Effects of Helicobacter pylori eradication on atrophic gastritis and intestinal metaplasia: A 3-year follow-up study

Pathogenesis and potential reversibility of intestinal metaplasia - a milestone in gastric carcinogenesis

BACKGROUND

Non-cardia gastric cancer remains a major cause of cancer-related mortality worldwide, despite declining incidence rates in many industrialized countries. The development of intestinal-type gastric cancer occurs through a multistep process in which normal mucosa is sequentially transformed into hyperproliferative epithelium, followed by metaplastic processes leading to carcinogenesis. Chronic infection with Helicobacter pylori is the primary etiological agent that causes chronic inflammation of the gastric mucosa, induces atrophic gastritis, and can lead to intestinal metaplasia and dysplasia. Both intestinal metaplasia and dysplasia are precancerous lesions, in which gastric cancer is more likely to occur. Atrophic gastritis often improves after eradication of Helicobacter pylori; however, the occurrence of intestinal metaplasia has been traditionally regarded as "the point of no return" in the carcinogenesis sequence. Helicobacter pylori eradication heals non-atrophic chronic gastritis, may lead to regression of atrophic gastritis, and reduces the risk of gastric cancer in patients with these conditions. In this article, we discuss the pathogenesis, epigenomics, and reversibility of intestinal metaplasia and briefly touch upon potential treatment strategy.

CONCLUSIONS

Gastric intestinal metaplasia no longer appears to be an irreversible precancerous lesion. However, there are still many controversies regarding the improvement of intestinal metaplasia after Helicobacter pylori eradication.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of Helicobacter pylori eradication on gastric precancerous lesions: A systematic review and meta-analysis

BACKGROUND

The question of whether eradication of Helicobacter pylori (Hp) can reverse gastric precancerous lesions, including intestinal metaplasia, remains uncertain, leading to ongoing debate. Therefore, a meta-analysis was performed to evaluate the effect of Hp eradication on gastric precancerous lesions.

MATERIALS AND METHODS

PubMed, Embase, Cochrane Library, Web of Science, Scopus database, and ClinicalTrials.gov were systematically searched from inception to April 2023 for studies that explored the impact of Hp eradication on gastric precancerous lesions. Risk ratios (RRs) and their 95% confidence intervals (95% CIs) were selected as the effect size. We used the random-effects model to assess pooled data. We also performed quality assessments, subgroup analyses, and sensitivity analyses.

RESULTS

Fifteen studies were included. Compared with placebo, Hp eradication could significantly prevent the progression of gastric precancerous lesions (RR = 0.87, 95% CI: 0.81-0.94, p < 0.01) and reverse them (RR = 1.32, 95% CI: 1.17-1.50, p < 0.01). Then, specific precancerous lesions were further explored. The progression of intestinal metaplasia was significantly prevented by Hp eradication compared to placebo or no treatment (RR = 0.80, 95% CI: 0.69-0.94, p < 0.01). Moreover, compared with placebo or no treatment, Hp eradication also improved chronic atrophic gastritis (RR = 1.84, 95% CI: 1.30-2.61, p < 0.01) and intestinal metaplasia (RR = 1.41, 95% CI: 1.15-1.73, p < 0.01). However, in terms of preventing dysplasia progression (RR = 0.86, 95% CI: 0.37-2.00) and improving dysplasia (RR = 0.89, 95% CI: 0.47-1.70), Hp eradication had no advantage compared to placebo or no treatment.

CONCLUSIONS

Hp eradication therapy could prevent the progression of gastric precancerous lesions and reverse them. Notably, intestinal metaplasia can be reversed, but this may only be appropriate for patients with epigenetic alterations and milder lesions.

Discussion on the common controversies of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori ( H. pylori ) can persistently colonize on the gastric mucosa after infection and cause gastritis, atrophy, metaplasia, and even gastric cancer (GC).

METHODS

Therefore, the detection and eradication of H. pylori are the prerequisite.

RESULTS

Clinically, there are some controversial issues, such as why H. pylori infection is persistent, why it translocases along with the lesser curvature of the stomach, why there is oxyntic antralization, what the immunological characteristic of gastric chronic inflammation caused by H. pylori is, whether H. pylori infection is associated with extra-gastric diseases, whether chronic atrophic gastritis (CAG) is reversible, and what the potential problems are after H. pylori eradication. What are the possible answers?

CONCLUSION

In the review, we will discuss these issues from the attachment to eradication in detail.

The 'reversibility' of chronic atrophic gastritis after the eradication of Helicobacter pylori

Gram-negative bacterium Helicobacter pylori (H. pylori) infection is lifelong and usually acquired in childhood, which is etiologically linked to gastric cancer (GC). H. pylori gastritis is defined as an infectious disease with varying severity in virtually all infected subjects. Chronic atrophic gastritis (CAG) is the precancerous condition with the decrease or the loss of gastric glands, which can further be replaced by metaplasia or fibrosis. Patients with advanced stages of CAG are at higher risk of GC and should be followed up with a high-quality endoscopy every 3 years. H. pylori infection is the most common cause and its eradication is recommended, which may contribute to the regression of CAG. However, it is controversial whether CAG is reversible after eradication therapy. In the review, we discuss recent studies which provide important insights into whether CAG is 'reversibility' and when it may progress into GC after eradicating H. pylori.

