Risk of recurrent Helicobacter pylori infection 1 year after initial eradication therapy in 7 Latin American communities

Recurrence Rate and Influencing Factors of Helicobacter Pylori Infection After Successful Eradication in Southern Coastal China

Purpose

Recurrence rate of Helicobacter pylori (H. pylori) infection after successful eradication have gained attention. This study was to assess the recurrence rate of H. pylori infection after successful eradication in the southern coastal provinces of China and to analyze its factors.

Patients and Methods

975 patients with upper gastrointestinal symptoms who were diagnosed with H. pylori infection using the 13C or 14C-urea breath test (UBT) underwent eradication treatment between August 2021 and December 2022. After eight to twelve weeks, repeat UBT was performed. Besides, 824 patients with successful eradication underwent a repeat UBT by completing questionnaires after a year. The 1-year recurrence rate was calculated, and the differences were analyzed based on baseline data, sociological characteristics, and lifestyle.

Results

A total of 734 patients completed the 1-year follow-up, out of which 26 (3.5%) patients experienced a recurrence of H. pylori infection. Exposure to other individuals infected with H. pylori (χ2=12.852, P<0.001), poor hygiene conditions at dining out places (χ2=6.839, P=0.009), frequent dining out (χ2=24.315, P<0.001), smoking (χ2=7.510, P=0.006), consumption of non-purified water (χ2=16.437, P<0.001), consumption of pickled foods (χ2=5.682, P=0.017), irregular meal patterns (χ2=16.877, P<0.001) and age (χ2=9.195, P=0.010) were significant factors for H. pylori infection recurrence. Exposure to other individuals infected with H. pylori, poor hygiene conditions at dining out places, consumption of non-purified water, frequent dining out and irregular meal patterns were independent risk factors (P=0.022, 0.016, 0.002, <0.001, <0.001; 95% CI 0.146-0.861, 0.121-0.806, 1.715-10.845, 0.085-0.521, 2.291-14.556).

Conclusion

The one-year recurrence rate of H. pylori infection post-eradication in the southern coastal provinces of China is 3.5%. Contacting with infected individuals, poor hygiene in dining places, consumption of non-purified water, frequent dining out, and irregular meal patterns were identified as significant independent factors influencing H. pylori recurrence.

Do atrophic gastritis and intestinal metaplasia reverse after Helicobacter pylori eradication?

BACKGROUND

It's still controversial whether Helicobacter pylori (H. pylori) eradication can reverse atrophic gastritis (AG) and intestinal metaplasia (IM). Therefore, we performed a meta-analysis to estimate the effect of H. pylori eradication on AG and IM.

METHODS

We searched the PubMed, Web of Science and EMBASE datasets through April 2023 for epidemiological studies, which provided mean glandular atrophy (GA) or IM score before and after H. pylori eradication, or provided ORs, RRs or HRs and 95% CIs for the association of AG or IM with H. pylori eradication. Weighted mean difference (WMD) and pooled ORs and 95%CIs were used to estimate the effect of H. pylori eradication on AG and IM.

RESULTS

Twenty articles with a total of 5242 participants were included in this meta-analysis. H. pylori eradication significantly decreased GA score in the antrum (WMD -0.36; 95% CI: -0.52, -0.19, p < 0.01), GA score in the corpus (WMD -0.35; 95% CI: -0.52, -0.19, p < 0.01), IM score in the antrum (WMD -0.16; 95% CI: -0.26, -0.07, p < 0.01) and IM score in the corpus (WMD -0.20; 95% CI: -0.37, -0.04, p = 0.01). H. pylori eradication significantly improved AG (pooled OR 2.96; 95% CI: 1.70, 5.14, p < 0.01) and IM (pooled OR 2.41; 95% CI: 1.24, 4.70, p < 0.01). The association remained significant in the subgroup analyses by study design, sites of lesions, regions and follow-up time. Although Publication bias was observed for AG, the association remained significant after trim-and-fill adjustment.

CONCLUSIONS

H. pylori eradication could significantly improve AG and IM at early stage.

Ornithine Decarboxylase in Gastric Epithelial Cells Promotes the Immunopathogenesis of Helicobacter pylori Infection

Colonization by Helicobacter pylori is associated with gastric diseases, ranging from superficial gastritis to more severe pathologies, including intestinal metaplasia and adenocarcinoma. The interplay of the host response and the pathogen affect the outcome of disease. One major component of the mucosal response to H. pylori is the activation of a strong but inefficient immune response that fails to control the infection and frequently causes tissue damage. We have shown that polyamines can regulate H. pylori-induced inflammation. Chemical inhibition of ornithine decarboxylase (ODC), which generates the polyamine putrescine from l-ornithine, reduces gastritis in mice and adenocarcinoma incidence in gerbils infected with H. pylori However, we have also demonstrated that Odc deletion in myeloid cells enhances M1 macrophage activation and gastritis. Here we used a genetic approach to assess the specific role of gastric epithelial ODC during H. pylori infection. Specific deletion of the gene encoding for ODC in gastric epithelial cells reduces gastritis, attenuates epithelial proliferation, alters the metabolome, and downregulates the expression of immune mediators induced by H. pylori Inhibition of ODC activity or ODC knockdown in human gastric epithelial cells dampens H. pylori-induced NF-κB activation, CXCL8 mRNA expression, and IL-8 production. Chronic inflammation is a major risk factor for the progression to more severe pathologies associated with H. pylori infection, and we now show that epithelial ODC plays an important role in mediating this inflammatory response.

Preliminary single-center experience of Helicobacter pylori eradication among the liver transplant recipients

OBJECTIVE

To investigate the prevalence of Helicobacter pylori infection among orthotopic liver transplant (LT) recipients and explore the efficacy and safety of H. pylori eradication therapy.

METHODS

Liver transplant recipients receiving regular follow-up in our center were assessed by 13C-urea breath test between February 2018 and July 2020. A group of healthy tested patients were selected as control group at a rate of 1:3. All LT recipients with H. pylori were recommended to receive eradication therapy with bismuth-containing quadruple therapy (BQT), which included esomeprazole 20 mg + clarithromycin 500 mg + amoxicillin 1 g + bismuth 220 mg, twice daily for 14 days.

RESULTS

The prevalence of H. pylori infection among the LT recipients was 19.6% (30/153), which was significantly lower than the control group (30/153 [19.6%] vs. 200/459 [43.6%], p < 0.001). In LT recipients who received transplantation at <1 year, 1-3 years, and >3 years, the prevalence of H. pylori infection was 10.6% (5/47), 17.5% (10/57), and 30.6% (15/49), respectively, which increased with the time after transplantation (p = 0.04). With BQT, the eradication rate of H. pylori was 91.3% (21/23). During the process of eradication, the blood trough concentration of immunosuppressants increased from 1.7 to 3.6 times, and reducing the dose of the drugs to one-third of what they were before the eradication therapy could avoid excessively elevated concentration of immunosuppressants. Adverse effects occurred in 55.2% (11/23), of the LT recipients and 21.0% (42/200) of the control group (p < 0.01), which was probably caused by the increased blood concentration of immunosuppressants. Normal liver function was observed, while transient abnormal kidney function was occurred in one recipient.

CONCLUSION

The prevalence of H. pylori infection was 19.6% among the LT recipients, which increased with the postoperative time. With BQT, H. pylori eradication was safe and effective in LT recipients.

