradication was considered if only one of the three tests (histology, urease and culture) was negative after therapy protocol. We used omeprazole, pantoprazole, lansoprazole in therapy protocols (in combination with two antibiotics).

RESULTS: We found no significant difference in resolution of IM by using different PPI between the groups of eradicated and noneradicated patients (P<0.4821 and P<0.4388, respectively).

CONCLUSION: There is no significant difference in resolu-tion of intestinal metaplasia by different proton pump inhibitors.

Chronic gastritis rat model and role of inducing factors

AIM: To establish an experimental animal model of chronic gastritis in a short term and to investigate the effects of several potential inflammation-inducing factors on rat gastric mucosa.

METHODS: Twenty-four healthy, male SD rats were treated with intragastric administration of 600 mL/L alcohol, 20 mmol/L sodium deoxycholate and 0.5 g/L ammonia (factor A), forage containing low levels of vitamins (factor B), and/or indomethacin (factor C), according to an L₈(2⁷) orthogonal design. After 12 wk, gastric antral and body mucosae were pathologically examined.

RESULTS: Chronic gastritis model was successfully induced in rats treated with factor A for 12 wk. After the treatment of animals, the gastric mucosal inflammation was significantly different from that in controls, and the number of pyloric glands at antrum and parietal cells at body were obviously reduced (P < 0.01). Indomethacin induced gastritis but without atrophy, and short-term vitamin deficiency failed to induce chronic gastritis and gastric atrophy. In addition, indomethacin and vitamin deficiency had no synergistic effect in inducing gastritis with the factor A. No atypical hyperplasia and intestinal metaplasia in the gastric antrum and body were observed in all rats studied.

CONCLUSION: Combined intragastric administration of 600 mL/L alcohol, 20 mmol/L sodium deoxycholate and 0.5 g/L ammonia induces chronic gastritis and gastric atrophy in rats. Indomethacin induces chronic gastritis only. The long-term roles of these factors in gastric inflammation and carcinogenesis need to be further elucidated.

Seroconversion and seroreversion of Helicobacter pylori antibodies over a 9-year period and related factors in Japanese adults

BACKGROUND

There are still insufficient data on the frequency of seroconversion and seroreversion of Helicobacter pylori antibodies. The frequency of serochange and related factors were investigated in this study over 9 years.

SUBJECTS AND METHODS

Using sera from 3104 workers who underwent health checks in 1989 and again in 1998, H. pylori antibodies were measured. Those with intermediate serology were excluded from the study. Information on past history was collected using a questionnaire.

RESULTS

Of the 912 seronegative and 1286 seropositive subjects in 1989, seroconversion was observed in 57 and seroreversion in 91 subjects. Seroconversion and seroreversion rates over the 9-year period were 6.3% and 7.1%, respectively, giving rates per 1000 person-years (with 95% confidence interval) of 7.0 (5.2-8.7) and 7.9 (6.3-9.4), respectively. Subjects that reported abdominal symptoms or gastric fiberscope use showed significantly higher seroconversion rates than controls (8.7 vs. 4.5 and 9.2 vs. 1.6, respectively), which remained significant after adjustment for age and gender. Those with a history of duodenal ulcers, a smoking habit or a drinking habit showed significantly lower seroreversion rates than controls (3.5 vs. 8.9, 5.4 vs. 9.2 and 5.9 vs. 13.3, respectively). After adjustment, the association between seroreversion and smoking habit disappeared, while the associations with history of duodenal ulcers and drinking habit remained.

CONCLUSIONS

Those with a history of nonspecific abdominal symptoms and those with a history of gastric fiberscope use showed higher seroconversion rates. Alcohol consumption and duodenal ulcers may inhibit the autoeradication of H. pylori, possibly through increased acid secretion.

Comparison of serum IgA and IgG antibodies for detecting Helicobacter pylori infection

OBJECTIVE

Although the diagnostic utility of serum IgG antibodies to Helicobacter pylori (H. pylori) is well established, the usefulness of IgA-based tests is less well documented. The aim of this study was to evaluate two commercially available ELISAs, both for IgG and IgA.