Differences in Regression Patterns of Complete and Incomplete Intestinal Metaplasia at Ten Years after Helicobacter pylori Eradication

This study was conducted to reveal the reversibility of subtype of intestinal metaplasia (IM) and Paneth cells after H. pylori eradication (HPE). Among 75 patients, we retrospectively examined the proportions of patients with complete type of IM (CIM), incomplete type of IM (IIM) and Paneth cells in their biopsy specimens obtained from the greater curvature of the antrum (A2) and the greater curvature of the middle corpus (B2) before and during a follow-up period of 10 years after HPE. Immunohistochemistry was used to determine IM type. Compared to before HPE, the proportion of patients with CIM did not decrease significantly during the 10-year follow-up after HPE both in A2 (32% vs. 21.3%, P = 0.13) and in B2 (6.7% vs. 2.7%, P = 0.60). IIM rates in A2 was significantly lower during this time (26.7% vs. 10.7%, P = 0.04), whereas no patients showed IIM in B2 before HPE. The proportion of patients with Paneth cells decreased significantly in A2 after 3, 8, and 9 years of HPE and in B2 after 4, 6 and 9 years of HPE (P < 0.05 for all). Thus, IIM and Paneth cells regressed during a period of 10 years after HPE.

Helicobacter pylori eradication: Exploring its impacts on the gastric mucosa

Helicobacter pylori (H. pylori) infects approximately 50% of all humans globally. Persistent H. pylori infection causes multiple gastric and extragastric diseases, indicating the importance of early diagnosis and timely treatment. H. pylori eradication produces dramatic changes in the gastric mucosa, resulting in restored function. Consequently, to better understand the importance of H. pylori eradication and clarify the subsequent recovery of gastric mucosal functions after eradication, we summarize histological, endoscopic, and gastric microbiota changes to assess the therapeutic effects on the gastric mucosa.

Factors associated with the progression of gastric intestinal metaplasia: a multicenter, prospective cohort study

Background and study aims  Gastric cancer (GC) is usually preceded by premalignant gastric lesions (GPLs) such as gastric intestinal metaplasia (GIM). Information on risk factors associated with neoplastic progression of GIM are scarce. This study aimed to identify predictors for progression of GIM in areas with low GC incidence. Patients and methods  The Progression and Regression of Precancerous Gastric Lesions (PROREGAL) study includes patients with GPL. Patients underwent at least two upper endoscopies with random biopsy sampling. Progression of GIM means an increase in severity according to OLGIM (operative link on gastric intestinal metaplasia) during follow-up (FU). Family history and lifestyle factors were determined through questionnaires. Serum Helicobacter pylori infection, pepsinogens (PG), gastrin-17 and GC-associated single nucleotide polymorphisms (SNPs) were determined. Cox regression was performed for risk analysis and a chi-squared test for analysis of single nucleotide polymorphisms. Results  Three hundred and eight patients (median age at inclusion 61 years, interquartile range (IQR: 17; male 48.4 %; median FU 48 months, IQR: 24) were included. During FU, 116 patients (37.7 %) showed progression of IM and six patients (1.9 %) developed high-grade dysplasia or GC. The minor allele (C) on TLR4 (rs11536889) was inversely associated with progression of GIM (OR 0.6; 95 %CI 0.4-1.0). Family history (HR 1.5; 95 %CI 0.9-2.4) and smoking (HR 1.6; 95 %CI 0.9-2.7) showed trends towards progression of GIM. Alcohol use, body mass index, history of H. pylori infection, and serological markers were not associated with progression. Conclusions  Family history and smoking appear to be related to an increased risk of GIM progression in low GC incidence countries. TLR4 (rs11536889) showed a significant inverse association, suggesting that genetic information may play a role in GIM progression.

Transporters HP0939, HP0497, and HP0471 participate in intrinsic multidrug resistance and biofilm formation in Helicobacter pylori by enhancing drug efflux

BACKGROUND

The multidrug resistance of Helicobacter pylori is becoming an increasingly serious issue. It is therefore necessary to study the mechanism of multidrug resistance of H pylori. We have previously identified that the HP0939, HP0497, and HP0471 transporters affect the efflux of drugs from H pylori. As efflux pumps participate in bacterial multidrug resistance and biofilm formation, we hypothesized that these transporters could be involved in the multidrug resistance and biofilm formation of H pylori.

MATERIALS AND METHODS

We therefore constructed three knockout strains, Δhp0939, Δhp0497, and Δhp0471, and three high-expression strains, Hp0939^he , Hp0497^he , and Hp0471^he , using the wild-type (WT) 26 695 strain of H pylori as the template. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of wild strains, knockout strains, and high-expression strains to amoxicillin, metronidazole, and other antibiotics were measured. The efflux capacity of high-expression strains and wild strains was compared by Hoechst 33 342 accumulation assay.

RESULTS

Determination of the MIC and MBC of the antibiotics revealed that the knockout strains were more sensitive to antibiotics, while the high-expression strains were less sensitive to antibiotics, compared to the WT. The ability of the high-expression strains to efflux drugs was significantly higher than that of the WT. We also induced H pylori to form biofilms, and observed that the knockout strains could barely form biofilms and were more sensitive to several antibiotics, compared to the WT. The mRNA expression of hp0939, hp0497, and hp0471 in the clinically sensitive and multidrug-resistant strains was determined, and it was found that these genes were highly expressed in the multidrug-resistant strains that were isolated from the clinics.

CONCLUSIONS

In this study, we found three transporters involved in intrinsic multidrug resistance of H pylori.