Dicarbonyl Electrophiles Mediate Inflammation-Induced Gastrointestinal Carcinogenesis

BACKGROUND & AIMS

Inflammation in the gastrointestinal tract may lead to the development of cancer. Dicarbonyl electrophiles, such as isolevuglandins (isoLGs), are generated from lipid peroxidation during the inflammatory response and form covalent adducts with amine-containing macromolecules. Thus, we sought to determine the role of dicarbonyl electrophiles in inflammation-associated carcinogenesis.

METHODS

The formation of isoLG adducts was analyzed in the gastric tissues of patients infected with Helicobacter pylori from gastritis to precancerous intestinal metaplasia, in human gastric organoids, and in patients with colitis and colitis-associated carcinoma (CAC). The effect on cancer development of a potent scavenger of dicarbonyl electrophiles, 5-ethyl-2-hydroxybenzylamine (EtHOBA), was determined in transgenic FVB/N insulin-gastrin (INS-GAS) mice and Mongolian gerbils as models of H pylori-induced carcinogenesis and in C57BL/6 mice treated with azoxymethane-dextran sulfate sodium as a model of CAC. The effect of EtHOBA on mutations in gastric epithelial cells of H pylori-infected INS-GAS mice was assessed by whole-exome sequencing.

RESULTS

We show increased isoLG adducts in gastric epithelial cell nuclei in patients with gastritis and intestinal metaplasia and in human gastric organoids infected with H pylori. EtHOBA inhibited gastric carcinoma in infected INS-GAS mice and gerbils and attenuated isoLG adducts, DNA damage, and somatic mutation frequency. Additionally, isoLG adducts were elevated in tissues from patients with colitis, colitis-associated dysplasia, and CAC as well as in dysplastic tumors of C57BL/6 mice treated with azoxymethane-dextran sulfate sodium. In this model, EtHOBA significantly reduced adduct formation, tumorigenesis, and dysplasia severity.

CONCLUSIONS

Dicarbonyl electrophiles represent a link between inflammation and somatic genomic alterations and are thus key targets for cancer chemoprevention.

Phytotherapeutic modalities for the management of Helicobacter pylori associated peptic ulcer

Due to an imbalance between aggressive factors known as hydrochloric acid (HCl), pepsin, leukotrienes, refluxed bile, defensive factors and reactive oxygen species, the peptic ulcer is formed in the stomach and duodenum which mostly include the function of prostaglandins, mucus bicarbonate barrier, enzymatic antioxidants, and some growth factors. H. pylori infection remained one of the considerable causes of peptic ulcer as it caused hypochlorhydria and struck off the defense mechanism of the stomach. The nonsteroidal anti-inflammatory drugs (NSAIDs) and stress are the most prevailing causes of peptic ulcer disease. Lack of physical exercise, little rest and due to poor leisure cause the peptic ulcer disease. Candies, chocolate, coffee, cigarettes, stress, and alcohol are the cause of peptic ulceration and suppression of acid in the stomach due to the utilization of antacid medication. Most of the ancient medical practices in the traditional alternative medicinal system include Unani, Ayurveda, Siddha, Homeopathy, Naturopathy, Chinese customary medicine, African conventional medicine, and Native American medicine. Without a hostile effect, the rate of curing the disease is the significance of natural products research. Peptic ulcer disease is the widespread nature of peptic ulcer in all class of population, which mostly may be due to rapidly changing the food habits and stress, causing the imbalance between gastric offensive and defensive factors. Curcuma longa is the most effective plant for the cure of peptic ulcer. Curcuma longa has anti-inflammatory and antioxidant activity. Curcuma longa remarkably reduces the level of inflammatory mediator (IL1) and (TNF) which was increased during the formation of an ulcer. In the rhizome of Curcuma longa, yellow pigment is present and widely used for the treatment of ulcer and decrease the inflammatory response. Symptoms include abdominal pain after taking a meal, nausea, vomiting, Anorexia and lose weight.

Controversias en cirugía: Erradicación del Helicobacter pylori ¿Terapia a todos o según indicaciones usuales?

La infección por Helicobacter pylori (H. pylori), es la infección bacteriana crónica más frecuente de la raza humana, afecta al 50 % de la población mundial y, por lo menos, al 80 % de la población colombiana. Esta bacteria es reconocida desde hace más de 15 años como un carcinógeno tipo I. De acuerdo con las indicaciones del Consenso de “Maastricht V” esta infección debe ser buscada y tratada en los pacientes con úlcera péptica activa, Linfoma MALT (por sus siglas en inglés, mucosa associated lymphoid tissue), cáncer gástrico temprano, púrpura que presenten síntomas dispépticos crónicos y usuarios crónicos de AINES. Debido al papel que tiene en la fisiopatología del cáncer gástrico, nace la iniciativa de realizar una búsqueda activa del H. pylori y erradicarlo en todas las personas, incluyendo aquellas asintomáticas en países con alta incidencia de esta neoplasia. Existen diversas publicaciones alrededor del mundo que así lo sugieren, mostrando resultados con impacto positivo en el curso y progresión de la enfermedad, sobre todo en las etapas más tempranas de la infección. Sin embargo, otros autores resaltan la creciente problemática de la resistencia bacteriana, y demuestran que el peso estadístico y los diferentes análisis de los estudios disponibles en la actualidad tienen poca validez para dar una recomendación extendida al paciente asintomático. Se cuestiona que tal vez, estamos utilizando las estrategias inadecuadas para manejar una situación de salud pública, ya que estamos enfocados en impactar a cada individuo con terapias antibióticas complejas, en vez de a la población en general con políticas de salud pública.

Spermine oxidase mediates Helicobacter pylori-induced gastric inflammation, DNA damage, and carcinogenic signaling

Helicobacter pylori infection is the main risk factor for the development of gastric cancer, the third leading cause of cancer death worldwide. H. pylori colonizes the human gastric mucosa and persists for decades. The inflammatory response is ineffective in clearing the infection, leading to disease progression that may result in gastric adenocarcinoma. We have shown that polyamines are regulators of the host response to H. pylori, and that spermine oxidase (SMOX), which metabolizes the polyamine spermine into spermidine plus H2O2, is associated with increased human gastric cancer risk. We now used a molecular approach to directly address the role of SMOX, and demonstrate that Smox-deficient mice exhibit significant reductions of gastric spermidine levels and H. pylori-induced inflammation. Proteomic analysis revealed that cancer was the most significantly altered functional pathway in Smox-/- gastric organoids. Moreover, there was also less DNA damage and β-catenin activation in H. pylori-infected Smox-/- mice or gastric organoids, compared to infected wild-type animals or gastroids. The link between SMOX and β-catenin activation was confirmed in human gastric organoids that were treated with a novel SMOX inhibitor. These findings indicate that SMOX promotes H. pylori-induced carcinogenesis by causing inflammation, DNA damage, and activation of β-catenin signaling.

Variations in cag pathogenicity island genes of Helicobacter pylori from Latin American groups may influence neoplastic progression to gastric cancer

Helicobacter pylori (HP) colonizes the human stomach and induces acute gastritis, peptic ulcer disease, atrophic gastritis, and gastric adenocarcinoma. Increased virulence in HP isolates derives from harboring the cag (cytotoxin-associated genes) pathogenicity island (cagPAI). We analyzed the microvariants in cagPAI genes with the hypothesis that they may play an important role in determining HP virulence. We tested DNAs from cagA positive patients HP isolates; a total of 74 patients with chronic gastritis (CG, N = 37), intestinal metaplasia (IM, N = 21) or gastric cancer (GC, N = 16) from Mexico and Colombia. We selected 520 non-synonymous variants with at least 7.5% frequency in the original sequence outputs or with a minimum of 5 isolates with minor allele. After adjustment for multiple comparisons, no variants were statistically significantly associated with IM or GC. However, 19 non-synonymous showed conventional P-values < 0.05 comparing the frequency of the alleles between the isolates from subjects with gastritis and isolates from subjects with IM or GC; 12 of these showed a significant correlation with the severity of the disease. The present study revealed that several cagPAI genes from Latin American Western HP strains contains a number of non-synonymous variants in relatively high frequencies which could influence on the clinical outcome. However, none of the associations remained statistically significant after adjustment for multiple comparison.

