Fourth Chinese National Consensus Report on the management of Helicobacter pylori infection

Primary Antibiotic Resistance of Helicobacter pylori in China

BACKGROUND AND AIMS

Antibiotic resistance is the most important factor leading to the failure of eradication regimens; thus, it is important to obtain regional antibiotic resistance information. This review focuses on the prevalence of Helicobacter pylori primary resistance to clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone in China.

METHODS

We searched the PubMed, EMBASE, the China National Knowledge Infrastructure, and Chinese Biomedical databases from the earliest date of each database to October 2016. The search terms included the following: H. pylori, antibiotic (including clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone) resistance with or without China or different regions of China. The data analysis was performed using MedCalc 15.2.2. Each article was weighted according to the number of isolated H. pylori strains. A pooled proportion analysis was performed.

RESULTS

Twenty-three studies (14 studies in English and 9 in Chinese) were included in this review. A total of 6274, 6418, 3921, 5468, 2802, and 275 H. pylori strains were included in this review to evaluate the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone, respectively. Overall, the primary resistance rates of clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone were 28.9, 63.8, 28.0, 3.1, 3.9, and 1.7%, respectively.

CONCLUSIONS

In China, the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, and levofloxacin was high and increased over time, whereas the resistance rates to amoxicillin, tetracycline, and furazolidone were low and stable over time.

Polaprezinc combined with clarithromycin-based triple therapy for Helicobacter pylori-associated gastritis: A prospective, multicenter, randomized clinical trial

The efficacy and safety of polaprezinc combined with triple therapy was compared with triple therapy alone in the eradication of Helicobacter pylori. A randomized, parallel-group, open-label, controlled, prospective multicenter study was conducted in 11 cities in China. Treatment-naive patients with H. pylori-associated gastritis were randomly assigned to one of three arms for a 14-day treatment: Arm A triple therapy (omeprazole 20 mg, amoxicillin 1 g, and clarithromycin 500 mg, each twice daily) plus polaprezinc 75 mg twice daily; Arm B triple therapy plus polaprezinc 150 mg twice daily, or Arm C triple therapy alone. The rate of H. pylori eradication was the primary endpoint. Secondary endpoints were symptom improvement and lower incidence of adverse events. 303 patients completed the study- 106, 96, and 101 patients in Arms A, B, and C, respectively. Intention-to-treat (ITT) analysis showed that the rate of H. pylori eradication was significantly higher for Arms A (77.0%) and B (75.9%) compared to Arm C (58.6%) (P < 0.01), whereas there was no difference between Arms A and B (P = 0.90). Per-protocol (PP) analysis showed that the rate of H. pylori eradication was significantly higher for Arms A (81.1%) and B (83.3%) compared to Arm C (61.4%) (P < 0.01), whereas there was no significant difference between Arms A and B (P = 0.62). All three groups reported significant symptom improvement at 7, 14, and 28 days after treatment, compared to baseline (P < 0.0001). The adverse event rate for Arm B (5.1%) was higher than for Arms A (2.8%) (P = 0.04) and C (1.9%) (P = 0.02). There were no serious adverse events in any group. It appears that standard dose polaprezinc combined with triple therapy can significantly improve the H. pylori eradication rate, without an increase in toxicity.

Population attributable burden of Helicobacter pylori-related gastric cancer, coronary heart disease, and ischemic stroke in China

Helicobacter pylori, a risk factor of cancer and chronic diseases, remains highly prevalent in China. This review aims to systematically evaluate the H. pylori-attributable burden for gastric cancer (GC), coronary heart disease (CHD), and ischemic stroke (IS) in the Chinese population. Helicobacter pylori prevalence was updated by pooling the results reported in studies across China. The population attributable fraction (PAF) was calculated based on the H. pylori prevalence 10 years ago and relative risks of specific disease by reviewing the prospective studies published from 2000 through 2015. In China, the nationwide average prevalence of H. pylori was estimated to be 42.06 % in the general population during 2009-2013. The fixed effects pooled relative risk (RR) of 1.89 [95 % confidence interval (CI): 1.57-2.26] was obtained for gastric cancer and H. pylori infection. Helicobacter pylori infection was responsible for around 37.38 % of noncardia GC, corresponding to about 105,536 cases in 2012. As for extra-gastric disorders, H. pylori infections had higher risk of CHD (RR = 1.55, 95 % CI: 1.37-1.76) and IS (RR = 1.54, 95 % CI: 1.42-1.66). About 23.15 % of CHD and 22.29 % of IS were attributable to H. pylori infection. The estimates of H. pylori-attributable burden reveal a great potential of reducing H. pylori-related chronic disease burden by H. pylori eradication. Large prospective studies are warranted to identify which H. pylori strains, which subtypes of the disease, and which subgroups of the population have the greatest risk of relevant diseases and the effect of H. pylori eradication on the prevention of H. pylori-related diseases.

The internalization of Helicobacter pylori plays a role in the failure of H. pylori eradication

BACKGROUND

Helicobacter pylori (H. pylori) internalization involves invasion of cells by the bacterium. Several studies have shown that H. pylori can invade human gastric epithelial cells, immune cells, and Candida yeast in vivo and in vitro. Whether bacterial invasion plays a role in eradication failure is unclear.

AIM

To investigate the relationship between H. pylori invasion of GES-1 cells and H. pylori eradication failure.

MATERIALS AND METHODS

Forty-two clinical strains isolated from H. pylori-positive patients with different outcomes after treatment with furazolidone-based therapy were examined (17 failures and 25 successes). The H. pylori strains were shown to be susceptible to amoxicillin and furazolidone, and the patients also exhibited good compliance. Genotyping was performed for cagA and vacA (s and m). The antibiotic susceptibility of the strains to amoxicillin, furazolidone, clarithromycin, metronidazole, and levofloxacin was determined by E-tests. The levels of H. pylori invasion of GES-1 cells were detected by gentamicin colony-forming unit assays.

RESULTS

The internalization level in the eradication success group was 5.40±5.78 × 10^-3  cfu/cell, and the median was 6.194 × 10^-3  cfu/cell; the internalization level in the eradication failure group was 8.98±5.40 × 10^-3  cfu/cell, and the median was 10.28 × 10^-3  cfu/cell. The eradication failure group showed a greater invasion level than the eradication success group (P<.05). No significant difference was observed between the susceptible strains and the resistant strains when the internalization levels were compared (P>.05).

CONCLUSIONS

The results showed that H. pylori invasion of the gastric epithelia might play a role in eradication failure.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Recurrence of Helicobacter pylori infection and the affecting factors: A follow-up study

OBJECTIVE

Recurrence of Helicobacter pylori (H. pylori) infection weakens the protective effect and long-term prognosis of eradication. With the widespread therapies, decreasing prevalence of H. pylori infection and improvement in living conditions, the recurrence of H. pylori infection may present with new features. We conducted this prospective, large-scale, multicenter follow-up study to determine the recurrence rate of H. pylori infection and its affecting factors.

