Is Helicobacter pylori infection in childhood a risk factor for gastric cancer?

Targeting PI3K/AKT/mTOR and MAPK Signaling Pathways in Gastric Cancer

Gastric cancer (GC) is the fourth leading cause of death worldwide, with more than 1 million cases diagnosed every year. Helicobacter pylori represents the main risk factor, being responsible for 78% of the cases. Increased amounts of salt, pickled food, red meat, alcohol, smoked food, and refined sugars negatively affect the stomach wall, contributing to GC development. Several gene mutations, including PIK3CA, TP53, ARID1A, CDH1, Ras, Raf, and ERBB3 are encountered in GC pathogenesis, leading to phosphatidylinositol 3-kinase (PI3K) protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-PI3K/AKT/mTOR-and mitogen-activated protein kinase (MAPK) signaling pathway activation and promoting tumoral activity. Helicobacter pylori, growth factors, cytokines, hormones, and oxidative stress also activate both pathways, enhancing GC development. In clinical trials, promising results have come from monoclonal antibodies such as trastuzumab and ramucirumab. Dual inhibitors targeting the PI3K/AKT/mTOR and MAPK signaling pathways were used in vitro studies, also with promising results. The main aim of this review is to present GC incidence and risk factors and the dysregulations of the two protein kinase complexes together with their specific inhibitors.

<p>Observation of Changes in <em>Helicobacter pylori</em> Antigen and Antibody Positivity According to Non-Invasive Tests Before and After <em>Helicobacter pylori</em> Eradication Therapy in Symptomatic Patients</p>

Background

Non-invasive tests can help with the diagnosis of Helicobacter pylori (H. pylori) infection and in determining patient prognosis following H. pylori eradication therapy. The aim of the study was to detect H. pylori antigens in the stool in symptomatic patients and to observe changes in the antigen test results following H. pylori eradication therapy.

Methods

A prospective study was conducted. Blood, urine and stool samples were collected from 62 dyspeptic patients. Anti-H. pylori IgM and IgG antibodies were detected in the serum by ELISA, anti-H. pylori IgG antibodies were detected in the urine by ICT and H. pylori antigens were detected in the stool by ELISA. Among the 62 patients, 39 (62.90%) were positive with all three methods. These 39 patients were asked to complete a 2-week course of medication and return after 6 weeks following completion of therapy to undergo repeated tests. In total, 3 dropped out of the study.

Results

Among the 62 dyspeptic patients, 41 (66.13%) were positive for serum IgG according to ELISA, 39 (62.90%) were positive for urine IgG according to ICT, 8 (12.90%) were positive for serum IgM according to ELISA, and 42 (67.74%) were positive for HpSA according to ELISA. After eradication therapy, 18 (50.00%) patients were positive for serum IgG, 19 (52.78%) were positive for urine IgG, 4 (11.11%) were positive for serum IgM and 5 (13.88%) were positive for HpSA. The difference in HpSA positivity before and after eradication therapy was statistically significant (P <0.05).

Conclusion

This study involved non-invasive procedures that can be used as first-line screening tools for the detection of active H. pylori infection to observe the role of HpSA test in diagnosis and assessment of prognosis following eradication therapy for H. pylori.

Recombinant mucin-type proteins carrying LacdiNAc on different O-glycan core chains fail to support H. pylori binding

The β4-N-acetylgalactosaminyltransferase 3 (B4GALNT3) transfers GalNAc in a β1,4-linkage to GlcNAc forming the LacdiNAc (LDN) determinant on oligosaccharides. The LacdiNAc-binding adhesin (LabA) has been suggested to mediate attachment of Helicobacter pylori to the gastric mucosa via binding to the LDN determinant. The O-glycan core chain specificity of B4GALNT3 is poorly defined. We investigated the specificity of B4GALNT3 on GlcNAc residues carried by O-glycan core 2, core 3 and extended core 1 precursors using transient transfection of CHO-K1 cells and a mucin-type immunoglobulin fusion protein as reporter protein. Binding of the LabA-positive H. pylori J99 and 26695 strains to mucin fusion proteins carrying the LDN determinant on different O-glycan core chains and human gastric mucins with and without LDN was assessed in a microtiter well-based binding assay, while the binding of ¹²⁵I-LDN-BSA to various clinical H. pylori isolates was assessed in solution. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and western blotting confirmed the requirement of a terminal GlcNAc for B4GALNT3 activity. B4GALNT3 added a β1,4-linked GalNAc to GlcNAc irrespective of whether the latter was carried by a core 2, core 3 or extended core 1 chain. No LDN-mediated adhesion of H. pylori strains 26 695 and J99 to LDN determinants on gastric mucins or a mucin-type fusion protein carrying core 2, 3 and extended core 1 O-glycans were detected in a microtiter well-based adhesion assay and no binding of a ¹²⁵I-labelled LDN-BSA neoglycoconjugate to clinical H. pylori isolates was identified.

Oral immunization of mice with a multivalent therapeutic subunit vaccine protects against Helicobacter pylori infection

Helicobacter pylori is a human class I carcinogen and no effective prophylactic or therapeutic H. pylori vaccine has yet been marketed. H. pylori can escape the host immune response, but the precise immune protection mechanisms in humans remain unknown. In this study, we developed a multivalent, subunit H. pylori vaccine candidate by formulating three commonly used H. pylori antigens, neutrophil-activating protein (NAP), urease subunit A (UreA) and subunit B (UreB) with the mucosal adjuvant, a double-mutant heat-labile toxin (dmLT) from Escherichia coli, and evaluated its immunogenicity and therapeutic efficacy in a mouse model of H. pylori infection. We found that oral immunization of H. pylori-infected mice significantly reduced gastric bacterial colonization at both 2 and 8 weeks after immunization. The reduction in bacterial burdens was accompanied with significantly increased serum antigen-specific IgG responses and mucosal IgA responses. Moreover, oral immunization also induced Th1/Th17 immune responses, which may play a synergistic role with the specific antibodies in the elimination of H. pylori. Thus, our vaccine candidate appears able to overcome the immune evasion mechanism of H. pylori, restore the suppression of Th2 immune responses with the induction of a strong humoral immune response. These results lay the foundation for the development of an optimized oral therapeutic H. pylori vaccine with increased immunogenicity of UreA and UreB, as well as providing long-term immunity.

Association Between Helicobacter pylori Exposure and Decreased Odds of Eosinophilic Esophagitis-A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Previous or current infection with Helicobacter pylori (exposure) has been reported to protect against eosinophilic esophagitis (EoE), perhaps owing to H pylori-induced immunomodulation. However, findings vary. We performed a systematic review and meta-analysis of comparative studies to define the association between H pylori exposure and EoE more clearly.

