Seroprevalence of Helicobacter pylori in Korea: A multicenter, nationwide study conducted in 2015 and 2016

Korean Registry on the Current Management of Helicobacter pylori (K-Hp-Reg): Interim Analysis of Adherence to the Revised Evidence-Based Guidelines for First-Line Treatment

Background/Aims

The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H. pylori infection in Korea.

Methods

This interim report describes the adherence to the revised guidelines and their impact on first-line eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form.

Results

A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed. The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001).

Conclusions

The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Korean Gastric Cancer Association-Led Nationwide Survey on Surgically Treated Gastric Cancers in 2023

PURPOSE

Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023.

MATERIALS AND METHODS

The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys.

RESULTS

Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023. Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014. The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023. However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively.

CONCLUSIONS

The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Efficacy of Rifabutin-Based Helicobacter pylori Eradication Regimen in Korea With High Prevalence of Tuberculosis Infection

BACKGROUND

As the antibiotic resistance and treatment failure rates of Helicobacter pylori are rising, the need for rescue therapy with rifabutin for H. pylori eradication (HPE) is also increasing. Therefore, in this study, we investigated the efficacy, resistance status, and adverse events in patients receiving rifabutin-based HPE.

MATERIALS AND METHODS

Between January 2020 and December 2022, 3006 patients underwent esophagogastroduodenoscopy (EGD) with H. pylori culture tests. Of these, culture results were successfully obtained from 1792 patients, who were subsequently enrolled in our study. The medical records of these patients were retrospectively reviewed, and their clinical features and outcomes assessed.

RESULTS

Among the 1792 patients, 14 (0.8%) were rifabutin-resistant. A total of 665 (37.1%) patients had multidrug-resistant (MDR) H. pylori infections. Patients with rifabutin-resistant H. pylori infections had a significantly higher rate of tuberculosis treatment history (2.8% vs. 28.6%, p < 0.001) and MDR H. pylori infections (49.6% vs. 85.7%, p < 0.001) than those in the rifabutin-susceptible H. pylori group. Among the 45 patients who received the rifabutin-based HPE regimen, 44 (97.8%) had MDR H. pylori infection, and 35 (77.8%) underwent rifabutin-based HPE as a third-line treatment or beyond. A total of 31 (68.9%) showed successful eradication. Nineteen (42.2%) patients experienced at least one symptom of adverse events; however, the severity of side effects was mild, and no patient discontinued treatment because of this.

CONCLUSIONS

The rifabutin-based HPE regimen could be an effective and safe treatment method. It is particularly considered a viable therapeutic option for patients who require HPE but have previously failed to respond to multiple HPEs.

Comparison of GastroPanel® and GENEDIA® in Diagnosing Helicobacter pylori Infection and Gastric Lesions

Serological tests for Helicobacter pylori needs local validation as the diagnostic accuracy may vary depending on the prevalence of H. pylori. This study examined the diagnostic performance of two ELISA, GastroPanel® (GastroPanel ELISA; Biohit Oyj) and GENEDIA® (GENEDIA® H. pylori ELISA, Green Cross Co.) in Korean population. One thousand seventy seven patients who visited for esophagogastroduodenoscopy between 2013 and 2023 were prospectively enrolled, and serum samples from the subjects were tested using both GastroPanel® and GENEDIA®. The two tests were compared for their diagnostic accuracy in detecting atrophic gastritis (AG), intestinal metaplasia (IM), gastric adenoma (GA), and gastric cancer (GC), and the positivity rates by age and sex were observed. There was substantial correlation (Pearson coefficient [r] = 0.512, P < 0.001) and agreement (Cohen's Kappa coefficient [κ] = 0.723, P < 0.001) between the results obtained using GastroPanel® and GENEDIA®. The test results from the two kits did not match perfectly with a discrepancy observed in approximately 16% of cases, that 67 subjects were positive only on GENEDIA® while 75 subjects were positive only on GastroPanel®. The area under receiver operating characteristic curve for AG, IM, GA, and GC using GastroPanel® were 0.666, 0.635, 0.540, and 0.575, while the results tested using GENEDIA® were 0.649, 0.604, 0.553, and 0.555, respectively, without significant difference between the two results. GastroPanel® and GENEDIA® showed similar performance in terms of diagnostic accuracy; but the test results did not match perfectly. A large-scale validation study in Koreans is needed.

Cancer mortality predictions for 2024 in selected Asian countries and Australia with focus on stomach cancer

INTRODUCTION

We estimated cancer mortality figures in five major Asian countries and Australia for 2024, focusing on stomach cancer, a leading cause of cancer-related deaths in Eastern Asia.

METHODS

We computed country- and sex-specific annual age-standardized rates (ASRs) for total cancers and the 10 most common cancer sites, using WHO and the United Nations Population Division databases from 1970 to 2021 or the latest available year. We predicted figures for 2024 and estimated the number of avoided cancer deaths in 1994-2024.

RESULTS

All cancers combined ASR declined between 2015-2019 and 2024 across considered countries and sexes. In 2024, the lowest predicted male rate is in the Philippines (75.0/100 000) and the highest in Australia (94.2/100 000). The Republic of Korea is predicted to have the lowest female ASR (42.1/100 000) while the Philippines the highest (74.5/100 000). Over the last three decades, 121 300 deaths were estimated to be avoided in Hong Kong SAR, 69 500 in Israel, 1 246 300 in Japan, 653 300 in the Republic of Korea, 303 300 in Australia, and 89 700 among Philippine men. Mortality from stomach cancer has been decreasing since 1970 in all considered countries and both sexes. Significant decreases are at all age groups Male rates remain, however, high in Japan (8.7/100 000) and the Republic of Korea (6.2/100 000).

CONCLUSION

Declining cancer mortality is predicted in the considered countries, notably reducing stomach cancer burden. Stomach cancer, however, remains a major public health issue in East Asia.

Factors associated with gastric and duodenal neuroendocrine tumors: A multicenter case-control study

BACKGROUND AND AIMS

The incidence of gastric and duodenal neuroendocrine tumors (GNET and DNET, respectively) is increasing, however associated factors of these diseases are not well known. Here, we investigated the factors associated with GNET and DNET.

METHODS

Patients with GNET and DNET presenting at eight tertiary referral centers between 2001 and 2020 were included and compared with healthy controls who underwent upper endoscopic screening. Clinical factors and laboratory data were analyzed to determine associated factors of GNET and DNET.

RESULTS

Overall, 396 patients with GNET and 193 patients with DNET were included and compared with 1725 healthy controls. Multivariate analysis showed that age (odds ratio [OR] 0.98), diabetes (OR 1.72), hypertension (OR 1.97), low serum high-density lipoprotein cholesterol (HDL-C) levels (OR 2.54), and past/present H. pylori infection (OR 1.46) were significantly associated with GNET. In contrast, DNET was significantly associated with diabetes (OR 1.80), hypertension (OR 1.68), low serum HDL-C levels (OR 2.29), and past/present H. pylori infection (OR 5.42). In the sex-based subgroup analysis in GNET, current smoking was strongly associated in women (OR 9.85), but not in men.

CONCLUSIONS

This study identified several common metabolic factors associated with GNET and DNET. Additionally, some factors had sex-specific associations.

The impact of physical disability on the risk of gastric cancer incidence in elderly patients with diabetes: a focus on regional disparity

PURPOSE

Elderly patients with type 2 diabetes mellitus (T2DM) may have a higher risk of physical disability. This study investigated the incidence of gastric cancer according to physical disability status in elderly patients with T2DM.

METHODS

The National Health Insurance Service claims data were used. A total of 76,162 participants aged 60 years or above, diagnosed with T2DM, were included. The association between physical disability status and gastric cancer incidence was evaluated using the Cox regression analysis. Additionally, subgroup analysis was performed according to region.

RESULTS

A total of 9,154 (12.0%) individuals had physical disability. Gastric cancer incidence was more common in participants with physical disability (3.3%) than those without (2.4%). A higher risk of gastric cancer incidence was found in elderly T2DM patients with physical disability (Hazard Ratio (HR) 1.18, 95% Confidence Interval (95% CI) 1.04-1.34). Such tendencies were maintained regardless of region, although the effect of physical disability status on gastric cancer incidence was particularly significant in individuals residing in non-metropolitan areas (HR: 1.19, 95% CI: 1.01-1.40).

CONCLUSION

Elderly patients with T2DM who had physical disability showed a higher risk of gastric cancer incidence. The findings suggest a need to monitor elderly T2DM patients with disability as they may be susceptible to difficulties in accessing cancer-related healthcare.

