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.

Characterization of a novel Helicobacter pylori East Asian-type CagA ELISA for detecting patients infected with various cagA genotypes.

Currently, Western-type CagA is used in most commercial Helicobacter pylori CagA ELISA kits for CagA detection rather than East Asian-type CagA. We evaluated the ability of the East Asian-type CagA ELISA developed by our group to detect anti-CagA antibody in patients infected with different cagA genotypes of H. pylori from four different countries in South Asia and Southeast Asia. The recombinant CagA protein was expressed and later purified using GST-tag affinity chromatography. The East Asian-type CagA-immobilized ELISA was used to measure the levels of anti-CagA antibody in 750 serum samples from Bhutan, Indonesia, Myanmar, and Bangladesh. The cutoff value of the serum antibody in each country was determined via Receiver-Operating Characteristic (ROC) analysis. The cutoff values were different among the four countries studied (Bhutan, 18.16 U/mL; Indonesia, 6.01 U/mL; Myanmar, 10.57 U/mL; and Bangladesh, 6.19 U/mL). Our ELISA had better sensitivity, specificity, and accuracy of anti-CagA antibody detection in subjects predominantly infected with East Asian-type CagA H. pylori (Bhutan and Indonesia) than in those infected with Western-type CagA H. pylori predominant (Myanmar and Bangladesh). We found positive correlations between the anti-CagA antibody and antral monocyte infiltration in subjects from all four countries. There was no significant association between bacterial density and the anti-CagA antibody in the antrum or the corpus. The East Asian-type CagA ELISA had improved detection of the anti-CagA antibody in subjects infected with East Asian-type CagA H. pylori. The East Asian-type CagA ELISA should, therefore, be used in populations predominantly infected with East Asian-type CagA.

New observations regarding Helicobacter pylori and gastric cancer in Mongolia.

BACKGROUND: The incidence and mortality of gastric cancer in Mongolia is among the highest in the world. METHODS: This was a case-control study in which upper gastrointestinal endoscopy, gastric histology, Helicobacter pylori testing, and risk factor questionnaires were obtained. Histologic subtypes were determined by Lauren's classification. RESULTS: We enrolled 45 gastric cancer and 108 non-gastric cancer patients. Gastric cancers were located in upper part of stomach in 53.3%, main gastric body in 37.8%, and lower part of stomach in 8.9%. The majority (60%) were diffuse type, followed by intestinal type (36.7%) and indeterminate type (3.3%). H. pylori infections were CagA positive in 100% with cancer vs 81% without cancer (P = .02). The majority of CagA was non-East Asian type (95% with cancer and 94.1% without cancer). Cancer patients had typically related with excessive use of salt, hot beverages, tobacco smoking, and low ingestion of fruits. CONCLUSION: The characteristic topography of gastric cancer in Mongolia being in the gastric corpus differed from East Asian countries and was more similar to western countries. The risk factors for gastric cancer in Mongolia were similar to other high-risk areas (ie, H. pylori infection, excessive use of salt, tobacco smoking, and low ingestion of fruits).

Changes in the first line Helicobacter pylori eradication rates using the triple therapy-a multicenter study in the Tokyo metropolitan area (Tokyo Helicobacter pylori study group).

BACKGROUND AND AIM: Helicobacter pylori (H. pylori) infection is a strong risk factor for the development of gastric cancer. In 2013, the Japanese government approved H. pylori eradication therapy in patients with chronic gastritis as well as peptic ulcer. However, the continuing decline in eradication rates for first-line H. pylori eradication therapies is an urgent problem. In this study, we investigated changes in the first-line eradication rate from 2001 to 2010. METHODS: Eradication rates for 7-day triple therapy [proton pump inhibitor (rabeprazole 20 mg, lansoprazole 60 mg, or omeprazole 40 mg)+amoxicillin 1500 mg + clarithromycin (CAM) 400 or 800 mg, daily] were collated from 14 hospitals in the Tokyo metropolitan area. The urea breath test was used for the evaluation of eradication. The cut-off value was less than 2.5%. RESULTS: The yearly eradication rates (intention to treat/per protocol) were 78.5/79.5% (2001, n=242), 71.2%/72.9% (2002, n=208), 67.8%/70.5% (2003, n=183), 75.6%/84.6% (2004, n=131), 56.4%/70.5% (2005, n=114), 70.5%/75.8% (2006, n=271), 67.4%/82.0% (2007, n=135), 64.0%/76.3% (2008, n=261), 60.5%/74.3% (2009, n=329), and 66.5%/78.8% (2010, n=370), respectively. Examination of eradication rates according to CAM dosage revealed an eradication rate of 65.6% (383/584) for CAM 400 mg daily, and 68.5% (1124/1642) for CAM 800 mg daily, with no significant difference seen between dosages. CONCLUSION: In recent years, eradication rates for first-line triple therapy have obviously decreased, but no noticeable decrease has occurred after 2001.

