Association between gastric atrophy and Helicobacter pylori infection in Japanese children: a retrospective multicenter study

Endoscopic and Histological Gastritis in University Students with Helicobacter pylori Infection

Objective Although the characteristics of Helicobacter pylori infection have been extensively reported, there is a lack of consensus regarding its characteristics in young adults. The present study examined the endoscopic and histological characteristics of young adults who underwent eradication therapy for H. pylori infection. Methods We examined the H. pylori infection status of first-year students at Okayama University School of Medicine and Dentistry between 2014 and 2020. A total of 152 (6.8%) students who were positive for H. pylori antibody or pepsinogen tests were enrolled in the study. Among them, 107 students underwent endoscopy, and their biopsy samples were investigated. Seventy-five students were diagnosed with H. pylori infections. Results Of 75 H. pylori-positive patients, 57 (76.0%) had endoscopic atrophic gastritis, and 42 (56.0%) had histological atrophy. A few patients had severe atrophic gastritis. All 65 patients who underwent an eradication assessment were successfully treated. After successful eradication, 26 patients underwent endoscopic follow-up. The mean follow-up period was 32.9 months. A histological evaluation revealed that gastric antrum atrophy had subsided in 11 of 14 patients, and atrophy in the lesser curvature of the gastric body had subsided in 7 of 8 patients. Conclusion More than half of young adults with H. pylori infection had atrophic gastritis. We found mild atrophy in young adults, which subsided shortly after eradication treatment. This study provides a foundation for future studies to evaluate the validity of eradication therapy in preventing gastric cancer in patients.

High galectin expression in Helicobacter pylori-infected gastric mucosa in childhood

BACKGROUND

Mild Th1 and Th17 immune responses in childhood against Helicobacter pylori are presumed to be responsible for H. pylori colonization and mucosal atrophy reduction. However, the mechanism remains unclear. In this study, we aimed to investigate the childhood-specific immune responses observed after H. pylori infection by analyzing galectin expression in the gastric mucosa. We focused on galectin-1 (Gal-1) and galectin-9 (Gal-9), which function to suppress Th1 and Th17 immune responses.

METHODS

We analyzed changes in the expression of Gal-1 and Gal-9 in the gastric mucosa of pediatric patients with H. pylori infection. Ten pediatric patients with and ten patients without H. pylori infection who underwent biopsy to assess the cause of chronic abdominal symptoms using esophagogastroduodenoscopy were evaluated. Gal-1 and Gal-9 expression in the biopsy tissues of the gastric antrum and corpus was analyzed by immunohistochemical staining.

RESULTS

Gal-1 expression was significantly increased in the stromal cells of the corpus owing to H. pylori infection. No alterations in Gal-1 expression due to H. pylori infection were observed in the antral tissue. Helicobacter pylori infection considerably increased Gal-9 expression in all tissues. According to previous reports, the increased expression of Gal-9 associated with H. pylori infection is not observed in adults. Therefore, the increased expression of Gal-9 associated with H. pylori infection is specific to pediatric patients.

CONCLUSION

The increased expression of Gal-1 and Gal-9 may suppress Th1 and Th17 immune responses against H. pylori infection during childhood, promote H. pylori colonization, and reduce inflammation in the gastric mucosa of pediatric patients.

Gastric Intestinal Metaplasia in Children: Natural History and Clinicopathological Correlation

INTRODUCTION

Gastric intestinal metaplasia (GIM) is defined as the replacement of the normal gastric epithelium by intestinal-type epithelium. GIM is considered a preneoplastic lesion for gastric adenocarcinoma in adults and is found in 25% of Helicobacter pylori ( H pylori ) exposed adults. However, the significance of GIM in pediatric gastric biopsies is still unknown.

METHODS

We conducted a retrospective study of children with GIM on gastric biopsies at Boston Children's Hospital between January 2013 and July 2019. Demographic, clinical, endoscopic, and histologic data were collected and compared to age and sex-matched cohort without GIM. Gastric biopsies were reviewed by the study pathologist. GIM was classified as complete/incomplete based on Paneth cell presence or absence and limited/extensive based on its distribution in the antrum or both antrum and corpus.

RESULTS

Of 38 patients with GIM, 18 were male (47%), mean age of detection was 12.5 ± 5.05 years (range, 1-18 years). The most common histologic was chronic gastritis (47%). Complete GIM was present in 50% (19/38) and limited GIM was present in 92% (22/24). H pylori was positive in 2 patients. Two patients had persistent GIM on repeat esophagogastroduodenoscopy (2/12). No dysplasia or carcinoma was identified. Proton-pump inhibitor use and chronic gastritis were more common in GIM patients compared to control ( P = 0.02).

CONCLUSION

Most children with GIM had low-risk histologic subtype (complete/limited) for gastric cancer; GIM was rarely associated with H pylori gastritis in our cohort. Larger multicenter studies are needed to better understand outcomes and risk factors in children with GIM.

Helicobacter pylori-Associated Iron Deficiency Anemia in Childhood and Adolescence-Pathogenesis and Clinical Management Strategy

Many epidemiological studies and meta-analyses show that persistent Helicobacter pylori infection in the gastric mucosa can lead to iron deficiency or iron deficiency anemia (IDA), particularly in certain populations of children and adolescents. Moreover, it has been demonstrated that H. pylori infection can lead to and be closely associated with recurrent and/or refractory iron deficiency and IDA. However, the pathogenesis and specific risk factors leading to this clinical outcome in H. pylori-infected children remain poorly understood. In general, most of pediatric patients with H. pylori-associated IDA do not show evidence of overt blood loss due to gastrointestinal hemorrhagic lesions. In adult populations, H. pylori atrophic gastritis is reported to cause impaired iron absorption due to impaired gastric acid secretion, which, subsequently, results in IDA. However, significant gastric atrophy, and the resultant substantial reduction in gastric acid secretion, has not been shown in H. pylori-infected children. Recently, it has been hypothesized that competition between H. pylori and humans for iron availability in the upper gastrointestinal tract could lead to IDA. Many genes, including those encoding major outer membrane proteins (OMPs), are known to be involved in iron-uptake mechanisms in H. pylori. Recent studies have been published that describe H. pylori virulence factors, including specific OMP genes that may be associated with the pathogenesis of IDA. Daily iron demand substantively increases in children as they begin pubertal development starting with the associated growth spurt, and this important physiological mechanism may play a synergistic role for the microorganisms as a host pathogenetic factor of IDA. Like in the most recent pediatric guidelines, a test-and-treat strategy in H. pylori infection should be considered, especially for children and adolescents in whom IDA is recurrent or refractory to iron supplementation and other definitive causes have not been identified. This review will focus on providing the evidence that supports a clear biological plausibility for H. pylori infection and iron deficiency, as well as IDA.

Gastric Antral Mucosal Changes in Children With Intestinal Metaplasia

Objectives: The gastric mucosal change accompanying gastric antral intestinal metaplasia (IM) in the pediatric population and its clinical implications remain unclear. Methods: We retrieved all patients younger than 18 years who had upper GI endoscopy with a pathology diagnosis of antral IM between 2009 and 2020. Each biopsy was evaluated for the presence of dysplasia, Helicobacter pylori, gastritis, and other pathologic changes. Results: A total of 134 patients with antral IM were identified; 72 (53.7%) with coexisting pathology including chronic gastritis (n = 22), reactive gastropathy (n = 16), focal mild chronic inflammation (n = 13), gastric eosinophilia (n = 9), chronic active gastritis associated with (n = 2) and without Helicobacter infection (n = 3), and others (n = 7). The remaining 62 (46.3%) showed isolated IM. Gastric IM increased with age, and was often accompanied by other pathologic changes, especially in female children. Twenty-seven patients had follow up biopsies; 11 of the 27 patients (40.7%) showed persistent IM in at least one repeat biopsies. None demonstrated dysplasia. Conclusions: In children, antral IM increases with age and often coexists with other pathologic changes. Gastric IM could persist for at least months to years in a significant subset of patients with chronic gastritis and gastric eosinophilia.