METHODS

A total of 827 patients receiving successful H. pylori eradication in our previous randomized controlled trial were enrolled. ¹³ C-urea breath test (UBT) was repeated one year after the eradication therapy to determine its recurrence. Moreover, a questionnaire survey was performed to explore the potential factors affecting the recurrence.

RESULTS

A total of 743 patients completed ¹³ C-UBT (follow-up rate 89.8%), and the result was positive in 13 patients one year after eradication therapy, with an annual recurrence rate of 1.75% (95% confidence interval [CI] 0.81-2.69%). Six hundred and ninety-two patients (13 with recurrence and 679 without recurrence) returned their questionnaires, with a response rate of >80%. Multivariate analysis revealed that peptic ulcer (odds ratio [OR] 3.385, 95% CI 1.016-11.274), close contact with individuals having H. pylori infection (OR 4.231, 95% CI 1.201-14.911), and hospitalization (OR 9.302, 95% CI 2.441-35.440) were independent risk factors of H. pylori infection recurrence.

CONCLUSIONS

The recurrence of H. pylori infection one year after eradication therapy is low in urban population of China. Peptic ulcer, contact history with individuals having H. pylori infection and hospitalization are risk factors.

Optimal First-Line Treatment for Helicobacter pylori Infection: Recent Strategies

A new treatment strategy is needed, as the efficacy of triple therapy containing clarithromycin—the current standard treatment for Helicobacter pylori infection—is declining. Increasing antibiotic resistance of H. pylori is the most significant factor contributing to eradication failure. Thus, selecting the most appropriate regimen depending on resistance is optimal, but identifying resistance to specific antibiotics is clinically challenging. In a region suspected to have high clarithromycin resistance, bismuth quadruple therapy and so-called nonbismuth quadruple therapies (sequential, concomitant, and sequential-concomitant hybrid) are some first-line regimen options. However, more research is needed regarding appropriate second-line treatments after first-line treatment failure. Tailored therapy, which is based on antibiotic sensitivity testing, would be optimal but has several limitations for clinical use, and an alternative technique is required. A novel potassium-competitive acid blocker-based eradication regimen could be a valuable eradication option in the near future.

Surveillance of Helicobacter pylori Antibiotic Susceptibility in Indonesia: Different Resistance Types among Regions and with Novel Genetic Mutations

Information regarding Helicobacter pylori antibiotic resistance in Indonesia was previously inadequate. We assessed antibiotic susceptibility for H. pylori in Indonesia, and determined the association between virulence genes or genetic mutations and antibiotic resistance. We recruited 849 dyspeptic patients who underwent endoscopy in 11 cities in Indonesia. E-test was used to determine the minimum inhibitory concentration of five antibiotics. PCR-based sequencing assessed mutations in 23S rRNA, rdxA, gyrA, gyrB, and virulence genes. Next generation sequencing was used to obtain full-length sequences of 23S rRNA, infB, and rpl22. We cultured 77 strains and identified 9.1% with clarithromycin resistance. Low prevalence was also found for amoxicillin and tetracycline resistance (5.2% and 2.6%, respectively). In contrast, high resistance rates to metronidazole (46.7%) and levofloxacin (31.2%) were demonstrated. Strains isolated from Sumatera Island had significantly higher metronidazole resistance than those from other locations. Metronidazole resistant strains had highly distributed rdxA amino acid substitutions and the 23S rRNA A2143G mutation was associated with clarithromycin resistance (42.9%). However, one strain with the highest MIC value had a novel mutation in rpl22 without an A2143G mutation. Mutation at Asn-87 and/or Asp-91 of gyrA was associated with levofloxacin-resistance and was related to gyrB mutations. In conclusions, although this is a pilot study for a larger survey, our current data show that Indonesian strains had the high prevalence of metronidazole and levofloxacin resistance with low prevalence of clarithromycin, amoxicillin, and tetracycline resistance. Nevertheless, clarithromycin- or metronidazole-based triple therapy should be administered with caution in some regions of Indonesia.

IV Spanish Consensus Conference on Helicobacter pylori infection treatment

Helicobacter pylori approximately infect 50% of Spanish population and causes chronic gastritis, peptic ulcer and gastric cancer. Until now, three consensus meetings on H.pylori infection had been performed in Spain (the last in 2012). The changes in the treatment schemes, and the increasing available evidence, have justified organizing the IVSpanish Consensus Conference (March 2016), focused on the treatment of this infection. Nineteen experts participated, who performed a systematic review of the scientific evidence and developed a series of recommendation that were subjected to an anonymous Delphi process of iterative voting. Scientific evidence and the strength of the recommendation were classified using GRADE guidelines. As starting point, this consensus increased the minimum acceptable efficacy of recommended treatments that should reach, or preferably surpass, the 90% cure rate when prescribed empirically. Therefore, only quadruple therapies (with or without bismuth), and generally lasting 14 days, are recommended both for first and second line treatments. Non-bismuth quadruple concomitant regimen, including a proton pump inhibitor, clarithromycin, amoxicillin and metronidazole, is recommended as first line. In the present consensus, other first line alternatives and rescue treatments are also reviewed and recommended.

Emerging Helicobacter pylori levofloxacin resistance and novel genetic mutation in Nepal

Background

The prevalence of Helicobacter pylori antibiotic susceptibility in the Nepalese strains is untracked. We determined the antibiotic susceptibility for H. pylori and analyzed the presence of genetic mutations associated with antibiotic resistance in Nepalese strains.

Results

This study included 146 consecutive patients who underwent gastroduodenal endoscopy in Kathmandu, Nepal. Among 42 isolated H. pylori, there was no resistance to amoxicillin and tetracycline. In contrast, similar with typical South Asian patterns; metronidazole resistance rate in Nepalese strains were extremely high (88.1 %, 37/42). Clarithromycin resistance rate in Nepalese strains were modestly high (21.4 %, 9/42). Most of metronidazole resistant strains had highly distributed rdxA and frxA mutations, but were relative coincidence without a synergistic effect to increase the minimum inhibitory concentration (MIC). Among strains with the high MIC, 63.6 % (7/11) were associated with frameshift mutation at position 18 of frxA with or without rdxA involvement. However, based on next generation sequencing data we found that one strain with the highest MIC value had a novel mutation in the form of amino acid substituted at Ala-212, Gln-382, Ile-485 of dppA and Leu-145, Thr-168, Glu-117, Val-121, Arg-221 in dapF aside from missense mutations in full-length rdxA. Mutations at Asn-87 and/or Asp-91 of the gyrA were predominantly in levofloxacin-resistant strains. The gyrB mutation had steady relationship with the gyrA 87–91 mutations. Although three (44.4 %) and two (22.2 %) of clarithromycin resistant strains had point mutation on A2143G and A2146G, we confirmed the involvement of rpl22 and infB in high MIC strains without an 23SrRNA mutation.

