Rifabutin-Based Triple Therapy (RHB-105) for Helicobacter pylori Eradication: A Double-Blind, Randomized, Controlled Trial

BACKGROUND

Although consensus supports eradication of Helicobacter pylori infections, antimicrobial resistance has substantially reduced eradication rates with most current therapies.

OBJECTIVE

To assess the effectiveness of a novel rifabutin-based therapy (RHB-105) for H pylori eradication.

DESIGN

Phase 3, double-blind trial (ERADICATE Hp2). (ClinicalTrials.gov: NCT03198507).

SETTING

55 clinical research sites in the United States.

PARTICIPANTS

455 treatment-naive adults with epigastric discomfort and confirmed H pylori infection.

INTERVENTION

RHB-105 (amoxicillin, 3 g; omeprazole, 120 mg; and rifabutin, 150 mg) versus active comparator (amoxicillin, 3 g, and omeprazole, 120 mg), given as 4 capsules every 8 hours for 14 days.

MEASUREMENTS

Between-group difference for H pylori eradication rate, demonstrated by ¹³C urea breath test 4 weeks after treatment, analyzed by using the χ² test.

RESULTS

In the intention-to-treat population, the eradication rate was higher with RHB-105 than with the active comparator (228 vs. 227 patients, respectively; 83.8% [95% CI, 78.4% to 88.0%] vs. 57.7% [95% CI, 51.2% to 64.0%]; P < 0.001). Eradication rates were unaffected by resistance to clarithromycin or metronidazole. No rifabutin resistance was detected. The most commonly reported adverse events (incidence ≥5%) were diarrhea (10.1% with RHB-105 vs. 7.9% with active comparator), headache (7.5% vs. 7.0%), and nausea (4.8% vs. 5.3%).

LIMITATION

Persons of Asian descent were excluded because of their higher prevalence of poor cytochrome P450 2C19 metabolizers.

CONCLUSION

These findings suggest potential for RHB-105 as first-line empirical H pylori therapy, addressing an unmet need in the current environment of increasing antibiotic resistance.

PRIMARY FUNDING SOURCE

RedHill Biopharma Ltd.

No Barrett's-No Cancer: A Proposed New Paradigm for Prevention of Esophageal Adenocarcinoma

Esophageal adenocarcinoma is inflammation-associated cancer with a recognizable preneoplastic stage, Barrett's. Barrett's describes the metaplastic transformation of esophageal squamous mucosa into columnar epithelium that typically results secondary to mucosal damage caused by acidic gastroduodenal reflux. Continued acid reflux may then result in mucosal inflammation which results in progressive inflammation-induced genetic instability that may eventuate in esophageal adenocarcinoma. Barrett's is the only recognized precursor lesion to esophageal carcinoma. Barrett's mucosa is unique among preneoplastic lesions; ablation therapy results in restitution of a squamous epithelium reducing or eliminating accumulated genetic instabilities and resetting the biological clock progressing toward invasive cancer. However, recurrence of Barrett's after ablation is common. We propose that both Barrett's and recurrence of Barrett's after ablation can be prevented and discuss how current approaches to therapy for gastroesophageal reflux disease, for Barrett's screening, chemoprevention, and ablation therapy all might be reconsidered. We propose (1) improved approaches to Barrett's prevention, (2) universal Barrett's screening by linking Barrett's screening to colon cancer screening, (3) ablation of all Barrett's mucosa along with (4) acid-suppressive-antireflux therapy tailored to prevent development of Barrett's or the recurrence of Barrett's after ablation therapy. We propose that ultimately, treatment decisions for gastroesophageal reflux disease and prevention of Barrett's and esophageal carcinoma should be based on assessing and maintaining esophageal mucosal integrity. This will require development and verification of specific measurements that reliably correlate with prevention of Barrett's. We outline the new research and technical advances needed to cost-effectively achieve these goals.

Bile acids and ceramide overcome the entry restriction for GII.3 human norovirus replication in human intestinal enteroids

Human noroviruses (HuNoVs) cause sporadic and epidemic outbreaks of gastroenteritis in all age groups worldwide. We previously reported that stem cell-derived human intestinal enteroid (HIE) cultures support replication of multiple HuNoV strains and that some strains (e.g., GII.3) replicate only in the presence of bile. Heat- and trypsin-treatment of bile did not reduce GII.3 replication, indicating a nonproteinaceous component in bile functions as an active factor. Here we show that bile acids (BAs) are critical for GII.3 replication and replication correlates with BA hydrophobicity. Using the highly effective BA, glycochenodeoxycholic acid (GCDCA), we show BAs act during the early stage of infection, BA-dependent replication in HIEs is not mediated by detergent effects or classic farnesoid X receptor or Takeda G protein-coupled receptor 5 signaling but involves another G protein-coupled receptor, sphingosine-1-phosphate receptor 2, and BA treatment of HIEs increases particle uptake. We also demonstrate that GCDCA induces multiple cellular responses that promote GII.3 replication in HIEs, including enhancement of 1) endosomal uptake, 2) endosomal acidification and subsequent activity of endosomal/lysosomal enzyme acid sphingomyelinase (ASM), and 3) ceramide levels on the apical membrane. Inhibitors of endosomal acidification or ASM reduce GII.3 infection and exogenous addition of ceramide alone permits infection. Furthermore, inhibition of lysosomal exocytosis of ASM, which is required for ceramide production at the apical surface, decreases GII.3 infection. Together, our results support a model where GII.3 exploits rapid BA-mediated cellular endolysosomal dynamic changes and cellular ceramide to enter and replicate in jejunal HIEs.

Susceptibility-guided therapy for Helicobacter pylori infection treatment failures

BACKGROUND

Empirical therapy of Helicobacter pylori frequently results in treatment failure due to unrecognized antimicrobial resistance. The aim of this study was to investigate the effectiveness of susceptibility-guided therapy for rescue treatment of H. pylori infection in China.

METHODS

This was a prospective study of consecutive 200 patients infected with H. pylori with one or more treatment failures. The therapy chosen was susceptibility based using the most effective, best-tolerated regimens first and a locally proven, reliably effective regimen for multidrug-resistant infections. All patients received 14-day triple therapy, i.e. esomeprazole 20 mg and amoxicillin 1 g twice a day plus clarithromycin 500 mg twice a day, metronidazole 400 mg twice a day, or levofloxacin 500 mg daily, or, for multidrug-resistant infections, amoxicillin-containing bismuth quadruple therapy with esomeprazole 20 mg twice a day, bismuth 220 mg twice a day, amoxicillin 1 g three times a day, and metronidazole 400 mg four times a day. Antibiotic resistance was determined by agar dilution.

