Helicobacter pylori eradication therapy

Proton Pump Inhibitors in Germany: Status Quo of a Growing Market

Introduction

The volume of prescriptions for proton pump inhibitors (PPIs) remains high, although the literature increasingly points to excessive prescribing in relation to guideline recommendations. No very recent data is available on the specific situation in Germany, particularly on the proportion of PPI consumption from over-the-counter (OTC) sales and self-selection, following PPI down-scheduling. The aim of this study was to determine the actual amount of prescribed and OTC PPIs in Germany.

Methods

For this retrospective study, several IQVIA databases were used, representing all prescriptions billed to statutory and private health insurers in Germany, as well as OTC sales. Analyses were performed for the period November 2020 to October 2021 or partially November 2018 to October 2021 and were descriptive in nature. Mainly, data were collected from IQVIATM PharmaScope National® as well as IQVIA TM DPM® databases.

Results

A total of 2.87 billion PPI tablets were shown to have been sold between November 2020 and October 2021, with most drugs prescribed in the largest packages and strengths. In addition, the OTC PPI market increased by an average of 14% per year over a 3-year period.

Conclusions

The results of this study suggest the substantial size of the PPI market in Germany is based on prescriptions, a consistent increase in OTC PPI purchases and a recent increase in prescriptions.

Abundance and prevalence of ESBL coding genes in patients undergoing first line eradication therapy for Helicobacter pylori

The spread of extended-spectrum beta-lactamases (ESBLs) in nosocomial and community-acquired enterobacteria is an important challenge for clinicians due to the limited therapeutic options for infections that are caused by these organisms. Here, we developed a panel of ESBL coding genes, evaluated the abundance and prevalence of ESBL encoding genes in patients undergoing H. pylori eradication therapy, and summarized the effects of eradication therapy on functional profiles of the gut microbiome. To assess the repertoire of known beta lactamase (BL) genes, they were divided into clusters according to their evolutionary relation. Primers were designed for amplification of cluster marker regions, and the efficiency of this amplification panel was assessed in 120 fecal samples acquired from 60 patients undergoing H. pylori eradication therapy. In addition, fecal samples from an additional 30 patients were used to validate the detection efficiency of the developed ESBL panel. The presence for majority of targeted clusters was confirmed by NGS of amplification products. Metagenomic sequencing revealed that the abundance of ESBL genes within the pool of microorganisms was very low. The global relative abundances of the ESBL-coding gene clusters did not differ significantly among treatment states. However, at the level of each cluster, classical ESBL producers such as Klebsiella sp. for blaOXY (p = 0.0076), Acinetobacter sp. for blaADC (p = 0.02297) and others, differed significantly with a tendency to decrease compared to the pre- and post-eradication states. Only 13 clusters were common across all three datasets, suggesting a patient-specific distribution profile of ESBL-coding genes. The number of AMR genes detected in the post-eradication state was higher than that in the pre-eradication state, which could be attributed, at least in part, to the therapy. This study demonstrated that the ESBL screening panel was effective in targeting ESBL-coding gene clusters from bacterial DNA and that minor differences exist in the abundance and prevalence of ESBL-coding gene levels before and after eradication therapy.

Vonoprazan-based triple and dual therapy versus bismuth-based quadruple therapy for Helicobacter pylori infection in China: a three-arm, randomised clinical trial protocol

BACKGROUND

Helicobacter pylori infection and associated diseases are a growing global public health issue. H. pylori infection is the major cause of gastric cancer, over 90% of duodenal ulcers, and over 70% of gastric ulcers. The infection rate of H. pylori is approximately 50%, and approximately 50% of new cases of gastric cancer worldwide occur in China. Bismuth (BI)-based quadruple therapy is recommended as the first-line treatment for H. pylori in China. Vonoprazan (VPZ), a new potassium-competitive acid blocker that can inhibit gastric acid secretion more effectively than proton pump inhibitors (PPIs), has been combined with antibiotics to effectively eradicate H. pylori. In this study, we compared the efficacy and safety of two VPZ-based therapies with that of BI-based therapy for H. pylori treatment.

METHODS

A three-armed randomised controlled trial (RCT) is being conducted in Shenzhen, with 327 participants recruited from the Gastroenterology Clinic of the University of Hong Kong-Shenzhen Hospital. Patients were diagnosed with H. pylori infection based on a positive ¹³C-urea breath test (UBT). Patients are kept naïve to their treatment and are randomly assigned in a 1:1:1 ratio to either VPZ-based triple, VPZ-based dual, or BI-based quadruple therapy for 14 days. All groups are subjected to follow-up evaluations of safety, adverse drug reactions, and clinical variables in the first, second, and fourth weeks after treatment. Successful eradication is confirmed by a negative ¹³C-UBT six weeks after treatment. If initial treatment fails, (1) those patients are turned to another regimen, or (2) a drug resistance test is conducted, after which an individualised treatment regimen shall be prescribed according to antimicrobial susceptibility testing. The resulting data will be evaluated using intention-treat and a per-protocol analysis.

DISCUSSION

This study is the a RCT aims to evaluate the efficacy and safety of 14-day VPZ-based triple and dual therapies in comparison with BI-based quadruple therapy. The outcomes of this study may allow treatment recommendations and update drug instructions in China.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (No. ChiCTR2200056375). Registered on February 4, 2022, https://www.chictr.org.cn/showproj.aspx?proj=141314.

Can Saccharomyces boulardii treat and eradicate Helicobacter pylori among children instead of bismuth?

Aim: The objective of this study is to compare the use of Saccharomyces boulardii (S. boulardii) in eradicating Helicobacter pylori (H. pylori) in children as an alternative to bismuth, which has a limited scope of application due to its side effects. Material and Method: Included in the study were 220 pediatric patients with symptomatic H. pylori gastritis. The patients were randomized into three treatment groups. Patients who received bismuth or S. boulardii in addition to the standard triple therapy for 14 days were compared with the control group who received only triple therapy. Results: Analysis of the bismuth, S. boulardii, and control groups’ treatment success showed that the H. pylori eradication rate was highest among study participants who received bismuth (95.2%), followed by patients who received S. boulardii (92.4%). The most frequent side effects were observed in the patient group that received bismuth (17.5%). Conclusion: Although bismuth continues to be successful in eradicating H. pylori, alternative treatment protocols are necessary because of its side effects and limited use in pediatric patients. S. boulardii can be administered instead when bismuth can not serve as alternative due to its side effects.

Decreased anti-parietal cell antibody titer in the advanced phase of autoimmune gastritis

BACKGROUND

Autoimmune gastritis (AIG) is histologically classified into three phases according to the severity of oxyntic mucosal atrophy: early, florid, and end phases. This study aimed to clarify the relationship between the AIG phase and the anti-parietal cell antibody titer.

METHODS

Patients who underwent upper gastrointestinal endoscopy were retrospectively reviewed in this study. We enrolled patients who were histologically diagnosed with AIG and serologically tested for anti-parietal cell antibody (APCA). AIG patients were classified into three groups: early, florid, and end phase groups. Clinical characteristics, including APCA titers, were compared among these three groups.