Identification of Potential Genomic Alterations Using Pan-Cancer Cell-Free DNA Next-Generation Sequencing in Patients With Gastric Cancer

Background

Molecular cancer profiling may lead to appropriate trials for molecularly targeted therapies. Cell-free DNA (cfDNA) is a promising diagnostic and/or prognostic biomarker in gastric cancer (GC). We characterized somatic genomic alterations in cfDNA of patients with GC.

Methods

Medical records and cfDNA data of 81 patients diagnosed as having GC were reviewed. Forty-nine and 32 patients were tested using the Oncomine Pan-Cancer Cell-Free Assay on the Ion Torrent platform and AlphaLiquid 100 kit on the Illumina platform, respectively.

Results

Tier I or II alterations were detected in 64.2% (52/81) of patients. Biomarkers for potential targeted therapy were detected in 55.6% of patients (45/81), and clinical trials are underway. ERBB2 amplification is actionable and was detected in 4.9% of patients (4/81). Among biomarkers showing potential for possible targeted therapy, TP53 mutation (38.3%, 35 variants in 31 patients, 31/81) and FGFR2 amplification (6.2%, 5/81) were detected the most.

Conclusions

Next-generation sequencing of cfDNA is a promising technique for the molecular profiling of GC. Evidence suggests that cfDNA analysis can provide accurate and reliable information on somatic genomic alterations in patients with GC, potentially replacing tissue biopsy as a diagnostic and prognostic tool. Through cfDNA analysis for molecular profiling, it may be possible to translate the molecular classification into therapeutic targets and predictive biomarkers, leading to personalized treatment options for patients with GC in the future.

Antibiotic Resistance of Helicobacter pylori: Mechanisms and Clinical Implications

Helicobacter pylori is a pathogenic bacterium associated with various gastrointestinal diseases, including chronic gastritis, peptic ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. The increasing rates of H. pylori antibiotic resistance and the emergence of multidrug-resistant strains pose significant challenges to its treatment. This comprehensive review explores the mechanisms underlying the resistance of H. pylori to commonly used antibiotics and the clinical implications of antibiotic resistance. Additionally, potential strategies for overcoming antibiotic resistance are discussed. These approaches aim to improve the treatment outcomes of H. pylori infections while minimizing the development of antibiotic resistance. The continuous evolution of treatment perspectives and ongoing research in this field are crucial for effectively combating this challenging infection.

Mucosal Immunity Related to CD8+ T Lymphocytes in Children with Helicobacter pylori Gastritis

Purpose

We investigated the role of CD8+T cells as host immune factors in pediatric patients with Helicobacter pylori gastritis.

Methods

Gastric mucosal tissue and blood samples were collected from 39 children, including 11 children with H. pylori infection and 28 children as controls. Anti-CD8 and anti-T-bet antibodies were used for immunohistochemistry of the gastric mucosa. For the cell surface and intracellular staining, peripheral blood mononuclear cells were stained with anti-IL7Rα, anti-CX3CR1, anti-CD8, anti-T-bet, and anti-IFN-γ antibodies. Cytokines of sera such as tumor necrosis factor alpha (TNF-α) and CX3CL1 were analyzed using enzyme- linked immunosorbent assay (ELISA).

Results

In the immunohistochemistry of gastric mucosa, the frequency of CD8+ and T-bet+ T cells cells was higher in the H. pylori-positive group than in the control group (26.9± 7.8% vs. 16.9±3.3%, p<0.001; 5.0±2.5% vs. 2.2±0.7%, p=0.001). Between the control and H. pylori-positive groups, the frequency of IL-7RαlowCX3CR1+ CD8+ and T-bet+ INF-γ+ CD8+ T cells were not significantly different between surface and intracellular staining, respectively (40.4±24.0% vs. 38.2±17.8%, p=0.914; 40.4±24.0% vs. 38.2±17.8%, p=0.914). In the ELISA, no significant differences in TNF-α and CX3CL1 concentrations were observed between the control and H. pylori-positive groups (34.3±12.1 pg/mL vs. 47.0±22.6 pg/mL, p=0.114/0.5± 0.1 pg/mL vs. 0.5±0.1 pg/mL, p=0.188).

Conclusion

CD8+ T and Th1 cells, which secrete IFN-γ, might play important roles in the mucosal immunity of the stomach in children with H. pylori infection.

Sero- and Feco-Prevalence of Helicobacter pylori Infection and Its Associated Risk Factors among Adult Dyspeptic Patients Visiting the Outpatient Department of Adet Primary Hospital, Yilmana Densa District, Northwest Ethiopia

Background

Most gastric cancers in the world are attributed to Helicobacter pylori (H. pylori) infections. The prevalence of H. pylori infection is influenced by socioeconomic status, hygiene, and lifestyle of the population. This study aimed to assess sero- and feco-prevalence of H. pylori infections and its associated risk factors among adult dyspeptic patients visiting the outpatient department of Adet Primary Hospital, Yilmana Densa District, northwest Ethiopia.

Methods

A hospital-based cross-sectional study was conducted from February 10, 2022 to April 10, 2022. The study participants were selected using a systematic random sampling technique. The data were collected by pretested questionnaires. Blood and stool specimens were collected from each patient for antibody and H. pylori antigen tests, respectively. The data were analyzed using Statistical Package for Social Science (SPSS) version 26.0. A logistic regression model was used to assess the strength of association between H. pylori positivity and risk factors.

Results

The sero- and feco-prevalence of H. pylori infection was 62% and 51.1%, respectively. In those patients who had a positive result with either the antibody (Ab) or antigen (Ag) test, rural residence (AOR = 5.55; 95% CI: 2.34-13.14; p < 0.001), alcohol consumption (AOR = 12.34; 95% CI: 2.29-66.51; p=0.003), having no awareness about H. pylori transmission (AOR = 4.76; 95% CI: 1.86-12.15; p=0.001), using pond/river as a source of drinking water (AOR = 5.22; 95% CI: 1.91-14.27; p=0.001), and open field defecation (AOR = 4.19; 95% CI: 1.67-10.52; p=0.002) were the explanatory risk factors significantly associated with H. pylori infection.

Conclusion

This study showed that the prevalence of H. pylori infection was very high. Most cases of gastric cancers are ascribed to H. pylori infection. Therefore, education should be given to communities so as to increase their awareness of the infection and the associated major explanatory risk factors identified in the present study.

Risk of upper gastrointestinal cancer and death in persons with negative screening results: results from the National Cancer Screening Program in South Korea

BACKGROUND

The Korea National Cancer Screening Program (KNCSP) offers upper endoscopy or upper gastrointestinal series (UGIS) biannually for people aged ≥ 40 years. This study aimed to assess the effect of negative screening results on the incidence of and mortality from upper gastrointestinal (GI) cancer.

METHODS

A population-based retrospective cohort of 15,850,288 men and women was constructed using data from 3 national databases. The participants were followed until the end of 2017 for data on cancer incidence and in 2019 for data on the vital status. Cox proportional hazard model with time-varying exposure was used to assess the association.

RESULTS

By the end of the follow-up period, 230,783 upper GI cancer cases and 99,348 upper GI cancer deaths were recorded. Negative gastric cancer screening was significantly associated with a lower risk of upper GI cancer in both UGIS (adjusted hazard ratio [aHR] = 0.81, 95% CI = 0.80-0.82) and upper endoscopy (aHR = 0.67, 95% CI = 0.67-0.68) groups. The HRs for upper GI mortality were 0.55 (95% CI = 0.54-0.56) and 0.21 (95% CI = 0.21-0.22) for the UGIS and upper endoscopy groups, respectively. The most significant reductions in the risk of upper GI cancer (UGIS: aHR = 0.76, 95% CI = 0.74-0.77; upper endoscopy: aHR = 0.60, 95% CI = 0.59-0.61) and death (UGIS: aHR = 0.54, 95% CI = 0.52-0.55; upper endoscopy: aHR = 0.19, 95% CI = 0.19-0.20) were observed among individual aged 60-69 years.

CONCLUSION

Negative screening cases, especially in upper endoscopy of the KNCSP, were associated with an overall reduction in the risk of and mortality from upper GI cancer.

Descriptive Analysis of Gastric Cancer Mortality in Korea, 2000-2020

PURPOSE

This study aimed to examine secular trends, age-period-cohort effects, and geographical differences in gastric cancer (GC) mortality in Korea.