The Resolution of Severe Iron-Deficiency Anemia After Successful Eradication of Helicobacter pylori in Teenagers

Long-term follow-up studies with Helicobacter pylori eradication therapy in children with H. pylori-associated iron-deficiency anemia (IDA) are scarce. We investigated whether successful H. pylori eradication would result in maintaining resolution of recurrent and/or refractory IDA in a cohort of teenagers in Japan.

Methods

In this case series, 7 H. pylori-infected patients with recurrent and/or refractory IDA (12-16 y old) received successful eradication therapy and were then followed for a median of 20 months (range, 9-76 mo) after oral iron supplementation therapy (1-4 mo) was discontinued. Five patients of our study cohort participated in rigorous sports activities.

Results

No visual appearance of ulcerations or erosions was found by esophagogastroduodenoscopy. In all patients studied, the gastric biopsies showed histological evidence of chronic gastritis without significant atrophy and intestinal metaplasia. Compared with the baseline (median values: hemoglobin, 6.3 g/dL; serum iron, 9 μg/dL; serum ferritin, 1.5 ng/mL), values of hemoglobin (P < 0.001), serum iron (P < 0.005), and ferritin (P < 0.001) significantly increased, on average, 2-3 months after eradication therapy and these iron indices were maintained at the same or higher levels at the endpoint of follow-up (median values: 14.2 g/dL, 102 μg/dL, and 29.3 ng/mL, respectively). No patient had recurrence of IDA at the time of final follow-up.

Conclusions

H. pylori infection can be closely associated with recurrent or refractory IDA in teenage children. It is speculated that increased iron demands as a result of growth spurt in adolescents may play a synergistic role in combination with H. pylori in the pathogenesis of IDA.

Gastric mucosal precancerous lesions in Helicobacter pylori-infected pediatric patients in central China: A single-center, retrospective investigation

BACKGROUND

Helicobacter pylori (H. pylori) infects about 50% of the world population and is the major cause of chronic gastritis, peptic ulcers, and gastric cancer. Chronic H. pylori infection induces gastric mucosal precancerous lesions mostly in adulthood, and it is debatable whether these pathological conditions can occur in childhood and adolescents as well. Since this is a critical issue to determine if intervention should be offered for this population group, we investigated the gastric mucosal precancerous lesions in pediatric patients in an area in central China with a high prevalence of H. pylori and gastric cancer.

AIM

To investigate the relationship of H. pylori infection and gastric mucosal precancerous lesions in children and adolescents in central China.

METHODS

We screened 4258 ward-admitted children and adolescent patients with upper gastrointestinal symptoms, and finally enrolled 1015 pediatric patients with H. pylori infection and endoscopic and histological data. H. pylori infection status was determined by rapid urease test and histopathological examination. Both clinical and pathological data were collected and analyzed retrospectively. Occurrence of gastric mucosal precancerous lesions, inflammatory activity and degree of inflammatory cell infiltration between H. pylori-positive and -negative groups were compared.

RESULTS

Among the 1015 eligible children and adolescents, the overall H. pylori infection rate was 84.14% (854/1015). The infection rate increased with age. The incidence of gastric mucosal precancerous lesions in H. pylori-infected children was 4.33% (37/854), which included atrophic gastritis (17 cases), intestinal metaplasia (11 cases) and dysplasia (9 cases). In H. pylori-negative patients, only 1 atrophic gastritis case [0.62%, (1/161)] was found (P < 0.05). Active inflammation in H. pylori-infected patients was significantly higher than that in non-infected patients, and the H. pylori-infected group showed more severe lymphocyte and neutrophil granulocyte infiltration (P < 0.001). In addition, endoscopy revealed that the most common findings in H. pylori-positive patients were antral nodularity, but in H. pylori-negative patients only superficial gastritis was observed.

CONCLUSION

In children and adolescents, gastric mucosal precancerous lesions occurred in 4.33% of H. pylori-infected patients in central China. These cases included atrophic gastritis, intestinal metaplasia, and dysplasia. The data revealed an obvious critical issue requiring future investigation and intervention for this population group.

Atrophic gastritis in Helicobacter pylori-infected children

BACKGROUND

Helicobacter pylori infection is the leading cause of peptic ulcer and chronic gastritis and may initiate gastric carcinogenesis following the Correa cascade. Another lineage of metaplasia, spasmolytic peptide-expressing metaplasia (SPEM) has recently been found to be an alternative precursor to gastric cancer. To date, few reports have investigated gastric precancerous lesions among children with H. pylori infection. This study aimed to evaluate the histopathological pattern of H. pylori atrophic gastritis in children and the extent of precancerous lesions.

MATERIALS AND METHODS

This study enrolled pediatric patients with H. pylori infection from 1998 to 2019. During esophagogastroduodenoscopy examinations, biopsy fragments were collected from the gastric antrum and corpus for rapid urease test, culture, and histology evaluation. The presence and degree of chronic inflammation, activity of gastritis, H. pylori density, atrophy, and intestinal metaplasia (IM) were assessed according to the modified Updated Sydney System. Trefoil factor 2 (TFF2) immunohistochemistry was also performed to assess SPEM in the gastric tissues collected from each case using rabbit anti-human TFF2 antibodies.

RESULTS

A total of 92 children with H. pylori infection and adequate gastric mucosa biopsies were enrolled. Esophagogastroduodenoscopy showed that 39 (42.4%) had duodenal ulcers, 11 (12.0%) had gastric ulcers, 41 (44.6%) had gastritis, and 1 (1.1%) had negative findings. Mild-to-moderate IM was identified in 4 patients (4.3%). SPEM was found in 8 patients (8.7%) with a significantly higher incidence among female patients (15.8% vs. 8.7%, p = .031). Gastric glandular atrophy presented in 28 patients (30.4%), and high-grade atrophy was more common in female patients (3.2% vs. 1.9%, p = .031).

CONCLUSIONS

The prevalence rates of atrophic gastritis in the children with H. pylori infection were 30.4% for gastric glandular atrophy, 4.3% for IM and 8.7% for SPEM. SPEM and high-grade atrophy were more common in female patients.

Chinese Consensus Report on Family-Based Helicobacter pylori Infection Control and Management (2021 Edition)

OBJECTIVE

Helicobacter pylori infection is mostly a family-based infectious disease. To facilitate its prevention and management, a national consensus meeting was held to review current evidence and propose strategies for population-wide and family-based H. pylori infection control and management to reduce the related disease burden.

METHODS

Fifty-seven experts from 41 major universities and institutions in 20 provinces/regions of mainland China were invited to review evidence and modify statements using Delphi process and grading of recommendations assessment, development and evaluation system. The consensus level was defined as ≥80% for agreement on the proposed statements.

RESULTS

Experts discussed and modified the original 23 statements on family-based H. pylori infection transmission, control and management, and reached consensus on 16 statements. The final report consists of three parts: (1) H. pylori infection and transmission among family members, (2) prevention and management of H. pylori infection in children and elderly people within households, and (3) strategies for prevention and management of H. pylori infection for family members. In addition to the 'test-and-treat' and 'screen-and-treat' strategies, this consensus also introduced a novel third 'family-based H. pylori infection control and management' strategy to prevent its intrafamilial transmission and development of related diseases.