Conclusions

The rates of resistance to clarithromycin, metronidazole and levofloxacin were high in Nepalese strains, indicating that these antibiotics-based triple therapies are not useful as first-line treatment in Nepal. Bismuth or non-bismuth-based quadruple regimens, furazolidone-based triple therapy or rifabutin-based triple therapy may become alternative strategy in Nepal.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-016-0873-6) contains supplementary material, which is available to authorized users.

Dietary Patterns are Associated with Helicobacter Pylori Infection in Chinese Adults: A Cross-Sectional Study

Previous studies indicated that food consumption was associated with Helicobacter pylori infection, but no study has yet investigated the association between Helicobacter pylori infection and dietary patterns. The aim of this study was to evaluate the associations between Helicobacter pylori infection and dietary patterns in Tianjin, China. The final cross-sectional study population comprised 10407 participants. Dietary consumption of participants was assessed via food frequency questionnaire. Factor analysis was used to identify dietary patterns, and Helicobacter pylori infection status was diagnosis by H. pylori urease Immunogold Testing kit. Participants in the highest quartile of the high-carbohydrate/sweet pattern showed a multivariable-adjusted OR (95% CI) of 1.65 (1.27–2.17) for the prevalence of H. pylori infection compared with those in the lowest quartile. The multiple adjusted OR for scores of the extreme quartile of high-protein/cholesterol pattern was 0.75 (95% CI, 0.57–0.98). This study demonstrated that a diet rich in carbohydrates and sweets was positively associated with the prevalence of H. pylori infection; interestingly, a diet characterized by high intake of animal offal, animal blood, fish, seafood, and poultry was associated with a reduction of prevalence of H. pylori infection.

Gastric mucosa-associated lymphoid tissue lymphoma and Helicobacter pylori infection: a review of current diagnosis and management

Helicobacter pylori (H. pylori)-associated gastritis is one of the most common infectious diseases in the United States, China and worldwide. Gastric mucosa-associated tissue lymphoma (MALT lymphoma) is a rare mature B-cell neoplasm associated with H. pylori infection that is curable by antibiotics therapy alone. The pathological diagnosis of gastric MALT lymphoma can be reached by histological examination, immunohistochemical staining and B-cell clonality analysis. H. pylori eradication is the choice of therapy for early-stage gastric MALT lymphoma. High response rates and long-term survival have been reported in refractory and localized diseases treated with low-dose radiation therapy. Systemic chemotherapy is recommended for advanced-stage gastric MALT lymphoma and cases with large B-cell lymphoma transformation. Recent advances in the pathological diagnosis and management of gastric MALT lymphoma are reviewed in this article.

Tailored versus Triple plus Bismuth or Concomitant Therapy as Initial Helicobacter pylori Treatment: A Randomized Trial

BACKGROUND

With markedly increased antibiotic resistance and unsatisfactory efficacies of common empiric eradication regimens in the mainland of China, tailored therapy may be the best choice to achieve good efficacy. This study compared the eradication rates, safety, and compliance of tailored therapy to those of triple therapy plus bismuth and concomitant therapy in the naïve patients with Helicobacter pylori infection.

MATERIALS AND METHODS

Between September 2013 and April 2014, 1050 patients with H. pylori infection at three tertiary hospitals were randomly assigned to 10-day treatment with tailored, triple plus bismuth, or concomitant regimens. In tailored therapy, medications were adjusted according to clarithromycin sensitivity and cytochrome P450 isoenzyme 2C19 genotype. The antimicrobial susceptibility testing (E test) was performed. Eradication status was assessed 4-12 weeks after treatment.

RESULTS

The eradication rate was significantly higher in tailored group than in triple plus bismuth and concomitant groups in both intention-to-treat (88.7 vs 77.4 vs 78.3%, p < .001) and per-protocol (93.3 vs 87.0 vs 87.4%, p = .021) analyses in a setting with high antibiotic resistance (clarithromycin 48.8%, metronidazole 65.7%, and dual resistance 35.3%). Significantly, fewer adverse effects occurred in tailored group than in concomitant group (22.0 vs 31.7%, p = .018). The eradication rates of dual clarithromycin and metronidazole resistance, isolated clarithromycin resistance, isolated metronidazole resistance, and dual susceptible were 78.7, 82.4, 94.8, and 94.4% in triple therapy plus bismuth and 75.9, 87.2, 92.9, and 95.2% in concomitant therapy, respectively.

CONCLUSIONS

First-line tailored therapy achieves significantly higher eradication rates and fewer side effects, compared to triple therapy plus bismuth and concomitant therapy in a setting with high rates of clarithromycin and metronidazole resistance.

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

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

Helicobacter pylori associated gastric intestinal metaplasia: Treatment and surveillance

Gastric cancer (GC) is one of the leading causes of cancer related death in the world, particularly in East Asia. According to the Correa’s cancer cascade, non-cardia GC is usually developed through a series of mucosal changes from non-atrophic gastritis to atrophic gastritis (AG), intestinal metaplasia (IM), dysplasia and adenocarcinoma. Atrophic gastritis and IM are therefore generally considered to be pre-neoplastic gastric lesions. Helicobacter pylori (H. pylori) infection is an important initiating and promoting step of this gastric carcinogenesis cascade. Emerging long-term data showed that eradication of H. pylori reduced the risk of subsequent cancer development. It however remains confusing whether eradication of the bacterium in individuals with pre-neoplastic gastric lesions could regress these changes as well as in preventing cancer. Whilst H. pylori eradication could likely regress AG, the presence of IM may be a point of no return in this cascade. Hence, surveillance by endoscopy may be indicated in those with extensive IM or those with incomplete IM, particularly in populations with high GC risk. The optimal interval and the best tool of surveillance endoscopy remains to be determined in future studies.

Diagnostic Methods of Helicobacter pylori Infection for Epidemiological Studies: Critical Importance of Indirect Test Validation

Among the methods developed to detect H. pylori infection, determining the gold standard remains debatable, especially for epidemiological studies. Due to the decreasing sensitivity of direct diagnostic tests (histopathology and/or immunohistochemistry [IHC], rapid urease test [RUT], and culture), several indirect tests, including antibody-based tests (serology and urine test), urea breath test (UBT), and stool antigen test (SAT) have been developed to diagnose H. pylori infection. Among the indirect tests, UBT and SAT became the best methods to determine active infection. While antibody-based tests, especially serology, are widely available and relatively sensitive, their specificity is low. Guidelines indicated that no single test can be considered as the gold standard for the diagnosis of H. pylori infection and that one should consider the method's advantages and disadvantages. Based on four epidemiological studies, culture and RUT present a sensitivity of 74.2–90.8% and 83.3–86.9% and a specificity of 97.7–98.8% and 95.1–97.2%, respectively, when using IHC as a gold standard. The sensitivity of serology is quite high, but that of the urine test was lower compared with that of the other methods. Thus, indirect test validation is important although some commercial kits propose universal cut-off values.