RESULTS

The eradication rate of susceptibility-guided therapy overall was 94.5% (189/200, 95% confidence interval: 90.4-97.2%). Around 28% (56/200) of patients carried strains susceptible to one of the tested antibiotics and were prescribed the triple therapy. A total of 144 multidrug-resistant patients received bismuth quadruple therapy. The eradication rates were all greater than 90%, i.e. 91.7% (11/12), 92.3% (12/13), and 93.5% (29/31) in those who received clarithromycin, metronidazole, and levofloxacin-containing triple therapy and 95.1% (137/144) for the bismuth quadruple therapy. There were no differences in eradication rates between the subgroups.

CONCLUSIONS

Although susceptibility-guided therapy proved high efficacious despite the high proportion of multidrug-resistant strains, the strategy suggested the best approach for this population would be empirical amoxicillin-containing bismuth quadruple therapy. ClinicalTrials.gov identifier: NCT03413020.

Gastric cancer risk stratification and surveillance after Helicobacter pylori eradication: 2020

Gastric cancer remains one of the most common causes of cancer deaths worldwide. The best current option for reducing gastric cancer deaths is Helicobacter pylori eradication combined with risk assessment and surveillance programs for those deemed to be at high risk for gastric cancer so as to identify lesions at a stage amenable to curative therapy. In this issue, Nam et al report a retrospective study of Helicobacter pylori eradication on gastric cancer incidence among 10,328 Korean adults undergoing health checkups including an H pylori test-and-treat program. With a median follow-up of time 5.5 years, they report that H pylori eradication resulted in a significant reduction of gastric cancer incidence in comparison with individuals with persistent infection (eg, hazard ratio [HR] 0.29). Additional important risk factors included atrophic gastritis, family history of gastric cancer, and possibly higher body mass index, which was significant in 1 model but not the other. They also noted that a low serum high-density lipoprotein (HDL) level was associated with a significant increased cancer risk (HR 2.67) when adjusted for low-density lipoprotein (LDL) level and use of lipid-lowering drug.

Dietary quality and the colonic mucosa-associated gut microbiome in humans

BACKGROUND

Despite tremendous interest in modulating the microbiome to improve health, the association between diet and the colonic mucosa-associated gut microbiome in healthy individuals has not been examined.

OBJECTIVE

To investigate the associations between Healthy Eating Index (HEI)-2005 and the colonic mucosa-associated microbiota.

METHODS

In this cross-sectional observational study, we analyzed bacterial community composition and structure using 16S rRNA gene (V4 region) sequencing of 97 colonic mucosal biopsies obtained endoscopically from different colon segments of 34 polyp-free participants. Dietary consumption was ascertained using an FFQ. Differences in α- and β-diversity and taxonomic relative abundances between the higher and lower score of total HEI and its components were compared, followed by multivariable analyses.

RESULTS

The structure of the microbiota significantly differed by the scores for total HEI, total and whole fruits (HEI 1 and HEI 2), whole grains (HEI 6), milk products and soy beverages (HEI 7), and solid fat, alcohol, and added sugar (HEI 12). A lower score for total HEI and HEIs 2, 7, and 12 was associated with significantly lower richness. A lower score for total HEI was associated with significantly reduced relative abundance of Parabacteroides, Roseburia, and Subdoligranulum but higher Fusobacterium. A lower score for HEI 2 was associated with lower Roseburia but higher Bacteroides. A lower score for HEI 7 was associated with lower Faecalibacterium and Fusobacterium but higher Bacteroides. A lower score for HEI 12 was associated with lower Subdoligranulum but higher Escherichia and Fusobacterium (false discovery rate-adjusted P values <0.05). The findings were confirmed by multivariate analysis. Less abundant bacteria such as Alistipes, Odoribacter, Bilophila, and Tyzzerella were also associated with dietary quality.

CONCLUSIONS

A lower score for total HEI-2005 was significantly associated with reduced relative abundance of potentially beneficial bacteria but increased potentially harmful bacteria in the colonic mucosa of endoscopically normal individuals.

High-dose PPI-amoxicillin dual therapy with or without bismuth for first-line Helicobacter pylori therapy: A randomized trial

BACKGROUND

A reliably highly effective high-dose proton-pump inhibitor plus amoxicillin (dual Helicobacter pylori therapy) has remained elusive. We compared whether the addition of bismuth to high-dose dual therapy would improve the efficacy of high-dose dual therapy as first-line treatment.

METHODS

This was an open-label, randomized single-center study of 160 treatment-naive patients with H. pylori infection who were randomly assigned to 14-day therapy with esomeprazole 40 mg twice a day plus amoxicillin 1 g three times a day with or without bismuth potassium citrate 600 mg (elemental bismuth 220 mg) twice a day. Antibiotic resistance was determined by agar dilution method and eradication by ¹³ C-urea breath test.

RESULTS

The per-protocol eradication rates were 96.1%; 95% CI = 88.9%-99.2% (73/76) without bismuth vs 93.3%; 95% CI = 85.1%-97.8% (70/75) with bismuth (P = 0.494). The intention-to-treat eradication rates were 92.5%; 95% CI = 84.4%-97.2% (74/80) without bismuth and 88.8%; 95% CI = 79.7%-94.7% (71/80) with bismuth (P = 0.416). Resistance to amoxicillin, clarithromycin, metronidazole, and levofloxacin was 0%, 31.7%, 81.4%, and 40.7%, respectively. Smoking reduced treatment effectiveness limited to those not receiving bismuth. The per-protocol eradication rates were 70% (7/10) vs 100% (66/66) in smokers vs non-smokers without bismuth (P = 0.002), and 100% (10/10) in smokers vs 92.3% (60/65) in non-smokers with bismuth (P = 1.0). The adverse event rates were 7.5% (6/80) without bismuth vs 11.3% (9/80) with bismuth (P = 0.416).

CONCLUSIONS

Fourteen-day high-dose dual therapy was both effective and safe for first-line treatment in a region of high prevalence antibiotic resistance. Adding bismuth only improved treatment effectiveness among smokers.