CONCLUSION

H. pylori is transmissible from person to person, and among family members. A family-based H. pylori prevention and eradication strategy would be a suitable approach to prevent its intra-familial transmission and related diseases. The notion and practice would be beneficial not only for Chinese residents but also valuable as a reference for other highly infected areas.

Systematic Review and Meta-analysis of Histological Gastric Biopsy Aspects According to the Updated Sydney System in Children

OBJECTIVES

A descriptive and comparative study of gastric histological aspects according to the updated Sydney classification (USC), obtained from Helicobacter pylori-positive versus H pylori-negative children referred for upper gastrointestinal endoscopy.

METHODS

The Prisma method was used to perform a systematic review and meta-analysis. Selection criteria were based on following key words USC, H pylori, children, endoscopy, or biopsy. Publication biases were assessed according to the Newcastle-Ottawa Scale, and a meta-regression analysis was done. The study was registered on the PROSPERO platform.

RESULTS

Between 1994 and 2017, 1238 references were found; 97 studies were retained for the systematic review with a total number of 25,867 children; 75 studies were selected for the meta-analysis concerning 5990 H pylori-infected and 17,782 uninfected children.H pylori-positive versus H pylori-negative children, according to the USC, showed significantly higher relative risk for gastric antral and corpus chronic inflammation, presence of neutrophils, and of lymphoid follicles, and gastric mucosa atrophy, whereas, intestinal metaplasia showed a significantly higher RR only in antral biopsies. The meta-regression analysis showed that H pylori-positive versus H pylori-negative children had significantly higher risk only for corpus activity according to age, recurrent abdominal pain, and geographical area of low H pylori prevalence.

CONCLUSIONS

H pylori infection in children was associated with higher relative risk for gastric antral and corpus chronic inflammation, presence of neutrophils, lymphoid follicles, and rare gastric mucosa atrophy, whereas, rare intestinal metaplasia was only significantly higher in the antral area.

Association between Helicobacter pylori antibody-positive status and extragastric diseases in Japanese junior high school students

BACKGROUND

Helicobacter pylori (H. pylori) infection causes various extragastric diseases. Its transmission route has still not been clarified. However, no large-scale studies have examined the extragastric diseases caused by H. pylori in adolescents. This study aimed to examine the association of H. pylori infection with anemia, serum cholesterol levels, physique, and birth delivery method (vaginal or cesarean) in a large number of Japanese adolescents.

METHODS

From 2016 to 2018, we screened 2,399 adolescents (aged 13-15 years) in their second and third years of junior high school using an enzyme-linked immunosorbent assay-based antibody test. Red blood cells, hemoglobin, hematocrit, total cholesterol, high-density lipoprotein (HDL) cholesterol, and serum antibody levels were measured.

RESULTS

Hemoglobin and hematocrit levels were significantly lower in the H. pylori antibody-positive group than in the H. pylori antibody-negative group in both sexes (boys: P = 0.0004 and 0.0022; girls: P = 0.0019 and 0.0005, respectively). Total cholesterol and non-HDL cholesterol levels were significantly higher in the H. pylori-positive group than in the H. pylori-negative group among boys (P = 0.0370 and 0.0293 respectively). There was no significant difference in body mass index percentile and birth delivery method between the H. pylori-positive and H. pylori-negative groups in both boys and girls.

CONCLUSIONS

Among Japanese junior high school students, H. pylori antibody-positive status was associated with anemia in both sexes while total cholesterol and non-HDL cholesterol levels were associated among boys. There was no association between H. pylori antibody status, body mass index percentile, and birth-delivery method.

Gut microbiota changes related to Helicobacter pylori eradication with vonoprazan containing triple therapy among adolescents: a prospective multicenter study

Currently, it is unclear whether treating Helicobacter pylori (H. pylori) infection is safe among adolescents. This study aimed to evaluate the safety of H. pylori eradication therapy by examining gut microbiota changes in adolescents 3 months after the therapy. H. pylori-infected adolescents were enrolled in this study. Their stool samples were collected at the following three time points: before treatment, 1-2 days after completion of treatment, and time of eradication successful judgment. We assessed the relative abundance, alpha-diversity, and beta-diversity of the gut microbiota and adverse events. The number of isolated Actinobacteria decreased immediately after eradication therapy in the 16 students included in the study, and it returned to pretreatment condition at the eradication judgment point. There was no change in the relative abundance at genus level. The alpha-diversity was lost immediately after eradication therapy; however, it recovered at the time of eradication judgment, and it was restored to pretreatment condition. Meanwhile, none of the participants experienced serious adverse events. H. pylori eradication therapy is safe for adolescents with respect to gut microbiota changes associated with H. pylori eradication therapy. Therefore, further long-term evaluations of gut microbiota changes following eradication therapy are warranted.

The updated JSPGHAN guidelines for the management of Helicobacter pylori infection in childhood

The Japan Pediatric Helicobacter pylori Study Group published the first guidelines on childhood H. pylori infection in 1997. They were later revised by the Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition (JSPGHAN). The H. pylori eradication rates, when employing triple therapy with amoxicillin and clarithromycin, currently recommended as the first-line therapy of H. pylori infection in Japan, have substantially decreased, creating an important clinical problem worldwide. In Japanese adults, the "test-and-treat" strategy for H. pylori infection is under consideration as an approach for gastric cancer prevention. However, the combined North American and European pediatric guidelines have rejected such a strategy for asymptomatic children. As risk for gastric cancer development is high in Japan, determining whether the "test-and-treat" strategy can be recommended in children has become an urgent matter. Accordingly, the JSPGHAN has produced a second revision of the H. pylori guidelines, which includes discussion about the issues mentioned above. They consist of 19 clinical questions and 34 statements. An H. pylori culture from gastric biopsies is recommended, not only as a diagnostic test for active infection but for antimicrobial susceptibility testing to optimize eradication therapy. Based upon antimicrobial susceptibility testing of H. pylori strains (especially involving clarithromycin), an eradication regimen including use of the antibiotics to which H. pylori is susceptible is recommended as the first-line therapy against H. pylori-associated diseases. The guidelines recommend against a "test-and-treat" strategy for H. pylori infection for asymptomatic children to protect against the development of gastric cancer because there has been no evidence supporting this strategy.

Prevalence of Helicobacter pylori among children in a training and research hospital clinic in Istanbul and comparison with Updated Sydney Classification Criteria

OBJECTIVE

Helicobacter pylori (H. pylori) is a gram-negative bacterium and one of the reasons for gastritis, peptic and duodenal ulcers. It is a crucial public health problem for both children and adults, especially in developing countries. This study aims to investigate the prevalence of Helicobacter pylori positivity in children and to compare with updated Sydney classification criteria.

METHODS

This study was conducted from January 2015 to June 2017. This study included 885 children aged 0-17 year(s). Endoscopic biopsies were evaluated for the diagnosis of infection due to H. pylori.

RESULTS

The findings showed that 418 (47.2%) of 885 children were positive for H. pylori, and this positivity had a significantly increasing correlation with the presence of chronic inflammation, neutrophilic activity, lymphoid aggregates, and follicles. Erythematous pangastritis and antral nodularity on endoscopic findings had a correlation with H. pylori positivity.

CONCLUSION

In this hospital-based study, the findings suggest that H. pylori infection is a problem for children and more extensive studies are needed to determine the prevalence of H. pylori positivity among children.

Atrophic gastritis and chronic diarrhea due to Helicobacter pylori infection in early infancy: A case report

RATIONALE

Helicobacter pylori infection causes atrophic gastritis in childhood, but atrophic gastritis due to H pylori infection is extremely rare in infancy. The relationship between H pylori infection and chronic diarrhea without protein leakage remains controversial.