METHODS

We searched 4 large databases to identify comparative clinical studies that included sufficient detail to determine the odds or risk of EoE (primary outcome) or esophageal eosinophilia (secondary outcome) among individuals exposed to H pylori (exposed) vs individuals who were tested and found to be unexposed. Estimates were pooled using a random-effects model. Meta-regression and sensitivity analyses were planned a priori. Studies were evaluated for quality, risk of bias, publication bias, and heterogeneity.

RESULTS

We analyzed 11 observational studies comprising data on 377,795 individuals worldwide. H pylori exposure vs nonexposure was associated with a 37% reduction in odds of EoE (odds ratio, 0.63; 95% CI, 0.51-0.78) and a 38% reduction in odds of esophageal eosinophilia (odds ratio, 0.62; 95% CI, 0.52-0.76). Fewer prospective studies found a significant association between H pylori exposure and EoE (P = .06) than retrospective studies. Effect estimates were not affected by study location, whether the studies were performed in pediatric or adult populations, time period (before vs after 2007), or prevalence of H pylori in the study population.

CONCLUSIONS

In a comprehensive meta-analysis, we found evidence for a significant association between H pylori exposure and reduced odds of EoE. Studies are needed to determine the mechanisms of this association.

Helicobacter pylori infection in children: an overview of diagnostic methods

Children differ from adults regarding Helicobacter pylori (H. pylori) infection in many terms. H. pylori infection represents a key factor in the pathogenesis of duodenal ulcer and chronic gastritis in children. H. pylori infection causes some extraintestinal diseases as well as gastrointestinal diseases. Although, among these illnesses in children, symptoms like recurrent abdominal pain are not specific. Moreover, the role of the pathogen in the growth faltering, iron deficiency anemia, and asthma still remains controversial. A reliable method to detect H. pylori infection is a crucial issue, sand is still a matter of active debate. The tests applied for H. pylori diagnosis are grouped as either invasive or non-invasive methods. Invasive methods consist of endoscopic evaluation, the rapid urease test (RUT), histology, and bacterial culture. Non-invasive tests include the urea breath test (UBT), stool antigen test (SAT), serology, and molecular diagnostic approaches. Use of endoscopy is a pre-requisite for all invasive methods and poses difficulties in children as it is a difficult procedure and requires patient's cooperation. For this reason, the non-invasive tests have been commonly used in children, although their accuracy is not very reliable in some cases. Invasive tests may be opted to confirm the diagnosis as and when needed. This review presents the diagnostic tests used to detect H. pylori infection in children.

Initiation of inflammatory tumorigenesis by CTLA4 insufficiency due to type 2 cytokines

CTLA4 insufficiency is genetically associated with stomach cancer. Miska et al. demonstrate that CTLA4 insufficiency causes stomach cancer by autoimmune inflammation, an effect largely attributed to type 2 cytokine stimulation of stomach mucosal cells. These findings suggest preventive strategies against tumor initiation by controlling type 2 inflammation while preserving type 1 immunity.

Genetically predisposed CTLA4 insufficiency in humans is associated with gastric cancer development, which is paradoxical to the prototypical role of CTLA4 in suppressing antitumor immunity. CTLA4 is a critical immune checkpoint against autoimmune disorders. Autoimmunity has been implicated in protumor or antitumor activities. Here, we show that CTLA4 insufficiency initiates de novo tumorigenesis in the mouse stomach through inflammation triggered by host-intrinsic immune dysregulation rather than microbiota, with age-associated progression to malignancy accompanied by epigenetic dysregulation. The inflammatory tumorigenesis required CD4 T cells, but not the T_H1 or T_H17 subsets. Deficiencies in IL-4 and IL-13 or IL-4 receptor α broke the link between inflammation and initiation of tumorigenesis. This study establishes the causality of CTLA4 insufficiency in gastric cancer and uncovers a role of type 2 inflammation in initiating gastric epithelial transformation. These findings suggest possible improvement of immune therapies by blocking tumorigenic type 2 inflammation while preserving antitumor type 1 immunity.

Loss of TFF1 promotes Helicobacter pylori-induced β-catenin activation and gastric tumorigenesis

Using in vitro and in vivo models, we investigated the role of TFF1 in suppressing H. pylori-mediated activation of oncogenic β-catenin in gastric tumorigenesis. A reconstitution of TFF1 expression in gastric cancer cells decreased H. pylori-induced β-catenin nuclear translocation, as compared to control (p < 0.001). These cells exhibited significantly lower β-catenin transcriptional activity, measured by pTopFlash reporter, and induction of its target genes (CCND1 and c-MYC), as compared to control. Because of the role of AKT in regulating β-catenin, we performed Western blot analysis and demonstrated that TFF1 reconstitution abrogates H. pylori-induced p-AKT (Ser473), p-β-catenin (Ser552), c-MYC, and CCND1 protein levels. For in vivo validation, we utilized the Tff1-KO gastric neoplasm mouse model. Following infection with PMSS1 H. pylori strain, we detected an increase in the nuclear staining for β-catenin and Ki-67 with a significant induction in the levels of Ccnd1 and c-Myc in the stomach of the Tff1-KO, as compared to Tff1-WT mice (p < 0.05). Only 10% of uninfected Tff1-KO mice, as opposed to one-third of H. pylori-infected Tff1-KO mice, developed invasive adenocarcinoma (p = 0.03). These findings suggest that loss of TFF1 could be a critical step in promoting the H. pylori-mediated oncogenic activation of β-catenin and gastric tumorigenesis.

Inverse Relationship Between Helicobacter Pylori Infection and Asthma Among Adults Younger than 40 Years: A Cross-Sectional Study

Recent studies have suggested that Helicobacter pylori could prevent allergic disease, particularly in children. However, whether this is true in adults is controversial. The aim of this study was to investigate whether there is negative association between H. pylori infection and asthma among adults in an area with a high prevalence of H. pylori.This was a cross-sectional study using 2011 health surveillance data. Blood samples were taken from all participants to measure serum H. pylori IgG status. Information on demographics, socioeconomic status, and medical history, including asthma and other allergic conditions were collected by a questionnaire.Of the 15,032 patients, 9492 (63.1%) had a history of H. pylori infection, 359 (2.4%) had asthma, and 3277 (21.8%) had other allergic conditions. H. pylori infection was positively correlated with age (OR, 1.050; 95% CI, 1.047-1.053, P < 0.001). Asthma history was positively correlated with age (OR, 1.022; 95% CI, 1.013-1.032, P < 0.001). H. pylori and age were shown to have interaction on asthma in the total participants (OR, 1.041; 95% CI, 1.021-1.062, P < 0.001). In subgroup analysis, H. pylori infection among those < 40 years old was inversely correlated with asthma (OR, 0.503; 95% CI, 0.280-0.904, P = 0.021). Other allergic conditions were not related with H. pylori infection among the total and those <40 years old.The inverse association between H. pylori infection and asthma among young adults suggests that the underlying immune mechanism induced by H. pylori infection may affect allergic reactions associated with asthma in young adults.