Temporin-SHa and Its Analogs as Potential Candidates for the Treatment of Helicobacter pylori

Helicobacter pylori is one of the most prevalent pathogens colonizing 50% of the world's population and causing gastritis and gastric cancer. Even with triple and quadruple antibiotic therapies, H. pylori shows increased prevalence of resistance to conventional antibiotics and treatment failure. Due to their pore-forming activity, antimicrobial peptides (AMP) are considered as a good alternative to conventional antibiotics, particularly in the case of resistant bacteria. In this study, temporin-SHa (a frog AMP) and its analogs obtained by Gly to Ala substitutions were tested against H. pylori. Results showed differences in the antibacterial activity and toxicity of the peptides in relation to the number and position of D-Ala substitution. Temporin-SHa and its analog NST1 were identified as the best molecules, both peptides being active on clinical resistant strains, killing 90-100% of bacteria in less than 1 h and showing low to no toxicity against human gastric cells and tissue. Importantly, the presence of gastric mucins did not prevent the antibacterial effect of temporin-SHa and NST1, NST1 being in addition resistant to pepsin. Taken together, our results demonstrated that temporin-SHa and its analog NST1 could be considered as potential candidates to treat H. pylori, particularly in the case of resistant strains.

Clinical background factors affecting outcomes of Helicobacter pylori eradication therapy in primary care

OBJECTIVE

Few studies have reported the influence of clinical background factors on the outcome of Helicobacter pylori eradication therapy in primary care practice. We aimed to determine which clinical background factors influence the outcome of eradication therapy in a primary care setting.

METHODS

This was a retrospective study of patients who received H pylori eradication therapy at Higashiohmi City Gamo Medical Center, Shiga, Japan, from January 2012 to December 2015. We investigated clinical background factors associated with success, failure, and self-interruption of H pylori eradication therapy: patients' age, gender, first- or second-line treatment, reasons for receiving gastroenterological endoscopic examination, method of drug administration, and attending physicians' age and their specialties.

RESULTS

There were 369 patients (208 females, 161 male), with a mean age of 59 years (range 30-88 years). The middle-aged group (50-69 years) was associated with successful eradication therapy compared with the young group (30-49 years). The elderly group (>70 years) was associated with eradication therapy failure compared with the middle-aged group. The young group was associated with self-interruption of eradication therapy. There was a marginally significant association between male patients and self-interruption. Older attending physicians (>50 years) were also associated with failure compared with younger physicians. There was no difference in outcome of eradication therapy between generalists and gastroenterology specialists.

CONCLUSION

We have identified clinical factors associated with success, failure, and self-interruption of H pylori eradication therapy in a primary care setting.

Molecular diagnosis of Helicobacter pylori infection in gastric biopsies: Evaluation of the Amplidiag® H. pylori + ClariR assay

BACKGROUND

Adapted treatments for Helicobacter pylori infection, guided by determining antimicrobial resistance, are associated with high eradication rates. We evaluated the performance of the Amplidiag^® H. pylori + ClariR PCR assay (Amplidiag^® ) for detecting H. pylori and its clarithromycin resistance from gastric biopsies taken during endoscopy in comparison to culture and our "in-house" PCR.

MATERIALS AND METHODS

A total of 127 gastric biopsies were analyzed (98 adults; 29 children). Culture, PCR Amplidiag^® , and in-house PCR were performed in parallel. The in-house PCR combined amplification and sequencing of a 267-bp fragment of the H. pylori 23S rRNA gene. Discrepancies were controlled by amplification of glmM gene.

RESULTS

For detection of H. pylori, Amplidiag^® and the in-house PCR were concordant in 118 of 127 of cases: 66 negative and 52 positive. Discrepancies were observed in nine cases, all with low bacterial load: Amplidiag^® did not detect seven biopsies positive on in-house PCR but detected two positive biopsies that were negative on in-house PCR. Among the 19 of 52 (36%) H. pylori cases resistant to clarithromycin, only four biopsies with mixed populations exhibited discordant results between the two PCR methods. The A2142T mutation was not detected by Amplidiag^® . With the in-house PCR and amplified glmM gene as the reference method, the sensitivity and specificity of Amplidiag^® was 88.5% (95% confidence interval 83-94.1) and 100%.

CONCLUSION

This study demonstrated the high sensitivity of the PCR-based Amplidiag^® H. pylori test, especially with low H. pylori load, and the probability of its clarithromycin resistance analysis. For clinical use, a well-designed trial with a large scale of samples may still be needed.

Rate and predictive factors of Helicobacter pylori recurrence: Analysis of a screening cohort

BACKGROUND/AIM

The aim of the study was to identify the recurrence rate of Helicobacter pylori after successful eradication in an endemic area and investigate baseline and clinical factors related to the recurrence.

PATIENTS AND METHODS

H. pylori infected patients from a screening cohort of National Cancer Center between 2007 and 2012 were enrolled in the study. A total of 647 patients who were confirmed to be successfully eradicated were annually followed by screening endoscopy and rapid urease test. Median follow-up interval was 42 months. Annual recurrence rate of H. pylori was identified. Demographics, clinical factors, and endoscopic findings were compared between H. pylori recurrence group and persistently eradicated group (control group).