PATIENTS AND METHODS

Rapid urease test and histology analysis were performed in 183 patients. A patient was considered to be H. pylori-positive when either biopsy test was positive, and considered to be noninfected when both tests were negative. Intestinal metaplasia was determined by dye endoscopy with methylene blue. ELISA testing was performed using the EPI HM-CAP IgG and PP-CAP IgA assays and EIAgen IgG and IgA assays.

RESULTS

Sensitivity was 94.7, 93.9, 94.8, and 97.0% for HM-CAP IgG, PP-CAP IgA, EIAgen IgG, and EIAgen IgA, respectively. Although sensitivity was excellent for both IgG and IgA antibodies, specificity of both IgA EIAs was low (PP-CAP 72.6%, EIAgen H. pylori IgA 59.2%). Three of 101 H. pylori-infected patients were PP-CAP positive and HM-CAP negative and four were EIAgen H. pylori IgA positive and EIAgen IgG negative. Of eight noninfected patients in whom intestinal metaplasia was found, PP-CAP IgA results were positive in three of five patients with a HM-CAP IgG negative result and EIAgen IgA was detected in one of four patients with an EIAgen IgG negative result.

CONCLUSIONS

Since some patients have IgA positive but IgG negative results, great care should be taken not to underestimate the prevalence of H. pylori infection from the results of IgG serology.

Expression of pepsinogen C in Helicobacter pylori-associated gastric lesions

AIM: To investigate the expression of pepsinogen C and its relation with H. pylori infection in gastric cancer and precancerous lesions.

METHODS: The method of immunohistochemistry was used to examine the expression of pepsinogen C in 318 cases of stomach mucosa; the H. pylori infection was determined by H-E stain, PCR and ELISA.

RESULTS: The rate of PGC over-expression in group of superficial gastritis of H. pylori infection was higher than that of non-infection (P < 0.05, 28/33 vs 15/25). The positive rate of PGC in group of atrophic gastritis of H. pylori infection was lower than that of non-infection (P < 0.01, 4/61 vs 9/30) and so were in dysplasia and gastric cancer.

CONCLUSION: There is a relationship between the H. pylori infection and the expression of PGC in gastric mucosa. The expression of PGC increases in superficial gastritis and decreases in atrophic gastritis, dysplasia and gastric cancer with H. pylori infection.

Association between Helicobacter pylori infection and expression of COX-2 and iNOS in chronic gastritis

AIM: To investigate the expression of COX-2 and iNOS in H. pylori associated chronic gastritis, and also to analyze the relationship between apoptosis and proliferation and COX-2, iNOS expression in gastric epithelia cells.

METHODS: A total of 22 patients were diagnosed as having chronic superficial gastritis by endoscopy and pathology. H. pylori infection was detected by fast urease and Giemsa stain. The expression of COX-1, COX-2, and iNOS was detected by RT-PCR and immunohistochemistry. Apoptosis and proliferation of gastric epithelial cells were quantitated by apoptosis index (AI) and PCNA labelling index (PCNA-LI).

RESULTS: There was a significant increase in both COX-2 and iNOS expression in H. pylori positive gastritis compared with normal mucosa. Epithelial cell proliferation index and apoptosis index in H. pylori gastritis were greater than that in normal mucosa; Expression of COX-2 and iNOS induced by H. pylori had positive correlation with apoptosis and proliferation in gastric epithelial cells (r = 0.716,0.603, P < 0.01; r = 0.665, 0.572, P < 0.01).

CONCLUSION: H. pylori infection leads to gastric mucosal overexpression of COX-2 and iNOS, which is involved in apoptosis and proliferation inbalance in gastric epithelial cells. Therefore, it may be one of the crucial mechanisms of H. pylori inducing gastric cancer.