Gastroduodenal pathology in patients with asymptomatic gallbladder stones.

BACKGROUND/AIMS: Gallbladder stones are still a common pathology worldwide, and the number of patients diagnosed without any symptoms is increasing due to the use of ultrasound and imaging tools such as CT and MRI. The aim of this study was to identify gastroduodenal pathologies in patients with diagnosed asymptomatic gallbladder stones, since some cases of epigastric pain may have led to unnecessary cholecystectomies. METHODOLOGY: Gastroscopic investigations were performed in 33 patients diagnosed with asymptomatic gallbladder stones during a gallstone screening program in Chiang Mai, Thailand, and followed-up with yearly ultrasound examinations. The mean age of the patients was 56.6 years, and mean follow-up time was 2.3 years. RESULTS: Our results showed that inflammatory-based gastroduodenal lesions in this group were common (15/33 patients, 45.4%). Lesions included gastric ulcers (1 patient, 3%), duodenal ulcers (5 patients, 15.1%), and gastroduodenal ulcers (2 patients, 6.1%). Almost all of the ulcers were in the healing or scarring stage. Inflammatory-based mucosal changes were also detected in these patients as follows: erosive gastritis (6 patients, 18.2%) and hemorrhagic gastritis (1 patient, 3%). CONCLUSIONS: Inflammatory-based gastroduodenal pathologies such as peptic ulcers and gastritis are common in patients with asymptomatic gallstones. If such patients become symptomatic, meticulous examinations are needed to avoid unnecessary cholecystectomies and resulting complications such as postcholecystectomy syndrome. The theory that gastroduodenal lesions occur after gallbladder removal needs to be re-evaluated given that lesions can be detected before surgery and even before the occurrence of symptoms.

Trends of second-line eradication therapy for Helicobacter pylori in Japan: a multicenter study in the Tokyo metropolitan area.

BACKGROUND: In Japan, the eradication rate of first-line therapy for Helicobacter pylori (H. pylori) with a proton pump inhibitor (PPI), amoxicillin (AMPC) and clarithromycin (CAM) has been decreasing because of a high prevalence of CAM resistance. A possible decrease of the eradication rate for second-line therapy with a PPI, AMPC and metronidazole (MNZ) is of concern. The aim of this study is to assess the trends in second-line eradication therapy for H. pylori in Japan. MATERIALS AND METHODS: We accumulated data retrospectively on patients administered second-line eradication therapy for Helicobacter pylori with a PPI, AMPC, and MNZ for 1 week after failure of first-line eradication therapy with a PPI, AMPC and CAM at 15 facilities in the Tokyo metropolitan area in Japan from 2007 to 2011. Trends for second-line eradication rates in modified intention-to-treat (ITT) analyses were investigated. Second-line eradication rates were categorized by three PPIs (rabeprazole (RPZ), lansoprazole (LPZ) or omeprazole (OMZ)) and evaluated. RESULTS: We accumulated data on 1373 patients. The overall second-line eradication rate was 92.4%. Second-line eradication rates in 2007, 2008, 2009, 2010 and 2011 were 97.7, 90.6, 94.5, 91.8 and 91.8%, respectively, with no significant trends revealed. Second-line eradication rates categorized by three PPIs for the entire 5-year period were 91.6, 93.4 and 92.4% (RPZ, LPZ and OPZ, respectively) with no significant differences among the three PPIs. CONCLUSIONS: From 2007 to 2011, there were no significant trends in the second-line eradication rates and the rates remained consistently high. From the viewpoint of high prevalence of CAM resistance in Japan, triple therapy with PPI, AMPC and MNZ may be a better strategy for first-line therapy compared to triple therapy with PPI, AMPC and CAM.