RESULTS

H. pylori recurrence was observed in 21 (3.25%) patients. Its annual recurrence rate was 0.91% (1.1% in males and 0.59% in females). Mean age was higher in the recurrence group than that in the control group (55.9 vs 50.7, P = 0.006). Median follow-up was shorter in the recurrence group than that in the control group (34 vs. 42.5 months, P = 0.031). In multivariate analysis, OR for H. pylori recurrence was 1.08 per each increase in age (P = 0.012). Adjusted ORs for H. pylori recurrence were 0.20 (95% CI: 0.06-0.69) and 0.25 (95% CI: 0.08-0.76) in age groups of 50-59 years and less than 50 years, respectively, compared to the group aged 60 years or older.

CONCLUSION

H. pylori recurrence rate in Korea is very low after successful eradication. Advanced age is at increased risk for H. pylori recurrence. Thus, H. pylori treatment for patients who are under 60 years of age is more effective, leading to maintenance of successful eradication status.

Molecular characterization of Helicobacter pylori resistance to rifamycins

INTRODUCTION

Antibiotic resistance is a major contributing factor in treatment failure of Helicobacter pylori eradication. Rifabutin (RB) is a rescue treatment and rifampicin (RP) is used to screen RB resistance in vitro. The aim of this study was to evaluate the rate of rifamycins resistance and to determine the mutations in the rpoB gene conferring resistance to discuss the current break point.

METHODS

Antimicrobial susceptibility to RP was first determined by E-test for 1015 H. pylori isolates. RP and RB MICs were then determined by agar dilution method for strains with MIC of RP > 1 mg/L, and the rpoB gene was sequenced.

RESULTS

Overall, 54 of 1015 strains exhibited a RP MIC > 1 mg/L by agar dilution method. Among these 54 strains, 10 had MICs of RP > 4 mg/L and RB ≥ 1 mg/L. They all carried at least one mutation in the rpoB gene at codons 530, 538, 540, 525 in the RP resistance-determining region (RRDR). Implication of the mutation L547F was confirmed by site-directed mutagenesis experiment. In contrast, among the 44 H. pylori isolates with a MIC of RP comprised between 2 and 4 mg/L, only 4 of 44 (9%) strains exhibited a mutation in rpoB, but outside RRDR (codons 470, 499, 636, or 657). For 31 of 44 tested strains, the RB MICs were ≤0.064 mg/L.

CONCLUSION

These results suggest that H. pylori isolates should be classified as resistant to RP for MICs > 4 mg/L. We considered that the optimal cut off for RB was ≥0.125 mg/L. We report a new mutation responsible for rifamycins, resistance, L547F.

Reversibility of atrophic gastritis and intestinal metaplasia after Helicobacter pylori eradication - a prospective study for up to 10 years

BACKGROUND

Atrophic gastritis and intestinal metaplasia are premalignant conditions for gastric cancer. Their reversibility by Helicobacter pylori eradication remains controversial.

AIM

To evaluate the reversibility of atrophic gastritis and intestinal metaplasia by H. pylori eradication with long-term follow-up.

METHODS

598 subjects were prospectively enrolled and followed for up to 10 years. They were categorised as H. pylori-negative (n = 65), H. pylori non-eradicated (n = 91), and H. pylori-eradicated (n = 442). Histological assessment was performed for antrum and corpus by Sydney classification.

RESULTS

Histological follow-up was performed regularly at 1, 2, 3-4 and ≥5 years, with mean follow-up of 1.07 ± 0.21, 2.29 ± 0.83, 3.93 ± 1.02, and 6.45 ± 1.28 years, respectively. Atrophic gastritis in antrum and corpus gradually and significantly (both P < .05 for all timepoints) improved only in the H. pylori-eradicated group compared to that at baseline. Significant difference in atrophic gastritis between H. pylori-eradicated and H. pylori-negative groups disappeared from 1-year follow-up. Similarly, intestinal metaplasia in antrum and corpus improved significantly (both P < .05 for all timepoints) only in the H. pylori-eradicated group in comparison with that at baseline. Significant difference in intestinal metaplasia between H. pylori-eradicated and H. pylori-negative groups disappeared from ≥5 years of follow-up in the antrum and from 3 years of follow-up in the corpus.

CONCLUSION

H. pylori eradication may be a preventative strategy for intestinal-type gastric cancer by regression of atrophic gastritis and intestinal metaplasia.

Diagnosis of Helicobacter pylori recurrence: relapse or reinfection? Usefulness of molecular tools

BACKGROUND AND AIMS

Infection due to Helicobacter pylori causes many gastrointestinal diseases including peptic ulcers and gastric carcinoma. Their treatment and prevention depends on the successful eradication of H. pylori. However, even after a well-conducted treatment, H. pylori persists in about 10-30% of patients. Recurrent infections can correspond to relapse or to re-infection and require appropriate medical care. In this study, we explore retrospectively three clinical cases using molecular methods, and propose new guidelines for the diagnosis of recurrence.

MATERIAL AND METHODS

Ten colonies of H. pylori were selected from the primary culture of biopsy samples taken from the antrum and fundus for each patient. The genotype of each isolated colony was determined by analyzing the polymorphism of two housekeeping genes, hspA and glmM. The genome-wide composition of H. pylori strains was studied using in house macro-arrays designed.

RESULTS

Relapses were demonstrated by the stability of genotypes and the slight genetic variability of strains on macro-arrays. Two patients suffered from relapses, one and three years after H. pylori treatment. For the third patient, both the polymorphism of glmM and hspA genotypes and the diversity of CDSs identified on macro-arrays suggested that several episodes of re-infection occurred, 1-8 years after eradication.