Validation of Urine Test for Detection of Helicobacter pylori Infection in Indonesian Population

We measured the accuracy of the urine test (RAPIRUN) for detection of Helicobacter pylori infection in Indonesia (Jakarta, Pontianak, and Jayapura) using histology confirmed by immunohistochemistry and/or culture as gold standards. We also used immunohistochemistry to identify CagA phenotype and analyzed H. pylori CagA diversity in Indonesia. The overall prevalence of H. pylori infection in 88 consecutive dyspeptic patients based on the urine test was 15.9% (14/88), 38.1% for patients in Jayapura that had higher prevalence of H. pylori infection than that in Jakarta (9.7%, P = 0.02) and Pontianak (8.3%, P = 0.006). Overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of RAPIRUN were 83.3%, 94.7%, 71.4%, 97.3%, and 93.2%, respectively. All of the H. pylori-positive patients were immunoreactive for anti-CagA antibody but not immunoreactive for East Asian specific anti-CagA antibody in all H. pylori-positive subjects. We confirmed the high accuracy of RAPIRUN in Indonesian population. In general, we found less virulent type of H. pylori in Indonesia, which partly explained the low incidence gastric cancer in Indonesia.

Helicobacter pylori in gastric carcinogenesis

Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori (H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to the occurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cagA and vacA are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis.

Bismuth, lansoprazole, amoxicillin and metronidazole or clarithromycin as first-line Helicobacter pylori therapy

OBJECTIVE

To evaluate the efficacy and tolerability of replacing tetracycline with amoxicillin in bismuth quadruple therapy.

DESIGN

Subjects who were infected with Helicobacter pylori and naïve to treatment were randomly (1:1) assigned to receive a 14-day modified bismuth quadruple therapy: lansoprazole 30 mg, amoxicillin 1 g, bismuth potassium citrate 220 mg (elemental bismuth), twice a day with metronidazole 400 mg four times a day (metronidazole group) or clarithromycin 500 mg twice a day (clarithromycin group). Six weeks after treatment, H. pylori eradication was assessed by 13C-urea breath test. Antimicrobial susceptibility was assessed by the twofold agar dilution method. This was a non-inferiority trial.

RESULTS

Two hundred and fifteen subjects were randomised. Metronidazole and clarithromycin containing regimens achieved high cure rates: 94 of 97 (96.9%, 95% CI 93.5% to 100%) and 93 of 98 (94.9%, 95% CI 90.5% to 99.3%) by per-protocol and 88.9% (95% CI 83.0% to 94.8%) and 88.8% (95% CI 82.8% to 94.8%) by intention-to-treat, respectively. Amoxicillin, metronidazole and clarithromycin resistance rates were 1.5%, 45.5% and 26.5%, respectively. Only clarithromycin resistance reduced treatment success (e.g., susceptible 98.6%, resistant 76.9%, p=0.001). Adverse events were more common in the metronidazole group.

CONCLUSIONS

These results suggest that amoxicillin can substitute for tetracycline in modified 14 day bismuth quadruple therapy as first-line treatment and still overcome metronidazole resistance in areas with high prevalence of metronidazole and clarithromycin resistance. Using clarithromycin instead of metronidazole was only effective in the presence of susceptible strains.

TRIAL REGISTRATION NUMBER

NCT02175901.

Diagnosis and management of high risk group for gastric cancer

Gastric cancer is associated with high morbidity and mortality worldwide. To reduce the socioeconomic burden related to gastric cancer, it is very important to identify and manage high risk group for gastric cancer. In this review, we describe the general risk factors for gastric cancer and define high risk group for gastric cancer. We discuss strategies for the effective management of patients for the prevention and early detection of gastric cancer. Atrophic gastritis (AG) and intestinal metaplasia (IM) are the most significant risk factors for gastric cancer. Therefore, the accurate selection of individuals with AG and IM may be a key strategy for the prevention and/or early detection of gastric cancer. Although endoscopic evaluation using enhanced technologies such as narrow band imaging-magnification, the serum pepsinogen test, Helicobacter pylori serology, and trefoil factor 3 have been evaluated, a gold standard method to accurately select individuals with AG and IM has not emerged. In terms of managing patients at high risk of gastric cancer, it remains uncertain whether H. pylori eradication reverses and/or prevents the progression of AG and IM. Although endoscopic surveillance in high risk patients is expected to be beneficial, further prospective studies in large populations are needed to determine the optimal surveillance interval.

Modified sequential therapy vs quadruple therapy as initial therapy in patients with Helicobacter infection

AIM: To evaluate the efficacy and safety of modified sequential therapy and to compare modified sequential therapy with standard quadruple therapy for Helicobacter pylori (H. pylori) eradication.

METHODS: In total, 200 consecutive patients who were diagnosed with H. pylori-infected chronic gastritis by electronic endoscopy and rapid urease testing from December 2012 to October 2013 were enrolled in this study. The patients had not previously received H. pylori eradication treatment, and were randomized into two groups. The patients in Group A (n = 101) were treated with ilaprazole + bismuth potassium citrate + amoxicillin and clavulanate potassium + levofloxacin, and the patients in Group B (n = 99) were administered a modified sequential therapy composed of ilaprazole at 5 mg bid and amoxicillin and clavulanate potassium at 914 mg for the first five days followed by ilaprazole at 5 mg bid, furazolidone at 100 mg bid and levofloxacin at 500 mg qid for the next five days. Four to six weeks after the end of treatment, a 14C-urea breath test was performed for all the subjects to confirm the eradication of H. pylori. The intention-to-treat and per-protocol eradication rates were determined.

RESULTS: A total of 190 of the 200 patients completed the study. All 200 patients were included in the intention-to-treat analysis, whereas 190 patients were included in the per-protocol analysis. In the intention-to-treat analysis, the rates of H. pylori eradication in Groups A and B were 85.15% (86/101) and 81.82% (81/99), respectively. In the per-protocol analysis, the H. pylori eradication rates in Groups A and B were 88.66% (86/97) and 87.09% (81/93), respectively. No significant difference was observed (χ² = 0.109, P = 0.741) in the eradication rate between Groups A and B. The rates of adverse effects observed in the groups were similar at 6.19% (6/97) for Group A and 7.53% (7/93) for Group B (P > 0.05). No mortality or major morbidities were observed in any of the patients. Symptomatic improvements in the presentation of stomachache, acid regurgitation, and burning sensation were not significantly different between the two groups.