Helicobacter pylori Recurrence after Eradication Therapy in Jiangjin District, Chongqing, China

Purpose

To investigate the recurrence rate of Helicobacter pylori infection after eradication in Jiangjin District, Chongqing, China, and to analyze the related causes.

Methods

Outpatients who were eradicated of H. pylori infection with standard therapy between August 2014 and August 2017 were included in this study. The recurrence rate was investigated 1 year later. Data regarding gender, smoking, alcohol intake, frequency of eating out, and treatment strategy were recorded, and their relationships with the recurrence rate were analyzed. Multivariate logistic regression analysis was performed to determine the independent risk factors for H. pylori infection recurrence.

Results

In total, 400 patients (225 males and 175 females) were included in this study. Of them, the recurrence rate of H. pylori infection was 4.75% (19/400), with 5.33% (12/225) in males and 4.57% (7/175) in females, showing no gender difference. The recurrence rate was 7.03% (9/128) in smokers and 3.68% (10/272) in nonsmokers, while it was 6.45% (12/186) in those who drink alcohol and 3.27% (7/214) in those who do not drink alcohol, showing no significant differences. The higher the frequency of eating out, the higher the recurrence rate of H. pylori infection (P = 0.001). There was a statistically significant difference in the recurrence rate between patients receiving treatment alone and patients whose family members also received treatment (6.08% vs. 0.96%, P = 0.035). Drinking and dining out were independent risk factors for H. pylori infection recurrence (P = 0.014 for drinkers and P = 0.015 and P = 0.003 for those who sometimes and often dine out, respectively).

Conclusions

The overall recurrence rate after H. pylori eradication by standard therapy in Jiangjin District is 4.75%. Reducing the frequency of eating out and family members receiving treatment may reduce the recurrence of H. pylori infection.

Helicobacter pylori recrudescence and its influencing factors

Helicobacter pylori (H pylori) is known as one of the most common infectious pathogens, with high infection and recurrence rates worldwide. The prevalence of H pylori is up to 90% in developing countries, while the annual recurrence rate is much higher than that in developed countries. Recurrence can occur either by recrudescence or reinfection. Compared with reinfection, the time window for recrudescence is generally shorter, followed by the recurrence of H pylori–associated diseases in the short‐term. Many factors are involved in the H pylori reinfection, such as the prevalence of H pylori infection, living conditions and economic development, health conditions and so forth. Previous studies focused less on H pylori recrudescence. Therefore, the influencing factors for H pylori recrudescence needed further exploration. This study reviewed the recrudescence of H pylori infection and its influencing factors.

Hierarchical-Clustering, Scaffold-Mining Exercises and Dynamics Simulations for Effectual Inhibitors Against Lipid-A Biosynthesis of Helicobacter pylori

Introduction

Treatment failures of standard regimens and new strains egression are due to the augmented drug resistance conundrum. These confounding factors now became the drug designers spotlight to implement therapeutics against Helicobacter pylori strains and to safeguard infected victims with devoid of adverse drug reactions. Thereby, to navigate the chemical space for medicine, paramount vital drug target opting considerations should be imperative. The study is therefore aimed to develop potent therapeutic variants against an insightful extrapolative, common target LpxC as a follow-up to previous studies.

Methods

We explored the relationships between existing inhibitors and novel leads at the scaffold level in an appropriate conformational plasticity for lead-optimization campaign. Hierarchical-clustering and shape-based screening against an in-house library of > 21 million compounds resulted in panel of 11,000 compounds. Rigid-receptor docking through virtual screening cascade, quantum-polarized-ligand, induced-fit dockings, post-docking processes and system stability assessments were performed.

Results

After docking experiments, an enrichment performance unveiled seven ranked actives better binding efficiencies with Zinc-binding potency than substrate and in-actives (decoy-set) with ROC (1.0) and area under accumulation curve (0.90) metrics. Physics-based membrane permeability accompanied ADME/T predictions and long-range dynamic simulations of 250 ns chemical time have depicted good passive diffusion with no toxicity of leads and sustained consistency of lead1-LpxC in the physiological milieu respectively.

Conclusions

In the study, as these static outcomes obtained from this approach competed with the substrate and existing ligands in binding affinity estimations as well as positively correlated from different aspects of predictions, which could facilitate promiscuous new chemical entities against H. pylori.

Penicillin‑binding protein 1A mutation‑positive Helicobacter pylori promotes epithelial‑mesenchymal transition in gastric cancer via the suppression of microRNA‑134

Evidence suggests that Helicobacter pylori (H. pylori) is not only the main cause of gastric cancer (GC), but is also closely associated with its metastasis. One of the major virulence factors in H. pylori is the cytotoxin-associated gene A (CagA). With the growing proportion of amoxicillin-resistant H. pylori strains, the present study aimed to explore the effects of CagA- and penicillin-binding protein 1A (PBP1A) mutation-positive H. pylori (H. pylori_CagA+/P+) on GC cells, and its clinical significance. The clinical significance of H. pylori_CagA+/P+ infection was analyzed in patients with GC. In vitro, GC cells were infected with H. pylori_CagA+/P+ to investigate whether it was involved in the epithelial-mesenchymal transition (EMT) of SGC-7901 cells using immunofluorescence and western blot analysis. The results of clinical analysis demonstrated that, although CagA-negative H. pylori infection had no significant association with the characteristics of patients with GC, H. pylori_CagA+/P+ infection was significantly associated with various clinicopathological parameters, including invasion depth, lymphatic metastasis and distant metastasis. In vitro, the results indicated that H. pylori_CagA+/P+ promoted proliferation, invasion and EMT of SGC-7901 cells. MicroRNA (miR)-134 was downregulated in H. pylori_CagA+/P+ infected tissues compared with in those with H. pylori_CagA+/P- infection. miR-134 overexpression significantly reversed H. pylori_CagA+/P+ infection-associated cell proliferation, invasion and EMT. Furthermore, the results revealed that Forkhead box protein M1 (FoxM1) was a direct target of miR-134, and FoxM1 knockdown impeded H. pylori_CagA+/P+-induced EMT. In conclusion, the present study demonstrated that miR-134 may suppress the proliferation, invasion and EMT of SGC-7901 cells by targeting FoxM1, and may serve a protective role in the process of H. pylori_CagA+/P+-induced GC. These findings may lead to an improved understanding of H. pylori_CagA+/P+-associated poor clinical characteristics in patients with GC.

Advancing Reliable Data for Cancer Control in the Central America Four Region

The Central America Four (CA-4) region, comprising Guatemala, Honduras, El Salvador, and Nicaragua, is the largest low- and middle-income country region in the Western Hemisphere, with over 36 million inhabitants. The CA-4 nations share a common geography, history, language, and development indices, and unified with open borders in 2006. The growing CA-4 cancer burden among the noncommunicable diseases is expected to increase 73% by 2030, which argues for a regional approach to cancer control. This has driven efforts to establish population-based cancer registries as a central component of the cancer control plans. The involvement of international and academic partners in an array of initiatives to improve cancer information and control in the CA-4 has accelerated over the past several years. Existing data underscore that the infectious cancers (cervical, stomach, and liver) are a particular burden. All four countries have committed to establishing regional population-based cancer registries and have advanced significantly in pediatric cancer registration. The challenges common to each nation include the lack of national cancer control plans and departments, competing health priorities, lack of trained personnel, and sustainability strategies. General recommendations to address these challenges are outlined. The ongoing regional, international, and academic cooperation has proven helpful and is expected to continue to be a powerful instrument to contribute to the design and implementation of long-term national cancer control plans.