Materials and Methods

Using cause of death data from the Korean Statistical Information Service for GC from 2000 to 2020, we calculated average annual percentage changes (AAPCs) in the age-standardized mortality of GC in 17 cities and provinces through joinpoint regression. Decomposition of age, period, and cohort effects on GC mortality were elucidated by applying a log-linear model and an intrinsic estimate method. Spatial patterns and the degree of spatial clustering in 250 administrative regions were explored via Moran's I statistics. Stratification by sex was performed for all analyses.

RESULTS

The age-standardized mortality of GC per 100,000 persons declined from 29.0 in 2000 to 7.9 in 2020 (AAPC, -6.28%). Age-period-cohort analyses of GC mortality showed a downward trend among five-year age groups from age 20-89 years across five-year periods from 2005-2020 and five-year birth cohorts from 1920-2000. Overall, the younger birth cohort showed lower mortality rates than the older cohort within the same period. In 2020, clusters of high GC mortality were observed in the central area for men (Chungcheongbuk, Jeollabuk, Gyeongsangbuk, and Gyeongsangnam) and in the eastern area for women (Gyeongsangbuk).

CONCLUSION

This study identified a downward trend in GC mortality among men and women from 2000 to 2020 in Korea. This trend was mainly attributed to birth cohort rather than period effects. Spatial analysis showed high GC mortality in the Chungcheong and Gyeongsangbuk areas.

Effectiveness of 7-day triple therapy with half-dose clarithromycin for the eradication of Helicobacter pylori without the A2143G and A2142G point mutations of the 23S rRNA gene in a high clarithromycin resistance area

BACKGROUND

Tailored therapy has been widely used for patients with Helicobacter pylori (H. pylori) infection in South Korea. Herein, we evaluated the treatment outcomes of tailored clarithromycin-based triple therapy (TT) in patients infected with H. pylori.

METHODS

We enrolled 460 patients without A2142G and A2143G point mutations by dual priming oligonucleotide-based polymerase chain reaction who had taken TT and undergone the urease breath test to evaluate eradication in clinical practice. Eradication rates according to the treatment duration and dose of clarithromycin were analyzed.

RESULTS

Among 460 patients (164 women, median age 63.0 years), 250 patients underwent TT with full-dose clarithromycin (TT-full CLA), and 216 patients underwent TT with half-dose clarithromycin (TT-half CLA). The eradication rates were 88.0% (220/250) in patients with TT-full CLA and 85.2% (179/210) in patients with TT-half CLA. In 250 patients with TT-full CLA, the eradication rates were 86.8% (33/38) in patients with 7-day TT-full CLA and 88.2% (187/212) in patients with 10-day or 14-day TT-full CLA (P = 0.788). In 210 patients with TT-half CLA, the eradication rates were 84.2% (139/165) in those with a 7-day TT-half CLA and 88.9% (40/45) in those with a 10-day or 14-day TT-half CLA (P = 0.436).

CONCLUSION

For patients with H. pylori infection without A2142G and A2143G point mutations by DPO-PCR in clinical practice, treatment extension above 7-day TT with full CLA did not improve the eradication rates. Future studies on the treatment outcomes of TT-half CLA considering effectiveness and compliance are warranted.

Association between alcohol consumption, cigarette smoking, and Helicobacter pylori infection in Iraqi patients submitted to gastrointestinal endoscopy

Objective: The aim of this paper was to assess the prevalence and association between H. pylori infection and alcohol, or cigarette use among Iraqi patients.

Methods: 115 individuals needed upper gastrointestinal endoscopies in total. Reverse transcription polymerase chain reaction (RT-PCR), urea breath test, rapid urease test, CagA-IgG, and culture were all used to confirm H. pylori infection. The information on alcohol consumption, smoking, sex, and age was collected using a standard questionnaire.

Results: The gold standard test, RT-PCR, was used to detect H. pylori infection in 81 (70.4%) of patients. H. pylori infection was not affected by age (OR: 0.976; CI: 95% (0.944-1.009; P > 0.05), sex (OR: 1.26, 95% CI: 0.57–2.75; P > 0.05), or alcohol intake (OR: 0.293; CI: 95% (0.081-1.058; P > 0.05) according to the binary logistic regression analysis. Additionally, there was a considerable inverse association between smoking and H pylori infection (OR: 0.094; CI: 95% (0.025-0.352; P < 0.05). According to binary logistic regression analysis, both smoking (OR: 0.036; CI: 95% (0.007-0.182; P < 0.05) and alcohol intake (OR: 0.179; CI: 95% (0.041-0.988; P < 0.05) were inversely and significantly related with H. pylori illness whereas H. pylori infection did not alter with age (OR: 1.001; CI 95% (0.959-1.044; P > 0.05) in the male subgroup.

Conclusions: According to the study, males who smoke and drink are more likely to have H. pylori infections. Furthermore, there was no positive association between age and H. pylori infection.

Prevalence of Helicobacter pylori Virulence Genes and Their Association with Chronic Gastritis in Beijing, China

Helicobacter pylori is closely related to chronic gastritis. The aim of the study was to investigate the correlation between H. pylori virulence genes and chronic gastritis in order to determine the pathogenic role of H. pylori virulence genes in chronic gastritis. Gastric mucosal tissues were obtained from 142 patients with chronic gastritis at three Beijing hospitals. The presence of virulence genes was determined by polymerase chain reaction (PCR) from H. pylori DNA. Multilocus sequence typing (MLST) and a phylogenetic tree were performed to characterize the overall genetic diversity. 91 new sequence types were identified by MLST in this study, and all strains showed high genetic diversity. The H. pylori isolates were divided into three types: hspEAsia strains (61 strains), hpEurope strains (15 strains), and mixed strains (16 strains). Some virulence genes were found to be significantly different between strains. The highest positive rates were found for dupA in chronic atrophic gastritis (AG), iceA1 in chronic non-atrophic gastritis with erosions, and iceA2 in chronic non-atrophic gastritis. The presence of dupA was found to be inversely related to the risk of AG. The H. pylori strains display high genetic diversity. Some virulence genes were found to be significantly different between diseases. The detection of various virulence genes is critical for screening high-risk populations for precancerous lesions and for the early prevention and control of gastric cancer.

Seroprevalence of Helicobacter pylori in human immunodeficiency virus-infected patients in a tertiary care hospital in Busan, South Korea

INTRODUCTION

Human immunodeficiency virus (HIV) infection management has recently become more successful. While the life expectancy of HIV-infected patients increased, the prevalence of non-acquired immunodeficiency syndrome-defining cancers, such as gastric cancer, also increased. Helicobacter pylori is associated with gastric cancer, the most common cancer and the fourth leading cause of cancer-related deaths in South Korea, which has the highest incidence of chronic gastric mucosa inflammation. Here, the seroprevalence and risk factors of H. pylori infection in Korean HIV-infected patients were evaluated.

METHODS

Three hundred HIV-infected patients attending the Outpatient Department of Pusan National University Hospital were prospectively enrolled from October 2018 to February 2019. Socio-demographic information was evaluated using questionnaires, and the serological status of H. pylori infection was analyzed for anti-H. pylori IgG antibodies.

RESULTS

The overall seropositivity of H. pylori was 32.7%, and 254 patients (84.7%) were male. The risk factors significantly associated with H. pylori seropositivity were: age of 40-49 years (odds ratio [OR] = 5.00; 95% confidence interval [CI] 1.30-19.17), age of 50-59 years (OR = 3.93; 95% CI 1.05-14.73), CD4 cell counts of 350-500/μL (OR = 4.23; 95% CI 1.53-11.65), CD4 cell counts ≥500/μL (OR = 2.78; 95% CI 1.15-6.72), and a weekly average alcohol consumption of at least one alcoholic beverage (OR = 1.78; 95% CI 1.05-2.99).

CONCLUSIONS

The seroprevalence of H. pylori is significantly associated with alcohol consumption, high CD4 cell count, and the age group of 40-59 years.

Current guidelines for Helicobacter pylori treatment in East Asia 2022: Differences among China, Japan, and South Korea

Helicobacter pylori (H. pylori) infection is highly prevalent in East Asia. The overall seroprevalence rate of H. pylori infection is 44.2% in China, 37.6%-43.2% in Japan, and 51.0% in South Korea. H. pylori can cause peptic ulcer disease and gastric cancer. East Asian countries have high rates of gastric cancer (age-standardized incidence rate: 20-30 per 100000). The Kyoto global consensus report emphasized that H. pylori gastritis should be considered the main cause for the development of gastric cancer. H. pylori treatment guidelines in China, Japan, and South Korea have recently been revised according to data from each of those countries. However, emerging antibiotic resistance is an important barrier to H. pylori eradication. The recommended H. pylori treatment regimens differ among those three East Asian countries. In this review, recent guidelines and up-to-date research on H. pylori treatment regimens from China, Japan, and South Korea are discussed.