CONCLUSION: Ilaprazole-based 10-d standard quadruple therapy does not offer an incremental benefit over modified sequential therapy for the treatment of H. pylori infection, as both treatment regimens appear to be effective, safe, and well-tolerated as initial treatment options.

Anti-Helicobacter pylori activities of Chenopodium ambrosioides L. in vitro and in vivo

AIM: To investigate the bactericidal effects of Chenopodium ambrosioides L. (CAL) against Helicobacter pylori (H. pylori) both in vitro and in vivo.

METHODS: For in vitro experiments, the inhibitory activity of CAL was tested using an agar dilution method; H. pylori strain NCTC11637 was incubated on Columbia blood agar plates containing serial concentrations of CAL. The minimal inhibitory concentration (MIC) was determined by the absence of H. pylori colonies on the agar plate. Time-kill curves were used to evaluate bactericidal activity; the average number of colonies was calculated at 0, 2, 8 and 24 h after liquid incubation with concentrations of CAL at 0.5, 1, and 2 × MIC. For in vivo experiments, H. pylori-infected mice were randomly divided into CAL, triple therapy (lansoprazole, metronidazole, and clarithromycin), blank control, or H. pylori control groups. The eradication ratios were determined by positive findings from rapid urease tests (RUTs) and by histopathology.

RESULTS: In vitro, the MIC of CAL against H. pylori was 16 mg/L. The time-kill curves showed a stable and persistent decreasing tendency with increasing CAL concentration, and the intensity of the bactericidal effect was proportional to dose; the 1 and 2 × MIC completely inhibited the growth of H. pylori at 24 h. In vivo, the eradication ratios in the CAL group were 60% (6/10) by RUT and 50% (5/10) by histopathology. Ratios in the triple therapy group were both 70% (7/10), and there was no difference between the CAL and triple therapy groups. Histopathologic evaluation revealed massive bacterial colonization on the surface of gastric mucosa and slight infiltration of mononuclear cells after inoculation with H. pylori, but no obvious inflammation or other pathologic changes in gastric mucosa of mice from CAL and triple therapy groups.

CONCLUSION: CAL demonstrates effective bactericidal activity against H. pylori both in vitro and in vivo.

Review of atrophic gastritis and intestinal metaplasia as a premalignant lesion of gastric cancer

Atrophic gastritis (AG) and intestinal metaplasia (IM) are the main precursor lesions of gastric cancer as the incidence of gastric cancer increases in the gastric mucosa involved with AG and IM. The prevalence of AG and IM vary depending on countries, even it represents diverse results in the same nation. Usually AG is antecedent of IM but the etiologies of AG and IM are not always the same. The sensitivity and specificity of diagnostic methods to detect AG and IM are different. Furthermore, the management strategy of AG and IM has not been established, yet. Helicobacter pylori infection has been proved as the most important cause of AG and IM. Thus the eradication of H. pylori is very important to prevent the progression to gastric cancer which is still placed in the high rank in morbidity and mortality among cancers. However, the reversibility of AG and IM by eradication of H. pylori which was assumed to be certain by meta-analysis is; however, controversial now. Therefore, the understanding and early diagnosis of AG and IM are very important, especially, in high incidence area of gastric cancer such as Republic of Korea.

Appropriate first-line regimens to combat Helicobacter pylori antibiotic resistance: an Asian perspective

Asia has the largest population of any continent and the highest incidence of gastric cancer in the world, making it very important in the context of Helicobacter pylori infection. According to current guidelines, standard triple therapy containing a proton pump inhibitor (PPI) and two antibiotics; amoxicillin (AMX) and clarithromycin (CAM) or metronidazole (MNZ), is still the preferred first-line regimen for treatment of H. pylori infection. However, the efficacy of legacy triple regimens has been seriously challenged, and they are gradually becoming ineffective. Moreover, some regions in Asia show patterns of emerging antimicrobial resistance. More effective regimens including the bismuth and non-bismuth quadruple, sequential, and dual-concomitant (hybrid) regimens are now replacing standard triple therapies as empirical first-line treatments on the basis of the understanding of the local prevalence of H. pylori antimicrobial resistance. Selection of PPI metabolized by the non-enzymatic pathway or minimal first pass metabolism and/or increasing dose of PPI are important to increase H. pylori eradication rates. Therefore, local antibiotic resistance surveillance updates, selection of appropriate first-line regimens with non-enzymatic PPI and/or increased doses of PPI, and detailed evaluation of patients' prior antibiotic usage are all essential information to combat H. pylori antibiotic resistance in Asia.

Primary antibiotic resistance of Helicobacter pylori strains isolated from patients with dyspeptic symptoms in Beijing: A prospective serial study

AIM: To determine the resistance patterns of Helicobacter pylori (H. pylori) strains isolated from patients in Beijing and monitor the change of antibiotic resistance over time.

METHODS: In this prospective, serial and cross-sectional study, H. pylori cultures were successfully obtained from 371 and 950 patients (never receiving eradication) during 2009-2010 and 2013-2014, respectively. Resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin was determined by Epsilometer test.

RESULTS: The resistance rates of isolates obtained during 2009-2010 were 66.8%, 39.9%, 34.5%, 15.4%, 6.7%, and 4.9% to metronidazole, clarithromycin, levofloxacin, rifampicin, amoxicillin and tetracycline, respectively; and the corresponding rates for isolates during 2013-2014 were 63.4%, 52.6%, 54.8%, 18.2%, 4.4% and 7.3%, respectively. The resistance rates to clarithromycin and levofloxacin were significantly increased after four years. In 2009-2010, 14.6% of H. pylori isolates were susceptible to all tested antibiotics, with mono (33.7%), double (28.3%), triple (16.7%), quadruple (6.2%), quintuple (0.3%) and sextuple resistance (0.3%) also being detected. In 2013-2014, 9.4% were susceptible to all tested antibiotics, and mono (27.6%), double (28.4%), triple (24.9%), quadruple (7.3%), quintuple (2.3%) and sextuple resistance (0.1%) was also observed. More multiple resistant H. pylori isolates were found during 2013-2014. Gender (to levofloxacin and metronidazole), age (to levofloxacin) and endoscopic findings (to clarithromycin) were independent factors influencing antibiotic resistance.

CONCLUSION: H. pylori resistance to commonly used antibiotics in Beijing is high with increased multiple antibiotic resistance.