RESULTS

A total of 44 AIG patients were enrolled. There were two patients in the early phase, 11 in the florid phase, and 31 in the end phase. APCA-positive rates were 100% in the early phase, 90.9% in the florid phase, and 90.3% in the end phase. The mean APCA titer was 480 U in the early phase, 220 U in the florid phase, and 150 U in the end phase. There was a stepwise decrease in the APCA titer from the early phase to the end phase. The mean APCA titer for the end phase was significantly lower than that of the early phase or florid phase. Additionally, there was a stepwise decrease in serum gastrin levels from the early phase to the end phase.

CONCLUSION

AIG progresses from the early phase to the end phase, and the APCA titer shows a decrease. The negativity of APCA could occur, especially in the end phase.

Clue of Diagnosis for Autoimmune Gastritis

BACKGROUND

The diagnostic clues for autoimmune gastritis (AIG) can be classified into 2 categories: endoscopic findings and pathological diagnosis. We believe that research on the AIG detection rate by endoscopists could provide a better understanding of the diagnosis of AIG. This study aimed to clarify the ratio of the endoscopic and the pathological diagnoses of AIG.

METHODS

We retrospectively reviewed consecutive patients who underwent esophagogastroduodenoscopy (EGD). During their first EGD, the gastric mucosa with C2 atrophy or more was biopsied for pathological evaluation based on the updated Sydney system. A gastric biopsy was also performed after Helicobacter pylori eradication, obtaining specimens from at least 2 sites, the greater curvature of the corpus and the antrum. We enrolled patients who were positive for the anti-parietal cell antibody and were diagnosed with AIG, histologically and/or endoscopically. The detection rates of AIG were compared between endoscopic diagnosis and pathological diagnosis.

RESULTS

A total of 10,822 patients underwent EGD during the study period. Finally, 41 patients with AIG were enrolled, leading to an AIG prevalence of 0.38% in this study. As for the clue leading to AIG detection, 31.7% (13/41) were diagnosed through endoscopy (proximal-predominant atrophy), and 68.3% (28/41) were diagnosed pathologically. The AIG detection rate by endoscopists in the posteradication group was significantly lower than in the H. pylori-negative group (p < 0.05).

CONCLUSION

Endoscopists frequently overlooked AIG, especially in posteradication cases. Pathological assessment using the updated Sydney system after H. pylori eradication might be a promising strategy to detect AIG better.

Overview of Helicobacter pylori Infection: Clinical Features, Treatment, and Nutritional Aspects

Helicobacter pylori (H. pylori) is a 0.5-1 µm wide, 2-4 µm long, short helical, S-shaped Gram-negative microorganism. It is mostly found in the pyloric region of the stomach and causes chronic gastric infection. It is estimated that these bacteria infect more than half of the world's population. The mode of transmission and infection of H. pylori is still not known exactly, but the faecal-oral and oral-oral routes via water or food consumption are thought to be a very common cause. In the last three decades, research interest has increased regarding the pathogenicity, microbial activity, genetic predisposition, and clinical treatments to understand the severity of gastric atrophy and gastric cancer caused by H. pylori. Studies have suggested a relationship between H. pylori infection and malabsorption of essential micronutrients, and noted that H. pylori infection may affect the prevalence of malnutrition in some risk groups. On the other hand, dietary factors may play a considerably important role in H. pylori infection, and it has been reported that an adequate and balanced diet, especially high fruit and vegetable consumption and low processed salty food consumption, has a protective effect against the outcomes of H. pylori infection. The present review provides an overview of all aspects of H. pylori infection, such as clinical features, treatment, and nutrition.

Helicobacter pylori Infection in Africa: Update of the Current Situation and Challenges

BACKGROUND

The burden of Helicobacter pylori infection (HPI) in Africa remains high with varying levels of prevalence among children and adults reported in different regions of the continent. Persistent and uneradicated HPI could result in gastric cancer, although less severe pathological outcomes have been reported among Africans - the so-called "African enigma."

SUMMARY

Analysis of endoscopic findings of the upper gastrointestinal tract demonstrates similarities with that of patients from the West. Thus, it could be asserted that the true picture of HPI in Africa is yet to be unveiled due to several challenges including inadequate health-care system, lack of treatment guidelines and standardized protocol for diagnosis, and lack of data. This review explores the prevalence, diagnosis, treatment, and health-care system in Africa as it relates to HPI, thus providing an update and highlighting the need for an African HPI guideline.

KEY MESSAGES

There is high prevalence of Helicobacter pylori infection (HPI) in Africa with an increasing burden of antibiotic resistance. Various methods including invasive and noninvasive methods are deployed in the diagnosis of HPI in Africa. There is a need for consensus on diagnosis and treatment of HPI in Africa.

Sitafloxacin for Third-Line Helicobacter pylori Eradication: A Systematic Review

BACKGROUND AND AIM

Sitafloxacin-based therapy is a potent candidate for third-line Helicobacter pylori eradication treatment. In this systematic review, we summarise current reports with sitafloxacin-based therapy as a third-line treatment.

METHODS

Clinical studies were systematically searched using PubMed, Cochrane library, Web of Science, and the Igaku-Chuo-Zasshi database. We combined data from clinical studies using a random-effects model and calculated pooled event rates, 95% confidence intervals (CIs), and the pooled odds ratio (OR).

RESULTS

We included twelve clinical studies in the present systematic review. The mean eradication rate for 7-day regimens of either PPI (proton pump inhibitor) or vonoprazan-sitafloxacin-amoxicillin was 80.6% (95% CI, 75.2-85.0). The vonoprazan-sitafloxacin-amoxicillin regimen was significantly superior to the PPI-sitafloxacin-amoxicillin regimen (pooled OR of successful eradication: 6.00; 95% CI: 2.25-15.98, p < 0.001). The PPI-sitafloxacin-amoxicillin regimen was comparable with PPI-sitafloxacin-metronidazole regimens (pooled OR: 1.06; 95% CI: 0.55-2.07, p = 0.86).

CONCLUSIONS

Although the 7-day regimen composed of vonoprazan, sitafloxacin, and amoxicillin is a good option as the third-line Helicobacter pylori eradication treatment in Japan, the extension of treatment duration should be considered to further improve the eradication rate. Considering the safety concern of fluoroquinolones, sitafloxcin should be used after confirming drug susceptibility.

Best Helicobacter pylori Eradication Strategy in the Era of Antibiotic Resistance

Antibiotic resistance is the major reason for Helicobacter pylori treatment failure, and the increasing frequency of antibiotic resistance is a challenge for clinicians. Resistance to clarithromycin and metronidazole is a particular problem. The standard triple therapy (proton pump inhibitor, amoxicillin, and clarithromycin) is no longer appropriate as the first-line treatment in most areas. Recent guidelines for the treatment of H. pylori infection recommend a quadruple regimen (bismuth or non-bismuth) as the first-line therapy. This treatment strategy is effective for areas with high resistance to clarithromycin or metronidazole, but the resistance rate inevitably increases as a result of prolonged therapy with multiple antibiotics. Novel potassium-competitive acid blocker-based therapy may be effective, but the data are limited. Tailored therapy based on antimicrobial susceptibility test results is ideal. This review discussed the current important regimens for H. pylori treatment and the optimum H. pylori eradication strategy.