PATIENT CONCERNS

An 8-month-old male infant presented to our hospital with severe watery diarrhea, erythema, and failure to thrive from approximately 1 month after birth. Blood, stool, esophagogastroduodenoscopy, total colonoscopy, and H pylori urease analysis results were positive, thereby suggesting atrophic gastritis.

DIAGNOSES

Atrophic gastritis and chronic diarrhea due to H pylori infection.

INTERVENTIONS

We performed H pylori eradication therapy using triple therapy with vonoprazan (6 mg/kg), amoxicillin (300 mg/d), and clarithromycin (120 mg/kg) for 7 days.

OUTCOMES

From approximately 1 week after the H pylori eradication therapy, the frequency of defecation had decreased, stool shape had improved, and body weight had gradually increased.

LESSONS

H pylori infection can cause atrophic gastritis and chronic diarrhea even in infancy. Early eradication therapy for H pylori infection may be useful for prevention of gastric cancer and improvement in growth disorders.

Clinical features of Helicobacter pylori antibody-positive junior high school students in Nagano Prefecture, Japan

BACKGROUND

Previously, we conducted an epidemiological study screening for Helicobacter pylori antibody positivity among Japanese junior high school students. In this study, we updated the epidemiological data and assessed the clinical features of H pylori antibody-positive junior high school students.

MATERIALS AND METHODS

We assessed H pylori antibody-positive subjects who were identified between 2012 and 2015 at four junior high schools in Nagano Prefecture, Japan. H pylori infection was confirmed by urea breath test (UBT) or endoscopic examination. Endoscopy was performed after obtaining consent from the subject and their guardians. Eradication therapy consisted of triple therapy with proton pump inhibitor (PPI), amoxicillin (AMPC), and clarithromycin (CAM) or metronidazole (MNZ) for seven days. Eradication of H pylori was confirmed by UBT. We reviewed subjects' characteristics, endoscopic findings, histological findings, eradication regimes, outcomes, and adverse effects.

RESULTS

The overall prevalence of H pylori antibody positivity was 3.2% (42/1298). We assessed thirteen H pylori antibody-positive subjects. Eight subjects had a family history of H pylori infection. Six subjects had abdominal pain, and two subjects had iron deficiency anemia (IDA). Twelve subjects underwent endoscopy; one subject had duodenal ulcer, eleven subjects had antral nodular gastritis, and six subjects showed grade 2 closed type atrophic border according to the Kimura-Takemoto classification. All subjects received eradication therapy; CAM was used in five subjects with CAM susceptibility as well as in three subjects with unknown information on CAM susceptibility, and MNZ was used in five subjects with CAM resistance. Eradication was successful in twelve subjects (one unconfirmed). There were three mild adverse effects (abdominal pain or diarrhea).

CONCLUSIONS

Helicobacter pylori test for junior high school students represents an opportunity to diagnose the peptic ulcer, iron deficiency anemia, and gastric atrophy.

Helicobacter pylori Infection in Children and Adolescents

About one-third of all children worldwide is infected with H. pylori and its prevalence is low in developed and high in developing countries. H. pylori is mainly acquired during childhood and transmission of the bacterium commonly proceeds from person to person, especially among family members. The most frequent transmission route is from the mother to children. Various gastrointestinal and extra-gastrointestinal diseases are reported to be associated with H. pylori in children and adolescents, but the strongest recommendation for testing and treating is introduced only with children and adolescents having peptic ulcer disease. Iron deficiency anemia and chronic immune thrombocytopenic purpura are also considered for testing and treating, but the effectiveness is somewhat controversial. Invasive diagnosis is recommended, whereas none of the available diagnostic tests have 100% accuracy for reliable diagnosis, and therefore at least two or more tests should be performed. Urea breath test is the most reliable among the non-invasive tests. Because the number of antibiotics-resistant H. pylori strains is increasing, it is desirable to conduct a drug susceptibility test before treatment and to select the corresponding regime. H. pylori has been proven to be a major cause of gastric cancer and 'screen-and-treat' strategies are recommended in communities at high risk of gastric cancer. However, the application to children and adolescents is controversial. An effective vaccine is desirable, but not yet available. Screen-and-treat for adolescents has started in a few areas in Japan, where conditions are well established. New prevention strategies for gastric cancer are awaited worldwide.

Non-Helicobacter pylori Gastric Intestinal Metaplasia in Children: A Series of Cases and Review of the Literature

In the pediatric population, Gastric Intestinal Metaplasia (GIM) is a finding with unknown frequency and, more importantly, unknown clinical implications. The relationship between Helicobacter pylori (HP) infection and GIM is well documented, as well as an association between duodenogastric reflux and GIM. We present two cases of pediatric patients with GIM along with a review of the literature. The diagnosis of GIM may have adverse clinical implications and should be made with caution in a child. The association of GIM and adenoma/dysplasia and carcinoma is rarely seen in children, primarily because the time required for these to develop takes the individual into adulthood. Treatment, long-term consequences, and surveillance protocols are not well established in the pediatric population. Studies to evaluate the long-term natural history, treatment, and surveillance protocols in children with GIM are needed.

Helicobacter pylori sabA gene is associated with iron deficiency anemia in childhood and adolescence

Background

Gastric Helicobacter pylori colonization leads to iron deficiency anemia (IDA), especially in children and adolescents. However the pathogenesis is poorly understood.

Objective

We sought to identify specific H. pylori genes involved in IDA development, by comparing bacterial genome-wide expression profiling in patients affected or not.

Methods

H. pylori were isolated from four children with IDA and four from matched controls without IDA. Based on these isolates, cDNA microarrays under iron-replete or depleted conditions were systematically performed to compare gene expression profiles at the whole genome level. Real-time reverse-transcription (RT-) PCR and protein assays were performed for further assessing the profile differentiation of the identified H. pylori IDA-associated genes.

Results

We identified 29 and 11 genes with significantly higher or lower expression in the IDA isolates compared to non-IDA isolates, respectively. Especially notable were higher expression of sabA gene encoding sialic acid-binding adhesin in the IDA isolates, which was confirmed by real-time RT-PCR study. Moreover, iron-depletion in vitro led to up-regulation of fecA1 and frpB1 genes and down-regulation of pfr, as predicted. Known iron-regulated genes such as fur, pfr, fecA, and feoB did not significantly differ between both groups. The IDA isolates had significantly higher expression of vacuolating cytotoxin gene vacA than non-IDA isolates, consistent with the results of VacA protein assays. There were no significant differences in bacterial growth value between IDA and non-IDA isolates.

Conclusions

It is likely that H. pylori carrying high expression of sabA causes IDA, especially in children and adolescents who have increased daily iron demand. In addition, it is possible that several host-interactive genes, including vacA, may play a synergistic role for sabA in IDA development.

Prevalence of Helicobacter pylori in children in eastern Turkey and molecular typing of isolates

The objectives of the present study were to determine Helicobacter pylori via culture, polymerase chain reaction and histopathological diagnosis in 101 children ranging in age from 4 to 18 years, to identify the association among restriction fragment length polymorphism types and clinical disease and to investigate the relationships among different isolates of H. pylori in different age groups. We observed a high prevalence of H. pylori infections in children between the ages of 13 and 18 (75.8%), while children aged 4 to 6 years had the lowest prevalence of infection (40%). H. pylori was detected in 30.7% (31 of 101), 66.3% (67 of 101) and 63.2% (60 of 95) of children as determined by culture methods, PCR and histological examination, respectively. H. pylori isolates with RFLP types I and III were the most common among children with antral nodularity, whereas RFLP types II and IV were the least detected types. Interestingly, all isolates from peptic ulcer patients were type III. Although our results show a high prevalence of H. pylori infections in the pediatric population in eastern Turkey, no association was identified between H. pylori infection with antral nodularity and recurring abdominal pain. In addition, we found low genetic variation among H. pylori isolates from children and no association between RFLP types and antral nodularity (p > 0.05). Additionally, we found that H. pylori isolates with specific RFLP types were predominant in different age groups.