Review: clinical management of Helicobacter pylori infection in China

Helicobacter pylori (H. pylori) infection has been associated with gastric disorders. The situation of H. pylori infection in China-where a high prevalence of H. pylori infection, a high incidence of gastric cancer, and widespread resistance to clarithromycin, metronidazole, and levofloxacin exist-is quite different from that in Western countries. In order for Chinese clinicians to better manage H. pylori infection, a Chinese Study Group on H. pylori published four consensus reports regarding the management of H. pylori infection in China between 1999 and 2012. The eradication rate with standard triple therapy was <80% in most areas of China. Bismuth is available in China, and bismuth-containing quadruple therapy has been shown to produce a high eradication rate; thus, bismuth quadruple therapy could be recommended both as an initial and as a rescue therapy in China. There is no advantage of sequential therapy over triple therapy in Chinese patients, but the efficacy of concomitant therapy must be studied further. This review introduces the epidemiology, diagnosis, indicators, and therapies for the eradication of H. pylori in China in recent years.

Prospective multi-region study on primary antibiotic resistance of Helicobacter pylori strains isolated from Chinese patients

BACKGROUND

Large-scale multi-region studies are urgently needed to provide comprehensive and up-to-date information on the antibiotic resistance of Helicobacter pylori that is critical for selecting the most optimal eradication regimens.

AIMS

To determine the resistance patterns of Helicobacter pylori strains isolated from dyspeptic patients.

METHODS

This is a prospective, multicentre, cross-sectional, observational study. Helicobacter pylori cultures were successful in 600 patients (never receiving eradication therapy) from Northern, Eastern, Middle, and Southern regions between 2008 and 2012. Resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin was determined by Epsilometer test.

RESULTS

The overall resistance rate was highest for metronidazole (403, 67.2%), followed by clarithromycin (225, 37.5%), levofloxacin (201, 33.5%), rifampicin (85, 14.2%), amoxicillin (41, 6.8%), and tetracycline (21, 3.5%). There were 16.3% isolates susceptible to all tested antibiotics, followed by mono-resistance (34.2%), double resistance (27.0%), triple resistance (16.8%), quadruple resistance (4.7%), quintuple resistance (0.7%) and sextuple resistance (0.3%). Independent factors influencing antibiotic resistance were gender (to levofloxacin), age (to levofloxacin), and endoscopic finding (to clarithromycin, metronidazole, and levofloxacin). Among the clarithromycin-resistant isolates, 75.6% and 48.0% were also resistant to metronidazole and levofloxacin, respectively.

CONCLUSIONS

Helicobacter pylori resistance to commonly used antibiotics in China is a very serious issue, due to the high resistance rate and general multiple resistance.

The impact of proton pump inhibitors on the human gastrointestinal microbiome

Potent gastric acid suppression using proton pump inhibitors (PPIs) is common in clinical practice but may have important effects on human health that are mediated through changes in the gastrointestinal microbiome. In the esophagus, PPIs change the normal bacterial milieu to decrease distal esophageal exposure to inflammatory gram-negative bacteria. In the stomach, PPIs alter the abundance and location of gastric Helicobacter pylori and other bacteria. In the small bowel, PPIs cause polymicrobial small bowel bacterial overgrowth and have been associated with the diagnosis of celiac disease. In the colon, PPIs associate with incident but not recurrent Clostridium difficile infection.

Effect of rabeprazole on the transport and distribution of levofloxacin in rat stomachs

The aim of this study was to determine the transport and distribution characteristics of levofloxacin in the rat stomach and investigate the effects of combination treatment with rabeprazole. A total of 160 Wistar rats were randomly divided into four treatment groups: 50 mg/kg levofloxacin, 100 mg/kg levofloxacin, 50 mg/kg levofloxacin + rabeprazole and 100 mg/kg levofloxacin + rabeprazole. For two hours after intravenous administration, serum, gastric juice and stomach mucosa samples were collected at 15-min intervals, and the levofloxacin concentrations in all the samples were measured to determine the transport and distribution characteristics of levofloxacin in the rat stomach. In the 50 mg/kg levofloxacin and the 100 mg/kg levofloxacin groups, the drug concentration in the gastric juice gradually exceeded the serum concentration within 45–60 min of administration (P<0.05) and the drug concentrations in the gastric body and antrum were higher than those in the serum and the forestomach (P<0.05). At 15–30 min after administration, the drug concentrations in the gastric juice in the 50 mg/kg levofloxacin + rabeprazole and the 100 mg/kg levofloxacin + rabeprazole groups gradually exceeded the serum concentration (P<0.05). However, the levofloxacin concentration in the gastric body and in the antrum did not significantly differ between the two groups (P>0.05). The levofloxacin concentrations in each stomach region in the groups also treated with rabeprazole were higher than those treated with levofloxacin alone, but the differences were not significant. The levofloxacin transport fractions in the stomach in the 50 mg/kg levofloxacin, 100 mg/kg levofloxacin, 50 mg/kg levofloxacin + rabeprazole and 100 mg/kg levofloxacin + rabeprazole groups were 2.36, 2.52, 2.42 and 2.55, respectively, and no significant difference was identified. Levofloxacin may be actively transported in the rat stomach. The levofloxacin concentration in the gastric antrum exceeded that in the forestomach, and the local concentration increased with increasing dosage. Combining a proton pump inhibitor with levofloxacin has little effect on the concentration and distribution of levofloxacin in the stomach within 2 h.

Endoscopic gastric cancer screening and surveillance in high-risk groups

Gastric cancer remains a major cancer problem world-wide and future incidence will likely increase due to rapidly aging population demographics. Population-based screening is being undertaken in Korea and Japan, where gastric cancer incidence rates are high, and seems to be effective in reducing mortality from gastric cancer. However, such strategies are difficult to implement in countries with a low incidence or limited resources. Thus, screening strategies should be directed towards high-risk population subgroups. Gastric cancer has a relatively long mean sojourn time, and prognosis of early-stage disease is excellent. In general population, screening at 2-year interval in Korea seems to be effective for early-stage diagnosis. In subjects with atrophic gastritis or intestinal metaplasia, surveillance is recommended at 1 to 3 years intervals according to European and Japanese recommendation. Screening intervals for family members with sporadic gastric cancer has not yet been adequately evaluated, but 1-year interval is recommended for hereditary diffuse gastric cancer family-members. Gastric cancer patients treated by endoscopic resection are the highest-risk group, and 1-year interval surveillance can detect most metachronous gastric cancers at an early stage. Future gastric cancer surveillance strategies using endoscopy should be guided by risk-stratification assessment, and further refinement of optimal surveillance intervals is needed.