Relation between bile acid reflux into the stomach and the risk of atrophic gastritis and intestinal metaplasia: a multicenter study of 2283 cases.

BACKGROUND: The relationship between bile acid reflux into the stomach and the risk of atrophic gastritis and intestinal metaplasia is still not well understood. Towards obtaining a better understanding, concentrations of bile acids were measured. PATIENTS AND METHODS: This study was carried out with the participation of 14 facilities in Japan, and 2283 samples were collected. The subjects with bile acid concentrations equal to or higher than the limit of detection were divided into four groups of equal size (group A: 0-25%, group B: 26-50%, group C: 51-75%, and group D: 76-100%). Thus, including the control group, there were five groups in total. The odds that the control group would develop atrophic gastritis and intestinal metaplasia was set as 1,and the odds ratios (OR) in groups A, B, C and D were calculated based on the odds in the control group. RESULTS: Regarding the development of atrophic gastritis, no increased risk was observed in either the Helicobacter pylori (H. pylori)-positive or -negative cases. The OR for the development of intestinal metaplasia were significantly higher, for both cases with and without H. pylori infection, in group D. CONCLUSION: High concentrations of bile acid seem to be associated with an elevated risk of intestinal metaplasia.

Observation of gastric mucosa in Bangladesh, the country with the lowest incidence of gastric cancer, and Japan, the country with the highest incidence.

BACKGROUND: The prevalence of Helicobacter pylori (H. pylori) infection is high, but the incidence of gastric cancer is low in natives of Bangladesh. The gastric mucosa was observed in Bangladeshi patients to investigate the differences between Bangladeshis and Japanese. MATERIALS AND METHODS: The study involved 418 Bangladeshi and 2356 Japanese patients with abdominal complaints who underwent endoscopy examinations and had no history of H. pylori eradication. The prevalence of H. pylori infection and the gastric mucosa in H. pylori-positive patients were compared between age-, gender-, and endoscopic diagnosis-matched Bangladeshi and Japanese subjects. RESULTS: The prevalence of H. pylori infection was higher in Bangladeshi than in Japanese subjects (60.2 and 45.1%, respectively). All the scores for chronic inflammation, neutrophil activity, glandular atrophy, and intestinal metaplasia were significantly lower in H. pylori-positive Bangladeshis than in H. pylori-positive Japanese. The ratio of the corpus gastritis score (C) to the antrum gastritis score (A) (C/A ratio) was <1 (antrum-predominant gastritis) in all age groups of Bangladeshi subjects, whereas the C/A ratio changed from <1 to more than 1 (corpus-predominant gastritis) with aging in Japanese subjects. CONCLUSIONS: The scores for glandular atrophy and intestinal metaplasia in H. pylori-positive Bangladeshis were significantly lower than those in Japanese. All age groups of Bangladeshis had antrum-predominant gastritis, whereas corpus-predominant gastritis was more common than antrum-predominant gastritis in older Japanese age groups. These results may explain the low incidence of gastric cancer in Bangladeshis and the high incidence in Japanese.

Next-Generation Sequencing-Based Study of Helicobacter pylori Isolates from Myanmar and Their Susceptibility to Antibiotics.