CONCLUSION

For the three clinical cases, molecular methods allowed identifying the causes of recurrent infections. We suggest to study genotype to distinguish between relapse and re-infection in order to adapt the treatment and the follow-up of patients to the nature of recurrence.

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.

[Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition]

Since the Korean College of Helicobacter and Upper Gastrointestinal Research has first developed the guideline for the diagnosis and treatment of Helicobacter pylori infection in 1998, the revised guideline was proposed in 2009 by the same group. Although the revised guideline was made by comprehensive review of previous articles and consensus of authoritative expert opinions, the evidence-based developmental process was not applied in the revision of the guideline. This new guideline has been revised especially in terms of changes in the indication and treatment of H. pylori infection in Korea, and developed by the adaptation process as evidence-based method; 6 guidelines were retrieved by systematic review and the Appraisal of Guidelines for Research and Evaluation (AGREE) II process, 21 statements were made with grading system and revised by modified Delphi method. After revision, 11 statements for the indication of test and treatment, 4 statements for the diagnosis and 4 statements for the treatment have been developed, respectively. The revised guideline has been reviewed by external experts before the official endorsement, and will be disseminated for usual clinical practice in Korea. Also, the scheduled update and revision of the guideline will be made periodically.

Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition

The Korean College of Helicobacter and Upper Gastrointestinal Research first developed guidelines for the diagnosis and treatment of Helicobacter pylori (H. pylori) infection in 1998, and revised guidelines were proposed in 2009 by the same group. Although the revised guidelines were based on a comprehensive review of published articles and the consensus of expert opinions, the revised guidelines were not developed using an evidence-based process. The new guidelines presented in this study include specific changes regarding indication and treatment of H. pylori infection in Korea, and were developed through the adaptation process using an evidence-based approach. After systematic review of the literature, six guidelines were selected using the Appraisal of Guidelines for Research and Evaluation (AGREE) II process. A total of 21 statements were proposed with the grading system and revised using the modified Delphi method. After the guideline revisions, 11 statements about indication of test and treatment, four statements about diagnosis, and four statements about treatment of H. pylori infection were developed. The revised guidelines were reviewed by external experts before receiving official endorsement from the Korean College of Helicobacter and Upper Gastrointestinal Research, and disseminated to physicians and other medical professionals for use in clinical practice in Korea. The guidelines will continue to be updated and revised periodically.

Chronic tamoxifen use is associated with a decreased risk of intestinal metaplasia in human gastric epithelium

BACKGROUND

Intestinal metaplasia (IM), a premalignant lesion, is associated with an increased risk of gastric cancer. Although estrogen exposure, including tamoxifen, has been studied in correlation with gastric cancer, little has been investigated about its effects on IM.

AIMS

Therefore, we investigated whether chronic tamoxifen use was associated with the risk of IM in human stomach.

METHODS

We evaluated 512 gastric biopsies from 433 female breast cancer patients that underwent endoscopic gastroduodenoscopy (EGD) ≥6 months after breast surgery. Histopathological findings were scored according to the updated Sydney classification. Demographic and clinical characteristics were also included to identify predictive factors for IM.

RESULTS

In a multivariate logistic regression analysis, age at EGD (odds ratio [OR], 1.04; P = 0.002), biopsies from antrum (OR 2.08; P < 0.001), and Helicobacter pylori positivity (OR 1.68; P = 0.016) were significantly associated with an increased risk of IM, whereas chronic tamoxifen use (≥3 months) was associated with a decreased risk of IM (OR 0.59; P = 0.025). After stratifying by biopsy site, association between tamoxifen use and IM persisted for corpus (OR 0.42; P = 0.026) but not for antrum (OR 0.74; P = 0.327). In analysis limited to patients with follow-up EGD, chronic tamoxifen use also correlated with improved IM score compared to no tamoxifen use (improved, 77.8 vs. 22.2%; no change, 65.4 vs. 34.6%; worsened, 30.0 vs. 70.0%; P = 0.019).

CONCLUSIONS

This study suggests that chronic tamoxifen use can decrease the risk of IM in human stomach. The effect of tamoxifen is predominantly observed in the corpus.

IL-11 is a parietal cell cytokine that induces atrophic gastritis

BACKGROUND AND AIMS

IL-is important in gastric damage, mucosal repair and gastric cancer progression. We analysed IL-11 expression in H.pylori infected mouse stomach, the site of gastric IL-11 expression in mice and humans, and the effect of exogenous IL-11 on gastric mucosal homeostasis.

METHODS

IL-11 protein was localised in mouse and human stomach. The impact of chronic, exogenous IL-11 on normal mouse stomach was examined histologically and transcriptionally by microarray, confirmed by mRNA and protein analysis. Functional impact of IL-11 on gastric acid secretion was determined.

RESULTS

In mice infected with H.pylori, IL-11 was increased in fundic mucosa with temporal expression similar to IL-1b. IL-11 protein was localised predominantly to parietal cells in mouse and human stomach. Application of exogenous IL-11 to resulted in fundic parietal and chief cell loss, hyperplasia, mucous cell metaplasia and inflammation. Coincident with cellular changes were an increased gastric pH, altered parietal cell ultrastructure and altered gene expression, particularly genes involved in immune response and ion transport which could result in compromised acid secretion. We confirmed that a single dose of IL-11 effectively ablated the gastric response to histamine.

CONCLUSIONS

IL-11 is a parietal cell cytokine that blocks gastric acid secretion, likely via reducing expression of parietal cell ion transport genes, CCKb and histamine H2 receptors. IL-11 expression is increased in H. pylori infected mouse stomach and treatment of wild type mice with IL-11 induced changes in the gastric fundic mucosa reminiscent of chronic atrophic gastritis, a precursor to gastric cancer.