Effect of gastric cancer screening on long-term survival of gastric cancer patients: results of Korean national cancer screening program

BACKGROUND

Gastric cancer (GC) is the most common cancer type in Korea. Korean National Cancer Screening Program (KNCSP) offer either upper gastrointestinal series (UGIS) or upper endoscopy biennially for adults aged ≥ 40. This study aimed to investigate the effect of cancer screening program on the long-term survival among GC patients.

METHODS

A nationwide population-based cohort was constructed based on three national databases. Overall, 46,701 GC patients diagnosed in 2008 and 2009 were included in our final analysis, and they were followed-up until the end of 2019. Survival curves were estimated using the Kaplan-Meier analysis with the log-rank test. Cox proportional-hazards regression analysis was used to report the hazard ratios (HRs) with 95% confidence intervals.

RESULTS

A total of 18,614/46,701 (39.9%) patients died during the median follow-up time of 10.5 years. The survival rate was higher among screened patients (65.8%) than never-screened patients (49.1%). Screened patients had 53% (HR, 0.47; 95% CI 0.45-0.48) lower risk of death from GC. The HRs of GC-specific mortality was lower in upper endoscopy group (HR = 0.36; 95% CI = 0.34-0.37) compared with UGIS (HR = 0.69; 95% CI = 0.67-0.73). Screened patients within 2 years prior to cancer diagnosis had a 35% reduction in risk of GC death. The figure decline to approximately 19% among patients with interval time since last screening of > 3 years.

CONCLUSIONS

Our findings emphasized the positive effects of GC screening on long-term GC patient survival. Also, patients screened by upper endoscopy or within 2 years before diagnosis had the best survival outcomes.

Health Status, Health-Related Factors and Work Environment in Korean Semiconductor Workers between 1984–2012: A Qualitative Study and a Cross-Sectional Study

Background: The environment of semiconductor facilities and exposure status has undergone changes. To identify changes in the work environment, health status, and risk factors, a qualitative and cross-sectional study was conducted. Methods: For the qualitative study, 38 current and retired workers who worked for at least 10-years were studied; for the cross-sectional study, 306 current workers who worked for at least 5-years based on JEM strata from Samsung Electronics were selected. Participants were asked about occupational history, cancer-relating risk factors during the working period, medical history, dietary habits for the past year, and hematological cancer-relating infection. Results: In the qualitative study, fabrication workers reported bladder cystitis, dermatitis in hands, gastritis/ulcer, and dry eye as frequent symptoms during work environment changes (manual to automatic process). In the cross-sectional study, there were no abnormal findings for infection biomarkers related to hematological cancer and spontaneous abortion, and their general health status was no different from the general population. Also, questionnaire feasibility was evaluated for the applicability in the prospective cohort. Conclusion: Current semiconductor workers’ health status was good compared to other populations. For lifelong health assessment, a cohort study is needed which considers health worker effects and current environments.

Risk factors for early gastric cancer: focus on Helicobacter pylori gastritis

Background: Gastric cancer is a global health problem, and the incidence and geographical distribution of different types of gastric cancer varies. Particularly, noncardiac gastric cancer is more prevalent in East Asia, Central and Eastern Europe, Latin America, and Africa. Infection with Helicobacter pylori, which was discovered in 1982, is a common cause of chronic gastritis, and the association between H. pylori infection and gastric adenocarcinoma is well established.Current Concepts: Gastric cancer is histologically divided into 2 types: intestinal and diffuse. H. pylori infection is considered as the main risk factor for the development of both types of gastric tumors. The most documented course of development of stomach cancer is following cellular metaplasia due to chronic inflammation, damage, and repair. Various molecular alterations caused by H. pylori are identified not only in gastric cancer but also in precancerous lesions. Recently, many studies have attempted to diagnose H. pylori gastritis and precancerous lesions using endoscopy.Discussion and Conclusion: Recent studies have shown that eradication therapy stabilizes or reduces the risk of developing gastric cancer. Therefore, the diagnosis and understanding of gastritis and precancerous lesions caused by H. pylori are the first step in the prevention of gastric cancer.

Current status of the gastric cancer screening program in Korea

Background: In 2019, gastric cancer was one of the most common cancers in Korea. As a secondary prevention strategy for gastric cancer, the cancer screening has been provided since 1999 by the National Cancer Screening Program every 2 years for adults aged ≥40 years.Current Concepts: The participation rates for gastric cancer screening program have increased from 7.4% in 2002 to 62.9% in 2019. Until 2017, either upper gastrointestinal series or endoscopy were recommended for screening method. Since 2018, endoscopy has become the preferred screening method and 89.1% of the participants underwent endoscopy in 2019. After the introduction of the screening program, the 5-year relative survival rates have markedly improved (43.9% between 1993 and 1995 vs. 77.5% between 2015 and 2019), and the proportion of early gastric cancer detection has increased (28.6% in 1995 vs. 63.6% in 2019). The risk of death from gastric cancer decreased by 47% in participants who had undergone endoscopy screening. Additionally, the gastric cancer screening program is cost-effective, and endoscopy-associated adverse events rarely occur.Discussion and Conclusion: With the implementation of the screening program, mortality due to gastric cancer has decreased owing to early detection. After the completion of ongoing clinical trials in the general population, the primary prevention strategy of Helicobacter pylori eradication should be considered to effectively reduce the incidence of gastric cancer. Further studies are also required to provide optimal screening interval according to the presence of risk factors including H. pylori infection and presence of gastric mucosal atrophy.

Helicobacter pylori infection and iron deficiency in non-elderly adults participating in a health check-up program

BACKGROUND/AIMS

Helicobacter pylori infection is presumably associated with iron deficiency and iron deficiency anemia (IDA). This study aimed to evaluate the relationship between H. pylori infection and the decline in iron stores in non-elderly adults during their health check-ups.

METHODS

We identified a total of 1,069 subjects who were tested for iron, ferritin, and total iron-binding capacity during their health check-ups, from January 2016 to May 2017. Of these, subjects who underwent endoscopy via rapid urease test and those aged 65 years or below were finally enrolled.

RESULTS

Overall, 281 subjects were enrolled, and 187 patients (66.5%) tested positive for H. pylori. The mean age was 36.1 years (range, 22 to 65), and 176 subjects (62.6%) were male. The mean levels of hemoglobin (14.1 ± 1.7 g/dL vs. 14.6 ± 1.4 g/dL, p = 0.019) and ferritin (121.7 ± 106.9 ng/mL vs. 151.8 ± 107.8 ng/mL, p = 0.027) in the H. pylori-positive group were significantly lower than those in the H. pylori-negative group. Iron deficiency (ferritin < 30 ng/mL) was more common in patients with H. pylori infection (p = 0.002). There was no significant difference in anemia (hemoglobin < 13 g/dL in men, < 12 g/dL in women) or IDA (anemia, ferritin < 10 ng/mL, and transferrin saturation < 16%) with H. pylori. Logistic regression analysis demonstrated that female sex (odds ratio, 197.559; 95% confidence interval, 26.461 to 1,475.015) and H. pylori infection (odds ratio, 3.033; 95% confidence interval, 1.216 to 7.567) were factors associated with iron deficiency.

CONCLUSION

H. pylori infection is associated with iron deficiency, suggesting a decline in iron stores among infected non-elderly adults.

Effect of Helicobacter pylori Eradication on Epigenetic Changes in Gastric Cancer-related Genes

It is known that gastric carcinogenesis results from the progressive changes from chronic gastritis to gastric atrophy, intestinal metaplasia, dysplasia, and invasive carcinoma. Several genetic and epigenetic alterations are involved in this process, and Helicobacter pylori (H. pylori) infection is believed to induce the initiation and progression of these steps. From an epigenetic point of view, H. pylori induces hypermethylation of genes involved in the development of gastric cancer and regulates the expression of various microRNAs (miRNAs). These H. pylori-related epigenetic changes are accumulated not only at the site of neoplasm but also in the adjacent non-cancerous gastric mucosa. Thereby, a state vulnerable to gastric cancer known as an epigenetic field defect is formed. H. pylori eradication can have an effective chemopreventive effect in gastric carcinogenesis. However, the molecular biological changes that occur in the stomach environment during H. pylori eradication have not yet been established. Several studies have reported that H. pylori eradication can restore infection-related changes, especially epigenetic alterations in gastric cancer-related genes, but some studies have shown otherwise. Simply put, it appears that the recovery of methylated gastric cancer-related genes and miRNAs during H. pylori eradication may vary among genes and may also differ depending on the histological subtype of the gastric mucosa. In this review, we will discuss the potential mechanism of gastric cancer prevention by H. pylori eradication, mainly from an epigenetic perspective.