Occurrence of Bifidobacteriaceae in human hypochlorhydria stomach

Background

The human stomach, when healthy, is not a suitable host for microorganisms, but in pathological conditions such as gastritis, when gastric acid secretion is impaired, microbial overgrowth can be observed. Apart from Helicobacter pylori, the composition of microbiota, resident or exogenously introduced during neutral/high pH conditions, has not been investigated thoroughly. Thus, it is possible that Bifidobacteriaceae, important autochthonous and beneficial bacteria of human gastrointestinal microbiota, could over-colonize the stomach of hypochlorhydria patients suffering from autoimmune atrophic gastritis (AAG) or omeprazole-treated (OME) gastritis. This prompted us to characterize the Bifidobacteriaceae in such patients’ gastric microbiota and to study its abnormal colonization.

Methods

Samples of gastric juices, and antrum and corpus mucosa from 23 hypochlorhydria patients (13 AAG and 10 OME) and from 10 control volunteers with base-line normochlorhydria, were cultivated in Brain Heart Infusion (BHI) and selective Bifidobacterium-Tryptone-Phytone-Yeast extract (Bif-TPY) media. The isolates were characterized by the fructose-6-phosphate phosphoketolase (F6PPK) test, electrophoresis of cellular proteins, the fermentation test, guanine-cytosine% DNA content, and DNA–DNA hybridization. Negative F6PPK isolates were characterized by order-specific polymerase chain reaction (PCR).

Results

A total of 125 isolates, assigned to the Bifidobacteriaceae family on the basis of their morphology, were obtained from AAG and OME patients, but not from normal subjects. Of these isolates, 55 were assigned to the Bifidobacteriaceae family on the basis of their fructose-6-phosphoketolase (PPK) activity, PPK being the key taxonomic enzyme of this family. The remaining 70 isolates, which were PPK-negative, were attributed to the Actinomycetales order following specific primer PCR analysis. We observed a significantly higher abundance of Bifidobacteriaceae (Bifidobacterium dentium, Scardovia inopinata, and Parascardovia denticolens) in OME group than the AAG group. Furthermore, the Actinomycetales distribution was homogeneous for both hypochlorhydria patient groups.

Conclusions

This study suggests that the Bifidobacteriaceae species, typically found in the oral cavity, readily colonizes the hypochlorhydria stomach of OME patients. The clinical relevance and the mechanism underlying this Bifidobacteriaceae presence in OME gastritis requires further functional studies.

Disease manifestations of Helicobacter pylori infection in Arctic Canada: using epidemiology to address community concerns

OBJECTIVES

Helicobacter pylori infection, linked to gastric cancer, is responsible for a large worldwide disease burden. H pylori prevalence and gastric cancer rates are elevated among indigenous Arctic communities, but implementation of prevention strategies is hampered by insufficient information. Some communities in northern Canada have advocated for H pylori prevention research. As a first step, community-driven research was undertaken to describe the H pylori-associated disease burden in concerned communities.

DESIGN

Participants in this cross-sectional study completed a clinical interview and gastroscopy with gastric biopsies taken for histopathological examination in February 2008.

SETTING

Study procedures were carried out at the health centre in Aklavik, Northwest Territories, Canada (population ∼600).

PARTICIPANTS

All residents of Aklavik were invited to complete a clinical interview and gastroscopy; 194 (58% female participants; 91% Aboriginal; age range 10-80 years) completed gastroscopy and had gastric biopsies taken.

PRIMARY AND SECONDARY OUTCOME MEASURES

This analysis estimates the prevalence of gastric abnormalities detected by endoscopy and histopathology, and associations of demographic and clinical variables with H pylori prevalence.

RESULTS

Among 194 participants with evaluable gastric biopsies, 66% were H pylori-positive on histology. Among H pylori-positive participants, prevalence was 94% for acute gastritis, 100% for chronic gastritis, 21% for gastric atrophy and 11% for intestinal metaplasia of the gastric mucosa, while chronic inflammation severity was mild in 9%, moderate in 47% and severe in 43%. In a multivariable model, H pylori prevalence was inversely associated with previous gastroscopy, previous H pylori therapy and aspirin use, and was positively associated with alcohol consumption.

CONCLUSIONS

In this population, H pylori-associated gastric histopathology shows a pattern compatible with elevated risk of gastric cancer. These findings demonstrate that local concern about health risks from H pylori is warranted and provide an example of how epidemiological research can address health priorities identified by communities.

Serum prolidase activity, oxidant and antioxidant status in nonulcer dyspepsia and healthy volunteers

Helicobacter pylori (H. pylori) infection is associated with increased oxidative stress and serum prolidase activity (SPA) in many diseases. We aimed to observe SPA and oxidative stress in nonulcer dyspepsia (NUD) infected with and without H. pylori among eastern Indians. 106 patients with H. pylori positive NUD, 82 patients with H. pylori negative NUD, and 50 healthy individuals were selected. SPA, total antioxidant capacity (TAOC), and total oxidant status (TOS) were measured with the use of spectrophotometer and an automated measurement method. SPA, TOS, and oxidative stress index (OSI) were significantly higher in patients with H. pylori positive than H. pylori negative NUD and healthy individuals (all P < 0.0001), whereas TAOC was significantly lower (P < 0.0001). Nonsignificant, increased SPA (P value = 0.6083) and decreased TAOC (P value = 0.1186) were observed in patients with H. pylori negative NUD than healthy individuals, while increased TOS and OSI were significant (P < 0.0001). Weak, nonsignificant correlations were observed between serum prolidase activity and TAOC, TOS, and OSI in H. pylori positive cases. Thus, increased SPA along with increased oxidative stress was observed, which seem to be closely associated with H. pylori infection. SPA and oxidative stress seem to be used as biomarkers for H. pylori infection in NUD.

Upper gastrointestinal histopathological findings in children and adolescents with nonulcer dyspepsia with Helicobacter pylori infection

OBJECTIVES

The aim of the study was to investigate the histopathological lesions in the upper gastrointestinal mucosa associated with Helicobacter pylori infection in children with nonulcer dyspepsia.

METHODS

A cross-sectional case-control study was performed on 185 Brazilian children and adolescents (4-17 years, mean 9.5 ± 2.7 years), 63.2% girls, submitted to upper gastrointestinal endoscopy. The histopathological lesions of the esophageal and gastric mucosa were analyzed in biopsy samples.

RESULTS

H pylori infection was identified in 96 children (51.8%). Moderate to severe chronic active gastritis was present in antrum (70.5%) and corpus (45.2%), with higher grading in antrum than in corpus (P < 0.05). The topographic distribution of inflammation was pangastritis (61.9%), followed by antral (32.1%) and corpus (5.9%). H pylori density was higher in antrum than in corpus. Intestinal metaplasia was not found in the H pylori-infected group, nor was significant gastric atrophy. The scores for esophagitis were significantly higher (P < 0.05) in the noninfected group (1.4 ± 0.8) than in the H pylori-infected group (1.07 ± 0.9), with significant negative correlation (r = 0.29; P < 0.05) with the scores of gastric inflammation.

CONCLUSIONS

The prevalence of H pylori infection was high among children with dyspepsia and associated with moderate/severe degrees of gastric inflammation. The high scores of esophagitis in the noninfected group point to 2 distinct groups of pathological conditions sharing similar clinical patterns.