Impact of Age, Gender, and Addition of Probiotics on Treatment Success for Helicobacter pylori in Children

The primary objective of this study was to evaluate the effect of age, gender, and the use of probiotics with standard treatment regimen on Helicobacter pylori eradication. Based on endoscopic findings and clinical presentation, selected patients were treated with standard triple therapy (omeprazole, clarithromycin, and amoxicillin). Those who failed were offered a repeat treatment with omeprazole, metronidazole, and amoxicillin. After the publications of the possible advantages of probiotic treatment on H pylori eradication, the probiotic agent “Probiotica Forte” was routinely added to the treatment. Eradication was noted for 94/130 patients (72%) and for 128/197 patients (65%) with or without probiotic agent, respectively (P = .23). For second-line treatment eradication was noted in 33/46 (72%) and in 9/20 (45%) with or without probiotic agent, respectively (P = .053). The addition of probiotics may improve eradication success especially in addition to second-line treatment.

Excretion kinetics of 13C-urea breath test: influences of endogenous CO2 production and dose recovery on the diagnostic accuracy of Helicobacter pylori infection

We report for the first time the excretion kinetics of the percentage dose of (13)C recovered/h ((13)C-PDR %/h) and cumulative PDR, i.e. c-PDR (%) to accomplish the highest diagnostic accuracy of the (13)C-urea breath test ((13)C-UBT) for the detection of Helicobacter pylori infection without any risk of diagnostic errors using an optical cavity-enhanced integrated cavity output spectroscopy (ICOS) method. An optimal diagnostic cut-off point for the presence of H. pylori infection was determined to be c-PDR (%) = 1.47 % at 60 min, using the receiver operating characteristic curve (ROC) analysis to overcome the "grey zone" containing false-positive and false-negative results of the (13)C-UBT. The present (13)C-UBT exhibited 100 % diagnostic sensitivity (true-positive rate) and 100 % specificity (true-negative rate) with an accuracy of 100 % compared with invasive endoscopy and biopsy tests. Our c-PDR (%) methodology also manifested both diagnostic positive and negative predictive values of 100 %, demonstrating excellent diagnostic accuracy. We also observed that the effect of endogenous CO2 production related to basal metabolic rates in individuals was statistically insignificant (p = 0.78) on the diagnostic accuracy. However, the presence of H. pylori infection was indicated by the profound effect of urea hydrolysis rate (UHR). Our findings suggest that the current c-PDR (%) is a valid and sufficiently robust novel approach for an accurate, specific, fast and noninvasive diagnosis of H. pylori infection, which could routinely be used for large-scale screening purposes and diagnostic assessment, i.e. for early detection and follow-up of patients.

Clinical practice: Helicobacter pylori infection in childhood

Helicobacter pylori infection is recognised as a cause of gastritis and peptic ulcer disease (PUD) and usually acquired during the first years of life. While there is a decline in the prevalence of H. pylori infection in northern and western European countries, the infection is still common in southern and eastern parts of Europe and Asia. Symptoms of H. pylori-related PUD are nonspecific in children and may include epigastric pain, nausea and/or vomiting, anorexia, iron deficiency anaemia and hematemesis. Besides, only a small proportion of children develop symptoms and clinically relevant gastrointestinal disease. H. pylori infection can be diagnosed either by invasive tests requiring endoscopy and biopsy or non-invasive tests including the (13)C-urea breath test, detection of H. pylori antigen in stool and detection of antibodies in serum, urine and saliva. The aim of treatment is at least 90 % eradication rate of the bacteria, and a combination of two antibiotics plus a proton pump inhibitor has been recommended as first-line treatment. However, frequent use of antibiotics during childhood is associated with a decline in eradication rates and the search for new treatment strategies as well. This is an overview of the latest knowledge and evidence-based guidelines regarding clinical presentation, diagnosis and treatment of H. pylori infection in childhood.

Update on Peptic Ulcers in the Pediatric Age

Background. Peptic ulcer disease (PUD) in children is reported worldwide, although it is relatively rare as compared with adults. Helicobacter pylori (HP) infection is a common cause of PUD in the pediatric age. Other risk factors include the use of nonsteroidal anti-inflammatory agents (NSAIDs), steroids, immunosuppressive drugs, and stressful events. Aim. To critically review the evidence on epidemiology, diagnostic management, and available treatments for PUD in the pediatric age. Methods. A MEDLINE search was performed indicating keywords as “Peptic Ulcer Disease,” “Epidemiology,” “Pediatric,” “Helicobacter pylori,” “Gastric ulcer,” “Bulbar Ulcer,” and “Upper Gastrointestinal Bleeding.” A selection of clinical trials, systematic reviews, and meta-analyses within the time period 2002–2012 was performed. Results. PUD in children is reported worldwide with an estimated frequency of 8.1% in Europe and of 17.4% in the US. When the underlying cause of PUD is addressed, the prognosis is excellent. Standard triple therapy, bismuth-based quadruple therapy, and the sequential therapy represent the current recommended treatments for HP related ulcers. NSAIDs related ulcers are treated by stopping the causative medications and by administration of proton-pump inhibitors or antisecretory drugs. Conclusions. PUD still represents a major concern in the paediatric age. A careful differential diagnosis and an adequate treatment constitute an excellent prognosis.

IL-1 polymorphisms in children with peptic symptoms in South China

BACKGROUND

Polymorphisms of IL-1 gene cluster are reported to be associated with histological changes and IL-1β expression in the gastric mucosa in adults, especially in Helicobacter pylori-infected subjects. As H. pylori infecting adults and children own different virulence genotypes, the aim of this study was to investigate whether IL-1 polymorphisms are risk factors in young children in South China.

MATERIALS AND METHODS

A total of 128 children with peptic symptoms were enrolled in this study. Polymorphisms of IL-1B-511 and IL-1B-31 were identified by dual fluorescence PCR. Variable number of tandem repeat region in IL-1RN was detected by conventional PCR and IL-1β mRNA expression by real-time PCR ddCT assay.