Epidermal growth factor receptor inhibition downregulates Helicobacter pylori-induced epithelial inflammatory responses, DNA damage and gastric carcinogenesis

OBJECTIVE

Gastric cancer is the third leading cause of cancer death worldwide and infection by Helicobacter pylori is the strongest risk factor. We have reported increased epidermal growth factor receptor (EGFR) phosphorylation in the H. pylori-induced human carcinogenesis cascade, and association with DNA damage. Our goal was to determine the role of EGFR activation in gastric carcinogenesis.

DESIGN

We evaluated gefitinib, a specific EGFR inhibitor, in chemoprevention of H. pylori-induced gastric inflammation and cancer development. Mice with genetically targeted epithelial cell-specific deletion of Egfr (Efgr^Δepi mice) were also used.

RESULTS

In C57BL/6 mice, gefitinib decreased Cxcl1 and Cxcl2 expression by gastric epithelial cells, myeloperoxidase-positive inflammatory cells in the mucosa and epithelial DNA damage induced by H. pylori infection. Similar reductions in chemokines, inflammatory cells and DNA damage occurred in infected Egfr^Δepi versus Egfr^fl/fl control mice. In H. pylori-infected transgenic insulin-gastrin (INS-GAS) mice and gerbils, gefitinib treatment markedly reduced dysplasia and carcinoma. Gefitinib blocked H. pylori-induced activation of mitogen-activated protein kinase 1/3 (MAPK1/3) and activator protein 1 in gastric epithelial cells, resulting in inhibition of chemokine synthesis. MAPK1/3 phosphorylation and JUN activation was reduced in gastric tissues from infected wild-type and INS-GAS mice treated with gefitinib and in primary epithelial cells from Efgr^Δepi versus Egfr^fl/fl mice. Epithelial EGFR activation persisted in humans and mice after H. pylori eradication, and gefitinib reduced gastric carcinoma in INS-GAS mice treated with antibiotics.

CONCLUSIONS

These findings suggest that epithelial EGFR inhibition represents a potential strategy to prevent development of gastric carcinoma in H. pylori-infected individuals.

The fourth Mexican consensus on Helicobacter pylori

Important advances have been made since the last Mexican consensus on the diagnosis and treatment of Helicobacter pylori (H. pylori) infection was published in 2007. Therefore, the Asociación Mexicana de Gastroenterología summoned 20 experts to produce "The Fourth Mexican Consensus on Helicobacter pylori". From February to June 2017, 4 working groups were organized, a literature review was performed, and 3 voting rounds were carried out, resulting in the formulation of 32 statements for discussion and consensus. From the ensuing recommendations, it was striking that Mexico is a country with an intermediate-to-low risk for gastric cancer, despite having a high prevalence of H. pylori infection. It was also corroborated that peptic ulcer disease, premalignant lesions, and histories of gastric cancer and mucosa-associated lymphoid tissue lymphoma should be considered clear indications for eradication. The relation of H. pylori to dyspeptic symptoms continues to be controversial. Eradication triple therapy with amoxicillin, clarithromycin, and a proton pump inhibitor should no longer be considered first-line treatment, with the following 2 options proposed to take its place: quadruple therapy with bismuth (proton pump inhibitor, bismuth subcitrate, tetracycline, and metronidazole) and quadruple therapy without bismuth (proton pump inhibitor, amoxicillin, clarithromycin, and metronidazole). The need for antimicrobial sensitivity testing when 2 eradication treatments have failed was also established. Finally, the promotion of educational campaigns on the diagnosis and treatment of H. pylori for both primary care physicians and the general population were proposed.

Systematic review with meta-analysis: the global recurrence rate of Helicobacter pylori

BACKGROUND

Up-to-date information regarding the recurrence rate of Helicobacter pylori (H. pylori) after eradication therapy is not available.

AIM

To evaluate the global recurrence rate following H. pylori eradication therapy and confirm its association with socioeconomic and sanitary conditions.

METHODS

A systematic search of PubMed, EMBASE and the Cochrane library was performed to identify potentially relevant publications using the following keywords: "Helicobacter pylori" or "H. pylori" or "Hp" and "recurrence" or "recrudescence" or "reinfection" or "recurrent" or "recurred" or "re-infect*" or "relapse*."

RESULTS

A total of 132 studies (53 934 patient-years) were analysed. Each study was weighted according to the duration of patient-years. The global annual recurrence, reinfection and recrudescence rate of H. pylori were 4.3% (95% CI, 4-5), 3.1% (95% CI, 2-5) and 2.2% (95% CI, 1-3), respectively. The H. pylori recurrence rate was inversely related to the human development index (HDI) (ie, 3.1% [95% CI, 2-4], 6.2% [95% CI, 4-8] and 10.9% [95% CI, 6-18] in countries with a very high, high and medium or low HDI) (P <.01) and directly related to H. pylori prevalence (10.9% [95% CI, 7-16], 3.7% [95% CI, 3-5], 3.4% [95% CI, 2-5] and 1.6% [95% CI, 0.5-3] in countries with a very high, high, medium or low local H. pylori prevalence) (P <.01). Global recurrence rates remained relatively stable between 1990s, 2000s and 2010s but varied across different regions (P <.05).

CONCLUSIONS

H. pylori recurrence remains a problem closely associated with socioeconomic and sanitary conditions. Methods to reduce recurrence in developing countries are needed.

Recurrence of infection and diversity of Helicobacter pylori strains in an adult population in Mexico treated with empirical standard triple therapy

BACKGROUND

After eradication treatment for Helicobacter pylori, infection could recur due to recrudescence or re-infection. The objective of this study was to determine the recurrence of Helicobacter pylori infection and identify virulent Helicobacter pylori strains one year after eradication with standard triple therapy.

MATERIAL AND METHODS

A quasi-experimental study was performed that included a patient population with digestive diseases associated with Helicobacter pylori who had received standard triple therapy. Cultures and Polymerase Chain Reaction was performed on gastric biopsies for strain identification in all patients prior to eradication treatment and those with a positive carbon 14 breath test one year after eradication treatment. Statistical analysis was performed using the student T test and Fisher's exact test, statistical significance was set at 0.05.

RESULTS

128 patients were studied, 51 (39.8%) were male and 77 (60.2%) were female with an average age of 54.8 years (DE 13.8). There was an annual recurrence of Helicobacter pylori infection in 12 (9.3%) patients. An annual re-infection and recrudescence occurred in 9 (7 %) and 3 (2.3%) patients respectively. The recrudescence rate for cagA was 1/30 (3.3%) patients and 2/112 (1.8%) patients for vacA. The re-infection rate for cagA was 3/30 (10%) patients and 6/112 (5.3%) patients for vacA.

CONCLUSIONS

The recurrence of infection in this study was higher than that recorded in developed countries with a low prevalence of H. pylori and lower than that recorded in developing countries with a higher prevalence of H. pylori. The cagA or vacA s2/m2 strains were isolated after re-infection and recrudescence.