Nodularity-like appearance in the cardia: novel endoscopic findings for Helicobacter pylori infection

Background and study aims   Helicobacter pylori -associated nodular gastritis, which is associated with follicular lymphoid hyperplasia, is mainly recognized in the antrum. However, we have also observed nodularity-like appearance in the cardia. This study aimed to investigate the clinical significance of cardiac nodularity-like appearance in H. pylori -associated gastritis. Patients and methods  Patients who underwent esophagogastroduodenoscopy and were evaluated for H. pylori infection for the first time were enrolled. A nodularity-like appearance in the cardia was defined as a miliary nodular appearance or scattered appearances of small circular whitish coloration. H. pylori infection was diagnosed according to serum anti- H. pylori antibody and the urea breath test or histology. Accuracy of the H. pylori infection diagnoses based on nodularity-like appearance were assessed. Results  Among 265 patients, 42 patients (15.8 %) were diagnosed as positive for H. pylori . Cardiac nodularity-like appearance and antral nodularity were recognized in 25 and 15 patients, respectively. In accuracy of predicting H. pylori by cardiac nodularity-like appearance, specificity was 0.996, sensitivity was 0.571, positive predictive value was 0.960, negative predictive value was 0.925, and accuracy was 0.928. The sensitivity of cardiac nodularity-like appearance was significantly higher than that of antral nodularity ( P  = 0.0284). Conclusions  Cardiac nodularity-like appearance had a high accuracy rate for H. pylori infection diagnosis. Cardiac nodularity-like appearance was found more frequently than antral nodularity.

Antibiotic resistance and clonal relatedness of Helicobacter pylori strains isolated from stomach biopsy specimens in northeast of Iran

BACKGROUND

Resistant Helicobacter pylori to commonly used antimicrobial agents are associated with severe upper gastrointestinal disorders. To provide an epidemiological picture of H pylori and characterize the resistance pattern and genetic variation of clinical isolates, stomach biopsies from patients with functional dyspepsia were evaluated in northeast of Iran.

MATERIALS AND METHODS

In this study, 80 patients were recruited. Finally, fifty H pylori strains were isolated from antrum and corpus biopsies by culturing on Columbia agar. All strains were identified by standard laboratory procedures. Susceptibility testing of antibiotics was performed using minimum inhibitory concentration test. Allele-specific primer (ASP)-PCR of 23S rRNA which associated with clarithromycin resistance was done among resistant strains. Moreover, cagA gene and polymorphism in vacA were detected. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) was applied to investigate the genetic variations among all strains.

RESULTS

Antibiotic resistance pattern of H pylori strains was as follows: 68% (34/50) to metronidazole, 50% (25/50) to rifampicin, 30% (15/50) to amoxicillin, 28% (14/50) to levofloxacin, 22% (11/50) to clarithromycin, and 16% (8/50) to tetracycline. Multidrug-resistant strains were observed in 19 strains (38%). ASP-PCR of 23S rRNA showed four strains had A2143G mutation, six strains had A2142G mutation, and one strain had a Wt+A2143G mutation. Amplification of virulence-associated genes revealed that cagA was present in 27 isolates (54%) and vacA in 36 isolates (72%). The most common genotype of H pylori was vacA s1am2 (40%) followed by vacA s2m2 (14%), vacA s1am1 (12%), vacA s1bm1 (4%), and vacA s1bm2 (2%). DNA fingerprinting pattern indicated a high heterogeneity among isolated strains.

CONCLUSION

An alarming level of resistance to metronidazole and rifampicin and high heterogeneity among H pylori isolates highlighted the importance of continued monitoring of antimicrobial susceptibility and epidemiological surveillance of this pathogen.

Current status of first- and second-line Helicobacter pylori eradication therapy in the metropolitan area: a multicenter study with a large number of patients

BACKGROUND

The environment surrounding Helicobacter pylori eradication treatment is dramatically changing. Recently, vonoprazan, a first-in-class potassium-competitive acid blocker (P-CAB), was introduced onto the market in 2015. The aging of Japan's demographic structure is becoming pronounced. In this study, we examined the trend of the eradication rate of H. pylori in the metropolitan area and examined factors concerning successful eradication.

METHODS

We collected data from 20 hospitals in the Tokyo metropolitan area on patients who received first-line eradication therapy with a proton-pump inhibitor (PPI)/P-CAB, amoxicillin, and clarithromycin for 1 week and second-line eradication therapy with a PPI/P-CAB, amoxicillin, and metronidazole for 1 week from 2013 to 2018. The annual eradication rate and associated factors for successful eradication were analyzed.

RESULTS

We collected data of 4097 and 3572 patients in the first- and second-line eradication therapies, respectively. The eradication rate decreased from 2013 to 2014 and increased again from 2015 to 2018 with the first-line therapy [the eradication rates in 2013, 2014, 2015, 2016, 2017 and 2018 were 71.8%, 63.7%, 78.5%, 84.6%, 89.7 and 90.1%, respectively, in the per protocol (PP)]. The second-line eradication rates were 90.0%, 82.6%, 88.8%, 87.5%, 91.8% and 90.1% in 2013, 2014, 2015, 2016, 2017 and 2018, respectively, in PP. Vonoprazan was an independent factor for successful eradication in not only first-line, but also second-line eradication. Age over 75 years was an independent factor for eradication failure in both first- and second-line eradication therapies.

CONCLUSION

The eradication rate improved from 2015 to 2018 with the first-line therapy because of the introduction of vonoprazan in the market. The eradication rates with first- and second-line regimens in elderly patients were lower than those in younger patients.

Molecular diagnosis of Helicobacter pylori antibiotic resistance in the Taif region, Saudi Arabia

Success in eradication of Helicobacter pylori is declining globally because H. pylori has developed resistance against most of the antibiotics proposed for eradication regimens, mainly through point mutations. The present study included 200 patients with dyspepsia attending Taif Hospital. Gastric biopsies were obtained during gastroscopy and subjected to rapid urease testing. Molecular methods were used to confirm diagnoses of H. pylori infection and to identify resistance gene variants of four antibiotics; namely, clarithromycin, metronidazole, fluoroquinolones and tetracycline (23S rRNA, gyrA, rdxA and 16S rRNA respectively). Of all investigated patients, Molecular diagnoses were made in 143 of all investigated patients; thus, the prevalence was .5%. The overall rate of resistance to clarithromycin among the H. pylori-positive patients was high (39.9%) and the rate of resistance significantly greater (48.2%) among the secondary resistance group, secondary resistance being defined as resistance as a result of previous exposure to the relevant antibiotic. The rate of resistance to fluoroquinolones was considered moderate; the difference in rate of resistance between the primary and secondary resistance groups (8.4% and 9.5%, respectively) was not significant Also, there was a low prevalence of both primary and the secondary tetracycline resistance in the study cohort. In contrast, the prevalence of metronidazole resistance was considered high with no significant difference between the two resistance groups. H. pylori showed an increased prevalence of resistance to all four of the commonly used therapeutic agents. Thus, eradication therapy should be based on the regional results of susceptibility testing. Moreover, treatment tailored according to individually determined H. pylori susceptibility may be a reasonable future goal.