RESULTS

IL-1B-31T and IL-1B-511C were completely linked in this study. Significant differences of IL-1B-511/-31 genotypes were observed among different clinical outcomes (p = .001). The IL-1B-511TT/-31CC was mostly found in the moderate gastritis and the above (severe gastritis or gastric ulcer) groups, with percentage of 60.7%. While no association was observed between IL-1RN genotypes and the gastric mucosal histological changes (p = .128). Also no relationships were found between IL-1 polymorphisms and H. pylori infection or gastric mucosal IL-1β mRNA expression level.

CONCLUSION

Children with IL-1B-511TT/-31CC may have a risk to develop relatively severe gastric mucosal histological changes in South China.

Association between peroxisome proliferator-activated receptor-γ gene polymorphism (Pro12Ala) and Helicobacter pylori infection in gastric carcinogenesis

OBJECTIVE

Helicobacter pylori infection is accompanied by inflammatory processes leading to peptic ulcer and gastric cancer in the minority of infected individuals. The interaction between H. pylori virulence factors, host defense mechanisms and environmental factors determine the outcome of clinical manifestations. One of the host factors involved in the processes of inflammation and carcinogenesis is the peroxisome proliferator-activated receptor-γ (PPAR-γ) molecule. The present case-control study aimed to determine polymorphism of PPAR-γ gene and its association with H. pylori infection and gastrointestinal diseases (peptic ulcer and non-cardia gastric cancer) in Iranian patients.

MATERIALS AND METHODS

One hundred and fifty-five patients with upper gastrointestinal diseases (76 peptic ulcer and 79 non-cardia gastric cancer) and 152 matched controls were genotyped for PPAR-γ gene polymorphism (Pro12Ala) by the PCR-RFLP method. Infection with H. pylori was confirmed by histology, the rapid urease test (RUT) and ELISA assay (IgG anti-H. pylori).

RESULTS

The frequency of PPAR-γ G (Ala 12) allele was significantly higher in H. pylori positive patients with non-cardia gastric cancer than in controls (22.8% vs. 3.9%, p = 0.027; OR = 3.28; 95% CI = 1.21-8.89), But there was no significant difference without infection (p = 0.7). Moreover, the PPAR-γ polymorphism was not associated with peptic ulcer in the presence or absence of H. pylori infection.

CONCLUSION

Our results indicated PPAR-γ G allele may be an important contributor to non-cardia gastric cancer in Iranian H. pylori infected patients.

Associations between Helicobacter pylori infection, co-morbid infections, gastrointestinal symptoms, and circulating cytokines in African children

BACKGROUND

Refugee children have complex medical needs and often have multiple infections. The relationship between infection, gastrointestinal symptoms, and systemic inflammation is poorly understood. We investigated these parameters in refugee children with a high prevalence of Helicobacter pylori, helminth, and malaria infection.

MATERIALS AND METHODS

African refugee children were recruited at resettlement health screening. Data were collected on demography, gastrointestinal symptoms, co-morbid infection, and serum for peripheral cytokine levels. Helicobacter pylori infection was diagnosed by a fecal-based immunoassay.

RESULTS

Data from 163 children were analyzed, of which 84.0% were positive for H. pylori. Infected children were significantly older (9.2 years +/- 3.7 vs 7.1 years +/- 3.9, p = .01). Half the cohort (84/163, 51.5%) described gastrointestinal symptoms but these were not strongly associated with co-morbid infections. Helicobacter pylori-infected children had significantly lower circulating log-interleukin-8 (IL-8) (odds ratio 0.61, 95% confidence interval (CI) 0.40, 0.94, p = .025). Helminth infections were common (75/163, 46%) and associated with elevated log-IL-5 (beta: 0.42, 95% CI 0.077, 0.76). Children with malaria (15/163, 9.2%) had elevated log-tumor necrosis factor-alpha (TNFalpha) and log-IL-10 (beta: 0.67, 95% CI 0.34, 1.0 and beta: 1.3, 95% CI 0.67, 1.9, respectively). IL-10 : IL-12 ratios were increased in H. pylori-infected children with malaria or helminth infections. Symptoms were generally not associated with levels of circulating peripheral cytokines irrespective of co-morbid infection diagnosis.

CONCLUSIONS

There is a high prevalence of asymptomatic H. pylori infection in recently resettled African refugee children. Gastrointestinal symptoms were not predictive of H. pylori nor of helminth infections. Serum cytokines, particularly IL-5, IL-10, and TNFalpha, were significantly elevated in children with malaria and helminth infections but not in those with H. pylori infection.

Epidemiology of Helicobacter pylori infection in asymptomatic children: a prospective population-based study from the Czech Republic. Application of a monoclonal-based antigen-in-stool enzyme immunoassay

BACKGROUND

Acquisition of Helicobacter pylori occurs mainly in childhood and is significantly influenced by geographical variations. The aim of this study is to evaluate the prevalence of H. pylori infection in a population-based sample of asymptomatic children in the Czech Republic. Furthermore, this study aims to identify potential risk factors associated with this infection.

MATERIALS AND METHODS

A prospective, cross-sectional, population-based study was undertaken in 1545 asymptomatic Czech children (aged 0-15 years; male 49.3%). Active H. pylori infection was diagnosed by monoclonal antibody-based antigen-in-stool enzyme immunoassay. Socio-demographic details of each subject were analyzed using a self-administered standardized questionnaire. Multiple regression analysis was performed.

RESULTS

Overall, 7.1% of asymptomatic children were diagnosed with H. pylori infection. Of the infected children, 5.8% lived in the general population. A positive association was found with increasing age, although not with gender. Independent risk factors associated with H. pylori infection in our pediatric population were: the number of children in a household (odds ratio [OR] 4.26; confidence interval [CI] 1.91-9.80); lack of formal education of fathers (OR 0.23; CI 0.18-0.64) and institutionalized children (OR 6.33; CI 2.25-26.50).

CONCLUSIONS

This study of a large cohort of children demonstrated that, independent of gender, H. pylori infection in the Czech Republic is among the lowest reported in Europe. Socioeconomically disadvantaged children, unfortunately, are still at risk of harboring this potentially preventable infection in this low-prevalence region.

Distinctiveness of the cagA genotype in children and adults with peptic symptoms in South China

BACKGROUND

Helicobacter pylori infection is different between children and adults, not only in infection rate but also in virulence genotypes. However, the 3' region of CagA, important in stomach carcinogenesis, still remains unclear in children. The present study aims to compare the frequency of cagA and the distribution of its subtypes between children and adults in South China.