Biological markers in Helicobacter pylori-associated gastritis and carcinoma: the value of a scoring system

BACKGROUND

Helicobacter pylori-associated gastritis has been linked to the pathogenesis of gastric adenocarcinoma (GA), especially when associated with intestinal metaplasia (IM) and atypia/dysplasia (A/D). We examined p53 expression, ploidy and proliferative activity and assessed H. pylori infection in relationship to IM and/or A/D in cases of gastritis not associated with GA and in cases of GA.

METHODS

We examined 53 gastric biopsies from patients with gastritis not associated with GA, including patients with gastritis not associated with IM and/or A/D (n=35) and with gastritis associated with IM and/or A/D (n=21). Thirty-six distal gastrectomy specimens from patients with GA constituted a third group of patients. A scoring system that encompassed the presence or absence of H. pylori, degree of gastritis, IM and/or A/D, p53, MIB-1 proliferative index (MPI) and ploidy was estimated in the cases of gastritis and in cancer-associated mucosa (CAM) and the adenocarcinoma from patients with GA.

RESULTS

Patients with GA had a higher median age than those with gastritis without IM and more were males (ratio, 2.2:1). H. pylori was detected in 75% (40/53) of gastritis specimens and in 55% (20/36) of GA cases. There was a statistically significant difference between the incidence of gastritis without IM and/or A/D and CAM (P=0.01). p53 expression was seen in 67% of cases (14/21) of gastritis with IM and/or A/D and in only 5% (2 cases) of gastritis without IM (P=0.0005). A statistically significant difference in MPI was seen between CAM and GA (P=0.01) and gastritis without IM and/or A/D and gastritis with IM (P=0.004). Cases of gastritis without IM and/or A/D had a median score of 8 while cases of gastritis with IM and/or A/D had a median score of 12 (P=0.0003). CAM had a median score of 13, which was significantly different than gastritis without IM and/or A/D (P=0.0003).

CONCLUSIONS

The presence of IM and/or A/D can be used in H. pylori-associated gastritis as a starting point to further investigate high-risk lesions. Those showing p53 expression, high proliferative activity and aneuploidy require closer follow up and perhaps additional biopsies. Although aneuploidy is commonly seen in GA, its presence in cases of gastritis as an isolated finding should not indicate a high-risk lesion.

Antimicrobial resistance in Helicobacter pylori isolates from children

OBJECTIVE

To determine the resistance rate to four antimicrobial agents commonly used in the treatment of Helicobacter pylori infection in children.

METHODS

Between July 1997 and January 2000, all H. pylori isolates from children undergoing gastroscopy were prospectively collected and subcultured to yield the susceptibility to four antimicrobial agents by E-test. In all, 23 isolates were tested. Demographic data, presenting symptoms, treatment regimen and clinical improvement after treatment were collected retrospectively.

RESULTS

The resistance rate of H. pylori to metronidazole and clarithromycin were 43.5% and 8.7%, respectively. No H. pylori strains were resistant to amoxycillin or tetracycline. There were no statistically significant differences in age, sex, ethnicity, presenting symptoms or clinical improvement after treatment between antimicrobial-susceptible and antimicrobial-resistant groups.

CONCLUSIONS

The frequent resistance of H. pylori to metronidazole and moderate resistance to clarithromycin in children are comparable with local adult data. The incidence of resistance tended to be higher in patients of non-European ethnicity, but this was not statistically significant. Given that the primary goal of therapy is eradication, and that local resistance rates are high, recommendations for H. pylori management may need to be modified to include sensitivity testing and/or determination of eradication in all patients.

Food/nutrient intake and risk of atrophic gastritis among the Helicobacter pylori-infected population of northeastern Japan