An ego network analysis approach identified important biomarkers with an association to progression and metastasis of gastric cancer

BACKGROUND

Gastric cancer (GC) is the fifth most common cancer type worldwide. The aim of this study was to identify gastric-related therapeutic indicators on the basis of the ego network analysis.

MATERIAL AND METHODS

The microarray data related to GC was downloaded from ArrayExpress database. All human protein-protein interaction (PPI) networks were downloaded from the STRING database. Ego genes were identified on the basis of PPI networks and the gene expression in GC, and then co-expression networks (ego networks) were constructed using these ego genes. On the basis of ego networks, the optimal GO terms and genes were predicted by affinity predictions and cold read predictions. Finally, the predicted genes as effective biomarkers for GC were verified by the bioinformatics analysis.

RESULTS

The differential expression networks were conducted and comprised of 365 edges and 232 nodes, which resulted in 218 ego genes. Although there was no significant difference in the expression of top ten ego genes among different groups of GC samples, it was eventually confirmed that top three optimal GO terms with highest cool read values were translational termination (cool read value = 0.987), translational elongation (cool read value = 0.986), and macromolecular complex disassembly (cool read value = 0.985) and top five optimal genes were UBA52, RPS27A, MAPK1, UBC, and UBB. UBA52, RPS27A, and MAPK1 were verified by the bioinformatics analysis to be related to the progression and metastasis of GC.

CONCLUSIONS

An ego network analysis approach is a very effective method for screening GC and the screened genes might be biomarkers for GC diagnosis and treatment.

Vonoprazan-Based Third-Line Therapy Has a Higher Eradication Rate against Sitafloxacin-Resistant Helicobacter pylori

Eradication of Helicobacter pylori (H. pylori) is an effective strategy for preventing various gastrointestinal diseases such as gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. However, the eradication success rate is decreasing because of a recent increase in drug-resistant strains of H. pylori. Here, we evaluated the success rate of eradication therapy with vonoprazan (VPZ), a new potassium-competitive acid blocker, against drug-resistant H. pylori. In total, 793 patients who received H. pylori eradication therapy were investigated retrospectively. All underwent esomeprazole (EPZ)-based triple therapy (n = 386) or VPZ-based triple therapy (n = 407) for first-, second- and third-line H. pylori eradication for 7 days. The overall success rates of first- and third-line H. pylori eradication were significantly higher for VPZ-based triple therapy (88.4% and 93.0%, respectively, per protocol (PP)) than for EPZ-based triple therapy (69.5% and 56.5%, respectively, PP). Moreover, the success rates of first- and third-line eradication of clarithromycin (CLR)- and sitafloxacin (STFX)-resistant H. pylori were significantly higher for VPZ-based triple therapy (72.0% and 91.7%, PP) than for EPZ-based triple therapy (38.5% and 20.0%, PP). In addition, patient age did not affect the eradication rate of VPZ-based first-line therapy, whereas the success rate of EPZ-based therapy was lower in patients under 65 years of age. Our results clearly demonstrated that VPZ-based therapy achieved a higher eradication rate even against CLR- and STFX-resistant H. pylori, and that patient age did not affect the eradication rate of VPZ-based therapy. These findings suggest that dual therapy using VPZ and amoxicillin may be sufficient for standard H. pylori eradication, and may thus also be beneficial for avoiding antibiotic misuse.

A combination of serum anti-Helicobacter pylori antibody titer and Kyoto classification score could provide a more accurate diagnosis of H pylori

Background

We previously showed that the endoscopic Kyoto classification for gastritis could predict Helicobacter pylori infection in individuals with a high negative titer of serum anti-H pylori antibodies. This study evaluated H pylori infection and the Kyoto classification score in patients with a low negative titer (<3 U/ml), high negative titer (3–9.9 U/ml), low positive titer (10–49.9 U/ml), and high positive titer (≥50 U/ml).

Methods

Serum antibody levels, Kyoto classification score and histology were investigated in 870 individuals with no history of H pylori-eradication therapy. Urea breath tests (UBTs) were additionally conducted for patients with a low negative titer and a Kyoto score ≥1 or an antibody titer ≥10 U/ml and a Kyoto score of 0 or 1. UBTs and/or histological studies were conducted for participants with a high negative titer.

Results

False diagnoses based on anti-H pylori antibody titers were observed in 0.3% of the low-negative-titer group, 11.7% of the high-negative-titer group, 18.9% of the low-positive-titer group and 2.2% of the high-positive-titer group. Surprisingly, false diagnoses based on antibody titers were noted in 63.2% of patients with a low positive titer and a Kyoto score of 0 and in 62.5% of patients with a high negative titer and a Kyoto score ≥2, respectively.

Conclusions

Endoscopic findings could predict false diagnoses determined using serum antibody titers.

Structural Aspects of Helicobacter pylori Antibiotic Resistance

Resistance to antibiotics of Helicobacter pylori infections is growing rapidly together with the need for more potent antimicrobials or novel strategies to recover the efficacy of the existing ones. Despite the main mechanisms according to which H. pylori acquires resistance are common to other microbial infections affecting humans, H. pylori has its own peculiarities, mostly due to the unique conditions experienced by the bacterium in the gastric niche. Possibly the most used of the antibiotics for H. pylori are those molecules that bind to the ribosome or to the DNA and RNA machinery, and in doing so they interfere with protein synthesis. Another important class is represented by molecules that binds to some enzyme essential for the bacterium survival, as in the case of enzymes involved in the bacterial wall biosynthesis. The mechanism used by the bacterium to fight antibiotics can be grouped in three classes: (i) mutations of some key residues in the protein that binds the inhibitor, (ii) regulation of the efflux systems or of the membrane permeability in order to reduce the uptake of the antibiotic, and (iii) other more complex indirect effects. Interestingly, the production of enzymes that degrade the antibiotics (as in the case of β-lactamases in many other bacteria) has not been clearly detected in H. pylori. The structural aspects of resistance players have not been object of extensive studies yet and the structure of very few H. pylori proteins involved in the resistance mechanisms are determined till now. Models of the proteins that play key roles in reducing antimicrobials susceptibility and their implications will be discussed in this chapter.

Effect of 25-hydroxyvitamin D on Helicobacter pylori eradication in patients with type 2 diabetes

BACKGROUND

Various studies have reported a lower Helicobacter pylori eradication rate and a more frequent reinfection rate in type 2 diabetes mellitus (T2DM). Vitamin D has anti-inflammatory and immunoregulatory activity and the role of the vitamin D receptor (VDR) in the antimicrobial activity against H. pylori has been reported. When it comes to the risk factors of H. pylori eradication, the function of vitamin D is not always taken into account. The aim of this study was to assess the role of 25-hydroxyvitamin D in H. pylori eradication in T2DM.