MATERIALS AND METHODS

One hundred and twenty-eight children and 99 adults with peptic symptoms were enrolled in our research. Histology, rapid urease test, and real-time polymerase chain reaction (PCR) assay were used to diagnose H. pylori infection. vacA s1 was detected by real-time PCR, and EPIYA motifs in the 3' region of CagA by conventional PCR and DNA sequencing.

RESULTS

H. pylori infection was diagnosed in 53 children and 62 adults. vacA s1 was identified in 90.6% and 91.9% of infected children and adults, respectively. Furthermore, cagA was identified in 73.6% and 82.3% of infected children and adults, respectively. No patient with multiple cagA subtypes was observed. A higher prevalence of more virulent cagA genotype was found in children compared to adults (p < .05). Thirty-eight of 39 (97.4%) cagA-positive children were found to have EPIYA-ABD and only one (2.6%) with EPIYA-ABC. In adults, four types of EPIYA motifs--ABC (29.4%), ABD (64.7%), ABAB (2%), and AAD (3.9%)--were identified, and the ABD type was found more commonly in severe diseases, such as atrophic gastritis (53.3%) and gastric cancer (71.4%).

CONCLUSION

cagA genotypes in children and in adults are different, and EPIYA-ABD may have potential clinical implication in the development of gastric cancer in South China.

Does the diagnostic accuracy of the 13C-urea breath test vary with age even after the application of urea hydrolysis rate?

BACKGROUND

Endogenous CO(2) production may be a possible explanation for higher false-positive results reported for (13)C-urea breath test (UBT) in children below 6 years. In this study, we evaluated whether age affects the diagnostic accuracy of the (13)C-UBT even after the application of urea hydrolysis rate (UHR) in children.

METHODS

A total of 612 (13)C-UBTs and endoscopic biopsies were performed on children divided into two groups; children under 6 years (n = 126) and children aged 6-18 years (n = 486). For (13)C-UBT, 75 mg (13)C-urea was ingested, and breath sample was collected 30 minutes later. Delta over baseline (DOB) was determined, and UHR was calculated to normalize the DOB values for endogenous CO(2) production.

RESULTS

There was significant difference between the DOB values of children under 6 years and those of children over 6 years in H. pylori-positive (p = .029) and -negative groups (p = .002). On applying the UHR, no significant difference was observed between the UHR values of children under 6 years and those of children over 6 years in H. pylori-positive (p = .877) and -negative groups (p = .427). In 12.6% children under 6 years, false-positive results were observed on applying the DOB, and in 9.0% on applying the UHR (p = .125).

CONCLUSIONS

The (13)C-UBT is a noninvasive method exhibiting high diagnostic accuracy with both UHR as well as DOB. However, high false-positive results for (13)C-UBT were noted in children below 6 years on applying both UHR as well as DOB. Thus, this may not only be due to the effects of endogenous CO(2) production but also due to other factors.

Helicobacter pylori infection in children: management and pharmacotherapy

Helicobacter pylori infection is mainly acquired during childhood: it is recognised as a cause of gastritis and peptic ulcer and it has been classified as a group A carcinogen by the World Health Organisation. The exact mode of transmission is as yet unknown. The aim of this review was to analyse the literature about H. pylori infection in paediatric patients. The large diffusion of H. pylori infection in paediatric patients, the absence of a specific clinical feature, the new non-invasive methods for diagnosis and follow-up, which are still not validated and the different therapeutic schedules have led to the necessity of determining the real clinical outcome in affected children and adolescents. The scope of the review was to identify better eradication therapy and the most important factors in treatment failure. The international literature has shown the importance of culture, antibiograms, the compliance of families and patients and the use of probiotics during triple eradication therapy. The review paid attention to the management, diagnostic techniques and therapy of this infection in paediatric patients.

Peptic ulcers and erosions are common in Israeli children undergoing upper endoscopy

BACKGROUND

Peptic ulcers and erosions (PU&E) are thought to be uncommon in children. Patients with early exposure to Helicobacter pylori may be at a higher risk for early onset PU&E. Children in Israel have a high prevalence and early acquisition of Helicobacter pylori (H. pylori) and have easy access to pediatric gastroenterologists and endoscopy. Our aim was to describe the prevalence and characteristics of PU&E in this population referred by Pediatric Gastroenterologists for an upper endoscopy.

METHODS

We conducted a retrospective study over the years January 2003-May 2006. Over these years we had information on 751 diagnostic upper endoscopies. PU&E was regarded as erosive gastritis/duodenitis or ulcer in either the stomach or duodenum. H. pylori status was assessed using rapid urease test and gastric biopsies.

RESULTS

PU&E was detected in 169 (22.5%) patients (ulcers 51 (6.8%), erosions 118 (15.7%)). One hundred twenty-four had gastric PU&E and 58 had duodenal PU&E. H. pylori was positive in 112 (66.3%). H. pylori-associated PU&E becomes common after age 10 years, with gastric PU&E presenting much earlier than duodenal disease. Most of the H. pylori-negative PU&E were idiopathic and improved symptomatically on PPI treatment. Interestingly, 43% of patients with PU&E in our cohort were either immigrants from the former Soviet Union or of Israeli Arab origin.

CONCLUSIONS

PU&E appears to be common in this selected population with a relatively high incidence of gastric PU&E. H. pylori associated PU&E becomes common after age 10 years with gastric PU&E presenting much earlier than duodenal disease. Non H. pylori PU&E in children comprises approximately a third of all PU&E, are mostly idiopathic and appear earlier than H. pylori associated PU&E.

Association of Helicobacter pylori and childhood lymphoma

We aimed to estimate the frequency of association between non-Hodgkin lymphoma (NHL) with abdominal, gastric, or intestinal involvement and Helicobacter pylori in childhood. Between February 2003 and June 2006, we evaluated 15 children with newly diagnosed NHL who were diagnosed and treated at the Pediatric Oncology Department of Hacettepe University. Patients who were given chemotherapy previously or who received H. pylori eradication therapy were excluded from the study. Routine procedures were done for staging. Pathologic diagnosis was made by examining the biopsy samples. The presence of H. pylori was confirmed by H. pylori IgG serology with urea breath test (UBT) in cooperated children. Endoscopic examination was also planned for patients with positive test results. Twelve male and 3 female patients, with a median age of 7 (range: 3 to 16), were evaluated. They had extensive abdominal, gastric, and/or intestinal involvement. Six had stage IV characteristics, whereas another 9 patients had stage III disease. Ten had high-grade B-cell lymphoma. Only 3 patients had H. pylori IgG and UBT positivity (20%). First patient had T-cell lymphoma and stage IV disease with involvement in stomach, mediastinum, peripheral lymph nodes, and bone marrow. The second one had anaplastic large cell lymphoma exclusively in abdominal lymph nodes. Last patient had Burkitt lymphoma and stage IV disease, with primary tumor localization in abdominal lymph nodes, liver, and kidneys. The H. pylori IgG and UBT were both positive in 3 patients on admission. We did not find any positive test results in the other 12 patients with intestinal, stomach, or abdominal disease. Preliminary results of our study suggest that H. pylori may not be the responsible agent for NHL involved the abdomen in childhood.