Human Norovirus Cultivation in Nontransformed Stem Cell-Derived Human Intestinal Enteroid Cultures: Success and Challenges

Noroviruses, in the genus Norovirus, are a significant cause of viral gastroenteritis in humans and animals. For almost 50 years, the lack of a cultivation system for human noroviruses (HuNoVs) was a major barrier to understanding virus biology and the development of effective antiviral strategies. This review presents a historical perspective of the development of a cultivation system for HuNoVs in human intestinal epithelial cell cultures. Successful cultivation was based on the discovery of genetically-encoded host factors required for infection, knowledge of the site of infection in humans, and advances in the cultivation of human intestinal epithelial cells achieved by developmental and stem cell biologists. The human stem cell-derived enteroid cultivation system recapitulates the multicellular, physiologically active human intestinal epithelium, and allows studies of virus-specific replication requirements, evaluation of human host-pathogen interactions, and supports the pre-clinical assessment of methods to prevent and treat HuNoV infections.

Randomised controlled trial: susceptibility-guided therapy versus empiric bismuth quadruple therapy for first-line Helicobacter pylori treatment

BACKGROUND

Increasing Helicobacter pylori resistance has led to decreases in treatment effectiveness.

AIM

To test the effectiveness of susceptibility-guided therapy vs a locally highly effective empiric modified bismuth quadruple therapy for first-line H pylori treatment in a region with high antimicrobial resistance.

METHODS

We compared 14-day susceptibility-guided with empiric therapy using a multicentre superiority-design trial, which randomised H pylori infected subjects 3:1 to (a) susceptibility-guided therapies contained esomeprazole 20 mg and amoxicillin 1 g b.d. plus clarithromycin 500 mg, metronidazole 400 mg b.d., or levofloxacin 500 mg daily for susceptible infections or bismuth 220 mg b.d. and metronidazole 400 mg q.d.s. for triple-resistant infections; (b) Empiric therapy contained esomeprazole 20 mg, bismuth 220 mg b.d., amoxicillin 1 g and metronidazole 400 mg t.d.s. Primary outcome was H pylori eradication.

RESULTS

Between February 2017 and March 2018, 491 subjects were screened and 382 were randomised. Both the susceptibility-guided and the empiric regimens were highly successful with per-protocol eradication rates of 97.7% (250/256) vs 97.6% (81/83, P = 1.00) and intent-to-treat eradication rates of 91.6% (262/286) vs 85.4% (82/96, P = 0.12). Overall, susceptibility-guided therapy was not superior to empiric therapy with 0.1% per-protocol (95% CI -3.1% to 3.2%) and 6.2% intent-to-treat (-0.3% to 12.7%) eradication difference. Both approaches had high adherence and low adverse event rates.

CONCLUSIONS

Both susceptibility-guided and empiric therapies provided excellent eradication rates. Clinically, the choice would hinge on availability of susceptibility testing and/or a locally highly effective empiric therapy.

Changes of tight junction and interleukin-8 expression using a human gastroid monolayer model of Helicobacter pylori infection

BACKGROUND

Lack of a model that mirrors Helicobacter pylori-induced gastric mucosal inflammation has hampered investigation of early host-bacterial interactions. We used an ex vivo model of human stomach, gastric epithelial organoid monolayers (gastroid monolayers) to investigate interactions of H pylori infection and the apical junctional complex and interleukin-8 (IL-8) expression.

METHOD

Morphology of human antral mucosal gastroid monolayers was evaluated using histology, immunohistochemical (IHC) staining, and transmission electron microscopy (TEM). Functional and gross changes in the apical junctional complexes were assessed using transepithelial electrical resistance (TEER), cytotoxicity assays, and confocal laser scanning microscopy. IL-8 expression was evaluated by real-time quantitative PCR and ELISA.

RESULTS

When evaluated by IHC and TEM, the morphology of gastroid monolayers closely resembled in vivo human stomach. Following inoculation of H pylori, TEER transiently declined (up to 51%) in an H pylori density-dependent manner. TEER recovered by 48 hours post-infection and remained normal despite continued presence and replication of H pylori. Confocal scanning microscopy showed minimal disruption of zonula occludens-1 or E-cadherin structure. IL-8 production was unchanged by infection with either CagA-positive or CagA-negative H pylori and JNK and MEK inhibitors did not suppress IL-8 production, whereas p38 and IKK inhibitor significantly did.

CONCLUSION

Human gastroid monolayers provide a model for experimental H pylori infection more consistent with in vivo human infections than seen with typical gastric epithelial cell lines. This ex vivo system should lead to better understanding of H pylori host-pathogen interactions.

Relative potency of proton-pump inhibitors, Helicobacter pylori therapy cure rates, and meaning of double-dose PPI

BACKGROUND

Helicobacter pylori treatment recommendations often recommend use of double-dose PPI or greater. This is confusing because PPIs very markedly in relative potency such that a double dose of one may not even be equivalent to the single dose of another.

OBJECTIVE

To relate the concept of double-dose to specific amounts of the different PPIs METHODS: We used data standardizing PPI potency in terms of the duration of intragastric pH >4/24 hours (pH4-time) to rank PPIs. Relative potency varies from 4.5 mg omeprazole equivalents (20 mg pantoprazole) to 72 mg omeprazole equivalents (40 mg rabeprazole).

RESULTS

We defined PPI dosing for H. pylori therapy as low dose (eg, approximately 20 mg omeprazole equivalents, b.i.d.), high or double dose as approximately 40 mg omeprazole equivalents, b.i.d.) and high dose as approximately 60 mg omeprazole equivalents, b.i.d.). For example, standard double dose PPI would thus be 40 mg of omeprazole, 20 mg of esomeprazole or rabeprazole, 45 mg of lansoprazole, or 120 mg of pantoprazole each given b.i.d.

CONCLUSIONS

Simply doubling the dose of any PPI achieves markedly different effects on pH4-time. However, PPIs can be used interchangeably and cost effectively based on their omeprazole equivalency.