Joint ESPGHAN/NASPGHAN Guidelines for the Management of Helicobacter pylori in Children and Adolescents (Update 2016)

BACKGROUND

Because of the changing epidemiology of Helicobacter pylori infection and low efficacy of currently recommended therapies, an update of the European Society for Paediatric Gastroenterology Hepatology and Nutrition/North American Society for Pediatric Gastroenterology, Hepatology and Nutrition recommendations for the diagnosis and management of H pylori infection in children and adolescents is required.

METHODS

A systematic review of the literature (time period: 2009-2014) was performed. Representatives of both societies evaluated the quality of evidence using GRADE (Grading of Recommendation Assessment, Development, and Evaluation) to formulate recommendations, which were voted upon and finalized using a Delphi process and face-to-face meeting.

RESULTS

The consensus group recommended that invasive diagnostic testing for H pylori be performed only when treatment will be offered if tests are positive. To reach the aim of a 90% eradication rate with initial therapy, antibiotics should be tailored according to susceptibility testing. Therapy should be administered for 14 days, emphasizing strict adherence. Clarithromycin-containing regimens should be restricted to children infected with susceptible strains. When antibiotic susceptibility profiles are not known, high-dose triple therapy with proton pump inhibitor, amoxicillin, and metronidazole for 14 days or bismuth-based quadruple therapy is recommended. Success of therapy should be monitored after 4 to 8 weeks by reliable noninvasive tests.

CONCLUSIONS

The primary goal of clinical investigation is to identify the cause of upper gastrointestinal symptoms rather than H pylori infection. Therefore, we recommend against a test and treat strategy. Decreasing eradication rates with previously recommended treatments call for changes to first-line therapies and broader availability of culture or molecular-based testing to tailor treatment to the individual child.

Helicobacter pylori recurrence after eradication in Latin America: Implications for gastric cancer prevention

AIM

To estimate Helicobacter pylori (H. pylori) recurrence rate in Latin America, a region with a significant H. pylori prevalence and gastric cancer burden.

METHODS

PubMed, LILACS, SciELO, Cochrane databases and abstracts from relevant meetings were reviewed. Information collected included: Participants’ characteristics, recruitment strategy, diagnostic modality, treatment arms, follow-up and recurrence rates. Recurrence was calculated using 100-patients-year rates, and data were pooled using a random effects model. The I² statistic assessed between study heterogeneity. Meta-regression analyses evaluated for effect modifying variables.

RESULTS

Literature search yielded 163 articles. Twelve studies involving 4848 patients from 9 countries met inclusion criteria. Four hundred and thirty-two reinfections were recorded in 5487 person-years of follow-up. Pooled analysis showed a recurrence rate of 7.9 cases per 100 person-years (95%CI: 5.3-10.5). Meta-regression revealed that neither the antibiotic schema, a second antibiotic course, nor the diagnostic modality had an impact on the observed risk of recurrence. The recurrence rate in the first year after treatment, predominantly recrudescence, was 11.2 (6.1-16.4) per 100 patient years. Recurrence in subsequent years, was only 6.2 (3.8-8.7).

CONCLUSION

H. pylori recurrence rates in Latin America are significant, and with geographic variability, yet are acceptable based upon the current literature for consideration of large scale intervention trials. Further research in Latin America is warranted to evaluate the efficacy, cost-effectiveness, and potential adverse outcomes of proposed eradication programs.

Polyamine- and NADPH-dependent generation of ROS during Helicobacter pylori infection: A blessing in disguise

Helicobacter pylori is a Gram-negative bacterium that specifically colonizes the gastric ecological niche. During the infectious process, which results in diseases ranging from chronic gastritis to gastric cancer, the host response is characterized by the activation of the innate immunity of gastric epithelial cells and macrophages. These cells thus produce effector molecules such as reactive oxygen species (ROS) to counteract the infection. The generation of ROS in response to H. pylori involves two canonical pathways: 1) the NADPH-dependent reduction of molecular oxygen to generate O₂^•-, which can dismute to generate ROS; and 2) the back-conversion of the polyamine spermine into spermidine through the enzyme spermine oxidase, leading to H₂O₂ production. Although these products have the potential to affect the survival of bacteria, H. pylori has acquired numerous strategies to counteract their deleterious effects. Nonetheless, ROS-mediated oxidative DNA damage and mutations may participate in the adaptation of H. pylori to its ecological niche. Lastly, ROS have been shown to play a major role in the development of the inflammation and carcinogenesis. It is the purpose of this review to summarize the literature about the production of ROS during H. pylori infection and their role in this infectious gastric disease.

Antibiotic resistance among Helicobacter pylori clinical isolates in Lima, Peru

Objectives

Gastric carcinoma is the most common cancer and cause of cancer mortality in Peru. Helicobacter pylori, a bacterium that colonizes the human stomach, is a Group 1 carcinogen due to its causal relationship to gastric carcinoma. While eradication of H. pylori can help prevent gastric cancer, characterizing regional antibiotic resistance patterns is necessary to determine targeted treatment for each region. Thus, we examined primary antibiotic resistance in clinical isolates of H. pylori in Lima, Peru.

Materials and methods

H. pylori strains were isolated from gastric biopsies of patients with histologically proven H. pylori infection. Primary antibiotic resistance among isolates was examined using E-test strips. Isolates were examined for the presence of the cagA pathogenicity island and the vacA m1/m2 alleles via polymerase chain reaction.

Results

Seventy-six isolates were recovered from gastric biopsies. Clinical isolates showed evidence of antibiotic resistance to 1 (27.6%, n=21/76), 2 (28.9%, n=22/76), or ≥3 antibiotics (40.8%). Of 76 isolates, eight (10.5%) were resistant to amoxicillin and clarithromycin, which are part of the standard triple therapy for H. pylori infection. No trends were seen between the presence of cagA, vacA m1, or vacA m2 and antibiotic resistance.

Conclusion

The rate of antibiotic resistance among H. pylori isolates in Lima, Peru, is higher than expected and presents cause for concern. To develop more targeted eradication therapies for H. pylori in Peru, more research is needed to better characterize antibiotic resistance among a larger number of clinical isolates prospectively.

Pathogenesis and risk factors for gastric cancer after Helicobacter pylori eradication

Helicobacter pylori (H. pylori) infection was thought to be the main cause of gastric cancer, and its eradication showed improvement in gastric inflammation and decreased the risk of gastric cancer. Recently, a number of studies reported the occurrence of gastric cancer after successful eradication. Patients infected with H. pylori, even after eradication, have a higher risk for the occurrence of gastric cancer when compared with uninfected patients. Metachronous gastric cancer occurs frequently following the endoscopic removal of early gastric cancer. These data indicate that metachronous cancer leads to the occurrence of gastric cancer even after successful eradication of H. pylori. The pathogenesis of this metachronous cancer remains unclear. Further research is needed to identify biomarkers to predict the development of metachronous gastric cancer and methods for gastric cancer screening. In this article, we review the role of the H. pylori in carcinogenesis and the histological and endoscopic characteristics and risk factors for metachronous gastric cancer after eradication. Additionally, we discuss recent risk predictions and possible approaches for reducing the risk of metachronous gastric cancer after eradication.

Early eradication has a lower risk of peptic ulcer bleeding in Helicobacter pylori-infected chronic kidney disease patients

BACKGROUND

End stage renal disease (ESRD) contributes to a higher mortality rate in peptic ulcer bleeding (PUB) patients. A crucial question is whether early Helicobacter pylori (H. pylori) eradication therapy is necessary for H. pylori-infected chronic kidney disease (CKD) patients. To explore whether H. pylori eradication therapy has a lower risk of PUB at the pre-ESRD stage than at the ESRD stage.