Gastric cancer: prevention, screening and early diagnosis

Gastric cancer continues to be an important healthcare problem from a global perspective. Most of the cases in the Western world are diagnosed at late stages when the treatment is largely ineffective. Helicobacter pylori (H. pylori) infection is a well-established carcinogen for gastric cancer. While lifestyle factors are important, the efficacy of interventions in their modification, as in the use of antioxidant supplements, is unconvincing. No organized screening programs can be found outside Asia (Japan and South Korea). Although several screening approaches have been proposed, including indirect atrophy detection by measuring pepsinogen in the circulation, none of them have so far been implemented, and more study data is required to justify any implementation. Mass eradication of H. pylori in high-risk areas tends to be cost-effective, but its adverse effects and resistance remain a concern. Searches for new screening biomarkers, including microRNA and cancer-autoantibody panels, as well as detection of volatile organic compounds in the breath, are in progress. Endoscopy with a proper biopsy follow-up remains the standard for early detection of cancer and related premalignant lesions. At the same time, new advanced high-resolution endoscopic technologies are showing promising results with respect to diagnosing mucosal lesions visually and targeting each biopsy. New histological risk stratifications (classifications), including OLGA and OLGIM, have recently been developed. This review addresses the current means for gastric cancer primary and secondary prevention, the available and emerging methods for screening, and new developments in endoscopic detection of early lesions of the stomach.

Tetracycline- and furazolidone-containing quadruple regimen as rescue treatment for Helicobacter pylori infection: a single center retrospective study

BACKGROUND AND OBJECTIVE

Eradication rate of Helicobacter pylori decreases worldwide, while antibiotics resistance rates of H. pylori increase rapidly in recent years. In most cases, H. pylori would be resistant to clarithromycin, metronidazole, and quinolone if these antibiotics had been used as component of eradication regimen. H. pylori strains resistant to both tetracycline and furazolidone are rare. The aim of our study was to evaluate efficacy and side effects of tetracycline- and furazolidone-containing quadruple regimen as rescue treatment.

METHODS

Patients with H. pylori infection given RTFB (rabeprazole 20 mg b.i.d. + tetracycline 750 mg b.i.d. +furazolidone 100 mg b.i.d. + colloidal bismuth subcitrate 200 mg b.i.d.) regimen for 14 days as rescue treatment were enrolled in this retrospective study. Eradication status was evaluated by (13) C-urea breath test, and side effects were collected.

RESULTS

One hundred and nine patients were enrolled. The intention-to-treat eradication rate was 91.74% (100 of 109) and 95.24% (100 of 105) per protocol analysis. Side effects including fever, palpitation, and skin rash occurred in 35 patients.

CONCLUSIONS

The 14-day tetracycline- and furazolidone-containing quadruple regimen can achieve a relatively high eradication rate as rescue treatment. Some side effects including fever may occur during the treatment.

Efficacy and safety of ecabet sodium as an adjuvant therapy for Helicobacter pylori eradication: a systematic review and meta-analysis

BACKGROUND

Several studies have reported that the application of ecabet sodium during the eradication of Helicobacter pylori can improve the eradication rate and reduce therapy-associated side effects. However, the efficacy and safety of this therapy are controversial.

OBJECTIVES

To determine whether ecabet sodium improves the eradication rate of H. pylori and examine treatment safety by conducting a meta-analysis based on randomized controlled trials (RCTs).

METHODS

Literature searches were conducted in the following databases: PubMed, Embase, the Cochrane Library, the Science Citation Index, the China National Knowledge Infrastructure Database, and the Wanfang Database. A meta-analysis of all RCTs comparing ecabet sodium supplementation with nonecabet sodium-containing therapy was performed.

RESULTS

Thirteen RCTs that included a total of 1808 patients were assessed. The meta-analysis showed that the eradication rate in the ecabet sodium-containing quadruple therapy group was higher than that in the standard triple therapy group (84.5% vs 74.55%, OR 1.757 (95%CI: 1.307 to 2.362), p < .001). The analysis also showed that the eradication rate in the ecabet sodium-containing triple therapy group was significantly higher than that in the PPI plus amoxicillin or clarithromycin therapy group (74.6% vs 43.9%,OR 3.727 (95%CI: 2.320 to 5.988), p < .001)(ITT), (74.6% vs 43.9%,OR 3.863 (95%CI: 2.369 to 6.298), p < .001) (PP). Furthermore, our meta-analysis suggested that the occurrence of side effects did not significantly differ between patients receiving ecabet sodium-containing therapy and patients receiving nonecabet sodium-containing therapy (14.0% vs 13.3%, OR 1.055 (95%CI: 0.632 to 1.759), p = .839).

CONCLUSION

Supplementation with ecabet sodium during H. pylori eradication therapy improves the eradication rate. The use of ecabet sodium does not increase the side effects based on our meta-analysis.

Hematologic manifestations of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is the most common infection in humans, with a marked disparity between developed and developing countries. Although H. pylori infections are asymptomatic in most infected individuals, they are intimately related to malignant gastric conditions such as gastric cancer and gastric mucosa-associated lymphoid tissue (MALT) lymphoma and to benign diseases such as gastritis and duodenal and gastric peptic ulcers. Since it was learned that bacteria could colonize the gastric mucosa, there have been reports in the medical literature of over 50 extragastric manifestations involving a variety medical areas of specialization. These areas include cardiology, dermatology, endocrinology, gynecology and obstetrics, hematology, pneumology, odontology, ophthalmology, otorhinolaryngology and pediatrics, and they encompass conditions with a range of clear evidence between the H. pylori infection and development of the disease. This literature review covers extragastric manifestations of H. pylori infection in the hematology field. It focuses on conditions that are included in international consensus and management guides for H. pylori infection, specifically iron deficiency, vitamin B₁₂ (cobalamin) deficiency, immune thrombocytopenia, and MALT lymphoma. In addition, there is discussion of other conditions that are not included in international consensus and management guides on H. pylori, including auto-immune neutropenia, antiphospholipid syndrome, plasma cell dyscrasias, and other hematologic diseases.

[Future trends of Helicobacter pylori eradication therapy in Korea]

The prevalence of Helicobacter pylori infection in Korea shows a decreasing trend and has changed to that of developed country, especially for those below 30 years old. However, the primary antibiotic resistance rates are higher than those of developed countries. The reason for the decrease in the efficacy of standard triple therapy is mainly due to the increase in the resistance against clarithromycin. Sequential therapy seems to be more effective than the standard triple therapy, but the intention-to-treat eradication rate of sequential therapy in Korea, which is mostly under 80.0%, is still not satisfactory. Therefore, a promising regimen is needed. Recently, the Japanese health insurance system admitted 'H. pylori-infected gastritis'as an indication of eradication. Furthermore, the Kyoto Consensus Meeting on H. pylori Gastritis held from January 30th to February 1st, 2014, proposed that 'all H. pylori positive patients should be offered to receive H. pylori eradication'. This suggests that the concept of eradication has been changed from 'treatment' to 'prevention'. Various individualized tailored therapy based on the polymorphism, age and other demographic factors and antibiotic resistance has been attempted to maximize H. pylori eradication therapy. The aim of this article is to review the current epidemiology, H. pylori resistance state, treatment guideline, and to assess the possible future strategy and treatment for H. pylori infection in Korea.