Bacteroides ovatus ATCC 8483 monotherapy is superior to traditional fecal transplant and multi-strain bacteriotherapy in a murine colitis model

Background and aims: Bacteriotherapy aimed at addressing dysbiosis may be therapeutic for Inflammatory Bowel Diseases (IBDs). We sought to determine if defined Bacteroides-based bacteriotherapy could be an effective and consistent alternative to fecal microbiota transplantation (FMT) in a murine model of IBD. Methods: We induced experimental colitis in 8- 12-week-old C57BL/6 mice using 2-3% dextran sodium sulfate. Mice were simultaneously treated by oral gavage with a triple-Bacteroides cocktail, individual Bacteroides strains, FMT using stool from healthy donor mice, or their own stool as a control. Survival, weight loss and markers of inflammation (histology, serum amyloid A, cytokine production) were correlated to 16S rRNA gene profiling of fecal and mucosal microbiomes. Results: Triple-Bacteroides combination therapy was more protective against weight loss and mortality than traditional FMT therapy. B. ovatus ATCC8483 was more effective than any individual strain, or a combination of strains, in preventing weight loss, decreasing histological damage, dampening inflammatory response, and stimulating epithelial recovery. Irrespective of the treatment group, overall Bacteroides abundance associated with treatment success and decreased cytokine production while the presence of Akkermansia correlated with treatment failure. However, the therapeutic benefit associated with high Bacteroides abundance was negated in the presence of Streptococcus. Conclusions: Bacteroides ovatus monotherapy was more consistent and effective than traditional FMT at ameliorating colitis and stimulating epithelial recovery in a murine model of IBD. Given the tolerability of Bacteroides ovatus ATCC 8483 in an active, on-going human study, this therapy may be repurposed for the management of IBD in a clinically expedient timeline.

Gastritis staging in the endoscopic follow-up for the secondary prevention of gastric cancer: a 5-year prospective study of 1755 patients

OBJECTIVE

Operative link on gastritis assessment (OLGA) staging for gastritis ranks the risk for gastric cancer (GC) in progressive stages (0-IV). This prospective study aimed at quantifying the cancer risk associated with each gastritis stage.

DESIGN

A cohort of 1755 consecutive patients with dyspepsia underwent initial (T-0) oesophagogastroduodenoscopy with mapped gastric biopsies, OLGA staging and assessment of Helicobacter pylori infection. Patients were followed for 55 months (median); patients with stages II III and IV underwent a second endoscopy/restaging (T-1), and those with stages 0 and I were followed clinically and through in-depth clinical and record checking. Endpoints were OLGA stage at T-1 and development of gastric epithelial neoplasia.

RESULTS

At T-0, 77.6% of patients had stage 0, 14.4% stage I, 5.1% stage II, 2.1% stage III and 0.85% stage IV. H. pylori infection was detected in 603 patients at T-0 and successfully eradicated in 602 of them; 220 had a documented history of H. pylori eradication; and 932 were H. pylori naïve-negative. Incident neoplastic lesions (prevalence=0.4%; low-grade intraepithelial neoplasia (IEN)=4; high-grade IEN=1; GC=2) developed exclusively in patients with stages III-IV. The risk for epithelial neoplasia was null in patients at stages 0, I and II (95% CI 0 to 0.4), 36.5 per 1000 person-years in patients at stage III (95% CI 13.7 to 97.4) and 63.1 per 1000 person-years in patients at stage IV (95% CI 20.3 to 195.6).

CONCLUSIONS

This prospective study confirms that OLGA staging reliably predicts the risk for development of gastric epithelial neoplasia. Although no neoplastic lesions arose in H. pylori-naïve patients, the H. pylori eradication in subjects with advanced stages (III-IV) did not abolish the risk for neoplastic progression.

The eradication of Helicobacter pylori to prevent gastric cancer: a critical appraisal

INTRODUCTION

Gastric cancer is one of the top causes of cancer-related death worldwide. How to eliminate gastric cancer is an urgent public-health issue. Areas covered: In this review, we present up-to-date results of studies on gastric cancer prevention through the eradication of Helicobacter pylori and discuss strategies and obstacles for the implementation of population-wide screening and treatment of this pathogen to prevent gastric cancer. Expert commentary: Gastric cancer is an inflammation-associated cancer with multistep carcinogenesis. The process consists of H. pylori infection, ongoing inflammation, development of metaplastic epithelia and genetic instability eventuating in gastric cancer. H. pylori infection is critical for development of the disease and studies have consistently shown that H. pylori eradication results in a reduction in (a) gastric mucosal inflammation, (b) progression of histologic damage, (c) risk of peptic ulcers and ulcer recurrence, and (d) risk of gastric cancer. Compared with a large number of clinical trials evaluating chemopreventive approaches, studies of population-wide screening, and eradication of H. pylori have only recently begun and only in high-risk populations. To eliminate gastric cancer requires information on how to implement an effective program for screening and treatment of H. pylori taking into consideration the other health priorities in any specific population.

Optimizing first line 7-day standard triple therapy for Helicobacter pylori eradication: Prolonging treatment or adding bismuth: which is better?

OBJECTIVE

The 7-day standard triple therapy (STT) gives unacceptablly low eradication rates of Helicobacter pylori (H. pylori). We aimed to examine whether extending STT from 7 days to 14 days or adding a bismuth compound to a 7-day STT would result in better eradication rates.

METHODS

H. pylori-positive patients were assigned to Group A (7-day STT; rabeprazole 20 mg twice daily, amoxicillin 1 g twice daily, and clarithromycin 500 mg twice daily, for 7 days), Group B (7-day STT with bismuth; rabeprazole 20 mg twice daily, amoxicillin 1 g twice daily, clarithromycin 500 mg twice daily and bismuth subcitrate 240 mg twice daily, for 7 days) and Group C (14-day STT; rabeprazole 20 mg twice daily, amoxicillin 1 g twice daily, and clarithromycin 500 mg twice daily for 14 days). Eradication was tested using ¹³ C-UBT at least 4 weeks after the completion of therapy.

RESULTS

A total of 364 patients were recruited. In the intention-to-treat analysis, eradication rates were 79.3% (96/121; 95% confidence interval [CI] 71.3-85.6%) for 7-day STT, 81.7% (98/120; 95% CI 73.8-87.6%) for 7-day STT with bismuth, and 88.6% (109/123; 95% CI 81.8-93.1%) for 14-day STT, respectively. Statistical significance was achieved between the 7-day and the 14-day STT treatment (P = 0.048).