The significance of small intestinal epithelium in gastric antral biopsies in children

Intestinal metaplasia of the gastric antrum is common in adults with chronic gastritis and occurs in Helicobacter -associated gastritis in children. This study examined the frequency and clinical correlates of intestinal epithelium in 1690 consecutive antral biopsies obtained from children over a 2-year period in a tertiary pediatric care facility. Intestinal epithelium in gastric glands not associated with overlying villi was present in 22 (1.3%) biopsies. These came from 20 patients, 2-17 years of age, none of whom had clinical or histologic evidence of Helicobacter infection or significant chronic gastritis. Eight (40%) had an antral pancreatic rest, 8 had some other localized antral abnormality, and 4 were endoscopically normal. Four additional patients with a pancreatic rest had no intestinal epithelium. Six surgically resected rests and 2 rests found at autopsy were also reviewed. Heterotopic intestinal epithelium was present in 1 of the 2 postmortem specimens but was absent from all 6 surgically resected lesions. No intestinal epithelium was present in 67 antral biopsies with Helicobacter gastritis observed during this same period. Although the intestinal epithelium in these patients could be metaplastic, it more likely represents inadvertent sampling of the gastroduodenal junction induced by a lesion in the distal antrum or a focus of heterotopic epithelium and might best be addressed in the surgical pathology report by a comment to this effect. The distinction from metaplasia is more than semantic, because a diagnosis of intestinal metaplasia can have adverse clinical implications and should be made with caution in a child.

Endocrine impact of Helicobacter pylori: Focus on ghrelin and ghrelin o-acyltransferase

Ghrelin is predominantly produced by the gastric enteroendocrine cell compartment and is octanoylated by the recently discovered ghrelin o-acyltransferase (GOAT) before secretion into the bloodstream. This octanoylation is essential for many of the biological properties of ghrelin including appetite stimulation and anti-inflammatory properties as only the acylated form of ghrelin binds to the ghrelin receptor, the growth hormone secretagogue receptor (GHS-R). Given the gastric location of ghrelin production, it is perhaps not surprising that insult to the gastric mucosa affects circulating ghrelin levels in humans. Helicobacter pylori (H. pylori) infects more than fifty percent of the world’s population and once established within the gastric mucosa, can persist for life. Infection is associated with chronic gastritis, gastric atrophy and ulceration, reduced appetite and a lower body mass index (BMI). The large majority of studies investigating levels of circulating ghrelin and ghrelin expression in the stomach in patients with H. pylori infection indicate that the bacterium has a negative impact on ghrelin production and/or secretion. Eradication of infection restores ghrelin, improves appetite and increases BMI in some studies, however, a causative relationship between H. pylori-associated serum ghrelin decline and food intake and obesity has not been established. Most studies measure total ghrelin in the circulation although the measurement of the ratio of acyl/total ghrelin gives a clearer indication that the ghrelin acylation process is altered during infection and atrophy. GOAT is essential for the production of biologically-active, acyl ghrelin and the impact of H. pylori on GOAT expression and activity will be highly informative in the future.

Chronic gastritis associated with Helicobacter pylori in Mexican children: histopathological patterns

The objective of this study was to analyze the histopathological patterns of inflammation, distribution, severity, and degree of gastric mucosa of Helicobacter pylori (Hp)-infected children in Northern Mexico, as well as the correlation between colonization density and inflammation intensity. We carried out a cross-sectional study of gastric biopsies performed on children ranging from 2 to 17 years of age who underwent upper gastrointestinal endoscopy for diverse gastroduodenal disorders. This study includes only children who were found to be Hp carriers, with positive results for tests of Hp antigens in feces and in gastric biopsy studies. We studied 107 patients (age 8.2 ± 3.7 years). In 47.7% of patients, the density of Hp colonization was low; only 21.5% had a marked density. Mononuclear leukocyte infiltration showed a similar distribution. Thirty-seven percent of patients had follicular gastritis. An acute inflammatory response was absent in 65% and mild in 20.6% of patients. When inflammation was present, it was primarily located in the antrum (79%). There were no cases of intestinal metaplasia or atrophy. A link was found between Hp density and age, infiltration by mononuclear cells, the presence of follicular gastritis, and the level of neutrophil infiltration (P  =  0.001). Despite the high rates of Hp infection in the region, the histopathological findings in these children were mild and were limited primarily to the antral mucosa. These data indicate the need to study the behavior of this disease in children in diverse study populations to provide localized prevention and treatment strategies.

Consequences of Helicobacter pylori infection in children

Although evidence is emerging that the prevalence of Helicobacter pylori (H. pylori) is declining in all age groups, the understanding of its disease spectrum continues to evolve. If untreated, H. pylori infection is lifelong. Although H. pylori typically colonizes the human stomach for many decades without adverse consequences, children infected with H. pylori can manifest gastrointestinal diseases. Controversy persists regarding testing (and treating) for H. pylori infection in children with recurrent abdominal pain, chronic idiopathic thrombocytopenia, and poor growth. There is evidence of the role of H. pylori in childhood iron deficiency anemia, but the results are not conclusive. The possibility of an inverse relationship between H. pylori and gastroesophageal reflux disease, as well as childhood asthma, remains a controversial question. A better understanding of the H. pylori disease spectrum in childhood should lead to clearer recommendations about testing for and treating H. pylori infection in children who are more likely to develop clinical sequelae.

Primary antimicrobial resistance of Helicobacter pylori in children during the past 9 years

BACKGROUND

Antimicrobial resistance of Helicobacter pylori is a growing problem in clinical practice, particularly clarithromycin resistance. The aim of the present study was therefore to investigate the prevalence of H. pylori resistance to antimicrobial agents in Japanese children.

METHODS

A total of 61 H. pylori strains isolated from children (mean age, 12.6 years; range, 4-18 years) between 1999 and 2007 were studied for primary antimicrobial resistance, using a microdilution method. In addition, the eradication rate with lansoprazole-based triple regimens was determined.

RESULTS

The overall resistance rate of clarithromycin, amoxicillin and metronidazole was 36.1%, 0% and 14.8%, respectively. Resistance to both clarithromycin and metronidazole was detected in 6.6% of the strains. The rate of clarithromycin-resistant strains was 32.4% from 1999 to 2002 and 40.7% from 2003 to 2007, and clarithromycin minimum inhibitory concentration at which 90% of the isolates were inhibited (MIC(90)) increased fourfold from 1999-2002 to 2003-2007, with all clarithromycin-resistant strains showing low-level resistance. Metronidazole resistance rates were not different between these two study periods. Regimens involving amoxicillin and clarithromycin (n= 49) had a higher eradication rate in clarithromycin-susceptible strains (97.1%) than in the resistant strains (57.1%; P < 0.001). There was no difference in the eradication rate between 7 day and 10 or 14 day courses of the regimens (P= 0.53). The regimen with amoxicillin and metronidazole produced successful eradication in all nine patients with clarithromycin-resistant strains.

CONCLUSIONS

Clarithromycin resistance of H. pylori is high, and triple regimen treatment containing clarithromycin should be decided based on susceptibility to the agent.