Quality of RCTs exploring Helicobacter pylori eradication for the prevention of gastric cancer and preneoplastic lesions

Randomized controlled trials (RCTs) are considered the gold standard for evaluating the efficacy of clinical interventions and developing evidence-based clinical practice guidelines; however, they can yield biased results when their methodology is less than rigorous, or their published reports fail to report key items. A number of RCTs have been carried out to explore the relationship between Helicobacter pylori eradication and gastric cancer, but their results remain controversial. In this article, we will comprehensively review searched medical electronic databases, and appraise the reporting and methodological quality of these relevant RCTs according to the Consolidated Standards of Reporting Trials 2010 statement and the Cochrane Handbook in order to learn about the internal and external validity of these RCTs.

Prevalence of upper digestive endoscopy and gastric histopathology findings in morbidly obese patients

CONTEXT: The prevalence of obesity has been increasing in modern society. Roux-en-y gastric bypass is a bariatric surgery that involves the exclusion of significant part of the stomach. Atrophy, intestinal metaplasia and gastric cancer have been associated with infection by Helicobacter pylori. OBJECTIVES: To evaluate the presence of endoscopy findings and histological changes in morbid obese patients for the presence of inflammatory cells, inflammatory activity, lymphoid hyperplasia, H. pylori infection, atrophy and intestinal metaplasia in the gastric mucosa. METHODS: Upper digestive endoscopy and gastric histopathological were studied in 126 obese patients in the preoperative evaluation for bariatric surgery. RESULTS: Upper digestive endoscopy abnormalities were diagnosed in 73/126 (57.9%) patients. In three patients (2.4%) the upper gastrointestinal endoscopy diagnosed gastric ulcer and one patient (0.8%) had duodenal ulcer. The histopathological from gastric biopsies of these obese patients showed 65.1% of mucosa inflammation, inflammatory activity in 50.0%, infection by H. pylori in 53.2%, lymphoid hyperplasia in 50.0% and atrophy and/or intestinal metaplasia in 16.7%. CONCLUSIONS: In present study, with routine preoperative upper gastrointestinal endoscopy and histopathological examination, were detected 57.9% patients with endoscopy abnormalities, high prevalence of infection by H. pylori (53%) and 16.7% of gastric atrophy and/or intestinal metaplasia.

Future candidates for indications of Helicobacter pylori eradication: do the indications need to be revised?

Since the discovery of Helicobacter pylori in 1982, the development of several treatment guidelines has allowed a consensus on the indications for H. pylori eradication. Beyond these currently accepted indications, including various upper gastrointestinal disorders and extragastric diseases, a significant amount of new information regarding H. pylori eradication is emerging. Certain types of acute gastritis, such as nodular gastritis, hypertrophic gastritis, Ménétrier's disease, hemorrhagic gastritis, and granulomatous gastritis are reversible after H. pylori eradication. Further, for chronic gastritis, closed-type atrophic gastritis and complete-type intestinal metaplasia appear to be more reversible after H. pylori eradication than open-type atrophic gastritis and incomplete-type intestinal metaplasia. Eradication can also be considered in subjects younger than 40 years who have a family history of gastric cancer and in subjects with long-term medications that might lead to bleeding (antiplatelet agents) or atrophy (proton pump inhibitors). Emerging evidence indicates that H. pylori eradication could be an effective treatment for some extragastric diseases that are unresponsive to conventional therapy. In such conditions, routine screening for eradication of H. pylori has not previously been recommended; a "test-and-treat" approach is suggested in the aforementioned situations. Given that H. pylori eradication is effective when the gastritis is reversible, future indications should be expanded to include acute gastric lesions that show marked improvement upon H. pylori eradication rather than just focusing on chronic gastric lesions. Future indications for H. pylori eradication should focus more on reversible lesions before preneoplastic conditions develop.

Reversal of atrophic body gastritis after H. pylori eradication at long-term follow-up

BACKGROUND

The effect of Helicobacter pylori treatment on the potential reversal of atrophic body gastritis (ABG) is controversial. Body atrophy reversal was evaluated in a cohort of H. pylori-negative and treated H. pylori-positive ABG patients.

METHODS

Observational long-term follow-up cohort study including 300 ABG patients with at least one follow-up gastroscopy with three biopsies from the antrum and three from the body performed no earlier than 1 year after diagnosis was included. H. pylori was diagnosed by Giemsa-stain and serology. H. pylori-positive patients (n = 192) were treated with bismuth-based triple regimen.

RESULTS

After a mean follow-up of 5.2 years, body atrophy reversal was observed in 42/300 patients (14%). Body atrophy reversal occurred more frequently in patients treated for H. pylori than in H. pylori-negative ones (21.3% vs 0.9%, p < 0.00001) and was observed between 2 and 8 years after treatment in 52% of cases. Predictive factors for body atrophy reversal at Cox-regression analysis were mild atrophy (HR 2.14; 95% CI 1.12-4.1), moderate-severe inflammation (HR 5.3; 95% CI 1.64-17.3), and absence of intestinal metaplasia (HR 2.4; 95% CI 1.2-4.8).

CONCLUSION

Body atrophy reversal was observed in about 20% of ABG patients treated for H. pylori infection, and about 50% of reversals occurred during long-term follow-up.