Helicobacter pylori infection in Mongolian gerbils does not initiate hematological diseases

AIM: To investigate whether Helicobacter pylori (H. pylori) infection contributes to idiopathic thrombocytopenic purpura (ITP) or iron-deficiency anemia (IDA) onset in gerbils.

METHODS: A total of 135 Mongolian gerbils were randomly divided into two groups: an H. pylori infection group and a control group. Both groups were fed the same diet and the same amount of food. Each group was then divided into three subgroups, which were sacrificed at 6, 12, or 18 mo for analysis. At each time point, arterial blood was collected from the abdominal aorta and a complete blood cell count was analyzed in the clinical laboratory in the First Affiliated Hospital of Nanchang University.

RESULTS: There were no significant differences in platelet counts (938.00 ± 270.27/L vs 962.95 ± 162.56 × 10⁹/L), red blood cell counts (8.11 ± 1.25/L vs 8.44 ± 1.48 × 10¹²/L), or hemoglobin levels (136.9 ± 8.76 g/L vs 123.21 ± 18.42 g/L) between the control and the H. pylori groups, respectively, at 18 mo. With the exception of the mean corpuscular volume (MCV), all other indicators, including white blood cell counts, hematocrit, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red blood cell distribution width, mean platelet volume, platelet distribution width, lymphocyte count, and lymphocyte count percentage, showed no significant differences between the control and H. pylori infection groups at each time point. The MCV in the H. pylori infection group (52.32 f/L ± 2.86 f/L) was significantly lower than the control group (55.63 ± 1.89 f/L) at 18 mo (P = 0.005), though no significant differences were observed at 6 (54.40 ± 2.44 f/L vs 53.30 ± 1.86 f/L) or 12 mo (53.73 ± 2.31 f/L vs 54.80 ± 3.34 f/L).

CONCLUSION: A single H. pylori infection is insufficient to cause onset of ITP or IDA and other factors may be required for disease onset.

Helicobacter pylori eradication for preventing gastric cancer

Helicobacter pylori (H. pylori) infection is a major risk factor for gastric cancer (GC) development, which is one of the most challenging malignant diseases worldwide with limited treatments. In the multistep pathogenesis of GC, H. pylori infection slowly induces chronic active gastritis, which progresses through the premalignant stages of atrophic gastritis, intestinal metaplasia, and dysplasia, and then finally to GC. Although eradication of H. pylori is a reasonable approach for the prevention of GC, there have been some contradictory reports, with only some long-term follow-up data showing efficacy of this approach. The inconsistencies are likely due to the insufficient number of participants, relatively short follow-up periods, poor quality of study designs, and the degree and extent of preneoplastic changes at the time of H. pylori eradication. This review analyzes recent high-quality studies to resolve the discrepancies regarding the eradication of H. pylori for GC prevention. The relationship between H. pylori eradication and GC/precancerous lesions/metachronous GC is examined, and the cost-effectiveness of this strategy in the prevention of GC is assessed. Although it is assumed that eradication of H. pylori has the potential to prevent GC, the feasibility and appropriate timing of this strategy for cancer prevention remain to be determined. As a result, additional well-designed trials with longer follow-up periods are needed to clarify this issue.

Current progress toward eradicating Helicobacter pylori in East Asian countries: Differences in the 2013 revised guidelines between China, Japan, and South Korea

New 2013 guidelines on Helicobacter pylori (H. pylori) infection have been published in China, Japan, and South Korea. Like the previous ones, these new guidelines differ between the three countries with regard to the indications for H. pylori eradication, diagnostic methods, and treatment regimens. The most profound change among all of the guidelines is that the Japanese national health insurance system now covers the expenses for all infected subjects up to second-line treatment. This makes the Japanese indications for eradication much wider than those in China and South Korea. With regard to the diagnosis, a serum H. pylori antibody test is not recommended in China, whereas it is considered to be the most reliable method in Japan. A decrease relative to the initial antibody titer of more than 50% after 6-12 mo is considered to be the most accurate method for determining successful eradication in Japan. In contrast, only the urea breath test is recommended after eradication in China, while either noninvasive or invasive methods (except the bacterial culture) are recommended in South Korea. Due to the increased rate of antibiotics resistance, first-line treatment is omitted in China and South Korea in cases of clarithromycin resistance. Notably, the Japanese regimen consists of a lower dose of antibiotics for a shorter duration (7 d) than in the other countries. There is neither 14 d nor bismuth-based regimen in the first-line and second-line treatment in Japan. Such differences among countries might be due to differences in the approvals granted by the governments and national health insurance system in each country. Further studies are required to achieve the best results in the diagnosis and treatment of H. pylori infection based on cost-effectiveness in East Asian countries.

Helicobacter pylori infection: selected aspects in clinical management

PURPOSE OF REVIEW

This review focuses on new aspects of recently published guidelines for the management of Helicobacter pylori infection as well as progress in diagnostic tests and treatment regimens. We also discuss new strategies for gastric cancer prevention.

RECENT FINDINGS

The general recommendation to treat H. pylori infection whenever diagnosed still faces resistance for reasons that are pertinent to the diversity of related clinical outcomes and to the complexity of eradication regimens. Thus, new updated guidelines for the management of H. pylori infection have been released in several continents. Progress has been made in molecular diagnostic tests for the detection of antibiotic resistance and serological tests for the detection of advanced gastric atrophic changes. Effective quadruple therapies in various combinations of 'traditional drugs' have been introduced with sequential or concomitant order of administration. Moreover, traditional drugs in a new galenic formulation have been introduced to overcome increasing H. pylori antibiotic resistance. Effective strategies for gastric cancer prevention have been adopted in some countries with high gastric cancer incidence, and have successfully contributed to lower the gastric cancer incidence. A screen-and-treat strategy for individuals at increased risk for gastric cancer needs to be further explored also in areas with low/moderate incidence of gastric cancer.

SUMMARY

New guidelines share many universal similarities across countries but respect and emphasize specific needs and requirements in individual communities. Various combinations of traditional drugs have been successfully introduced to overcome the increasing H. pylori antibiotic resistance. Gastric cancer prevention by a screen and treat strategy showed promising results.

Current evidence of effects of Helicobacter pylori eradication on prevention of gastric cancer

Gastric cancer is the second most common cause of cancer death worldwide and is usually detected at a late stage, except in Korea and Japan where early screening is in effect. Results from animal and epidemiological studies suggest that Helicobacter pylori infection, and subsequent gastritis, promote development of gastric cancer in the infected mucosa. Relatively effective treatment regimens are available to treat H. pylori infection, and in general, mass eradication of the organism is not currently recommended as a gastric cancer prevention strategy. However, regional guidelines vary regarding the indications and recommendations for H. pylori treatment for gastric cancer prevention. In this review, we discuss the results from intervention studies, provide insight regarding current guideline recommendations, and discuss future study directions.