Evaluation of Helicobacter pylori resistance to antibiotics is crucial for treatment strategy in Myanmar. Moreover, the genetic mechanisms involved remain unknown. We aimed to investigate the prevalence of H. pylori infection, antibiotic resistance, and genetic mechanisms in Myanmar. One hundred fifty patients from two cities, Mawlamyine (n = 99) and Yangon (n = 51), were recruited. The prevalence of H. pylori infection was 43.3% (65/150). The successfully cultured H. pylori isolates (n = 65) were tested for antibiotic susceptibility to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline by Etest, and the resistance rates were 80%, 33.8%, 7.7%, 4.6%, and 0%, respectively. In the multidrug resistance pattern, the metronidazole-levofloxacin resistance was highest for double-drug resistance (16/19; 84.2%), and all triple-drug resistance (3/3) was clarithromycin-metronidazole-levofloxacin resistance. Twenty-three strains were subjected to next-generation sequencing to study their genetic mechanisms. Interestingly, none of the strains resistant to clarithromycin had well-known mutations in 23S rRNA (e.g., A2142G, A2142C, and A2143G). New type mutation genotypes such as pbp1-A (e.g., V45I, S/R414R), 23S rRNA (e.g., T248C), gyrA (e.g., D210N, K230Q), gyrB (e.g., A584V, N679H), rdxA (e.g., V175I, S91P), and frxA (e.g., L33M) were also detected. In conclusion, the prevalence of H. pylori infection and its antibiotic resistance to metronidazole was high in Myanmar. The H. pylori eradication regimen with classical triple therapy, including amoxicillin and clarithromycin, can be used as the first-line therapy in Myanmar. In addition, next-generation sequencing is a powerful high-throughput method for identifying mutations within antibiotic resistance genes and monitoring the spread of H. pylori antibiotic-resistant strains.

Pepsinogen and Serum IgG Detection Is a Valuable Diagnostic Method for Helicobacter pylori Infection in a Low-Prevalence Country: A Report from Sri Lanka.

The use of serum anti-Helicobacter pylori IgG and pepsinogen (PG) detection as a diagnostic method was evaluated in Sri Lanka. Gastric biopsies were performed (353 patients), and the prevalence of H. pylori infection was 1.7% (culture) and 2.0% (histology). IgG serology testing showed an area under the curve (AUC) of 0.922 (cut-off, 2.95 U/mL; specificity, 91.56%; sensitivity, 88.89%). Histological evaluation showed mild atrophy (34.3%), moderate atrophy (1.7%), metaplasia (1.7%), chronic gastritis (6.2%), and normal tissue (56%). The PGI/PGII ratio was significantly higher in H. pylori-negative patients (p < 0.01). PGII and PGI/PGII levels were lower in patients with metaplasia than in those with normal mucosa (p = 0.049 and p < 0.001, respectively). The PGI/PGII ratio best discriminated metaplasia and moderate atrophy (AUC 0.88 and 0.76, respectively). PGI and PGII alone showed poor discriminative ability, especially in mild atrophy (0.55 and 0.53, respectively) and chronic gastritis (0.55 and 0.53, respectively). The best cut-off to discriminate metaplasia was 3.25 U/mL (95.19% specificity, 83.33% sensitivity). Anti-H. pylori IgG and PG assessment (ABC method) was performed (group B, 2.0%; group A, 92.1%). The new cut-off more accurately identified patients with metaplasia requiring follow-up (group B, 5.4%). Assessment of anti-H. pylori IgG and PG is valuable in countries with a low prevalence of H. pylori infection.

Helicobacter pylori infection and gastroduodenal diseases in Vietnam: a cross-sectional, hospital-based study.

BACKGROUND: The rate of H. pylori infection in Vietnam is reportedly high, but the spectrum of H. pylori-associated gastroduodenal diseases has not been systematically investigated. Moreover, despite the similarities of ethnicity and diet, the age-standardized incidence rate of gastric cancer in the northern city of Hanoi is higher than that in the southern city of Ho Chi Minh, but the reason for this phenomenon is unknown. The virulence of Vietnamese H. pylori has also not been investigated in detail. METHODS: Individuals undergoing esophagogastroduodenoscopy were randomly recruited. H. pylori infection status was determined based on the combined results of culture, histology, immunohistochemistry, rapid urine test and serum ELISA. Peptic ulcer (PU) and gastroesophageal reflux disease was diagnosed by endoscopy, and chronic gastritis was determined histologically. H. pylori virulence factors were investigated by PCR and sequencing. RESULTS: Among the examined patients, 65.6% were infected with H. pylori. The prevalence of infection was significantly higher in those over 40 years of age than in those aged ≤40. Chronic gastritis was present in all H. pylori-infected individuals, 83.1% of whom had active gastritis, and 85.3% and 14.7% had atrophy and intestinal metaplasia, respectively. PU was present in 21% of infected patients, whereas its incidence was very low in non-infected individuals. The prevalence of PU was significantly higher in Hanoi than in Ho Chi Minh. The prevalence of vacA m1, which has been identified as an independent risk factor for PU in Vietnam, was significantly higher among H. pylori isolates from Hanoi than among those from Ho Chi Minh. CONCLUSIONS: H. pylori infection is common in Vietnam and is strongly associated with PU, active gastritis, atrophy and intestinal metaplasia. vacA m1 is associated with an increased risk for PU and might contribute to the difference in the prevalence of PU and gastric cancer between Hanoi and Ho Chi Minh.