Long-Term Clinical Outcomes of Gastric MALT Lymphoma: A Nationwide Multicenter Study in Korea

Background

Treatment recommendations for gastric mucosa-associated lymphoid tissue (MALT) lymphoma are based on case series and expert opinions. Only a few previous studies have focused on the long-term outcomes of gastric MALT lymphoma, especially according to stage.

Methods

Patients diagnosed with gastric MALT lymphoma from January 2000 to December 2018 at nine university hospitals in Korea were included. Clinical data of medical history, endoscopic features, histological diagnosis, results of Helicobacter pylori (H. pylori) testing, stage, treatment conditions, and outcomes were collected.

Results

A total of 1,163 patients was enrolled, and 97.6% (n=1,038) of patients were diagnosed as stage IE. 10-year overall survival (OS) for the entire population was 99.1% and was better for patients in stage IE compared with patients in stage III/IV (p=0.002). The 10-year OS for H. pylori-positive patients was better than that of H. pylori-negative patients (p=0.022). Multivariate analyses revealed initial stage III/IV as a prognostic factor associated with over-all survival.

Conclusion

The majority of gastric MALT lymphoma patients are diagnosed at an early localized stage in Korea. The overall survival rate of gastric MALT lymphoma is excellent and is associated with the initial stage of the disease.

Helicobacter pylori Eradication Therapy-associated Diarrhea

Eradication of Helicobacter pylori has contributed to the treatment of peptic ulcers and mucosa-associated lymphoid tissue lymphoma. Moreover, it has possibly decreased the prevalence of gastric cancer. However, eradication therapy is associated with various adverse effects, of which diarrhea is the most common. The incidence of diarrhea after eradication treatment varies from 8% to 48%. In particular, the incidence is higher in patients who receive first-line standard triple therapy compared with those who receive second-line therapy. Both antibiotics and proton pump inhibitors, components of eradication therapy, have short-term and long-term impacts on gut microbiota. The alterations of gut microbiota may not recover until 1 year after eradication therapy. Most cases of diarrhea that occur after eradication therapy are antibiotic-associated diarrhea caused by the destruction of the normal gut microbiota. In some cases, Clostridioides difficile-associated diarrhea occurs after eradication therapy. If bloody diarrhea occurs after eradication therapy and the Clostridioides difficile toxin is not detected, antibiotic-associated hemorrhagic colitis associated with Klebsiella oxytoca infection should be suspected. It is crucial to explain the possibility of diarrhea before initiating eradication therapy to increase compliance. Furthermore, probiotics may be administered to reduce diarrhea. If severe diarrhea or symptoms other than the usual antibiotic-associated diarrhea occur during or after eradication therapy, antibiotics should be discontinued. In addition, appropriate tests to determine the cause of diarrhea should be performed. This review summarizes the alteration of the gut microbiota, the causes of diarrhea after Helicobacter pylori eradication therapy, and its management.

Serum Helicobacter pylori antibody reactivity in seven Asian countries using an automated latex aggregation turbidity assay

BACKGROUND AND AIM

To determine the application range of diagnostic kits utilizing anti-Helicobacter pylori antibody, we tested a newly developed latex aggregation turbidity assay (latex) and a conventional enzyme-linked immunosorbent assay (E-plate), both containing Japanese H. pylori protein lysates as antigens, using sera from seven Asian countries.

METHODS

Serum samples (1797) were obtained, and standard H. pylori infection status and atrophy status were determined by culture and histology (immunohistochemistry) using gastric biopsy samples from the same individuals. The two tests (enzyme-linked immunosorbent assay and latex) were applied, and receiver operating characteristics analysis was performed.

RESULTS

Area under the curve (AUC) from the receiver operating characteristic of E-plate and latex curves were almost the same and the highest in Vietnam. The latex AUC was slightly lower than the E-plate AUC in other countries, and the difference became statistically significant in Myanmar and then Bangladesh as the lowest. To consider past infection cases, atrophy was additionally evaluated. Most of the AUCs decreased using this atrophy-evaluated status; however, the difference between the two kits was not significant in each country, but the latex AUC was better using all samples. Practical cut-off values were 3.0 U/mL in the E-test and 3.5 U/mL in the latex test, to avoid missing gastric cancer patients to the greatest extent possible.

CONCLUSIONS

The kits were applicable in all countries, but new kits using regional H. pylori strains are recommended for Myanmar and Bangladesh. Use of a cut-off value lower than the best cut-off value is essential for screening gastric cancer patients.

Prevalence and risk factors of Helicobacter pylori infection in Wuwei, a high-risk area for gastric cancer in northwest China: An all-ages population-based cross-sectional study

OBJECTIVE

This study aimed to determine the prevalence and risk factors of Helicobacter pylori infection across all age groups in Wuwei City, a high-risk area for gastric cancer in Northwest China.

METHODS

We conducted this study from 2016 to 2017 in an urban and a rural community in Wuwei City. Stool antigen tests targeted individuals aged 0 to 3 years old, and ¹³ C-urea breath tests targeted individuals aged above 3 years. We selected participants based on hierarchical cluster sampling. We assessed the association between variables and H. pylori infection based on logistic regression models.

RESULTS

Ultimately, the results of 2,163 participants (age: 0 to 77 years old) were included (1,238 minors and 925 adults) in the analysis. The overall prevalence of H. pylori infection was 35.6%. It increased with age, reaching the peak in the 30 to 39 age group, and then began to decline. In multivariate analysis, age was positively associated with prevalence of H. pylori infection, and factors negatively associated with the prevalence were drinking running water, the frequency of yoghurt consumption, and an annual household income of Renminbi (¥) 30,000-100,000 or 100,000 above. In the subgroup analyses, however, the same variables associated differently in different age groups. Additionally, we interestingly noticed that boarding, eating at school cafeterias over six times per week, and frequently drinking untreated water were independent predictors of H. pylori infection in junior and senior high school students.

CONCLUSION

The prevalence of H. pylori infection is moderate and closely associated with the socioeconomic conditions of Wuwei City, as well as the sanitary situations and dietary habits of the participants in the city. Boarding, eating at school, and drinking untreated water are the main factors explaining the rising infection rate in junior-senior high school students.

A Nationwide Cohort Study Shows a Sex-Dependent Change in the Trend of Peptic Ulcer Bleeding Incidence in Korea between 2006 and 2015

Background/Aims

The incidence of peptic ulcer disease has decreased in past decades; however, the trends in peptic ulcer bleeding (PUB) are inconsistent among regions. This study aimed to investigate the trends in PUB incidence and the effect of risk factors on PUB in Korea.

Methods

The records of patients hospitalized with PUB from 2006 to 2015 were retrieved from the Korean National Health Insurance Service Database. Standardized incidences of PUB were calculated, and the clinical characteristics such as age, sex, Helicobacterpylori infection, drug exposure, comorbidities, and mortality were obtained.

Results

In total, 151,507 hospitalizations with PUB were identified. The overall annual hospitalization rate was 34.98 per 100,000 person-years. The incidence of PUB showed no significant change from 2006 to 2008 and decreased from 2008 to 2015, with an annual change of –2.7% (p<0.05); however, this change was only significant in men. The incidence of PUB was higher in men than in women between 40 and 70 years old and higher in women than in men older than 80 years. From 2006 to 2015, the H. pylori infection rate increased significantly in patients with PUB; however, there was no significant change in exposure to nonsteroidal anti-inflammatory drugs or other drugs that increase the risk of PUB.

Conclusions

Over the past decade, the incidence of PUB has decreased in a sex-specific manner. There has been a decreasing trend in the H. pylori infection rate and no change in exposure to drugs that increase the risk of PUB in Korea.