METHODS

In this retrospective study data from 160 patients with T2DM who underwent eradication therapy for H. pylori in Anhui Provincial Hospital between July 2015 and September 2017 were analyzed. According to eradication status, patients were divided into two groups, the successful eradication group (n = 124) and the eradication failure group (n = 36). The following information was obtained from participants' records before eradication treatment: age, sex, body mass index (BMI), duration of T2DM, prescription of medication use, smoking and drinking history. All patients were tested for glycated hemoglobin (HbA1c), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL‑C), triglyceride (TG) and 25-hydroxyvitamin D (25-OHD) at baseline.

RESULTS

The H. pylori was eradicated in 124 (77.5%) patients, while in 36 (22.5%) patients the treatment was unsuccessful. The eradication failure group had a lower mean vitamin D concentration than the group with successful eradication (15.09 ± 7.72 ng/ml vs. 19.87 ± 6.35 ng/ml, p = 0.004). The estimated odds ratio (OR) for eradication failure in individuals with serum vitamin D deficiency (<20 ng/ml) compared to those with sufficient vitamin D levels (>30 ng/ml) were 1.489 (95% confidence interval, CI: 1.046-2.121, P = 0.027), Individuals with long duration of diabetes (≥10 years) had odds of eradication failure of 1.467 (95% CI: 1.017-2.114, P = 0.040) compared to subjects with short duration of diabetes (<10 years).

CONCLUSIONS

Lower 25-OHD was not only associated with H. pylori eradication failure but was also related to dyslipidemia in T2DM patients. Increasing serum 25-OHD to appropriate levels by activated vitamin D use may improve the eradication rate.

Antibiotic resistance in Helicobacter pylori: A mutational analysis from a tertiary care hospital in Kashmir, India

Background

Helicobacter pylori infection is recognised as type 1 carcinogen by the International Agency of Research on Cancer. Previous studies in our hospital have revealed high prevalence of H. pylori in our population with a high recurrence rate after completion of treatment. This prompted us to undertake this study.

Aim

This study aimed to determine common gene mutations leading to resistance to clarithromycin, metronidazole, tetracycline and quinolones in H. pylori in patients attending our hospital.

Settings and Design

This is a cross-sectional hospital-based study. The study was approved by the Institutional Ethics Committee.

Materials and Methods

This study was conducted on 196 adult dyspeptic patients with an indication for upper gastrointestinal endoscopy. Gastric biopsies collected from them were subjected to histopathological examination, rapid urease test (RUT) and culture. Of the 196 patients, 95 met the inclusion criteria. Drug susceptibility testing (DST) by various polymerase chain reaction-based methods was done for 47 RUT-positive biopsies and 13 H. pylori isolates.

Results

Maximum resistance was seen to metronidazole (81.66%) followed by clarithromycin (45%) and quinolones (3.33%). No high-level resistance was seen to tetracycline. In clarithromycin-resistant cases, A2142G mutation was more prevalent than A2143G mutation. Multidrug resistance (resistance to metronidazole and clarithromycin) was seen in 41.66% of patients.

Conclusions

Tetracycline and quinolones could be the antibiotics of choice in the eradication of H. pylori in this region, while recurrence of the infection with H. pylori could be expected among patients receiving either metronidazole or clarithromycin, for eradication therapy. DST should be done on a routine basis utilising both phenotypic and genotypic methods to prevent further emergence of resistance in this region.

Vonoprazan, a Novel Potassium-Competitive Acid Blocker, Should Be Used for the Helicobacter pylori Eradication Therapy as First Choice: A Large Sample Study of Vonoprazan in Real World Compared with Our Randomized Control Trial Using Second-Generation Proton Pump Inhibitors for Helicobacter pylori Eradication Therapy

BACKGROUND/AIMS

Phase III study demonstrated that vonoprazan-based Helicobacter pylori eradication therapy achieved higher eradication rate compared with lansoprazole. However, there is no study that evaluated the efficacy of vonoprazan in a large sample in real world. We investigated the eradication rate and safety of vonoprazan-based eradication therapy compared with our randomized control trial using second-generation proton pump inhibitor (PPIs).

METHODS

(First study) A total of 147 patients who have H. pylori infection were randomly assigned to receive either, esomeprazole (EPZ) group and rabeprazole (RPZ) group. (Second study) 1,688 patients who have H. pylori infection underwent primary eradication with triple therapy involving vonoprazan. In both studies, triple therapy with amoxicillin, clarithromycin, and PPI or vonoprazan was performed, and eradication effect was assessed by an urea breath test.

RESULTS

(First study) Eradication rate was 77.5% in the EPZ group and 68.4% in the RPZ group; no significant difference was observed between the 2 groups. (Second study) The successful primary eradication rate was 90.8%. There was no severe adverse effect.

CONCLUSIONS

The eradication rate of vonoprazan-based triple therapy was remarkably higher compared with second-generation PPIs-based triple therapy in real world. Vonoprazan is very likely to become the first option for future eradication therapy.

World trends for H. pylori eradication therapy and gastric cancer prevention strategy by H. pylori test-and-treat

Helicobacter pylori-associated gastritis leads to the development of gastric cancer. Kyoto global consensus report on H. pylori gastritis recommended H. pylori eradication therapy to prevent gastric cancer. To manage H. pylori infection, it is important to choose the appropriate regimen considering regional differences in resistance to clarithromycin and metronidazole. Quinolones and rifabutin-containing regimens are useful as third- and fourth-line rescue therapies.

Meta-analysis: High-dose vs. low-dose metronidazole-containing therapies for Helicobacter pylori eradication treatment

Objective

The purpose of this study was to evaluate the efficacy of high dose of metronidazole in the treatment of Helicobacter pylori (H. pylori) infection.

Methods

Studies were identified from databases (Pubmed, Embase, Cochrane Library, ClinicalTrials.gov) searched from January 1990 to September 2017 using a battery of keywords. We included randomized controlled trials (RCTs) of H. pylori treatment comparing the high-dose and low-dose metronidazole-containing therapies (high-dose and low-dose therapies). Two reviewers independently selected studies, extracted relevant data and assessed study quality. A meta-analysis was performed by using Review Manager 5.3. Dichotomous data were pooled to obtain the relative risk (RR) of the eradication rate, with 95% confidence intervals (CIs).

Results

Four randomized controlled trials, a total of 612 patients with a diagnosis of H. pylori infection were included. Overall the meta-analysis showed that both high-dose and low-dose therapies achieved similar efficacy of intention-to-treat (ITT) eradication rate 82% vs. 76%, RR 1.12 (95%CI: 0.96 to 1.30), P = 0.15, and adherence 94% vs. 94%, RR 1.00 (95%CI: 0.97 to 1.04), P = 0.81, but side effects were more likely in high-dose therapies [32% vs. 17%, RR 1.84 (95%CI: 1.17 to 2.88), P = 0.008]. In subgroup analysis, increasing the dose of metronidazole enhanced eradication rates in areas with high metronidazole resistance [74% vs 52%, RR 1.40 (95%CI: 1.08 to 1.82), P = 0.01] and in individuals with metronidazole-resistant strains [71% vs. 46%, RR 1.50 (95%CI: 1.02 to 2.19), P = 0.04].