CONCLUSIONS

Adding bismuth to the 7-day STT did not result in an increase in the eradication rate. Extending the STT to 14 days, however, achieved a significantly higher eradication rate. Nevertheless, this did not achieve the targeted 90% eradication rate on intention-to-treat analysis.

Prevalence of Antibiotic Resistance in Helicobacter pylori: A Systematic Review and Meta-analysis in World Health Organization Regions

BACKGROUND & AIMS

In 2017, the World Health Organization (WHO) designated clarithromycin-resistant Helicobacter pylori a high priority for antibiotic research and development. However, there are no clear data on the global distribution of resistance or its clinical effects. We performed a systematic review and meta-analysis to assess the distribution of H pylori resistance to commonly used antibiotics and to measure the association between antibiotic resistance and treatment failure.

METHODS

We searched publication databases for studies that assessed rates of H pylori resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, or tetracycline. Pooled estimates of primary and secondary resistance and 95% confidence intervals (CIs) were grouped by WHO region. The association between antibiotic resistance and treatment failure was measured by extracting data on treatment efficacy in patients with resistant and susceptible isolates and pooling odds ratios with 95% CIs.

RESULTS

We identified 178 studies, comprising 66,142 isolates from 65 countries. Primary and secondary resistance rates to clarithromycin, metronidazole, and levofloxacin were ≥15% in all WHO regions, except primary clarithromycin resistance in the Americas (10%; 95% CI, 4%-16%) and South-East Asia region (10%; 95% CI, 5%-16%) and primary levofloxacin resistance in the European region (11%; 95% CI, 9%-13%). There was considerable heterogeneity (I2 > 75%) among all analyses-this might have resulted from the grouping of resistance rates by country. Increasing antibiotic resistance was observed in most WHO regions. Resistance to clarithromycin was significantly associated with failure of clarithromycin-containing regimens (odds ratio, 6.97; 95% CI, 5.23-9.28; P < .001).

CONCLUSIONS

Resistance of H pylori to antibiotics has reached alarming levels worldwide, which has a great effect on efficacy of treatment. Local surveillance networks are required to select appropriate eradication regimens for each region.

Enzyme therapy for functional bowel disease-like post-prandial distress

Post-prandial gastrointestinal symptoms such as diarrhea, abdominal distension, flatulence, bloating and a feeling of fullness are common complaints of often unknown etiology and pathogenesis. There is a long history of trials reporting the successful use of products containing a variety of combinations of digestive enzymes including a number of randomized placebo-controlled trials. We provide a narrative review of studies describing the use of multi-digestive enzymes for symptoms consistent with irritable bowel syndrome. We describe clinical trials reported over the past 60 years including double-blinded randomized, placebo-controlled studies and recent trials that focused on post-prandial diarrhea consistent with diarrhea-predominant irritable bowel syndrome. Disaccharidase deficiencies or deficiencies of other carbohydrate digesting enzymes were excluded. Worldwide studies have generally reported success with multi-enzyme preparations although none used a factorial design to identify subgroups or attempted to link specific symptom responses to specific components of therapy. Although there is a long history of the successful use of multi-enzyme preparations for post-prandial symptoms consistent with irritable bowel syndrome, long-term studies using validated scoring systems and factorial designs are needed to confirm the results for specific symptoms and the components of the combination drugs received.

Equivalent Efficacies of Reverse Hybrid and Bismuth Quadruple Therapies in Eradication of Helicobacter pylori Infection in a Randomized Controlled Trial

BACKGROUND & AIMS

Bismuth quadruple therapy is recommended as a first-line treatment for Helicobacter pylori infection in the United States but hybrid therapy is an alternative option. Reverse hybrid therapy (proton pump inhibitor plus amoxicillin for 14 days, and clarithromycin plus metronidazole for the initial 7 days) is a simplified hybrid treatment. We aimed to assess the efficacies of reverse hybrid therapy vs bismuth quadruple therapy as first-line treatments for patients with H pylori infection in a randomized trial.

METHODS

In a prospective study, patients with H pylori infection were randomly assigned to groups that received either reverse hybrid therapy (n = 176) or a bismuth quadruple therapy (pantoprazole, bismuth, tetracycline, and metronidazole for 14 days; n = 176). Patients were examined the end of therapy for adverse events. The study was performed from August 2015 through February 2017. The primary outcome was cure of H pylori infection, determined based on a negative result from the urea breath test, or negative results from histologic analysis, the urease test, and bacterial culture analyses.

RESULTS

H pylori infection was eradicated from 96.6% of patients who received reverse hybrid therapy and 96.0% who received bismuth quadruple therapy-this difference was not significant in the intention-to-treat analysis (95% CI, 8.0% ∼ 2.2%; P = .281). There were no significant differences between therapies eradication of clarithromycin-resistant strains (88.2% with reverse hybrid therapy vs 92.3% with bismuth quadruple therapy) or metronidazole-resistant strains (100% vs 96.9%). However, reverse hybrid therapy was associated with fewer adverse events (18.7% of patients) than bismuth quadruple therapy (47.7%) (P < .001).

CONCLUSIONS

In a randomized trial, we found 14-day reverse hybrid therapy to not be inferior to bismuth quadruple therapy as a first-line treatment for H pylori infection. Reverse hybrid therapy was associated with fewer adverse events. ClincialTrials.gov no: NCT02547038.

Understanding treatment guidelines with bismuth and non-bismuth quadruple Helicobacter pylori eradication therapies

INTRODUCTION

Recent Helicobacter pylori treatment guidelines recommend the 4-drug combinations bismuth quadruple therapy and concomitant therapy. Areas covered: We review antimicrobial therapy for H. pylori in the context of antimicrobial therapy in general and specifically in relation to good antimicrobial stewardship (defined as optimal selection, dose, and duration of an antimicrobial that results in the best clinical outcome for the treatment of infection, with minimal toxicity to the patient and minimal impact on subsequent resistance). Expert commentary: The lack of regional and local H. pylori susceptibility data prevents implementation of susceptibility-based antimicrobial therapy and forces compromises. Bismuth quadruple therapy employing at least 1,500 mg of metronidazole for 14 days is effective despite metronidazole resistance. The main drawback is side effects causing reduced adherence. Versions where amoxicillin replaces metronidazole or tetracycline also appear effective. It is likely that bismuth quadruple therapy can be simplified by giving bismuth and possibly tetracycline b.i.d., possibly with fewer side effects. Concomitant therapy (a proton pump inhibitor, metronidazole, clarithromycin, amoxicillin) is ineffective with dual clarithromycin-metronidazole resistance and all patients receive at least one unnecessary antibiotic thus promoting antimicrobial resistance worldwide. Concomitant therapy should be abandoned when susceptibility testing becomes widespread or an alternate becomes available.