Seven-day triple therapy is sufficient to eradicate infection caused by Helicobacter pylori without 23S rRNA point mutation

ABSTRACT

Tailored therapy based on dual priming oligonucleotide-based polymerase chain reaction (DPO-PCR) can be considered an alternative to overcome the low eradication rate in high clarithromycin-resistance areas. The triple therapy (TT) duration of the tailored approach in most studies was 7 days for patients without point mutation. However, recent western guidelines have recommended a treatment duration of 14 days. The aim of this study was to compare the success rate of 7 and 14 days of TT for eradicating Helicobacter pylori without point mutation, as determined by DPO-PCR.Between Feb 2016 and Feb 2019, medical records of patients who underwent DPO-PCR were reviewed. Patients without point mutation as determined by DPO-PCR were enrolled in this study. The eradication success rate and adverse events were evaluated.A total of 366 patients without A2142G and A2143G point mutation were enrolled. The success rates of 7-day and 14-day TT were 88.4% (168/190) and 85.9% (151/176) by intention to treat analysis (P = .453) and 90.8% (168/185) and 90.4% (151/167) by per-protocol analysis (P = .900), respectively. The adverse event rates showed no significant difference between the 2 groups.In patients without point mutation based on DPO-PCR results, 7-day TT is as effective as 14-day TT. Therefore, 7 days may be considered as a cost-effective treatment duration in Korea.

Implementation effect of institutional policy of EGD observation time on neoplasm detection

BACKGROUND AND AIMS

The observation time in EGD is associated with detection rate of premalignant or neoplastic lesions in the upper GI (UGI) tract. The aim of this study was to evaluate an institutional policy of EGD observation time on the detection rate of UGI neoplasms.

METHODS

From July 2017 to March 2019, all endoscopists were requested to comply with our institutional policy of spending more than 3 minutes of observation time in every screening EGD. Observation time was defined as the time from when the endoscope reached the duodenum to when it was withdrawn. We obtained a neoplasm detection rate (NDR) during this period and compared it with that of a baseline period from 2009 to 2015.

RESULTS

During the study period, 30,506 EGDs were performed. Mean subject age was 49.9 ± 10.5 years, and 56.5% were men. All endoscopists achieved an average EGD observation time of more than 3 minutes during this period. Mean observation time was 3:35 ± 0:50, which was significantly longer than the baseline (2:38 ± 0:21, P < .001). NDR was .33%, which was higher than the baseline (.23%, P < .001). Even after adjusting for subjects' age and gender, smoking history, and endoscopists' biopsy sampling rate, prolonged EGD observation time of more than 3 minutes increased the NDR of UGI neoplasms (odds ratio, 1.51; 95% confidence interval, 1.21-1.75).

CONCLUSIONS

This study provides evidence that implementing a protocol of a prolonged observation time could increase NDR. Observation time should be an important quality indicator of the EGD examination.

Multicenter, Randomized, Placebo-controlled Trial to Evaluate the Efficacy and Safety of a Controlled-release, Once-daily UIC201609/UIC201610 Combination Therapy for Functional Dyspepsia: Preliminary Study

Backgrounds/Aims

Functional dyspepsia is a disease involving a range of upper gastrointestinal symptoms derived from various pathophysiologies. Tablets containing a combination of rabeprazole and controlled-release (CR) mosapride were recently developed. To investigate a more effective treatment, this trial evaluated the efficacy and safety of UIC201609/UIC201610 as a preliminary study.

Methods

A multicenter, double-blind, randomized study was performed on 30 subjects. UIC201609/UIC201610 (combination of rabeprazole and CR mosapride) was the case group, and the two control groups were rabeprazole 10 mg once a day and mosapride 15 mg CR tablet once a day. As a primary efficacy endpoint of the study, the changes in the total score of eight items of the Nepean Dyspepsia Index-Korean version were analyzed at 2 weeks and 4 weeks. The outcomes regarding safety were collected.

Results

The total symptom score of Nepean Dyspepsia Index-Korean decreased in the rabeprazole single group (29.4±17.1), mosapride CR single group (33.4±15.6), and UIC201609/UIC201610 group (33.4±11.8) at 4 weeks without significant differences. On the other hand, the UIC201609/UIC201610 combination group showed more score reduction of pain in the upper abdomen, burning in the upper abdomen compared to each control group, but it did not reach statistical significance. No difference was found in safety analysis.

Conclusions

UIC201609/UIC201610 once daily showed some improvement in epigastric pain and dyspepsia in patients with functional dyspepsia, but there was no significance. Further study based on the advanced clinical trial design will be needed to confirm the efficacy of UIC201609/UIC201610 combination therapy in the future.

Salvage Regimens after Failure of Previous Helicobacter pylori Eradication Therapy: A Systematic Review and Meta-analysis

Background/Aims: As antibiotic resistance increases and new first-line therapies emerge, salvage therapies for <i>Helicobacter pylori</i> (<i>H. pylori</i>) eradication failures are becoming more common and complicated. This study aimed to systematically review overall salvage regimens after previous failure of <i>H. pylori</i> eradication.Materials and Methods: A systematic review of randomized clinical trials evaluating salvage therapies after previous <i>H. pylori</i> eradication failure was performed. A meta-analysis was conducted when an adequate number of studies suitable for grouping was found.Results: Overall, 36 studies with 77 treatment arms were identified, and they were highly heterogeneous regarding previously failed regimens and salvage regimens under comparison. Bismuth quadruple therapy after failure of standard triple therapy showed a pooled intention-to-treat (ITT) eradication rate of 75.5% (95% CI, 71.6~79.1%), and the rates were significantly higher with 14-day therapy than 7-day therapy by 9% (95% CI, 2~15%). Levofloxacin triple therapy after failure of standard triple therapy demonstrated a pooled ITT eradication rate of 73.3% (95% CI, 68.4~77.3%). In direct comparison, the two regimens were not significantly different in eradication rates. No study evaluated salvage regimens after the failure of bismuth or non-bismuth quadruple therapy.Conclusions: The current studies regarding salvage regimens are highly heterogeneous. Bismuth quadruple therapy and levofloxacin triple therapy may be a reliable option after failure of standard triple therapy, but the regional profile of antibiotic resistance should be considered. Further studies are needed for salvage regimens after failure of non-bismuth or bismuth quadruple therapy.

Role of Antimicrobial Susceptibility Testing before First-Line Treatment Containing Clarithromycin for Helicobacter pylori Eradication in the Clinical Setting

BACKGROUND

Checking Helicobacter pylori susceptibility tests in the clinical setting before first-line treatment is considered difficult. We compared susceptibility-guided therapy (SGT) with empirical therapy (ET) as a first-line treatment containing clarithromycin and investigated the eradication rate using antimicrobial susceptibility testing (AST).

METHODS

257 patients with H. pylori infection, with AST, performed before the eradication of clarithromycin-containing regimens were enrolled and divided into two groups: the SGT and ET groups.

RESULTS

Eradication rates in the SGT and ET groups were 85.4% and 58.4% (P < 0.01), respectively. In triple therapy (TT), eradication rates of the SGT and ET groups were 85.1% and 56.6% (P < 0.01), respectively. In sequential therapy (SET), eradication rates of the SGT and ET groups were 86.2% and 65.6% (P = 0.06), respectively. According to AST, TT had an eradication rate of 84.6% with strains susceptible to clarithromycin and amoxicillin and 11.1% with strains resistant to both. SET had an eradication rate of 89.5% with strains susceptible to clarithromycin, amoxicillin, and metronidazole, whereas it was 0% with strains resistant to clarithromycin and metronidazole.

CONCLUSIONS

SGT as first-line treatment improved eradication rates of TT and SET by 28.5 (P < 0.01) and 20.6 (P = 0.06) percent points, respectively, compared with ET.

The Prevalence of Multidrug Resistance of Helicobacter pylori and Its Impact on Eradication in Korea from 2017 to 2019: A Single-Center Study

Antimicrobial resistance is one of the major factors determining the efficacy of Helicobacter pylori eradication therapy. This study aimed to estimate the recent prevalence of multidrug resistance of H. pylori and its impact on eradication in Korea. A total of 174 patients were prospectively enrolled at Chung-Ang University Hospital from 2017 to 2019. H. pylori strains were isolated from the gastric body and antrum. The minimum inhibitory concentrations of antibiotics were determined by the serial twofold agar dilution method. Eradication results were reviewed and analyzed in connection with antibiotic resistance. The prevalence of H. pylori infection was 51.7% (90/174). The culture success rate was 77.8% (70/90). The resistance rates for clarithromycin, metronidazole, amoxicillin, tetracycline, levofloxacin, and moxifloxacin were 28.6% (20/70), 27.1% (19/70), 20.0% (14/70), 18.6% (13/70), 42.9% (30/70), and 42.9% (30/70), respectively. The multidrug resistance (resistance to two or more classes of antimicrobials) rate was 42.9% (30/70). Dual resistance to clarithromycin and metronidazole was confirmed in 8.6% (6/70). Eradication with a first-line treatment was successful in 75% (36/48), and those who received second-line treatment all achieved successful eradication. The rate of multidrug resistance is increasing, and standard triple therapy (STT) is no longer an acceptable first-line option for H. pylori eradication in Korea.