13C urea breath test for (Helicobacter pylori): determination of the optimal cut-off point in a Canadian community population

AIM

To determine the test characteristics and the optimal cut-off point for the (13)C urea breath test ((13)C UBT) in a Canadian community laboratory setting.

METHODS

Of 2232 patients (mean age +/- SD: 51+/-21 years, 56% female) who completed a (13)C UBT, 1209 were tested to evaluate the primary diagnosis of (Helicobacter pylori) infection and 1023 were tested for confirmation of eradication following treatment. Cluster analysis was performed on the (13)C UBT data to determine the optimal cut-off point and the risk of false-positive and false-negative results. Additionally, 176 patients underwent endoscopic biopsy to allow validation of the sensitivity and specificity of the (13)C UBT against histology and microbiology using the calculated cut-off point.

RESULTS

The calculated cut-off points were 3.09 delta/1000 for the whole study population (n=2232), 3.09 delta/1000 for the diagnosis group (n=1209) and 2.88 delta/1000 for the post-treatment group (n=1023). When replacing the calculated cut-off points by a practical cut-off point of 3.0 delta/1000, the risk of false-positive and false-negative results was lower than 2.3%. The (13)C UBT showed 100% sensitivity and 98.5% specificity compared with histology and microbiology (n=176) for the diagnosis of active (H pylori) infection.

CONCLUSIONS

The (13)C UBT is an accurate, noninvasive test for the diagnosis of (H pylori) infection and for confirmation of cure after eradication therapy. The present study confirms the validity of a cut-off point of 3.0 delta/1000 for the (13)C UBT when used in a large Canadian community population according to a standard protocol.

Gastric adenocarcinoma: reduction of perioperative mortality by avoidance of nontherapeutic laparotomy

National trends indicate a longstanding decline in gastric adenocarcinoma due presumably to a decreasing prevalence of Helicobacter pylori infection. Nonetheless, surgical outcomes continue to include relatively high morbidity and mortality rates owing to the advanced stage of disease encountered. We hypothesize that recent immigration patterns are responsible for a leveling off or even reversal of the declining incidence of gastric cancer associated with H. pylori infection. Furthermore, advances in preoperative tumor staging and nonoperative palliation currently permit better patient selection for operation with lower perioperative morbidity and mortality. A retrospective review of a consecutive case series at a public teaching hospital located in an area of high immigration was conducted that included all patients presenting, from 1995 through 2004, with gastric adenocarcinoma. For time comparison purposes, patients were divided into early (1995-1999) and recent (2000-2004) periods. There was no decline in the frequency of gastric adenocarcinoma among the study population over the 10 years. A total of 260 patients were treated of whom 137 (53%) underwent operation. The operation rate decreased and the gastric resection rate increased from the early period to the recent period as fewer incurable advanced stage (M1) patients underwent exploratory laparotomy and were palliated by nonoperative means. Perioperative morbidity and mortality rates also declined over time. Of the four total perioperative deaths, two followed 11 nontherapeutic laparotomies (18% mortality), whereas the only two additional deaths followed 122 curative or palliative laparotomies (2% mortality) (p = 0.034). We conclude that in an area of high immigration there has been no decline in gastric adenocarcinoma rates over the past decade, and the marked reduction in perioperative mortality was due to near elimination of nontherapeutic laparotomy.

Usefulness of a serological panel test in the assessment of gastritis in symptomatic children

BACKGROUND

Non-invasive methods are advisable for the detection of Helicobacter pylori-related chronic gastritis in pediatric patients. Serum pepsinogens I and II (sPGII and sPGII), gastrin-17 (G-17) and anti-H. pylori antibodies (IgG-Hp) have been proposed as a 'serological gastric biopsy'.

AIM

To assess H. pylori infection and to evaluate gastric mucosa status in a pediatric population by means of serological parameters such as sPGI, sPGII, G-17 and IgG-Hp.

METHODS

45 consecutively children evaluated for upper gastrointestinal symptoms were analyzed. All children were submitted to upper gastrointestinal endoscopy with biopsies. Serum samples were analyzed for IgG-Hp, sPGII, sPGI and G-17 (Biohit, Helsinki, Finland).

RESULTS

18 children had H. pylori-related mild or moderate non-atrophic chronic gastritis. They presented significantly higher mean levels of sPGII and of IgG-Hp than negative ones, either under or up to 10 years. sPGI showed significantly increased levels in H. pylori-positive patients only over 10 years. G-17 levels were not different between H. pylori-positive and -negative ones. The best cut-offs of IgG-Hp, sPGII and of product IgG-Hp x sPGII, to identify H. pylori infection, were 30 IU/l, 9 microg/l, and 241 IU/l x microg/l, respectively. The product IgG-Hp x sPGII identified H. pylori infection with a 100% sensitivity, 92% specificity, 90% positive predictive value and 100% negative predictive value. IgG-Hp and IgG-Hp showed a correlation (r = 0.94; p < 0.001).

CONCLUSIONS

Combined analysis of sPGII and IgG-Hp antibody levels could be recommended as a non-invasive panel for the assessment of H. pylori-related histological alterations of gastric mucosa in childhood.

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.

Metal speciation, phytochemicals and Helicobacter pylori infection

Helicobacter pylori (HP) acquired in childhood is an important risk factor for gastric carcinoma. Once colonization is established, infection may be carried for life. The relationship between food intake and HP infection, the presence of metals and phytochemicals closely associated with oxidative stress within everyday diet are important topics to be considered. The possible anti-HP effects of phytochemicals, prooxidant effects exerted in the presence of metal species, intimate relations between some metals and HP, bivalent effects of some metal species in cancer, interactions between metal species and phytochemicals in HP infection are the topics, which require further research. Formulas or diets enriched with phytochemicals and metals against HP and, which are devoid of metals known to favour the growth of HP, may be suggested as the supplements to the classical treatment regimens. The importance of collective consideration of HP, metal species and phytochemicals should be emphasized.