Treating Helicobacter pylori effectively while minimizing misuse of antibiotics

Experts now recommend that all Helicobacter pylori infections be eradicated unless there are compelling reasons not to. As with other infectious diseases, effective therapy should be based on susceptibility.

Differential blood pressure effects of ibuprofen, naproxen, and celecoxib in patients with arthritis: the PRECISION-ABPM (Prospective Randomized Evaluation of Celecoxib Integrated Safety Versus Ibuprofen or Naproxen Ambulatory Blood Pressure Measurement) Trial

Aims

Non-steroidal anti-inflammatory drugs (NSAIDs), both non-selective and selective cyclooxygenase-2 (COX-2) inhibitors, are among the most widely prescribed drugs worldwide, but associate with increased blood pressure (BP) and adverse cardiovascular (CV) events. PRECISION-ABPM, a substudy of PRECISION was conducted at 60 sites, to determine BP effects of the selective COX-2 inhibitor celecoxib vs. the non-selective NSAIDs naproxen and ibuprofen.

Methods and results

In this double-blind, randomized, multicentre non-inferiority CV-safety trial, 444 patients (mean age 62 ± 10 years, 54% female) with osteoarthritis (92%) or rheumatoid arthritis (8%) and evidence of or at increased risk for coronary artery disease received celecoxib (100-200 mg bid), ibuprofen (600-800 mg tid), or naproxen (375-500 mg bid) with matching placebos in a 1: 1: 1 allocation, to assess the effect on 24-h ambulatory BP after 4 months. The change in mean 24-h systolic BP (SBP) in celecoxib, ibuprofen and naproxen-treated patients was -0.3 mmHg [95% confidence interval (CI), -2.25, 1.74], 3.7 (95% CI, 1.72, 5.58) and 1.6 mmHg (95% CI, -0.40, 3.57), respectively. These changes resulted in a difference of - 3.9 mmHg (P = 0.0009) between celecoxib and ibuprofen, of - 1.8 mmHg (P = 0.12) between celecoxib and naproxen, and of - 2.1 mmHg (P = 0.08) between naproxen and ibuprofen. The percentage of patients with normal baseline BP who developed hypertension (mean 24-h SBP ≥ 130 and/or diastolic BP ≥ 80 mmHg) was 23.2% for ibuprofen, 19.0% for naproxen, and 10.3% for celecoxib (odds ratio 0.39, P = 0.004 and odds ratio 0.49, P = 0.03 vs. ibuprofen and naproxen, respectively).

Conclusions

In PRECISION-ABPM, allocation to the non-selective NSAID ibuprofen, compared with the COX-2 selective inhibitor celecoxib was associated with a significant increase of SBP, and a higher incidence of new-onset hypertension.

ClinicalTrials

gov number NCT00346216.

Houston Consensus Conference on Testing for Helicobacter pylori Infection in the United States

Despite guidelines for detection and treatment of Helicobacter pylori infection, recommendations to test patients before and after therapy are commonly not followed in the United States. At the Houston Consensus Conference, 11 experts on management of adult and pediatric patients with H pylori, from different geographic regions of the United States, met to discuss key factors in diagnosis of H pylori infection, including identification of appropriate patients for testing, effects of antibiotic susceptibility on testing and treatment, appropriate methods for confirmation of infection and eradication, and relevant health system considerations. The experts divided into groups that used a modified Delphi panel approach to assess appropriate patients for testing, testing for antibiotic susceptibility and treatment, and test methods and confirmation of eradication. The quality of evidence and strength of recommendations were evaluated using the GRADE system. The results of the individual workshops were presented for a final consensus vote by all panel members. After the Expert Consensus Development meeting, the conclusions were validated by a separate panel of gastroenterologists, who assessed their level of agreement with each of the 29 statements developed at the Expert Consensus Development. The final recommendations are provided, on the basis of the best available evidence, and provide consensus statements with supporting literature to implement testing for H pylori infection at health care systems across the United States.

Effects of Helicobacter pylori Treatment on Incidence of Gastric Cancer in Older Individuals

BACKGROUND & AIMS

Although eradication of Helicobacter pylori infection reduces the risk of gastric cancer, few data are available on its effects in older subjects. We compared the age-specific risk of gastric cancer in a large cohort of subjects who received H pylori eradication therapy vs a matched general population.

METHODS

We searched the Hospital Authority database of Hong Kong to identify individuals with H pylori infection who had received a course of clarithromycin-containing eradication therapy from January 2003 through December 2012. We compared the gastric cancer incidence in this cohort with the expected incidence for the local general population by retrieving the gastric cancer incidence of the age- and sex-matched population from 2003 through 2014 (the latest available year) from the Hong Kong Cancer Registry. The primary outcome was the incidence of gastric cancer development in the cohort treated for H pylori infection vs the expected number of gastric cancer cases in the general population. Analyses were conducted by a priori age groups of less than 40 years, 40-59 years, and 60 years or older.

RESULTS

Among 73,237 subjects infected with H pylori who received eradication therapy, 200 (0.27%) developed gastric cancer during a median follow-up time of 7.6 years. Compared with the matched general population, the gastric cancer risk was significantly lower in subjects 60 years or older who had received H pylori treatment (standardized incidence ratio [SIR], 0.82; 95% confidence interval [CI], 0.69-0.97; P = .02) but not in younger groups. When data were stratified based on time from H pylori treatment (less than 5 years, 5-9 years, and 10 or more years), the risk of gastric cancer was significantly lower than the general population 10 or more years after eradication in the group 40-59 years old (SIR 0.32; 95% CI, 0.08-0.88; P = .04) and the group 60 years or older (SIR, 0.42; 95% CI, 0.42-0.84; P = .02) than the other age groups.

CONCLUSIONS

In an analysis of data from a public hospital database on Hong Kong, we associated treatment of H pylori infection with a lower risk of gastric cancer, particularly in older subjects, 10 or more years after treatment.

An Investigation into the Recent Increase in Gastric Cancer in the USA

BACKGROUND

The USA has among the lowest gastric cancer incidence rates worldwide.