Guidelines for Nonvariceal Upper Gastrointestinal Bleeding

Nonvariceal upper gastrointestinal bleeding (NVUGIB) refers to bleeding that develops in the gastrointestinal tract proximal to the ligament of Treitz. NVUGIB requires hospitalization and is associated with significant morbidity and mortality. Although European and Asian-Pacific guidelines have been published, there have been no previous guidelines regarding management of NVUGIB in Korea. Korea has a high prevalence of Helicobacter pylori infections, and patients have easy accessibility to endoscopy. Therefore, we believe that guidelines regarding management of NVUGIB in Korea are essential. The Korean Society of Gastroenterology reviewed the recent evidence and recommends practical management guidelines on NVUGIB in Korea.

Alterations in Gastric Microbial Communities Are Associated with Risk of Gastric Cancer in a Korean Population: A Case-Control Study

Simple Summary

The gastric microbial community has been identified as a specific risk factor for the gastric cancer (GC) risk in recent molecular epidemiology studies. The equilibrium of the gastric microbial community and their functions are very important to keep a proper gastric related health. However, dysbiosis where there is an imbalance of the microbiome in gastric environment leads to several pathological conditions including GC. Thus, understanding how alterations in gastric microbial communities are associated with GC risk in large population-based studies is needed to implement possible preventive and curative strategies in the future. We derived a microbial dysbiosis index to observe the association with GC risk. Further, we predicted the microbial functions that are associated with GC risk. The findings of our study are important to understand certain pathogenic bacteria and their functions associated with GC risk. It might be helpful to develop novel preventive guidelines to prevent GC risk.

Abstract

Although the microbiome has a potential role in gastric cancer (GC), little is known about microbial dysbiosis and its functions. This study aimed to observe the associations between the alterations in gastric microbial communities and GC risk. The study participants included 268 GC patients and 288 controls. The 16S rRNA gene sequencing was performed to characterize the microbiome. Streptococcus_NCVM and Prevotella melaninogenica species were highly enriched in cases and controls, respectively. Those who were in the third tertile of P. melaninogenica showed a significantly decreased risk of GC in total (odds ratio (OR): 0.91, 95% confidence interval (CI): 0.38–0.96, p-trend = 0.071). Class Bacilli was phylogenetically enriched in cases, while phylum Actinobacteria, class Actinobacteria were related to the controls. The microbial dysbiosis index (MDI) was significantly higher for the cases compared with the healthy controls in the female population (p = 0.002). Females in the third tertile of the MDI showed a significantly increased risk of GC (OR: 2.66, 95% CI: 1.19-5.99, p-trend = 0.017). Secondary bile acid synthesis and biosynthesis of ansamycins pathways were highly abundant in cases and controls, respectively. Dysbiosis of gastric microbial communities is associated with an increased risk of GC specifically in females.

Adenocarcinoma and Neuroendocrine Collision Tumor in a Giant Gastric Hyperplastic Polyp

Screening esophagogastroduodenoscopy of a 65-year-old man revealed a 4.7-cm polypoid in the gastric high body. Clinical and laboratory findings, including serum gastrin level (460 pg/mL) and biopsy findings, were consistent with a diagnosis of type I neuroendocrine tumor (NET). Histologically, the mass consisted of dilated tortuous glands at the surface and grade 1 NET in deeper tissue. Some hyperplastic glands exhibited a transition to adenocarcinoma, which invaded the NET, simulating a "tumor in tumor" appearance. Next-generation sequencing revealed that the adenocarcinoma component harbored a TP53 mutation, whereas the NET component showed no pathogenic mutation. To our knowledge, this unusual collision of adenocarcinoma and NET within a single gastric hyperplastic polyp has not been previously described. This case suggests that large gastric hyperplastic polyps should be carefully examined because of the possibility of underlying NET and malignant transformation of surface epithelium.

Optimized diagnosis of Helicobacter pylori and tailored eradication therapy for preventing gastric cancer: a proposal for SHAKE strategy

INTRODUCTION

To decrease gastric cancer-related mortality, the Korean National Cancer Screening Program provides biennial screening gastroscopy to all individuals aged >40 years. However, a test-and-treat strategy of Helicobacter pylori for preventing gastric cancer has not been established.

AREAS COVERED

In this review, we present up-to-date results of endoscopic findings of H. pylori gastritis, optimal sites for H. pylori detection, gastric cancer risk assessment using serum pepsinogen, tailored eradication based on the antimicrobial resistance against H. pylori, and post-eradication surveillance.

EXPERT OPINION

Here we propose approaches to H. pylori diagnosis and treatment for preventing gastric cancer, termed 'Screening for H. pylori in Korea and Eradication (SHAKE)' strategy. This strategy consists of the following: (1) optimized H. pylori diagnosis, (2) individualized management based on the H. pylori infection status, and (3) tailored eradication therapy. H. pylori gastritis can be diagnosed by endoscopic observation of the gastric mucosal pattern at the greater curvature of the corpus. Measurement of the serum pepsinogen I/II ratio is useful for assessing the risk of gastric cancer. As a first-line treatment, tailored eradication based on the results of molecular testing is effective in a country with a high rate of clarithromycin-resistant H. pylori.

[Guidelines for Non-variceal Upper Gastrointestinal Bleeding]

Non-variceal upper gastrointestinal bleeding (NVUGIB) refers to bleeding that develops in the gastrointestinal tract proximal to the ligament of Treitz. NVUGIB is an important cause for visiting the hospital and is associated with significant morbidity and mortality. Although European and Asian-Pacific guidelines have been published, there has been no previous guidelines regarding management of NVUGIB in Korea. Korea is a country with a high prevalence of Helicobacter pylori infection and patients have easy accessibility to receive endoscopy. Therefore, we believe that guidelines regarding management of NVUGIB are mandatory. The Korean Society of Gastroenterology reviewed recent evidence and recommends practical management guidelines on NVUGIB in Korea.

Genotypic and Phenotypic Resistance to Clarithromycin in Helicobacter pylori Strains

BACKGROUND

The increasing prevalence of antimicrobial resistance, together with the lack of novel treatment options, negatively affects successful eradication of Helicobacter pylori. The aim of this study was to investigate genetic mutations in the 23S rRNA genes, which is associated with clarithromycin resistance, and to determine the clinical impact of genotype on phenotypic antimicrobial resistance.

METHODS

A total of 46 H. pylori strains were obtained from 13 patients, before and after unsuccessful eradication with clarithromycin-based triple therapy. The phenotypic resistance of each H. pylori strain was determined by minimum inhibitory concentration against clarithromycin using the serial two-fold agar dilution method. The genomic sequences of 23S rRNA genes were identified through next-generation sequencing, and nucleotide variants were determined based on comparison with genome sequences of the reference strain H. pylori 26695.

RESULTS

Clarithromycin resistance was found in 9 of 13 subjects before treatment and all subjects after unsuccessful eradication. Whole-genome sequencing of the 23S rRNA genes detected 42 mutations on 40 nonidentical loci, including 2147A>G (formerly 2143A>G) and 2146A>G (formerly 2142A>G). All strains with clarithromycin-resistant phenotype had either 2147A>G or 2146A>G mutation. When comparing genotype and phenotype for clarithromycin resistance, there was a significant association between 2147A>G mutation and clarithromycin-resistant phenotype.

CONCLUSIONS

All clarithromycin-resistant strains had either 2146A>G or 2147A>G mutation, suggesting that tests targeting these two mutations may be enough for the prediction of clarithromycin resistance in this population.

Sex differences in the relationship among alcohol, smoking, and Helicobacter pylori infection in asymptomatic individuals

OBJECTIVE

We aimed to investigate the relationship of Helicobacter pylori infection with alcohol and smoking.

METHODS

We conducted a cross-sectional study among participants who underwent health check-ups for H. pylori infection between January 2013 and March 2017. We subsequently investigated the relationship of H. pylori infection with alcohol and smoking.