Screening test for anti-Helicobacter pylori activity of traditional Chinese herbal medicines

AIM

To evaluate the anti-Helicobacter pylori (H. pylori) activity of 50 traditional Chinese herbal medicines in order to provide the primary evidence for their use in clinical practice.

METHODS

A susceptibility test of water extract from 50 selected traditional Chinese herbal medicines for in vitro H. pylori Sydney strain 1 was performed with broth dilution method. Anti-H. pylori activity of the selected Chinese herbal medicines was evaluated according to their minimum inhibitory concentration (MIC).

RESULTS

The water extract from Rhizoma Coptidis, Radix Scutellariae and Radix isatidis could significantly inhibit the H. pylori activity with their MIC less than 7.8 mg/mL, suggesting that traditional Chinese herbal medicines have anti-inflammatory and antibacterial effects and can thus be used in treatment of H. pylori infection.

CONCLUSION

Rhizoma Coptidis, Radix Scutellariae and Radix isatidis are the potential sources for the synthesis of new drugs against H. pylori.

Eradication of Helicobacter pylori infection improved gastric mucosal atrophy and prevented progression of intestinal metaplasia, especially in the elderly population: a long-term prospective cohort study

BACKGROUND AND AIMS

It still remains controversial whether gastric mucosal atrophy and intestinal metaplasia are reversible after eradication of Helicobacter pylori infection. The aims of this study were to evaluate the histological changes in gastric mucosa after H. pylori eradication during long-term follow-up periods, and to verify the propriety of H. pylori eradication for the elderly population.

METHODS

Two hundred and forty-one patients with H. pylori infection and 84 cases more than 60 years old were classified as the elderly group. The mean follow-up period was 101 months. A series of endoscopic examinations with five-point biopsies were performed before and every year after H. pylori eradication. We evaluated the histological grades according to the Updated Sydney System. Statistical analysis was performed using the Wilcoxon signed rank test and the Mann-Whitney U-test, and P < 0.05 was considered to be statistically significant.

RESULTS

The atrophic grades improved only at the angle in the 5th year and at all points, except for the antrum, in the 10th year after H. pylori eradication. In the elderly group, the atrophic score improved in both the 5th and 10th year. However, improvement in the younger group was achieved only in the 10th year. The metaplastic score did not change in either the 5th or 10th year after H. pylori eradication in all patients.

CONCLUSION

Eradication of H. pylori infection improved gastric atrophy and prevented the progression of intestinal metaplasia in the elderly population during the long-term follow-up periods. H. pylori eradication for the elderly population is effective.

Guidelines for the management of Helicobacter pylori infection in Japan: 2009 revised edition

BACKGROUND

Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan.

MATERIALS AND METHODS

Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines.

RESULTS

Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori-associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy.

CONCLUSION

The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions.

Reinfection rate and endoscopic changes after successful eradication of Helicobacter pylori

AIM: To determine the long-term outcomes regarding reinfection with Helicobacter pylori (H. pylori) and endoscopic changes after successful H. pylori eradication.

METHODS: From June 1994 to January 2007, 186 patients (M:F = 98:88; mean age 50.0 ± 11.4 years), in whom H. pylori had been successfully eradicated, were enrolled. The mean duration of follow up was 41.2 ± 24.0 mo.

RESULTS: H. pylori reinfection occurred in 58 patients (31.2%). The average annual reinfection rate was 9.1% per patient year. No recurrence of peptic ulcer was detected at the follow up endoscopy. There were no significant differences between the H. pylori eradication regimens for the reinfection rate and no significant differences in endoscopic findings between the H. pylori-recurred group and the H. pylori-cured group.

CONCLUSION: The reinfection rate in Korea is 9.1% which represents a decreasing trend. There was no relationship between H. pylori infection status and changes in endoscopic findings. There was also no recurrence or aggravation of ulcers.

Genetic association of interleukin-1 haplotypes with gastritis and precancerous lesions in North Indians

BACKGROUND

We evaluated the association of functional variants of IL-1 genes with the development of gastritis and precancerous lesions, which are known to be influenced by inflammatory response against Helicobacter pylori.

METHODS

After upper gastrointestinal (GI) endoscopy, 120 patients with gastritis were tested for H. pylori infection using rapid urease test, modified Giemsa staining and IgG anti-CagA ELISA. All patients and 243 healthy controls were genotyped for IL-1B (-511 C/T) and IL-IRN (VNTR) genes using PCR-RFLP/PCR.

RESULTS

IL-1B: (-511 C/T) genotype/allele were not associated with gastritis. IL-1RN 1/2 genotype carriers had susceptibility to gastritis (p=0.025, OR=1.7). Individuals with the IL-1RN 1/1 genotype (p=0.05, OR=0.65) and IL-1B -511*T-IL-1RN *1 haplotype were at low risk for gastritis (p=0.043, OR=0.72). High secretor haplotype combinations (C1-/T2+, C1-T1+ and T1+/T2+) did not influence neutrophilic infiltration, glandular atrophy or intestinal metaplasia.

CONCLUSIONS

We identified that individuals with the IL-1RN 1/2 genotype had increased risk for gastritis. IL-1B -511*T-IL-1RN *1 (T1) haplotype carriers were at decreased risk for gastritis and no significant association was observed for precancerous lesions in North Indians.

The role of serum pepsinogen and gastrin test for the detection of gastric cancer in Korea

BACKGROUND AND AIM

This study was performed to determine whether serum pepsinogen (PG) and gastrin testing can be used to detect gastric cancer in Korea.