AIM

To investigate whether increasing immigration from high cancer incidence countries has altered the GC incidence in a large US metropolitan area.

METHODS

This was a retrospective cohort study among an underprivileged, multiethnic population in Texas. Gastric cancer cases diagnosed during 2005-2015 were identified using the cancer registry of the public medical care system for Harris County. All cases were histologically confirmed; demographic and clinical data were obtained from review of electronic medical records. Census data were used to determine the distribution of the adult county population by race/ethnicity and age. Two time periods (2005-2009 and 2010-2015) were studied to correspond with census reporting intervals.

RESULTS

In total, 299 cases were included: average age 55 years, 59% males and 63% Hispanics (predominantly recent immigrants of Central-American origin). The gastric cancer incidence remained stable among non-Hispanic Whites and Blacks but increased significantly among Hispanics (from 10 to 17 cases/100,000 persons/year, RR = 2.0, 95% CI 1.4-2.5, p = 0.001). Among Hispanics, gastric cancer incidence rose significantly among persons aged 40-59 years and ≥ 60 years and was likely to be at advanced stage at the time of diagnosis even in the younger age population.

CONCLUSION

Gastric cancer incidence significantly increased among Hispanics residing in Houston resulting in changes in gastric cancer incidence becoming more unevenly experienced across the US population. Consideration should be given to gastric cancer preventive efforts, especially among immigrant populations from high gastric cancer risk countries.

Interchangeable Use of Proton Pump Inhibitors Based on Relative Potency

Although proton pump inhibitors (PPIs) are widely used, their relative potency and ideal dosing regimens remain unclear. We analyzed data from randomized clinical trials that performed pH testing in patients receiving solid-dose PPI formulations (omeprazole, esomeprazole, lansoprazole, pantoprazole, rabeprazole) for a minimum of 5 days. We used omeprazole equivalency and the surrogate biomarker, percentage time pH > 4 over a 24-hour period (pH4time), to compare PPI effectiveness for different PPIs given once, twice, or 3 times daily. We found that increasing strength of once-daily PPIs (9-64 mg omeprazole equivalents) increased pH4time linearly from approximately 10.0 to 15.6 hours; higher doses produced no further increase in pH4time. Increasing the frequency to twice-daily PPI increased pH4time linearly, from approximately 15.8 to 21.0 hours. Three-times daily PPIs performed similarly to twice-daily PPIs. The costs of PPIs varied greatly, but the cost variation was not directly related to potency. We conclude that PPIs can be used interchangeably based on potency. Using twice-daily PPIs is more effective in increasing efficacy increasing once-daily PPI dosage. Omeprazole and lansoprazole (30 mg) and 20 mg of esomeprazole rabeprazole are functionally equivalent.

Randomised clinical trial: gastrointestinal events in arthritis patients treated with celecoxib, ibuprofen or naproxen in the PRECISION trial

AIM

To evaluate GI safety of celecoxib compared with 2 nonselective (ns) NSAIDs, as a secondary objective of a large trial examining multiorgan safety.

METHODS

This randomised, double-blind controlled trial analysed 24 081 patients. Osteoarthritis or rheumatoid arthritis patients, needing ongoing NSAID treatment, were randomised to receive celecoxib 100-200 mg b.d., ibuprofen 600-800 mg t.d.s. or naproxen 375-500 mg b.d. plus esomeprazole, and low-dose aspirin or corticosteroids if already prescribed. Clinically significant GI events (CSGIE-bleeding, obstruction, perforation events from stomach downwards or symptomatic ulcers) and iron deficiency anaemia (IDA) were adjudicated blindly.

RESULTS

Mean treatment and follow-up durations were 20.3 and 34.1 months. While on treatment or 30 days after, CSGIE occurred in 0.34%, 0.74% and 0.66% taking celecoxib, ibuprofen and naproxen. Hazard ratios (HR) were 0.43 (95% CI 0.27-0.68, P = 0.0003) celecoxib vs ibuprofen and 0.51 (0.32-0.81, P = 0.004) vs naproxen. There was also less IDA on celecoxib: HR 0.43 (0.27-0.68, P = 0.0003) vs ibuprofen; 0.40 (0.25-0.62, P < 0.0001) vs naproxen. Even taken with low-dose aspirin, fewer CSGIE occurred on celecoxib than ibuprofen (HR 0.52 [0.29-0.94], P = 0.03), and less IDA vs naproxen (0.42 [0.23-0.77, P = 0.005]). Corticosteroid use increased total GI events and CSGIE. H. pylori serological status had no influence.

CONCLUSIONS

Arthritis patients taking NSAIDs plus esomeprazole have infrequent clinically significant gastrointestinal events. Co-prescribed with esomeprazole, celecoxib has better overall GI safety than ibuprofen or naproxen at these doses, despite treatment with low-dose aspirin or corticosteroids.

Incidence of gastric cancer in the USA during 1999 to 2013: a 50-state analysis

BACKGROUND

The incidence of gastric cancer, while declining in many places worldwide, is characterized by considerable geographical variability. The USA has large racial, ethnic and regional variation; we collected data from all 50 states to better characterize recent changes in gastric cancer incidence nationwide.

METHODS

Annual gastric cancer incidence rates from 1999 to 2013 were extracted from the United States Cancer Statistics (USCS) registry. Secular trends of gastric cancer incidence were examined overall and by sociodemographic factors and states. We used Joinpoint regression to compute annual percent change (APC) and average annual percent change (AAPC) and corresponding 95% confidence intervals (CIs). SEER 13 registries data were extracted to examine the secular trends by cardia and non-cardia gastric cancers.

RESULTS

Overall gastric cancer incidence decreased until 2007 (APC = -1.55, 95% CI: -1.88, -1.21), and remained stable thereafter (APC = -0.32, 95% CI: -0.84, 0.20). However, rates increased among persons <50 years of age (AAPC = 0.89, 95% CI: 0.61, 1.16), especially among non-Hispanic white females and Hispanic females. Incidence of non-cardia gastric cancer increased among persons <50 years of age (AAPC = 0.69, 95% CI: -0.06, 1.44), whereas rates of gastric cardia cancer remained unchanged. States with rapid increases in high-risk population groups (e.g. Hispanic females aged <50), including California and Texas, had highest annual increases in gastric cancer incidence.