RESULTS

A total of 7169 participants were enrolled in this study. The overall prevalence of H. pylori infection was 55.2%. Participants with H. pylori infection were more likely to be older than those without H. pylori infection. For male participants with H. pylori infection, multivariable logistic regression analysis indicated that both smoking (odds ratio (OR): 1.61; 95% confidence interval (CI): 1.41-1.83) and alcohol consumption (OR: 1.30; 95% CI: 1.10-1.52) were independently positively associated with H. pylori infection. For female participants, multivariable logistic regression analysis indicated that both smoking (OR: 0.03; 95% CI: 0.02-0.07) and alcohol consumption (OR: 0.20; 95% CI: 0.12-0.33) were inversely significantly associated with H. pylori infection after adjustment for age.

CONCLUSIONS

Smoking and alcohol consumption were risk factors for male participants but these were protective factors for female individuals with H. pylori infection.

ABC Classification Is Less Useful for Older Koreans Born before 1960

Background/Aims

In the ABC classification system, group A consists of seronegative subjects without gastric corpus atrophy. This study aimed to determine the prevalence and characteristics of pseudo group A subjects.

Methods

Group A subjects were identified among consecutive Korean adults who underwent a serum anti-Helicobacter pylori immunoglobulin G (IgG) test and pepsinogen (PG) assay on the day of endoscopy. Past infection was defined as the presence of either eradication history or endoscopic findings suggesting past infection (i.e., gastric xanthoma, metaplastic gastritis, or advanced atrophy >closed-type 1).

Results

Among 2,620 group A subjects, 448 (17.1%) had eradication history, and 133 (5.1%) showed endoscopic findings suggesting past infection. Older age (odds ratio [OR], 1.148; 95% confidence interval [CI], 1.067 to 1.236) and earlier year of birth (OR, 1.086; 95% CI, 1.009 to 1.168) were independent risk factors for classification into pseudo group A, with cutoff points at 50.5 years and birth year of 1959.5, respectively. Positive H. pylori test findings were found in 22 subjects (3.1%) among the 715 subjects who underwent the urea breath test or Giemsa staining on the same day. Current infection was positively correlated with PG I and PG II levels (p<0.001) but not with age, anti-H. pylori IgG titer, or classification into pseudo group A.

Conclusions

Among the group A subjects, 22.2% had past infection. The risk was higher in subjects older than 50 years, especially those born before 1960. Furthermore, current infection was found in 3.1% of the subjects and was correlated with increased gastric secretory ability.

Clinical Practice Guidelines for Functional Dyspepsia in Korea

Functional dyspepsia (FD) is a chronic upper gastrointestinal (GI) symptom complex that routine diagnostic work-up, such as endoscopy, blood laboratory analysis, or radiological examination, fails to identify a cause. It is highly prevalent in the World population, and its response to the various available therapeutic strategies is only modest because of the heterogenous nature of its pathogenesis. Therefore, FD represents a heavy medical burden for healthcare systems. We constituted a guideline development committee to review the existing guidelines on the management of functional dyspepsia. This committee drafted statements and conducted a systematic review and meta-analysis of various studies, guidelines, and randomized control trials. External review was also conducted by selected experts. These clinical practice guidelines for FD were developed based on evidence recently accumulated with the revised version of FD guidelines released in 2011 by the Korean Society of Neurogastroenterology and Motility. These guidelines apply to adults with chronic symptoms of FD and include the diagnostic role of endoscopy, Helicobacter pylori screening, and systematic review and meta-analyses of the various treatment options for FD (proton pump inhibitors, H.pylori eradication, and tricyclic antidepressants), especially according to the FD subtype. The purpose of these new guidelines is to aid the understanding, diagnosis, and treatment of FD, and the targets of the guidelines are clinicians, healthcare workers at the forefront of patient care, patients, and medical students. The guidelines will continue to be revised and updated periodically.

Evaluating Diagnostic Tests for Helicobacter pylori Infection Without a Reference Standard: Use of Latent Class Analysis

Evaluation of diagnostic tests requires reference standards, which are often unavailable. Latent class analysis (LCA) can be used to evaluate diagnostic tests without reference standards, using a combination of observed and estimated results. Conditionally independent diagnostic tests for Helicobacter pylori infection are required. We used LCA to construct a reference standard and evaluate the capability of non-invasive tests (stool antigen test and serum antibody test) to diagnose H. pylori infection compared with the conventional method, where histology is the reference standard. A total of 96 healthy subjects with endoscopy histology results were enrolled from January to July 2016. Sensitivity and specificity were determined for the LCA approach (i.e., using a combination of three tests as the reference standard) and the conventional method. When LCA was used, sensitivity and specificity were 83.8% and 99.4% for histology, 80.0% and 81.9% for the stool antigen test, and 63.6% and 89.3% for the serum antibody test, respectively. When the conventional method was used, sensitivity and specificity were 75.8% and 71.1% for the stool antigen test and 77.7% and 60.7% for the serum antibody test, respectively. LCA can be applied to evaluate diagnostic tests that lack a reference standard.

Analysis of factors associated with recovery of the serum pepsinogen ratio after Helicobacter pylori eradication: a long-term follow-up study in Korea

Objective: Serum levels of pepsinogen (PG) are related to Helicobacter pylori-induced inflammation of the gastric mucosa. This study aimed to examine the influence of H. pylori eradication on serum PG, analyze its associated factors, and evaluate the long-term outcomes.Methods: H. pylori-positive patients who underwent gastroscopy and serum PG measurement were enrolled in a single academic hospital. After H. pylori eradication, the measurement of serum PG level was performed. Recovery of serum PG I/II ratio was defined as a PG I/II ratio after eradication of >3.0 in patients with a PG I/II ratio ≤ 3.0 before eradication. Follow-up involved serum PG measurement and gastroscopy with a rapid urease test annually.Results: In all, 327 patients were eligible for study inclusion. Compared to those before H. pylori eradication, serum PG I (74.9 vs. 44.3 ng/mL, p < .001) and PG II (25.4 vs. 9.1 ng/mL, p < .001) levels significantly decreased after successful eradication. In addition, there was a significant increase in serum PG I/II ratio after eradication (3.07 vs. 4.98, p < .001). In multivariate analyses, the following were independently associated with failed recovery of serum PG I/II ratio despite successful eradication: age ≥ 60 years (odds ratio [OR] = 0.231, 95% confidence interval [CI] = 0.084-0.629, p = .004) and severe gastric atrophy (OR = 0.156, 95% CI = 0.055-0.440, p < .001).Conclusions: Recovery of serum PG I/II ratio after H. pylori eradication may be achieved in H. pylori-infected patients aged <60 years without severe gastric atrophy.

Helicobacter pylori eradication rates with concomitant and tailored therapy based on 23S rRNA point mutation: A multicenter randomized controlled trial

BACKGROUND

We evaluated the efficacy of tailored therapy based on point mutation presence identified with the dual-priming oligonucleotide (DPO)-based multiplex polymerase chain reaction (PCR) method compared with concomitant therapy.

MATERIALS AND METHODS

Subjects were randomly assigned concomitant therapy (amoxicillin 1 g, clarithromycin 500 mg, metronidazole 500 mg, and lansoprazole 30 mg twice/day for 14 days) or tailored therapy (amoxicillin 1 g, clarithromycin 500 mg, and lansoprazole 30 mg twice/day for 14 days in point mutation-negative subjects; and amoxicillin 1 g, metronidazole 500 mg, and lansoprazole 30 mg twice/day for 14 days in point mutation-positive subjects).

RESULTS

A total of 397 and 352 subjects were included in the intention-to-treat (ITT) and per-protocol (PP) analyses, respectively. Point mutations were identified in 25.9% of the subjects. The overall eradication rate was not significantly different between the groups by ITT (86.2% vs 81.6%, P = .132) and PP analyses (90.2% vs 86.5%, P = .179). There was no significant difference in the eradication rates between the groups in both the point mutation-negative subjects (91.7% vs 87.3%, P = .154) and the point mutation-positive subjects (71.2% vs 64.7%, P = .312). The eradication rates were significantly lower in the point mutation-positive subjects than in the point mutation-negative subjects in both the concomitant and tailored therapy groups.

CONCLUSIONS

Tailored therapy based on point mutation presence identified with the DPO-based multiplex PCR method was as effective as concomitant therapy. The eradication rates of both therapy regimens were suboptimal in point mutation-positive subjects.