Conclusions

Both high-dose and low-dose therapies can achieve similar eradication rates and adherence and generally low-dose therapies cause fewer side effects. In populations with high metronidazole resistance, high dose of metronidazole can increase the eradication rates of H. pylori infection.

Effects of patient age and choice of antisecretory agent on success of eradication therapy for Helicobacter pylori infection

The effects of patient age on the efficacy of eradication treatment for Helicobacter pylori (H. pylori) remain unclear. The present study aimed to determine whether age affects eradication therapy involving vonoprazan, a novel potassium-competitive acid blocker (PCAB). We reviewed the cases of 3,261 patients who were administered first-line and second-line H. pylori eradication therapy at Toyoshima Endoscopy Clinic. The first-line treatment was clarithromycin and amoxicillin combined with a proton pump inhibitor (PPI) or a PCAB. The second-line treatment was metronidazole and amoxicillin combined with a PPI or PCAB. The patients were divided into a young to middle-aged group (age ≤50 years) and an older group (age >50 years) as well as into PPI and PCAB groups. The PPI-clarithromycin-amoxicillin regimen demonstrated a significantly lower H. pylori eradication rate than the PCAB-clarithromycin-amoxicillin regimen (p<0.001). With the PPI-clarithromycin-amoxicillin regimen, the eradication rate in the young to middle-aged group was significantly lower than that in the older group (p<0.001). Lastly, age had no impact on the eradication rate of PCAB-based therapy or metronidazole-based therapy. In conclusion, with clarithromycin-based triple therapy, PCAB is a better choice of antisecretory agent compared to PPIs, especially in young to middle-aged patients.

Antibiotic resistance and gyrA mutation affect the efficacy of 10-day sitafloxacin-metronidazole-esomeprazole therapy for Helicobacter pylori in penicillin allergic patients

BACKGROUND AND AIM

Helicobacter pylori (H. pylori) eradication regimen has not been standardized for patients with penicillin allergy. We investigated the association between the efficacy of a 10-day sitafloxacin, metronidazole, and esomeprazole triple regimen and antibiotic resistance, in patients with penicillin allergy.

METHODS

Penicillin-allergic patients infected with H. pylori were enrolled between March 2014 and November 2015. The minimum inhibitory concentrations (MICs) of sitafloxacin and metronidazole, and the gyrA mutation status of the H. pylori strains were determined before treatment. The cut-off points for antimicrobial resistance were defined as 8.0 µg/ml for metronidazole and 0.12 µg/ml for sitafloxacin. The patients received the triple therapy (20 mg esomeprazole, bid; 250 mg metronidazole, bid; and 100 mg sitafloxacin, bid) for 10 days. Successful eradication was evaluated using the [¹³C] urea breath test or the H. pylori stool antigen test.

RESULTS

Fifty-seven patients were analyzed, and the overall eradication rate was 89.5%. The eradication rate in cases of double antibiotic resistance to metronidazole and sitafloxacin was 40.0%, whereas for other combinations of resistance, this was above 90.0%. Finally, the eradication rate of gyrA mutation-negative strains was 96.2%, whereas for gyrA mutation-positive strains, it was 83.9%. Adverse events were reported in 31.6% of cases, all of which were mild and tolerable.

CONCLUSION

Ten days of sitafloxacin and metronidazole triple therapy was safe and highly effective in eradicating H. pylori in penicillin-allergic patients. Double resistance to metronidazole and sitafloxacin was an important predicting factor for eradication failure. However, 10 days of the sitafloxacin and metronidazole triple therapy was highly effective if the strain was susceptible to either sitafloxacin or metronidazole.

Rifabutin Containing Triple Therapy and Rifabutin with Bismuth Containing Quadruple Therapy for Third-Line Treatment of Helicobacter pylori Infection: Two Pilot Studies

AIM

To evaluate the therapeutic gain of the addition of bismuth to a rifabutin containing triple therapy with amoxicillin and pantoprazole at standard dosages for the treatment of third-line Helicobacter pylori infection after a preliminary susceptibility test.

METHODS

Two separate groups of patients in two pilot studies which were carried out simultaneously. One group was treated with rifabutin 150 mg b.i.d., pantoprazole 20 mg b.i.d., and amoxicillin 1 g b.i.d. for 10 days and the other group with rifabutin 150 mg b.i.d., pantoprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and bismuth subcitrate 240 mg b.i.d. for 10 days. All patients underwent to culture and susceptibility testing prior to their inclusion in the study. A successful outcome was confirmed with an Urea Breath test performed 8 weeks after the end of treatment. A blood cell count was performed for all patients at the start and after 5 days of treatment since rifabutin has been shown to inhibit the growth of leucocytes.

RESULTS

Twenty-nine patients were recruited in the pantoprazole, amoxicillin, rifabutin group and 30 in the pantoprazole, amoxicillin, rifabutin, and bismuth subcitrate group. All patients had a positive H. pylori culture and the susceptibility test used showed H. pylori sensitivity to rifabutin and amoxicillin. H. pylori eradication during follow-up was 18/27 (66.7%, 95% CI: 47.7-85.7%) in the pantoprazole, amoxicillin, rifabutin group and 28/29 (96.6%, 95% CI: 89.5-100.0%) in the pantoprazole, amoxicillin, rifabutin, and bismuth subcitrate group. Both treatments were well-tolerated with no reported side effects. Blood cell count remained normal in all patients.

CONCLUSION

The addition of bismuth subcitrate to a triple therapy that includes proton pump inhibitors, amoxicillin, and rifabutin in patients who are treated for the third time for H. pylori infection resulted in a 30% therapeutic gain.

Characteristics of gastric cancer detected within 1 year after successful eradication of Helicobacter pylori

Gastric cancers are sometimes diagnosed in patients who have successfully undergone Helicobacter pylori (H. pylori) eradication. We analyzed the clinicopathological features of gastric cancers detected after eradication to clarify their characteristics. We reviewed 31 patients with 34 cases of gastric cancer detected after successful H. pylori eradication. Clinicopathological characteristics analyzed included interval since eradication, interval since last endoscopy, tumor size, and depth of invasion. Patients were classified into two groups: early detection (<1 year since eradication) and delayed detection (≥1 year since eradication). The interval since last endoscopy was significantly shorter in the early detection group than in the delayed detection group. However, gastric cancers were significantly larger and more invasive in the early detection group than in the delayed detection group. In conclusion, diligent endoscopy is necessary during the first year after successful H. pylori eradication. (The University Hospital Medical Information Network clinical trial registration number is UMIN000018541.)