CONCLUSIONS

Divergent trends for gastric cancer incidence were observed in the USA. Incidence rates, particularly for non-cardia gastric cancer, were stable or increasing among persons aged  <50 years.

Brief report: Lactobacillus bulgaricus GLB44 (Proviotic™ ) plus esomeprazole for Helicobacter pylori eradication: A pilot study

BACKGROUND

Recent studies of Lactobacillus delbrueckii subsp. bulgaricus GLB44 plus a proton-pump inhibitor (PPI) reported cures of more than 90% of patients with active Helicobacter pylori infections.

AIM

To confirm the high H. pylori cure rates reported previously.

METHOD

A pilot study was done in healthy H. pylori-infected volunteers using 3-gram sachet (3 billion cells) of L. delbrueckii GLB44 plus 22.3 mg of esomeprazole b.i.d., for 14 days. The result was determined by urea breath testing 4 weeks after therapy. Stopping rules required for ending enrollment if less than 3 of the first 10 subjects were cured.

RESULTS

Nine subjects were entered and because all failed to achieve negative urea breath test, the stopping rule required the study to end.

CONCLUSION

We were unable to confirm reports of achieving a high H. pylori cure rate with L. delbrueckii GLB44 plus a PPI.

Genome and Methylome Variation in Helicobacter pylori With a cag Pathogenicity Island During Early Stages of Human Infection

BACKGROUND & AIMS

Helicobacter pylori is remarkable for its genetic variation; yet, little is known about its genetic changes during early stages of human infection, as the bacteria adapt to their new environment. We analyzed genome and methylome variations in a fully virulent strain of H pylori during experimental infection.

METHODS

We performed a randomized Phase I/II, observer-blind, placebo-controlled study of 12 healthy, H pylori-negative adults in Germany from October 2008 through March 2010. The volunteers were given a prophylactic vaccine candidate (n = 7) or placebo (n = 5) and then challenged with H pylori strain BCM-300. Biopsy samples were collected and H pylori were isolated. Genomes of the challenge strain and 12 reisolates, obtained 12 weeks after (or in 1 case, 62 weeks after) infection were sequenced by single-molecule, real-time technology, which, in parallel, permitted determination of genome-wide methylation patterns for all strains. Functional effects of genetic changes observed in H pylori strains during human infection were assessed by measuring release of interleukin 8 from AGS cells (to detect cag pathogenicity island function), neutral red uptake (to detect vacuolating cytotoxin activity), and adhesion assays.

RESULTS

The observed mutation rate was in agreement with rates previously determined from patients with chronic H pylori infections, without evidence of a mutation burst. A loss of cag pathogenicity island function was observed in 3 reisolates. In addition, 3 reisolates from the vaccine group acquired mutations in the vacuolating cytotoxin gene vacA, resulting in loss of vacuolization activity. We observed interstrain variation in methylomes due to phase variation in genes encoding methyltransferases.

CONCLUSIONS

We analyzed adaptation of a fully virulent strain of H pylori to 12 different volunteers to obtain a robust estimate of the frequency of genetic and epigenetic changes in the absence of interstrain recombination. Our findings indicate that the large amount of genetic variation in H pylori poses a challenge to vaccine development. ClinicalTrials.gov no: NCT00736476.

Helicobacter pylori urease for diagnosis of Helicobacter pylori infection: A mini review

The stomach contents contain of both acid and proteolytic enzymes. How the stomach digests food without damaging itself remained a topic of investigation for decades. One candidate was gastric urease, which neutralized acid by producing ammonia from urea diffusing from the blood and potentially could protect the stomach. Discovery that gastric urease was not mammalian resulted in a research hiatus until discovery that gastric urease was produce by Helicobacter pylori which caused gastritis, peptic ulcer and gastric cancer. Gastric urease allows the organism to colonize the acidic stomach and serves as a biomarker for the presence of H. pylori. Important clinical tests for H. pylori, the rapid urease test and urea breath test, are based on gastric urease. Rapid urease tests use gastric biopsies or mucus placed in a device containing urea and an indicator of pH change, typically phenol red. Urea breath tests measure the change in isotope enrichment of ¹³C- or ¹⁴CO₂ in breath following oral administration of labeled urea. The urea breath test is non-invasive, convenient and accurate and the most widely used test for non-invasive test for detection of active H. pylori infection and for confirmation of cure after eradication therapy.

Changing Trends in Stomach Cancer Throughout the World

PURPOSE OF REVIEW

The paper aims to discuss the global trends in gastric cancer incidence in relation to important factors involved in the pathogenesis of gastric cancer.

RECENT FINDINGS

Despite a significant worldwide decline, gastric cancer remains a common cause of cancer death. The decline has been multifactorial and preceded the fall in Helicobacter pylori prevalence. The initial decline was associated with changes in food preservation and availability, especially of fresh fruits and vegetables, followed by a decline in the primary etiologic factor, H. pylori. Gastric cancer incidence remains high in East Asia, intermediate in Latin America, and low in developed countries. Significant racial/ethnic variability exists. The rapid decline in incidence in East Asia will continue as primary and secondary prevention strategies are implemented. The incidence in Latin America is unlikely to decline significantly over the next few decades given high H. pylori prevalence in the young. Ultimately, global H. pylori eradication will be needed to largely eliminate gastric cancer.

Gastric Cancer as Preventable Disease

Gastric cancer, 1 of the 5 most common causes of cancer death, is associated with a 5-year overall survival rate less than 30%. A minority of cancers occurs as part of syndromic diseases; more than 90% of adenocarcinomas are considered as the ultimate consequence of a longstanding mucosal inflammation. Helicobacter pylori infection is the leading etiology of non-self-limiting gastritis, which may result in atrophy of the gastric mucosa and impaired acid secretion. Gastric atrophy establishes a field of cancerization prone to further molecular and phenotypic changes, possibly resulting in cancer growth. This well-understood natural history provides the clinicopathologic rationale for primary and secondary cancer prevention strategies. A large body of evidence demonstrates that combined primary (H pylori eradication) and secondary (mainly endoscopy) prevention efforts may prevent or limit the progression of gastric oncogenesis. This approach, which is tailored to different country-specific gastric cancer incidence, socioeconomic, and cultural factors, requires that the complementary competences of gastroenterologists, oncologists, and pathologists be amalgamated into a common strategy of health policy.