Gastrointestinal tumors in children and adolescents

Tumors of the pediatric gastrointestinal tract are extremely rare. Their infrequent presentation at treatment centers has not allowed for the development of standardized treatment protocols and prospective review. The most prevalent gastrointestinal neoplasms and malignancies are described, including gastrointestinal lymphoma, colorectal carcinoma, carcinoid tumors, gastrointestinal stromal tumors, leiomyomas, juvenile polyps, inflammatory pseudotumors, gastric tumors, and Peutz-Jeghers polyposis syndrome. Current recommendations for the medical and surgical management of these tumors are reviewed and summarized for this vast group of gastrointestinal neoplasms in children.

Helicobacter pylori and recurrent pain abdomen

OBJECTIVE

Pain abdomen is a common problem in childhood. Many factors i.e., organic changes in the gut, psychological and environment contribute to recurrent pain abdomen (RAP) in children. Helicobacter pylori infects children very early in childhood and stays indefinitely in the gut without its eradication. It may be responsible for pain abdomen and peptic ulcers in children. This study was done to assess the HP status in children with RAP diagnosed and evaluate the effects of eradication of HP infection in them.

METHODS

76 children were included in the study.

RESULT

Out of 76 children studied 14.8% had evidence of a secondary cause for pain abdomen and responded to appropriate therapy. 65.45% of children who had undergone UGIE, had evidence of HP infection in the upper gastrointestinal tract. Most of these children responded to HP eradication therapy by becoming free of abdominal pain after the eradication therapy with OCA or OMA regimen. We could not do repeated endoscopies in all of them to prove the eradication due to parents' refusal and this is the main drawback of this study.

CONCLUSION

However, in view of clinical response to HP eradication therapy in almost all the cases, we strongly advocate this therapy for those children with RAP, in whom HP infection of the upper gastrointestinal tract can be established beyond doubt.

Important bacterial gastrointestinal pathogens in children: a pathogenesis perspective

This article focuses on the five most common bacterial enteropathogens of the developed world--Helicobacter pylori, Escherichia coli, Shigella, Salmonella, and Campylobacter--from the perspective of how they cause disease and how they relate to each other. Basic and recurring themes of bacterial pathogenesis, including mechanisms of entry, methods of adherence, sites of cellular injury, role of toxins, and how pathogens acquire particular virulence traits (and antimicrobial resistance), are discussed.

Diagnostic accuracy of the C-urea breath test in children: adjustment of the cut-off value according to age

BACKGROUND AND AIMS

The (13)C-urea breath test ((13)C-UBT) is a reliable non-invasive method of diagnosing Helicobacter pylori infection in adults and children. However, only a few validation studies have been performed on the (13)C-UBT in very young children. The purpose of the present study was to evaluate the diagnostic accuracy of the (13)C-UBT according to age, and to determine the optimal cut-off value in children.

METHODS

A total of 307 (13)C-UBT were performed in 274 children. All were compared with the results of endoscopic biopsy-based methods to confirm H. pylori infection. Seventy-five milligrams of (13)C-urea was ingested without a test meal. Two breath samples were collected at 0 and 30 min. The optimal cut-off value of the (13)C-UBT was assessed by determining the sensitivity, specificity, false negative, and false positive results, at cut-off values ranging from 2.0 to 10.0 per thousand.

RESULTS

The delta over baseline (DOB) values of the (13)C-UBT showed a significant negative correlation with age in both the H. pylori-positive group (r = -0.309; P = 0.005) and the H. pylori-negative group (r = -0.162; P = 0.015). High false positive results and low specificity were noted in children aged 6 years or less compared with children older than 6 years at a cut-off value of 4.0 per thousand (false positives; 8.3%vs 0.85%, specificity; 89.8%vs 98.8%). After adjusting the cut-off value, the optimal cut-off values were found to be 4.0 per thousand in children older than 6 years and 7.0 per thousand in children aged 6 years or less.

CONCLUSIONS

The cut-off value of the (13)C-UBT recommended regardless of age must be adjusted in preschool children to reduce the false positive results.

Will eradication of Helicobacter pylori infection influence the risk of gastric cancer?

Gastric adenocarcinoma is a disease of high mortality and poor prognosis that is second only to lung cancer as a leading cause of cancer-related deaths worldwide. Although gastric cancer has a multifactorial etiology, infection with Helicobacter pylori is highly associated with its development. New information on bacterial and host genetics and results of epidemiologic studies suggest that better identification of individuals at high risk for gastric malignancy may be possible. Studies suggest that cure of H pylori infection may be associated with retardation of glandular atrophy and intestinal metaplasia but not reversal of dysplasia. Theoretically, it is attractive to believe that eradication of H pylori infection might prevent gastric cancer; however, studies supporting this hypothesis are not yet available. Public policy strategies for the identification of patients at risk for H pylori-related gastric malignancy are likely to be complex, but testing and treating for the infection earlier rather than later in life is anticipated to be the more beneficial approach.

Symptomatic response to Helicobacter pylori eradication in children with recurrent abdominal pain: double blind randomized placebo-controlled trial

BACKGROUND

Controlled trials considering the effect of Helicobacter pylori (H. pylori) eradication on gastrointestinal symptoms in children are scant. We aimed to study the connection between recurrent abdominal pain and dyspepsia and H. pylori infection in children.

STUDY

This was a double blind randomised controlled trial. Twenty children with recurrent abdominal pain (RAP) being H. pylori positive as measured with the C urea breath test (UBT) were randomized either to receive omeprazole, amoxycillin and clarithromycin (n = 10), or omeprazole and 2 placebos (n = 10) for 1 week after gastroscopy. Symptoms were registered prior to the treatment and at follow up visits 2, 6, 24, and 52 weeks after stopping the treatment. Control UBT was performed on all patients 6 weeks post-treatment and again at the 52 week follow-up visit, when also re-endoscopy with biopsies was done to all participants.

RESULTS

All infected children had histologic gastritis. Bacterial eradication was achieved in 8/10 in the triple treatment group and in none in the placebo group. There was no change in symptom index in either group at 2 weeks post treatment. At 52 weeks a similar reduction in symptom index was observed in both groups irrespective of the healing of gastritis, which was more commonly achieved along the eradication.

CONCLUSIONS

Bacterial eradication and healing of gastric inflammation does not lead to symptomatic relief of chronic abdominal pain in children.

Helicobacter pylori infection in Burkina Faso: an enigma within an enigma

BACKGROUND

In Burkina Faso, in contrast with high rates of Helicobacter pylori infection from an early age, the prevalence of H. pylori-associated diseases (ulcer and gastric cancer) is low.

AIMS

To look for the prevalence of H. pylori in healthy natives of Burkina Faso, both children and adults.