METHODS AND PATIENTS

Patients meeting 2 criteria were defined as newly diagnosed ESRD cases: (1) patients diagnosed with ESRD and receiving regular dialysis between 2000 and 2009; and (2) patients with no history of dialysis between 1997 and 1999. We divided the study participants into pre-ESRD and ESRD groups on the basis of the time between H. pylori eradication and dialysis. The date of the first PUB diagnosis was defined as the primary endpoint. Stratified Cox proportional hazard regression analysis was used to estimate the effect of H. pylori eradication at the pre-ESRD and ESRD stage on the occurrence of PUB.

RESULTS

We included 476 patients in the pre-ESRD cohort and 476 patients in the matched ESRD cohort. After adjustment for age, sex, the presence of comorbidities, and medication use, the hazard ratio of PUB was 0.66 times less in the pre-ESRD cohort than in the ESRD cohort. Factors such as Charlson's score more than 3, and nonsteroidal anti-inflammatory drugs were associated with an increased risk of PUB.

CONCLUSION

Our result supports that early H. pylori eradication has a lower risk of PUB in H. pylori-infected CKD patients.

Recurrence of Helicobacter pylori infection after successful eradication

Helicobacter pylori (H. pylori) is a gram-negative, micro-aerobic bacterium that lives in the stomach and duodenum. Infection with H. pylori would cause some diseases such as peptic ulcer disease and gastric cancer. Some H. pylori associated gastric diseases could be prevented by the eradication of H. pylori. However, some people develop recurrence after successful H. pylori eradication. Many factors affect the recurrence such as human development index, treatment for the whole family, standard treatment combined with supragingival scaling, and iatrogenic transmission. This article reviews the recurrence of H. pylori infection after successful treatment.

Efficacy of a quadruple therapy regimen for Helicobacter pylori eradication after partial gastrectomy

We aimed to evaluate the effectiveness and safety of bismuth-containing quadruple therapy plus postural change after dosing for Helicobacter pylori eradication in gastrectomized patients. We compared 76 gastric stump patients with H. pylori infection (GS group) with 50 non-gastrectomized H. pylori-positive patients who met the treatment indication (controls). The GS group was divided into GS group 1 and GS group 2. All groups were administered bismuth potassium citrate (220 mg), esomeprazole (20 mg), amoxicillin (1.0 g), and furazolidone (100 mg) twice daily for 14 days. GS group 1 maintained a left lateral horizontal position for 30 min after dosing. H. pylori was detected using rapid urease testing and histologic examination of gastric mucosa before and 3 months after therapy. Mucosal histologic manifestations were evaluated using visual analog scales of the updated Sydney System. GS group 1 had a higher prevalence of eradication than the GS group 2 (intention-to-treat [ITT]: P=0.025; per-protocol [PP]: P=0.030), and the control group had a similar prevalence. GS group 2 had a lower prevalence of eradication than controls (ITT: P=0.006; PP: P=0.626). Scores for chronic inflammation and activity declined significantly (P<0.001) 3 months after treatment, whereas those for atrophy and intestinal metaplasia showed no significant change. Prevalence of adverse reactions was similar among groups during therapy (P=0.939). A bismuth-containing quadruple therapy regimen plus postural change after dosing appears to be a relatively safe, effective, economical, and practical method for H. pylori eradication in gastrectomized patients.

The diagnosis and treatment of Helicobacter pylori infection in Arctic regions with a high prevalence of infection: Expert Commentary

Helicobacter pylori infection is a major cause of peptic ulcer and is also associated with chronic gastritis, mucosa-associated lymphoid tissue (MALT) lymphoma, and adenocarcinoma of the stomach. Guidelines have been developed in the United States and Europe (areas with low prevalence) for the diagnosis and management of this infection, including the recommendation to 'test and treat' those with dyspepsia. A group of international experts performed a targeted literature review and formulated an expert opinion for evidenced-based benefits and harms for screening and treatment of H. pylori in high-prevalence countries. They concluded that in Arctic countries where H. pylori prevalence exceeds 60%, treatment of persons with H. pylori infection should be limited only to instances where there is strong evidence of direct benefit in reduction of morbidity and mortality, associated peptic ulcer disease and MALT lymphoma and that the test-and-treat strategy may not be beneficial for those with dyspepsia.

Challenges to the Treatment and New Perspectives for the Eradication of Helicobacter pylori

Helicobacter pylori (H. pylori) is one of the leading causes of gastric diseases such as chronic gastritis, peptic ulcer, and gastric adenocarcinoma. The current treatment of H. pylori infection with antibiotics and proton pump inhibitors has several limitations, including poor adherence and intrinsic patient-related factors, drug resistance, and the absence of adequate treatments. This review summarizes the current therapeutic approaches to eradicating H. pylori, the difficulties associated with its treatment, and several new perspectives aimed at improving existing treatment strategies.

The Globalization of Cooperative Groups

The National Cancer Institute (NCI)-supported adult cooperative oncology research groups (now officially Network groups) have a longstanding history of participating in international collaborations throughout the world. Most frequently, the US-based cooperative groups work reciprocally with the Canadian national adult cancer clinical trial group, NCIC CTG (previously the National Cancer Institute of Canada Clinical Trials Group). Thus, Canada is the largest contributor to cooperative groups based in the United States, and vice versa. Although international collaborations have many benefits, they are most frequently utilized to enhance patient accrual to large phase III trials originating in the United States or Canada. Within the cooperative group setting, adequate attention has not been given to the study of cancers that are unique to countries outside the United States and Canada, such as those frequently associated with infections in Latin America, Asia, and Africa. Global collaborations are limited by a number of barriers, some of which are unique to the countries involved, while others are related to financial support and to US policies that restrict drug distribution outside the United States. This article serves to detail the cooperative group experience in international research and describe how international collaboration in cancer clinical trials is a promising and important area that requires greater consideration in the future.

Increased Helicobacter pylori-associated gastric cancer risk in the Andean region of Colombia is mediated by spermine oxidase

Helicobacter pylori infection causes gastric cancer, the third leading cause of cancer death worldwide. More than half of the world's population is infected, making universal eradication impractical. Clinical trials suggest that antibiotic treatment only reduces gastric cancer risk in patients with non-atrophic gastritis (NAG), and is ineffective once preneoplastic lesions of multifocal atrophic gastritis (MAG) and intestinal metaplasia (IM) have occurred. Therefore, additional strategies for risk stratification and chemoprevention of gastric cancer are needed. We have implicated polyamines, generated by the rate-limiting enzyme ornithine decarboxylase (ODC), in gastric carcinogenesis. During H. pylori infection, the enzyme spermine oxidase (SMOX) is induced, which generates hydrogen peroxide from the catabolism of the polyamine spermine. Herein, we assessed the role of SMOX in the increased gastric cancer risk in Colombia associated with the Andean mountain region when compared with the low-risk region on the Pacific coast. When cocultured with gastric epithelial cells, clinical strains of H. pylori from the high-risk region induced more SMOX expression and oxidative DNA damage, and less apoptosis than low-risk strains. These findings were not attributable to differences in the cytotoxin-associated gene A oncoprotein. Gastric tissues from subjects from the high-risk region exhibited greater levels of SMOX and oxidative DNA damage by immunohistochemistry and flow cytometry, and this occurred in NAG, MAG and IM. In Mongolian gerbils, a prototype colonizing strain from the high-risk region induced more SMOX, DNA damage, dysplasia and adenocarcinoma than a colonizing strain from the low-risk region. Treatment of gerbils with either α-difluoromethylornithine, an inhibitor of ODC, or MDL 72527 (N(1),N(4)-Di(buta-2,3-dien-1-yl)butane-1,4-diamine dihydrochloride), an inhibitor of SMOX, reduced gastric dysplasia and carcinoma, as well as apoptosis-resistant cells with DNA damage. These data indicate that aberrant activation of polyamine-driven oxidative stress is a marker of gastric cancer risk and a target for chemoprevention.