Efficacy of 10-day Sitafloxacin-Containing Third-Line Rescue Therapies for Helicobacter pylori Strains Containing the gyrA Mutation

BACKGROUND AND AIM

Sitafloxacin-containing Helicobacter pylori eradication therapy is a promising third-line therapeutic approach, but there is no previous studies between gyrA mutation status of H. pylori strains and the efficacy of 10-day sitafloxacin-containing regimens. Here, we assessed the efficacy of 2 different 10-day sitafloxacin-containing rescue regimens.

METHODS

Patients who failed first- and second-line eradication therapies were enrolled. The minimum inhibitory concentrations (MICs) of sitafloxacin, amoxicillin, and metronidazole and the gyrA mutation status of the H. pylori strains were determined before treatment. The patients were randomized to receive a 10-day triple therapy containing either esomeprazole (20 mg, b.i.d.), amoxicillin (500 mg, q.i.d.), and sitafloxacin (100 mg, b.i.d.) (EAS regimen) or esomeprazole (20 mg, b.i.d.), metronidazole (250 mg, b.i.d.), and sitafloxacin (100 mg, b.i.d.) (EMS regimen). Eradication rates were evaluated by the [13C] urea breath test or the H. pylori stool antigen test.

RESULTS

All patients with gyrA mutation-negative strains (24 in EAS and 16 in EMS) showed successful eradication, irrespective of the regimen they received. In patients with gyrA mutation-positive strains, we found eradication rates of 70.3% (26/37) and 66.7% (26/39) in the EAS and EMS groups in per-protocol population, respectively (p = .81). According to logistic regression analyses, the MICs of sitafloxacin, which were strongly associated with gyrA mutation status, were independently associated with successful eradication in both groups. This study was registered in the UMIN Clinical Trials Registry as UMIN000006483.

CONCLUSION

There is no significant difference in the eradication rates between EAS and EMS, regardless of the gyrA mutation status of the H. pylori strains. GyrA mutation status was an important factor in predicting successful eradication with sitafloxacin-containing rescue therapies.

Novel class of Bi(iii) hydroxamato complexes: synthesis, urease inhibitory activity and activity against H. pylori

A novel class of bismuth hydroxamato complexes of type Bi(L_-1H)₂·NO₃ (where L is hydroxamic acid) were specifically designed to and demonstrated to inhibit urease, H. pylori's Achilles heel.

First-line eradication for Helicobacter pylori-positive gastritis by esomeprazole-based triple therapy is influenced by CYP2C19 genotype

AIM: To evaluate the effect of first line esomeprazole (EPZ)-based triple therapy on Helicobacter pylori (H. pylori) eradication.

METHODS: A total of 80 Japanese patients with gastritis who were diagnosed as positive for H. pylori infection by endoscopic biopsy-based or ¹³C-urea breath tests were included in this study. The average age of the patients was 57.2 years (male/female, 42/38). These patients were treated by first-line eradication therapy with EPZ 40 mg/d, amoxicillin 1500 mg/d, and clarithromycin 400 mg/d for 7 d. All drugs were given twice per day. Correlations between H. pylori eradication, CYP2C19 genotype, and serum pepsinogen (PG) level were analyzed. This study was registered with the UMIN Clinical Trials Registry (UMIN000009642).

RESULTS: The H. pylori eradication rates by EPZ-based triple therapy evaluated by intention-to-treat and per protocol were 67.5% and 68.4%, respectively, which were similar to triple therapies with other first-generation proton pump inhibitors (PPIs). The eradication rates in three different CYP2C19 genotypes, described as extensive metabolizer (EM), intermediate metabolizer, and poor metabolizer, were 52.2%, 72.1%, and 84.6%, respectively. The H. pylori eradication rate was significantly lower in EM than non-EM (P < 0.05). The serum PG I level and PG I/II ratio were significantly increased after eradication of H. pylori (P < 0.01), suggesting that gastric atrophy was improved by H. pylori eradication. Thus, first-line eradication by EPZ-based triple therapy for patients with H. pylori-positive gastritis was influenced by CYP2C19 genotype, and the eradication rate was on the same level with other first-generation PPIs in the Japanese population.

CONCLUSION: The results from this study suggest that there is no advantage to EPZ-based triple therapy on H. pylori eradication compared to other first-generation PPIs.

Antibiotic treatment for Helicobacter pylori: Is the end coming?

Infection with the Gram-negative pathogen Helicobacter pylori (H. pylori) has been associated with gastro-duodenal disease and the importance of H. pylori eradication is underscored by its designation as a group I carcinogen. The standard triple therapy consists of a proton pump inhibitor, amoxicillin and clarithromycin, although many other regimens are used, including quadruple, sequential and concomitant therapy regimens supplemented with metronidazole, clarithromycin and levofloxacin. Despite these efforts, current therapeutic regimens lack efficacy in eradication due to antibiotic resistance, drug compliance and antibiotic degradation by the acidic stomach environment. Antibiotic resistance to clarithromycin and metronidazole is particularly problematic and several approaches have been proposed to overcome this issue, such as complementary probiotic therapy with Lactobacillus. Other studies have identified novel molecules with an anti-H. pylori effect, as well as tailored therapy and nanotechnology as viable alternative eradication strategies. This review discusses current antibiotic therapy for H. pylori infections, limitations of this type of therapy and predicts the availability of newly developed therapies for H. pylori eradication.

A Triple and Quadruple Therapy with Doxycycline and Bismuth for First-Line Treatment of Helicobacter pylori Infection: A Pilot Study

BACKGROUND

Tetracycline-containing triple therapy has been suggested as an alternative first-line therapy for H. pylori infection.

AIM

To evaluate the effect of two dosages of doxycycline (DOX) associated with amoxicillin and esomeprazole with and without bismuth subcitrate as first-line treatment of H. pylori infection.

METHODS

Helicobacter pylori-positive patients underwent a 10-day therapy randomized into four groups: Group A received esomeprazole, amoxicillin, and DOX-100 mg b.i.d. (EAD-100), Group B a quadruple therapy with esomeprazole, amoxicillin, DOX-100 mg b.i.d. and bismuth subcitrate (EADB-100), Group C a triple therapy with esomeprazole, amoxicillin, and DOX-200 mg b.i.d. (EAD-200) and Group D a quadruple therapy with esomeprazole, amoxicillin, DOX-200 mg b.i.d., and bismuth subcitrate (EADB-200). Success was accessed by (13)C urea breath test 2 months after the end of treatment. The number of patients to be recruited for each group had to be at least 50 subjects. Treatment success of 80% or less was considered unacceptable. Stopping rules therefore were anytime six failures had occurred.

RESULTS

In the EAD-100 group and in EAD-200 group, the recruitment was stopped at the 14th and 15th patient, respectively. Fifty-two patients entered in the EADB-100 group and 51 in the EADB-200 group. Intention to treat eradication was in EADB-100 group 46/52 (88.5%, 95% CI 76.6-95.6); in the EADB-200 group 47/51 (92.1%, 95% CI: 81.1-97.8) (n.s.). Side effects were absent.