METHODS

We studied the prevalence of H. pylori infection in 258 healthy natives of Burkina Faso (70 children aged 6 months-15 years and 188 adults aged 16-65 years), using a serological screening (IgA and IgG H. pylori antibodies). All the studied subjects underwent a questionnaire regarding their life-style, socio-economic status, dietary habits and hygienic sanitary conditions. Data concerning the questionnaire were compared between H. pylori positive and negative subjects.

RESULTS

The rates of H. pylori positivity in children were significantly higher than in adults, and in adults the positivity for H. pylori infection decreased with increasing age. The comparison of the questionnaire's data between H. pylori seropositive and seronegative subjects showed that poor socio-economic status and hygienic sanitary conditions were similar in the two groups. Instead, a higher prevalence of H. pylori positivity was observed in subjects belonging to families living in close contact with sheep, because of their labour and agro-pastoral tradition (shepherds and sedentary farmers).

CONCLUSION

H. pylori infection in Burkina Faso is acquired early in life and is related not only to some yet well-known risk factors (poor socio-economic and hygienic status), but also to a close contact with sheep. The gradually decreasing H. pylori seropositivity in adult population of Burkina Faso represents an unexplained enigma, which needs further studies.

Helicobacter pylori modulation of gastric and duodenal mucosal T cell cytokine secretions in children compared with adults

BACKGROUND

In contrast to adults, ulcers are un-common in Helicobacter pylori-infected children. Since immunological determinants influence the outcome of H. pylori infection, we have investigated mucosal T cell responses in H. pylori-infected children and compared them with those of adults and negative controls.

MATERIAL AND METHODS

Mucosal biopsies were obtained from 43 patients undergoing an upper GI endoscopy for dyspeptic symptoms. The concentrations of released cytokines and the density of CD3+, CD25+ and CD69+cells were evaluated by flow cytometry, and the numbers of cytokine-secreting cells were measured by ELISPOT.

RESULTS

The numbers of isolated antral CD3+ lymphocytes were only significantly raised in infected adults compared with noninfected controls (p < 0.05), whereas the proportion of CD3+ cells expressing activation markers (CD25 or CD69) remained low. In the stomach, IFN-gamma concentrations increased in infected children and infected adults compared with controls (p < 0.05), but IFN-gamma concentrations were tenfold lower in children than in adults (p < 0.01). IL-2, IL-4, IL-10 and TNF-alpha concentrations were similar in infected and in uninfected children and adults. In contrast, in the duodenum, IFN-gamma, as well as IL-4 and IL-10 concentrations were only increased in infected children compared with controls (p < 0.05). The concentrations of these cytokines were similar in both groups of adults who, however, like children, displayed a higher number of duodenal IL-4-secreting cells compared to controls (p < 0.05).

CONCLUSION

These results suggest that IFN-gamma secretion in the stomach of H. pylori-infected patients is lower in children than in adults. This could protect children from development of severe gastro-duodenal diseases such as ulcer disease. In addition, infected patients are characterised by a dysregulation of the mucosal cytokine secretion at distance from the infection site.

Helicobacter pylori infection and gastric cancer: evidence from a retrospective cohort study and nested case-control study in China

AIM: To explore the association between Helicobacter pylori (Hp) infection and risk of gastric cancer in China.

METHODS: Utilizing gastroendoscopic biospsy tissue banks accumulated from1980 to1988 in Shandong, Zhejiang, and Jiangsu, where stomach cancer incidence was high, during stomach cancer screening conducted by Health Science Center of Peking University, School of Medicine of Zhejiang University, and Zhongshan Hospital of Fudan University. Warthin Starry silver staining method was applied to determine H. pylori infection status of biopsies collected during gastroendoscopic examination. In the retrospective study, the subjects were divided into two cohorts, the exposure cohort was positive H. pylori infection, and the non-exposure cohort was negative. Death from stomach cancer was determined as the outcome of the study. Logistic regression and Cox regression were applied to analyze the association between Helicobacter pylori infection and gastric cancer risk. In the nested case-control study, there were 28 deaths from gastric cancer in the fields of Muping, Shandong province, and Zhoushan, Zhejiang provinces. 4 controls were matched to each case on the basis of age ( ± 5 years old), sex, residential place at the same time entered into the study. Conditional logistic regression analysis was used to analyze the data.

RESULTS: There were a total of 2719 subjects (male 1399, female 1320) with gastroendoscopic biopsies stored available treated as a cohort. H. pylori positive cohort included 1671 subjects (61.5%) and H. pylori negative cohort 1048 subjects(38.5%). These subjects were followed up for 1-19 years, averaged 10.88 years. The outcome of death from stomach cancer in the exposure cohort was 33, and in the non-exposure cohort 11. After adjustment for age and sex, RR = 1.9850 (P = 0.0491), 95%CI was 1.0026, and 3.9301. The results of conditional logistic regression showed an OR of 4.467 and 95%CI of 1.161, and 17.190 for the nested case control study.

CONCLUSION: The results from the retrospective cohort study and the nested-case control study on the association of H. pylori infection and gastric cancer in China suggested that Helicobacter pylori infection might increase the risk of stomach cancer.

Helicobacter pylori infection: treatment

Current standard treatment regimens for Helicobacter pylori infection provide eradication rates 80 to 90%. These rates have been achieved with a variety of 1-week triple therapies using two antibiotics and an acid suppressant. Antibiotic resistance, which may develop during failed treatment, is becoming increasingly common and has led to studies of new regimens for primary therapy, and new strategies for salvage of failed therapy. Other regimens have been designed and tested with the aim of decreasing the cost of initial therapy or to improve compliance, but abbreviated regimens have high incidence of failure and may add to the problem of resistance. Increasing attention has been paid to the need for, and timing of, the determination of antibiotic resistance of H. pylori isolates either at the time of initial diagnosis or after treatment failure. New, simpler, and noninvasive methods are offered for follow-up to determine if eradication has been successful. Treatment regimens should be chosen based on local drug susceptibility patterns and the availability of approved therapeutic agents in each country. Established indications for testing for H. pylori and administering therapy include active or inactive peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma, as well as hyperplastic polyps, hyperplastic gastropathy, postendoscopic resection for gastric malignancy, and acute H. pylori gastritis. It is now largely accepted that noninvestigated dyspepsia is an indication for testing for and treating H. pylori, but that dyspeptic symptoms shown not to be associated with ulcer (nonulcer dyspepsia) do not now provide an indication for testing. Controversial or unresolved indications for testing and treating include planned use of chronic antisecretory therapy, planned use of nonsteroidal anti-inflammatory drugs, and use as a general approach to the prevention of gastric cancer.