Early or late antibiotic intervention prevents Helicobacter pylori-induced gastric cancer in a mouse model

H. pylori infection causes gastritis, peptic ulcers and gastric cancer. Eradicating H. pylori prevents ulcers, but to what extent this prevents cancer remains unknown, especially if given after intestinal metaplasia has developed. H. pylori infected wild-type (WT) mice do not develop cancer, but mice lacking the tumor suppressor p27 do so, thus providing an experimental model of H. pylori-induced cancer. We infected p27-deficient mice with H. pylori strain SS1 at 6-8 weeks of age. Persistently H. pylori-infected WT C57BL/6 mice served as controls. Mice in the eradication arms received antimicrobial therapy (omeprazole, metronidazole and clarithromycin) either "early" (at 15 weeks post infection, WPI) or "late" at 45 WPI. At 70 WPI, mice were euthanized for H. pylori determination, histopathology and cytokine/chemokine expression. Persistently infected mice developed premalignant lesions including high-grade dysplasia, whereas those given antibiotics did not. Histologic activity scores in the eradication groups were similar to each other, and were significantly decreased compared with controls for inflammation, epithelial defects, hyperplasia, metaplasia, atrophy and dysplasia. IP-10 and MIG levels in groups that received antibiotics were significantly lower than controls. There were no significant differences in expression of IFN-γ, TNF-α, IL-1β, RANTES, MCP-1, MIP-1α or MIP-1β among the three groups. Thus, H. pylori eradication given either early or late after infection significantly attenuated gastric inflammation, gastric atrophy, hyperplasia, and dysplasia in the p27-deficient mice model of H. pylori-induced gastric cancer, irrespective of the timing of antibiotic administration. This was associated with reduced expression of IP-10 and MIG.

Epidemiology of Helicobacter pylori infection in dyspeptic Ghanaian patients

Introduction

Helicobacter pylori is a gram-negative urease-producing bacterium causally linked with gastritis, peptic ulcer disease and gastric adenocarcinoma. Infection is more frequent and acquired at an earlier age in developing countries compared to European populations. The incidence of Helicobacter pylori infection in dyspeptic Ghanaian patients was 75.4%. However, epidemiological factors associated with infection vary across populations.

Methods

This study used a cross-sectional design to consecutively sample dyspeptic patients at the Endoscopy Unit of the Korle-Bu Teaching Hospital, Accra between 2010 and 2012. The study questionnaire elicited their epidemiological clinical characteristics. Helicobacter pylori infection was confirmed by rapid-urease examination of antral biopsies at upper Gastro-intestinal endoscopy.

Results

The sample population of dyspeptic patients attending the Endoscopy Unit for upper GI endoscopy yielded 242 patients of which 47.5% were females. The age distribution of H. pylori-infection was even across most age – groups, ranging from 69.2% (61 – 70) years to 80% (21 – 30) years. Helicobacter pylori prevalence decreased across areas mapping to the three residential classes in accordance with increasing affluence with rural areas having the highest prevalence. The unemployed and patients in farming had relatively high Helicobacter pylori infection rates of 92.3% and 91.7% respectively.

Conclusion

Helicobacter pylori is endemic in Ghana but the persistently high prevalence across age groups despite significant community anti-microbial use suggests likely re-crudescence or re-infection from multiple sources in a developing country. Socio-cultural factors such as residential class and farming may be facilitating factors for its continued prevalence.

Evidence-based assessment of proton-pump inhibitors in Helicobacter pylori eradication: A systematic review

Peptic ulcer disease continues to be issue especially due to its high prevalence in the developing world. Helicobacter pylori (H. pylori) infection associated duodenal ulcers should undergo eradication therapy. There are many regimens offered for H. pylori eradication which include triple, quadruple, or sequential therapy regimens. The central aim of this systematic review is to evaluate the evidence for H. pylori therapy from a meta-analytical outlook. The consequence of the dose, type of proton-pump inhibitor, and the length of the treatment will be debated. The most important risk factor for eradication failure is resistance to clarithromycin and metronidazole.

Recurrence of Helicobacter pylori infection in Bolivian children and adults after a population-based "screen and treat" strategy

BACKGROUND

Strategies to prevent gastric cancer by decreasing Helicobacter pylori infections in high-prevalence, low-income countries could include a population-based "screen and treat" eradication program.

METHODS

We tested residents of two rural villages for H. pylori infection using urea breath test (UBT), treated infected persons using directly observed therapy (DOT), retested for cure, and retested after 1 year later for H. pylori infection.

FINDINGS

We tested 1,065 (92%) of 1153 residents from two villages in rural Bolivia. Baseline H. pylori prevalence was 80% (95% confidence interval [CI]: 78-84). Age-specific cure rates were similar (≥92%) after DOT. Among those cured, 12% (95% CI: 8-15) had recurrent infection. Age-specific annual H. pylori recurrence rates for combined villages were 20% (95% CI: 10-29) in persons <5 years, 20% (95% CI: 10-29) in 5-9 years, 8% (95% CI: 1-15) in 10-14 years, and 8% (95% CI: 4-12) in persons ≥15 years. Compared with the referent population, those ≥15 years, recurrent infections were significantly more likely in children <5 years (odds ratios [OR] 2.7, 95% CI: 1.2-5.8) and 5-9 years (OR 2.7, 95% CI: 1.4-5.1).

INTERPRETATION

Children <10 years had high H. pylori recurrence rates following a population-based screen and treat program; this H. pylori eradication strategy may not be feasible in high-prevalence, low-income settings.

Early or late antibiotic intervention prevents Helicobacter pylori-induced gastric cancer in a mouse model

H. pylori infection causes gastritis, peptic ulcers and gastric cancer. Eradicating H. pylori prevents ulcers, but to what extent this prevents cancer remains unknown, especially if given after intestinal metaplasia has developed. H. pylori infected wild-type (WT) mice do not develop cancer, but mice lacking the tumor suppressor p27 do so, thus providing an experimental model of H. pylori-induced cancer. We infected p27-deficient mice with H. pylori strain SS1 at 6-8 weeks of age. Persistently H. pylori-infected WT C57BL/6 mice served as controls. Mice in the eradication arms received antimicrobial therapy (omeprazole, metronidazole and clarithromycin) either "early" (at 15 weeks post infection, WPI) or "late" at 45 WPI. At 70 WPI, mice were euthanized for H. pylori determination, histopathology and cytokine/chemokine expression. Persistently infected mice developed premalignant lesions including high-grade dysplasia, whereas those given antibiotics did not. Histologic activity scores in the eradication groups were similar to each other, and were significantly decreased compared with controls for inflammation, epithelial defects, hyperplasia, metaplasia, atrophy and dysplasia. IP-10 and MIG levels in groups that received antibiotics were significantly lower than controls. There were no significant differences in expression of IFN-γ, TNF-α, IL-1β, RANTES, MCP-1, MIP-1α or MIP-1β among the three groups. Thus, H. pylori eradication given either early or late after infection significantly attenuated gastric inflammation, gastric atrophy, hyperplasia, and dysplasia in the p27-deficient mice model of H. pylori-induced gastric cancer, irrespective of the timing of antibiotic administration. This was associated with reduced expression of IP-10 and MIG.