Although Helicobacter pylori (H. pylori ) infection is considered a key risk factor for atrophic gastritis, along with other environmental factors, it is still unclear which factor is involved in the development of atrophic gastritis among H. pylori-infected subjects. In the present cross-sectional study, therefore, we analyzed various dietary factors in relation to the presence of atrophic gastritis among H. pylori-infected subjects who participated in a health check-up program in a town in northeastern Japan. One thousand and seventy-one subjects (362 males and 709 females) who provided both self-administered validated food frequency questionnaires and blood samples were the basis for the study, and all of them were serologically positive for H. pylori immunoglobulin G (IgG) antibody. Among them, 663 (223 males and 440 females) were diagnosed as having atrophic gastritis on the basis of serum pepsinogen levels. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated based on tertile categories of subjects without atrophic gastritis, using logistic regression analysis. Among females, high consumptions of rice (OR = 1.6, 95% CI: 1.1-2.3), cod roe (OR = 1.5, 95% CI: 1.0-2.2) and cuttlefish (OR = 1.5, 95% CI: 1.0-2.3) were associated with a moderately increased risk of atrophic gastritis after adjustment for age (P for trend = 0.02 for these items). Among males, high consumptions of rice and miso soup showed a tendency toward an increased risk (P for trend = 0.12 and 0.13, respectively). Vegetables and fruits showed no association among either males or females. From these results, it is suggested that the dietary habits of consumers of traditional Japanese foods may play a role in the development of atrophic gastritis after H. pylori infection.

Expression of UreI is required for intragastric transit and colonization of gerbil gastric mucosa by Helicobacter pylori

Helicobacter pylori colonizes the antral mucosa of the human stomach. There is a controversy as to whether the microorganism is exposed to acidity in its ecological niche. In vitro, the microorganism requires urease for gastric colonization and survival at pH < 4.0. UreI encodes an acid activated urea channel enabling urea access to intrabacterial urease at acidic pH. UreI is also necessary for survival at pH < 4.0. However, the role of UreI for both intragastric transit and colonization of the epithelial gastric mucosa has never been analyzed in detail. We therefore infected gerbils, whose intragastric pH and response to infection resemble those of man, with H. pylori G1.1 wild type bacteria and their corresponding isogenic ureI mutants. Inhibitors of gastric acid secretion and colonization were used for manipulation of gastric pH. Gastric colonization was determined by urease assay and PCR. Gastric pH was measured with pH electrodes. Whereas H. pylori wild type or ureI complemented ureI knockout bacteria colonized the antrum, ureI deletion mutants were unable to colonize. However, continuous inhibition of acid secretion resulted in gastric colonization by the ureI mutants, as also observed with the wild type strain. Restoration of acid secretion resulted in eradication of ureI mutants but not wild type bacteria. The data show that ureI is essential for both gastric transit after inoculation and mucosal colonization in the untreated stomach. The eradication of ureI mutants following restoration of acid secretion suggests that the organism is exposed to pH < 4.0 at the surface of the antral mucosa and that UreI provides a target for specific monotherapy of H. pylori infections.

Endoscopically demonstrable esophageal changes after Helicobacter pylori eradication in patients with gastric disease

BACKGROUND AND AIMS

An increased prevalence of reflux esophagitis has been reported following Helicobacter pylori (H. pylori) eradication in patients with duodenal ulcers in Western countries. However, it has remained unknown whether this might also appertain to individuals with other diseases. We therefore carried out this study to determine the effect of eradicating H. pylori infection in a series of Japanese patients.

METHODS

Of a total of 203 H. pylori-positive patients successfully cured of infection, 82 cases (58 males, 24 females) with gastric disease, but not duodenal ulcers, were included in the present study; median age 56 years (range 18-80) and median follow up of 24 months (range 6-65). The patients were investigated clinically and endoscopically at regular intervals.

RESULTS

Mild reflux esophagitis developed after eradication in three of 55 (5.5%) patients formerly without this condition, while it improved after eradication in five of 27 (18.5%) patients, with the disease endoscopically diagnosed prior to eradication. The estimated incidence of esophagitis within 3 years was 4.8% after cure of infection. Short segment Barrett's esophagus developed after eradication in six of 58 (10.3%) patients who did not have it prior to the therapy, while the condition did not improve in 24 patients affected before eradication.

CONCLUSIONS

Endoscopic esophageal changes after H. pylori eradication in the present series of Japanese patients were relatively infrequent and mild. This therapeutic approach thus appears to be safe and unproblematic.