Helicobacter pylori diagnostic tests in children: review of the literature from 1999 to 2009

The array of tests that can be used for diagnosis of Helicobacter pylori infection is large, and it can be confusing to define which test to use particularly in children where results may not be comparable to those obtained in adult patients. Using PubMed, we reviewed the English literature from January 1999 to May 2009 to identify articles that determined sensitivity and specificity of H. pylori invasive and non-invasive diagnostic tests in children. We excluded articles that presented a review of the literature, abstracts, case reports, or series where children's results could not be separated from adult populations. Of the tissue based methods, rapid urease tests have better sensitivity than histology to detect presence of H. pylori; however, histology can detect the pathology associated with disease including gastritis, intestinal metaplasia, and other conditions that could be the cause of the child's symptoms. Culture of gastric tissues or stool has 100% specificity but sensitivity is low. Of the serologic tests, immunoblot has the best sensitivity. The urea breath tests have >75% sensitivity for detection of H. pylori before and after treatment. Immunoassays in stool using monoclonal antibodies have >95% sensitivity for detection of H. pylori before and after treatment. PCR testing can be performed in tissue and stool samples and can detect genes associated to antibiotic resistance. In summary, the current commercial non-invasive tests have adequate sensitivity and specificity for detecting the presence of H. pylori; however, endoscopy with histopathology is the only method that can detect H. pylori and lesions associated with the infection.

Molecular characterization of the stomach microbiota in patients with gastric cancer and in controls

Persistent infection of the gastric mucosa by Helicobacter pylori can initiate an inflammatory cascade that progresses into atrophic gastritis, a condition associated with reduced capacity for secretion of gastric acid and an increased risk of developing gastric cancer. The role of H. pylori as an initiator of inflammation is evident but the mechanism for development into gastric cancer has not yet been proven. A reduced capacity for gastric acid secretion allows survival and proliferation of other microbes that normally are killed by the acidic environment. It has been postulated that some of these species may be involved in the development of gastric cancer; however, their identities are poorly defined. In this study, the gastric microbiota from ten patients with gastric cancer was characterized and compared with that from five dyspeptic controls using the molecular profiling approach terminal restriction fragment length polymorphism (T-RFLP), in combination with 16S rRNA gene cloning and sequencing. T-RFLP analysis revealed a complex bacterial community in the cancer patients that was not significantly different from that in the controls. Sequencing of 140 clones revealed 102 phylotypes, with representatives from five bacterial phyla (Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria). The data revealed a relatively low abundance of H. pylori and showed that the gastric cancer microbiota was instead dominated by different species of the genera Streptococcus, Lactobacillus, Veillonella and Prevotella. The respective role of these species in development of gastric cancer remains to be determined.

Controlled, household-randomized, open-label trial of the effect of treatment of Helicobacter pylori infection on iron deficiency among children in rural Alaska: results at 40 months

BACKGROUND

Helicobacter pylori infection treatment was found not to reduce the prevalence of iron deficiency or anemia among Alaska Native children at 14 months after treatment initiation. We hypothesized that 14 months was to early to resolve H. pylori-induced gastric damage. Consequently, we conducted a 40-month follow-up.

METHODS

We enrolled 219 children 7-11 years old who had H. pylori infection (as diagnosed by (13)C-labeled urea breath test) and iron deficiency (serum ferritin level, <22.47 pmol/L) in a controlled, household-randomized trial of the effect of treatment of H. pylori on iron deficiency and anemia (hemoglobin level, <115 g/L). At 40 months, 176 children were evaluated.

RESULTS

Forty-four (52%) of 85 children in the intervention group and 53 (58%) of 91 in the control group had iron deficiency (adjusted relative risk [ARR], 0.92 [95% confidence interval {CI}, 0.68-1.26]), versus 4 (5%) and 17(19%), respectively, with both iron deficiency and anemia (ARR, 0.25 [95% CI, 0.09-0.73]). Reinfection occurred among 33 (52%) of 64 children who had cleared their infection. H. pylori-negative children had lower prevalences of iron deficiency (ARR, 0.62 [95% CI, 0.38-1.01]) and iron deficiency and anemia (ARR, 0.22 [95% CI, 0.03-1.50]), compared with H. pylori -positive children.

CONCLUSIONS

The resolution of H. pylori infection for >14 months modestly reduced the prevalence of iron deficiency and substantially reduced the prevalence of iron deficiency and anemia. H. pylori likely plays a casual role in hematological outcomes for some children.

Helicobacter pylori: prevalence and relationship with abdominal pain in school children in Makkah City, western Saudi Arabia

BACKGROUND/AIM

The published data on Helicobacter pylori (H. pylori) prevalence and its relationship with abdominal pain in Saudi Arabia is scarce. This study was carried out to determine the prevalence of H. pylori and its relationship with chronic recurrent abdominal pain (RAP) among school students in Makkah City, Saudi Arabia.

MATERIALS AND METHODS

Three hundred and fourteen school students, 103 at the intermediate level (grades 7-9) aged 12-15 years and 211 at the secondary level (grades 10-12) aged 15-18 years were tested for H. pylori. Urea breath test (UBT) was used for this purpose. Children with chronic RAP were identified as per the Apley criteria.

RESULTS

Overall, the UBT was positive in 86/314 (27.4%) students. It was positive in 45/103 (43.7%) intermediate school students and 41/211 (19.4%) secondary students. Out of the 55 students with chronic RAP, 40 (73%) were positive for H. pylori. Further, 62.9% and 82.1% were positive among the intermediate and secondary school students with RAP, respectively. The overall and specific odds ratios of RAP were 12.35 [95% confidence interval (C.I.) 6.30-24.22] and 10.40 (95% C.I. 1.75-11.73) for the intermediate school students and 22.69 (95% C.I. 7.99-64.44) for the secondary school students.

CONCLUSION

The prevalence of H. pylori among the school children in Makkah, Saudi Arabia, is relatively low compared with developing countries. The prevalence was found to be higher among the younger age group. Further, there was a significant relation between H. pylori infection and RAP among the school students.

Endoscopic and histopathologic findings associated with H. pylori infection in very young children

Most of the individuals infected with H. pylori acquire the infection early in life. However, there is limited data regarding endoscopic and histopathologic findings of H. pylori infection when it is acquired during infancy. The aim of this study was to investigate the H. pylori-related endoscopic and histopathological findings in children younger than 2 years of age. One hundred and fifty-two infants who underwent upper gastrointestinal endoscopy were included in the study. The diagnosis of H. pylori infection was based on histopathology and a positive rapid urease test. Forty of 152 (26.3%) infants were infected with H. pylori, and 65% of the infected infants had histopathologic gastritis. There were no clinical or endoscopic findings suggestive of H. pylori infection. No correlation could be found between the density of H. pylori and the severity of gastritis. H. pylori infection is associated with various degrees of gastritis in more than half of the infected infants. Since the likelihood of normal histopathology is rare in H. pylori-infected infants, its long-term complications should be cautiously followed up in endemic areas.

When does gastric atrophy develop in Japanese children?

BACKGROUND

Long-term Helicobacter pylori infection causes inflammatory sequelae such as atrophy and intestinal metaplasia in the stomach, which is thought to increase the risk of developing gastric malignancy. We previously reported that gastric atrophy can develop in Japanese children with H. pylori infection, predominantly in the antrum. However, detailed data about the age of children with atrophy are largely lacking.

METHODS AND RESULTS

In the present study, 131 children (79 boys) with H. pylori infection were re-analyzed for an association between age and the grade of gastric atrophy. The gastric antrum was histologically evaluated in all 131 patients and the corpus in 46 patients. Grade 2 and 3 antral atrophy was observed in 13 and one patients, respectively: the mean age was 12.1 years. Two patients (11 and 14 years old) had grade 2 corpus atrophy but no patients had grade 3. No significant difference was found in age among patients with grade 0, 1 and 2 or 3 atrophy in the antrum (p = .97) and in the corpus (p = .59). None of the patients with grade 2 or 3 atrophy had intestinal metaplasia either in the antrum or in the corpus.

CONCLUSIONS

The results of the present study require a careful interpretation because of the retrospective analysis. In high-risk countries of gastric cancer, however, eradicating H. pylori in childhood could prove more effective in preventing gastric atrophy, ultimately, the development of cancer.

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.