CONCLUSION

The adjunction of bismuth subcitrate to a triple therapy that includes esomeprazole, amoxicillin, and DOX in patients who are treated for the first time for the H. pylori infection potentiates the therapeutic effect. This regimen, however, deserves to be optimized in terms of duration and dose of DOX.

Pharmacogenomics of antimicrobial agents

Antimicrobial efficacy and toxicity varies between individuals owing to multiple factors. Genetic variants that affect drug-metabolizing enzymes may influence antimicrobial pharmacokinetics and pharmacodynamics, thereby determining efficacy and/or toxicity. In addition, many severe immune-mediated reactions have been associated with HLA class I and class II genes. In the last two decades, understanding of pharmacogenomic factors that influence antimicrobial efficacy and toxicity has rapidly evolved, leading to translational success such as the routine use of HLA-B*57:01 screening to prevent abacavir hypersensitivity reactions. This article examines recent advances in the field of antimicrobial pharmacogenomics that potentially affect treatment efficacy and toxicity, and challenges that exist between pharmacogenomic discovery and translation into clinical use.

Clarithromycin Versus Metronidazole as First-line Helicobacter pylori Eradication: A Multicenter, Prospective, Randomized Controlled Study in Japan

BACKGROUND

Helicobacter pylori eradication rates achieved with a first-line regimen of clarithromycin (CLR) combined with amoxicillin (AMX) and a proton pump inhibitor have recently fallen to ≤80% because of the increasing incidence of CLR resistance in Japan. This randomized multicenter trial aimed to compare the eradication success of 2 first-line triple therapy regimens: rabeprazole, amoxicillin, and clarithromycin (RAC) versus rabeprazole, amoxicillin, and metronidazole (RAM).

METHODS

A total of 124 consecutive patients infected with H. pylori were randomized into one of two 7-day therapeutic regimens: RAC (n=60) or RAM (n=64). Eradication was confirmed by the C-urea breath test. Adverse effects were also assessed.

RESULTS

Intention-to-treat and per protocol H. pylori eradication rates were 73.3%/77.2% in the RAC group and 90.6%/93.5% in the RAM group. The eradication rate of RAM therapy was significantly higher than that of RAC therapy. CLR, metronidazole, and AMX resistance was found in 36.2%, 2.1%, and 0% of patients, respectively. In addition, no relevant differences in adverse effects were observed.

CONCLUSIONS

Metronidazole-based therapy (RAM) was superior to standard CLR-based therapy (RAC) for first-line H. pylori eradication. This reflects the progressive increase in CLR resistance observed in Japan.

Centralized isolation of Helicobacter pylori from multiple centers and transport condition influences

AIM: To evaluate the efficacy of centralized culture and possible influencing factors.

METHODS: From January 2010 to July 2012, 66452 patients with suspected Helicobacter pylori (H. pylori) infection from 26 hospitals in Zhejiang and Jiangsu Provinces in China underwent gastrointestinal endoscopy. Gastric mucosal biopsies were taken from the antrum for culture. These biopsies were transported under natural environmental temperature to the central laboratory in Hangzhou city and divided into three groups based on their transport time: 5, 24 and 48 h. The culture results were reported after 72 h and the positive culture rates were analyzed by a χ² test. An additional 5736 biopsies from H. pylori-positive patients (5646 rapid urease test-positive and 90 ¹⁴C-urease breath test-positive) were also cultured for quality control in the central laboratory setting.

RESULTS: The positive culture rate was 31.66% (21036/66452) for the patient samples and 71.72% (4114/5736) for the H. pylori-positive quality control specimens. In the 5 h transport group, the positive culture rate was 30.99% (3865/12471), and 32.84% (14960/45553) in the 24 h transport group. In contrast, the positive culture rate declined significantly in the 48 h transport group (26.25%; P < 0.001). During transportation, the average natural temperature increased from 4.67 to 29.14 °C, while the positive culture rate declined from 36.67% (1462/3987) to 24.12% (1799/7459). When the temperature exceeded 24 °C, the positive culture rate decreased significantly, especially in the 48 h transport group (23.17%).

CONCLUSION: Transportation of specimens within 24 h and below 24 °C is reasonable and acceptable for centralized culture of multicenter H. pylori samples.

Gastric Carcinogenesis and Underlying Molecular Mechanisms: Helicobacter pylori and Novel Targeted Therapy

The oxygen-derived free radicals that are released from activated neutrophils are one of the cytotoxic factors of Helicobacter pylori-induced gastric mucosal injury. Increased cytidine deaminase activity in H. pylori-infected gastric tissues promotes the accumulation of various mutations and might promote gastric carcinogenesis. Cytotoxin-associated gene A (CagA) is delivered into gastric epithelial cells via bacterial type IV secretion system, and it causes inflammation and activation of oncogenic pathways. H. pylori infection induces epigenetic transformations, such as aberrant promoter methylation in tumor-suppressor genes. Aberrant expression of microRNAs is also reportedly linked to gastric tumorogenesis. Moreover, recent advances in molecular targeting therapies provided a new interesting weapon to treat advanced gastric cancer through anti-human epidermal growth factor receptor 2 (HER-2) therapies. This updated review article highlights possible mechanisms of gastric carcinogenesis including H. pylori-associated factors.

Effect of supplementation with rebamipide for Helicobacter pylori eradication therapy: a systematic review and meta-analysis

BACKGROUND AND AIM

Several studies have reported that the application of rebamipide during the eradication of Helicobacter pylori can improve the eradication rate. However, the efficacy and safety are controversial. The present study systematically evaluated whether rebamipide improves the eradication rate of H. pylori by conducting a meta-analysis based on randomized controlled trials (RCTs).

METHODS

Literature searches were conducted in the following database: PubMed, the Cochrane Library, and the Igaku-chuo-zasshi database in Japan. A meta-analysis of all RCTs comparing rebamipide supplementation with non-rebamipide-containing therapy was performed.

RESULTS

We identified six randomized trials (611 patients). Pooled H. pylori eradication rates by per-protocol analysis were 73.3% and 61.4% for patients with or without rebamipide, respectively. The odds ratio was 1.74 (95% confidence interval. 1.19-2.53).

CONCLUSIONS

Supplementation with rebamipide might be effective in increasing the H. pylori eradication rates of proton-pump inhibitor-amoxicillin dual therapy.

Mechanisms of Helicobacter pylori antibiotic resistance and molecular testing

Antibiotic resistance in Helicobacter pylori (H.pylori) is the main factor affecting the efficacy of current treatment methods against infection caused by this organism. The traditional culture methods for testing bacterial susceptibility to antibiotics are expensive and require 10–14 days. Since resistance to clarithromycin, fluoroquinolone, and tetracycline seems to be exclusively caused by specific mutations in a small region of the responsible gene, molecular methods offer an attractive alternative to the above-mentioned techniques. The technique of polymerase chain reaction (PCR) is an accurate and rapid method for the detection of mutations that confer antibiotic resistance. This review highlights the mechanisms of antibiotic resistance in H. pylori and the molecular methods for antibiotic susceptibility testing.