Epidemiology of Helicobacter pylori infection

Medline and PubMed databases were searched on epidemiology of Helicobacter pylori for the period of April 2013-March 2014. Several studies have shown that the prevalence of H. pylori is still high in most countries. In north European and North American populations, about one-third of adults are still infected, whereas in south and east Europe, South America, and Asia, the prevalence of H. pylori is often higher than 50%. H. pylori remains highly prevalent in immigrants coming from countries with high prevalence of H. pylori. However, the lower prevalence of infection in the younger generations suggests a further decline of H. pylori prevalence in the coming decades. Low socioeconomic conditions in childhood are confirmed to be the most important risk factors for H. pylori infection. Although the way the infection is transmitted is still unclear, interpersonal transmission appears to be the main route. Finally, H. pylori recurrence after successful eradication can still occur, but seems to be an infrequent event.

Management of Helicobacter pylori infection in Latin America: a Delphi technique-based consensus

AIM

To optimize diagnosis and treatment guidelines for this geographic region, a panel of gastroenterologists, epidemiologists, and basic scientists carried out a structured evaluation of available literature.

METHODS

Relevant questions were distributed among the experts, who generated draft statements for consideration by the entire panel. A modified three-round Delphi technique method was used to reach consensus. Critical input was also obtained from representatives of the concerned medical community. The quality of the evidence and level of recommendation supporting each statement was graded according to United States Preventive Services Task Force criteria.

RESULTS

A group of ten experts was established. The survey included 15 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 50% in the first round, 73.3% in the second round and 100% in the third round. Main consensus recommendations included: (1) when available, urea breath and stool antigen test (HpSA) should be used for non-invasive diagnosis; (2) detect and eradicate Helicobacter pylori (H. pylori) in all gastroscopy patients to decrease risk of peptic ulcer disease, prevent o retard progression in patients with preneoplastic lesions, and to prevent recurrence in patients treated for gastric cancer; (3) further investigate implementation issues and health outcomes of H. pylori eradication for primary prevention of gastric cancer in high-risk populations; (4) prescribe standard 14-d triple therapy or sequential therapy for first-line treatment; (5) routinely assess eradication success post-treatment in clinical settings; and (6) select second- and third-line therapies according to antibiotic susceptibility testing.

CONCLUSION

These achievable steps toward better region-specific management can be expected to improve clinical health outcomes.

Reinfection after successful eradication of Helicobacter pylori in three different populations in Alaska

We performed a study to determine rates of reinfection in three groups followed for 2 years after successful treatment: American Indian/Alaska Native (AI/AN) persons living in urban (group 1) and rural (group 2) communities, and urban Alaska non-Native persons (group 3). We enrolled adults diagnosed with H. pylori infection based on a positive urea breath test (13C-UBT). After successful treatment was documented at 2 months, we tested each patient by 13C-UBT at 4, 6, 12 and 24 months. At each visit, participants were asked about medication use, illnesses and risk factors for reinfection. We followed 229 persons for 2 years or until they became reinfected. H. pylori reinfection occurred in 36 persons; cumulative reinfection rates were 14·5%, 22·1%, and 12·0% for groups 1, 2, and 3, respectively. Study participants who became reinfected were more likely to have peptic ulcer disease (P = 0·02), low education level (P = 0·04), or have a higher proportion of household members infected with H. pylori compared to participants who did not become reinfected (P = 0·03). Among all three groups, reinfection occurred at rates higher than those reported for other US populations (<5% at 2 years); rural AI/AN individuals appear to be at highest risk for reinfection.

Effects of Helicobacter pylori treatment on gastric cancer incidence and mortality in subgroups

Among 2258 Helicobacter pylori-seropositive subjects randomly assigned to receive one-time H. pylori treatment with amoxicillin-omeprazole or its placebo, we evaluated the 15-year effect of treatment on gastric cancer incidence and mortality in subgroups defined by age, baseline gastric histopathology, and post-treatment infection status. We used conditional logistic and Cox regressions for covariable adjustments in incidence and mortality analyses, respectively. Treatment was associated with a statistically significant decrease in gastric cancer incidence (odds ratio = 0.36; 95% confidence interval [CI] = 0.17 to 0.79) and mortality (hazard ratio = 0.26; 95% CI = 0.09 to 0.79) at ages 55 years and older and a statistically significant decrease in incidence among those with intestinal metaplasia or dysplasia at baseline (odds ratio = 0.56; 95% CI = 0.34 to 0.91). Treatment benefits for incidence and mortality among those with and without post-treatment infection were similar. Thus H. pylori treatment can benefit older members and those with advanced baseline histopathology, and benefits are present even with post-treatment infection, suggesting treatment can benefit an entire population, not just the young or those with mild histopathology.

Helicobacter pylori recurrence after first- and second-line eradication therapy in Korea: the problem of recrudescence or reinfection

BACKGROUND

Recurrence of Helicobacter pylori (H. pylori) infection is the result of either recrudescence or reinfection. Annual recurrence rates per patient-year of follow-up have been reported to vary across countries. The aim of this study was to analyze recurrence rates of H. pylori after first-line and second-line eradication therapies in Korea.

MATERIALS AND METHODS

From 2007 to 2010, 2691 patients with H. pylori infection received first-line therapy and 573 patients who failed to respond to first-line therapy received second-line therapy. H. pylori infection and the success of eradication were assessed by endoscopic biopsy and rapid urease test or (13) C-urea breath test. All patients were advised to undergo (13) C-urea breath test or esophagogastroduodenoscopy with biopsy or rapid urease test 6 months after eradication, with annual follow-up thereafter.

RESULTS

The eradication rate of the first-line therapy was 79.9% (1283/1605) and that of the second-line therapy was 90.4% (394/436) by per protocol analysis. Annual recurrence rates sharply declined after 2-year follow-up. Annual recurrence rates within and after 2-year follow-up were 9.3 and 2.0% after first-line therapy and those of second-line therapy were 4.5 and 2.9%, respectively.

CONCLUSIONS

Annual recurrence rates of H. pylori showed a sharp decline after 2-year follow-up after eradication in Korean adults, which is not higher than that of Western countries. Enough time interval after treatment (i.e., 2 years) is necessary to confirm eradication, and it would not be easy to distinguish between recurrence and recrudescence before 2 years without identifying H. pylori strains.

At the Bench: Helicobacter pylori, dysregulated host responses, DNA damage, and gastric cancer

Helicobacter pylori infection is the strongest known risk factor for the development of gastric cancer. Given that ∼50% of the global population is infected with this pathogen, there is great impetus to elucidate underlying causes that mediate progression from infection to cancer. Recent evidence suggests that H. pylori-induced chronic inflammation and oxidative stress create an environment conducive to DNA damage and tissue injury. DNA damage leads to genetic instability and eventually, neoplastic transformation. Pathogen-encoded virulence factors induce a robust but futile immune response and alter host pathways that lower the threshold for carcinogenesis, including DNA damage repair, polyamine synthesis and catabolism, antioxidant responses, and cytokine production. Collectively, such dysregulation creates a protumorigenic microenvironment within the stomach. This review seeks to address each of these aspects of H. pylori infection and to call attention to areas of particular interest within this field of research. This review also seeks to prioritize areas of translational research related to H. pylori-induced gastric cancer based on insights garnered from basic research in this field. See related review by Dalal and Moss, At the Bedside: H. pylori, dysregulated host responses, DNA damage, and gastric cancer.