Prevalence and risk factors for Helicobacter pylori infection in Chinese populations

BACKGROUND

The prevalence of Helicobacter pylori is higher in developing countries. The aim of this study was to investigate the prevalence and risk factors of H. pylori infection in areas with high prevalence of gastric cancer in Jiangsu Province, China.

METHODS

A prospective epidemiologic survey of H. pylori infection was accomplished in a natural population of 1457 individuals in Xiangshui and Gaoyou counties, Jiangsu Province, China. Questionnaires and laboratory tests for H. pylori infection ((13)C-urea breath test and serum IgG antibodies to H. pylori) were used and performed, respectively.

RESULT

Among 1371 subjects who completed questionnaires and H. pylori detection, 851 (62%) were H. pylori positive. The prevalence reached a peak at the age of 30-40 years (67%). There was no sex difference. The annual family income level was shown to be positively correlated with the risk of H. pylori infection. The prevalence of H. pylori infection was also associated with family size, education level, and several diet-related factors, such as the number of times cooked rice and potatoes eaten per week, and a family history of stomach diseases. Compared to nonsymptomatic individuals, people with dyspeptic symptoms (nausea, vomiting, and belching) presented a low prevalence of H. pylori infection. No association between H. pylori prevalence and smoking or drinking was found. Using multivariate logistic regression analysis, annual family income and education level were the independent predictors for H. pylori infection.

CONCLUSION

High prevalence of H. pylori infection was found in areas with a high risk of gastric cancer and was related to several risk factors. The underlying mechanisms need to be further investigated.

Nodular gastritis and pathologic findings in children and young adults with Helicobacter pylori infection

PURPOSE

The aim of this study was to investigate the pathologic characteristics of nodular gastritis in children and young adults infected with Helicobacter pylori (H. pylori).

MATERIALS AND METHODS

A total of 328 patients were enrolled in this study, and the diagnosis of H. pylori infection was done with gastroduodenal endoscopy concomitant with a CLO(TM) test and pathologic analysis of the biopsy specimens. Diagnoses of normal, superficial gastritis, nodular gastritis, and peptic ulcer disease were made from the gastroduodenal endoscopic findings. The density of H. pylori organisms in the gastric mucosa was rated as normal, mild, moderate, or marked. The pathologic findings of nodular gastritis were based on the histopathologic findings of inflammation, immune activity, glandular atrophy and intestinal metaplasia. Each of these findings was scored as either normal (0), mild (1), moderate (2), or marked (3) according to the updated Sydney system and using visual analog scales. The gastritis score was the sum of the four histopathologic scores.

RESULTS

In this study, nodular gastritis (50.6%) was most common, and mild density (51.5%) H. pylori infection was also common upon microscopic examination. Intestinal metaplasia occurred in 9 patients (2.7%).

CONCLUSION

Logistic regression revealed a significant increase in the incidence of nodular gastritis with gastritis score (p=0.008), but not an association with sex, age, or H. pylori density. Gastritis score was the only significant factor influencing the occurrence of nodular gastritis. Intestinal metaplasia, which was originally thought to be a pre-malignant lesion, occurred in 2.7% of the patients with H. pylori infection.

Serum prolidase activity and oxidative status in Helicobacter pylori infection

OBJECTIVES

During the course of Helicobacter pylori infection, increased oxidative stress plays an important role in the pathogenesis of gastroduodenal mucosal inflammation, which can cause gastric mucosal atrophy that characterized by the replacement of the gastric mucosal glands by collagen fibers. In the present study, we aimed to determine serum prolidase activity and oxidative status, and to find out if there is any association between serum prolidase activity and oxidative status in H. pylori infection.

DESIGN AND METHODS

Forty H. pylori-positive and 32 H. pylori-negative subjects were enrolled. Serum prolidase activity was measured spectrophotometrically. Oxidative status was determined using total antioxidant capacity and total oxidant status measurement and calculation of oxidative stress index.

RESULTS

Total antioxidant capacity level was lower in H. pylori-positive group than H. pylori-negative group (p<0.001), whereas total oxidant status, oxidative stress index and prolidase activity were higher (all p<0.05). Significant correlation was observed between serum prolidase activity, and total antioxidant capacity, total oxidant status and oxidative stress index (p<0.01, r=-0.367; p<0.05, r=0.283; p<0.01, r=0.379; respectively) in H. pylori-positive subjects.

CONCLUSION

H. pylori infection may be associated with increased oxidative stress and increased serum prolidase activity. Increased oxidative stress seems to be associated with increased serum prolidase activity and this association may help to provide a better understanding about the pathogenesis of H. pylori infection.

Does gastric atrophy exist in children?

Several clinical reports confirmed that gastric atrophy is a pathology not only limited to adult patients. In pediatrics, it is most often described in association with a H pylori infection but this bacteria does not seem to be the only etiological factor of this preneoplastic state in children. The frequency of gastric atrophy and intestinal metaplasia in children are unknown because they are not systematically sought during upper gastrointestinal endoscopy. The lack of specific histological classification of children’s gastropathies makes their diagnosis difficult for pathologists. Based on our knowledge to date, we think that it is necessary to describe, in detail, the natural course of this lesion during childhood. A close and prolonged clinical and endoscopic follow-up is important for children with gastric atrophy.

Pathogenesis of Helicobacter pylori infection

Much interest has been shown in the relationship between Helicobacter pylori infection and gastric carcinogenesis. It is becoming clearer that H. pylori strains carrying a functional cag pathogenicity island (cagPAI), which encodes the type IV secretion system (TFSS) and its effector CagA, play an important role in the development of gastric carcinoma. Furthermore, genetic polymorphism present in the cagA gene appears to influence the degree of an individual cagPAI-positive H. pylori to elicit gastric mucosal lesions, and this process is significantly affected by host genetic polymorphisms such as proinflammatory cytokine gene polymorphisms. Pathomechanism of gastric carcinogenesis associated with H. pylori includes bacteria-host interaction leading to morphologic alterations such as atrophic gastritis and gastrointestinal metaplasia mediated by COX-2 overexpression, cancer cell invasion, and neo-angiogenesis via TLR2/TLR9 system and transcription factors (e.g., NF-kappaB) activation. In addition, H. pylori infection triggers adhesion molecule expression and activity and produces an enhancement in oxidative stress interacting with gastric production of appetite hormone ghrelin and nonsteroidal anti-inflammatory drugs.

Non-Helicobacter bacterial flora rarely develops in the gastric mucosal layer of children

Non-Helicobacter bacteria can be cultured from the gastric mucosa in adults but in children, there are no studies about such microflora. The purpose of this study, therefore, was to clarify whether gastric biota develops in children. In 10 children and 10 adults or elderly (5 H. pylori-infected and 5 uninfected in each group), biopsy specimens of the gastric antrum and corpus and gastric juice were studied for bacterial examinations and the data were compared between both age groups in relation to H. pylori status and luminal pH. Bacterial genera and species were analyzed using both culture and real-time polymerase chain reaction (PCR) with the 52 genus- and species-specific primer sets. Non-Helicobacter bacteria in the mucosa were cultured from all adult patients, whereas microorganisms were cultured in only one child (p < .001). Gastric pH was lower in children (median, 1.4) than in adults (median, 2.6) (p < .005). The grade of endoscopic gastric atrophy was moderate or severe in 8 adults, but absent or mild in all 10 children. Among adults, there was a significant positive correlation between gastric pH and total bacterial counts of both the mucosa and juice. These data indicate that impaired gastric acid secretion associated with long-term H. pylori infection enables non-Helicobacter bacteria to colonize in the human stomach. Such microorganisms rarely colonize in the gastric mucosa in children regardless of H. pylori status.