METHODS

Serum levels of PG I (sPGI) and sPGII, PG I/II ratios, and gastrin levels were measured in 1006 patients with gastroduodenal diseases including cancer. Follow-up tests were performed 1 year after Helicobacter pylori eradication.

RESULTS

sPGI and sPGII levels increased and PG I/II ratios decreased in line with the severity of activity, chronic inflammation, and the presence of H. pylori (p < .01). In contrast, sPGI levels and PG I/II ratios decreased in proportion with the severity of atrophic gastritis (AG)/intestinal metaplasia (p < .01). Gastrin levels were found to be correlated with chronic inflammation negatively in the antrum but positively in the corpus. H. pylori eradication reduced sPGI, sPGII, and gastrin levels, and increased PG I/II ratios to the levels of H. pylori-negative patients, and was found to be correlated with reductions in activity and chronic inflammation of gastritis. The sensitivity and specificity of a PG I/II ratio of < or = 3.0 for the detection of dysplasia or cancer were 55.8-62.3% and 61%, respectively. In addition, sPGI and sPGII levels of intestinal-type cancer were significantly lower than those of the diffuse type, respectively (p = .008 and p = .05, respectively). Gastric cancer risk was highest in the H. pylori-positive, low PGI/II ratio (< or = 3.0) group with an odds ratio of 5.52 (confidence interval: 2.83-10.77).

CONCLUSION

PG I/II ratio (< or = 3.0) was found to be a reliable marker for the detection of dysplasia or gastric cancer, especially of the intestinal type. This detection power of PG I/II ratio (< or = 3.0) significantly increased in the presence of H. pylori, and thus, provides a means of selecting those at high risk of developing gastric cancer in Korea.

Association of Toll-like receptor-4 (Asp299Gly and Thr399Ileu) gene polymorphisms with gastritis and precancerous lesions

A Toll-like receptor-4 (TLR-4) Asp299Gly and Thr399Ileu substitution reduces responsiveness to Helicobacter pylori (H. pylori) lipopolysaccharide. CagA+ strains of H. pylori are known to be associated with gastroduodenal diseases. Therefore we aimed to evaluate association of TLR-4 substitutions and CagA seropositivity with gastritis and precancerous lesions in a northern Indian population. After upper gastrointestinal endoscopy, 130 rapid urease test (RUT)-positive patients with nonulcer dyspepsia (NUD) were included. Patients with NUD were also screened for H. pylori infection using modified Giemsa staining and anti-CagA IgG enzyme-linked immunoabsorbent assay. All patients and 200 asymptomatic control subjects were genotyped for TLR-4 substitutions using polymerase chain reaction-restriction fragment length polymorphism. We observed that frequencies of TLR-4 Asp299Gly variants were comparable between patients and control subjects, and also between positive and negative groups of precancerous lesions in patients. Frequencies of TLR-4 399Ileu allele (8% vs 3%, p = 0.008) and Asp299-Ileu399 haplotype (6.5% vs 3%, p = 0.022) were higher in patients than in control subjects at risk for gastritis (OR = 2.6 and 2.5, respectively). TLR-4 399Ileu allele carriers had higher risk for plasma cell infiltration (p = 0.023, OR = 10.6) that led to atrophy (p = 0.028, OR = 4.2) and intestinal metaplasia (p = 0.009, OR = 4.7). CagA positivity was more frequently associated with lymphoid follicle formation (p = 0.033, OR = 2.53). In conclusion TLR-4 Thr399Ileu substitution may be a risk factor for gastritis and precancerous lesions. CagA positivity may be a risk factor for lymphoid follicle development but not for other precancerous lesions in a northern Indian population.

The long-term impact of Helicobacter pylori eradication on gastric histology: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori infection is a crucial factor in the multistep carcinogenic process of gastric cancer. In this process the gastric mucosa evolves through the stages of acute gastritis, chronic gastritis, gastric atrophy (GA), and intestinal metaplasia (IM) before developing gastric adenocarcinoma.

AIMS

The main aim of this study was to systematically review the long-term effects of H. pylori eradication on gastric histology (i.e. effects on GA and IM for both antrum and corpus) by meta-analyzing all relevant studies.

METHODS

Extensive English-language medical literature searches for human studies were performed through October 2006, using suitable key words. Pooled estimates [odds ratio (OR) with 95% confidence intervals (CI)] were obtained using random-effects model.

RESULTS

For antrum GA the pooled OR with 95% CI was 0.554 (0.372-0.825), p=0.004. For corpus GA the pooled OR was 0.209 (0.081-0.538), p<0.001. For antrum IM the pooled OR was 0.795 (0.587-1.078), p=0.14. For corpus IM the pooled OR was 0.891 (0.663-1.253), p=0.506.

CONCLUSION

The results showed significant improvement of GA, whereas improvement was not shown for IM.

Is the eradication of Helicobacter pylori a way to prevent gastric cancer?

Helicobacter pylori is a major pathogen of chronic gastritis and peptic ulcers, as well as type I carcinogenesis. Inflammation of gastric mucosa is improved after eradication of H. pylori. However, does eradication of H. pylori reverse atrophic gastritis and intestinal metaplasia, and therefore may it be a way to prevent gastric cancer? This paper reviews studies of the relationship between H. pylori and gastric cancer. It was concluded that eradication of H. pylori is a potential method to prevent gastric cancer, and that H. pylori should especially be tested for and treated in high-risk populations.