Evaluation of rapid urine test for the detection of Helicobacter pylori infection in the Vietnamese population.

PURPOSE: This study attempted to assess the value of the RAPIRUN test for the diagnosis of Helicobacter pylori infection in the Vietnamese population. METHODS: We recruited 148 Vietnamese patients undergoing upper gastrointestinal endoscopy during which five gastric biopsies were taken; blood and urine samples were collected from each patient. Helicobacter pylori infection status was determined by a combination of three different methods, including culture, immunohistochemistry, and serum ELISA. RAPIRUN tests were performed using urine samples. RESULTS: The sensitivity, specificity, and accuracy of the RAPIRUN test in these Vietnamese patients were 79.5, 90.7, and 84.5%, respectively. CONCLUSIONS: The RAPIRUN test is useful for the diagnosis of H. pylori infection in the Vietnamese population, showing high specificity, acceptable sensitivity, non-invasiveness, convenience, and rapidity.

Analysis of virulence factors of Helicobacter pylori isolated from a Vietnamese population.

BACKGROUND: The incidence of gastric cancer differs among countries in Asia, and it has been suggested that virulence factors associated with Helicobacter pylori are partly responsible. The aim of this study was to investigate several genetic factors regarded as virulence or molecular epidemiologic markers in H. pylori isolates from Vietnamese subjects. RESULTS: The cagA, vacA and cag right-end junction genotypes of 103 H. pylori strains from Vietnam (54 from Hanoi and 49 from Ho Chi Minh) were determined by PCR and sequencing. Three types of deletion in the region located upstream of the cagA Glu-Pro-Ile-Tyr-Ala (EPIYA) repeat region were identified: the 39-bp deletion type, the 18-bp deletion type, and the no-deletion type. The majority of strains studied (77%; 80/103) had the 18-bp deletion irrespective of geographical location in the country or clinical outcome. All of the 39-bp and 18-bp deletion-type strains possessed the East Asian type cagA repeat region. The type II cag right-end junction genotype was predominant (84%). The vacA m1 genotype was significantly more common in strains isolated in Hanoi, where the incidence of gastric cancer is higher, than in strains from Ho Chi Minh. CONCLUSION: Pre-EPIYA-region typing of the cagA gene could provide a new genetic marker of H. pylori genomic diversity. Our data support the hypothesis that vacA m1 is closely associated with gastric carcinogenesis.

Western-Type Helicobacter pylori CagA are the Most Frequent Type in Mongolian Patients.

Helicobacter pylori infection possessing East-Asian-type CagA is associated with carcinogenesis. Mongolia has the highest mortality rate from gastric cancer. Therefore, we evaluated the CagA status in the Mongolian population. High risk and gastric cancer patients were determined using endoscopy and histological examination. H. pylori strains were isolated from different locations in Mongolia. The CagA subtypes (East-Asian-type or Western-type, based on sequencing of Glu-Pro-Ile-Tyr-Ala (EPIYA) segments) and vacA genotypes (s and m regions) were determined using PCR-based sequencing and PCR, respectively. In total, 368 patients were examined (341 gastritis, 10 peptic ulcer, and 17 gastric cancer). Sixty-two (16.8%) strains were cagA-negative and 306 (83.1%) were cagA-positive (293 Western-type, 12 East-Asian-type, and one hybrid type). All cagA-negative strains were isolated from gastritis patients. In the gastritis group, 78.6% (268/341) had Western-type CagA, 2.9% (10/341) had East-Asian-type, and 18.2% (61/341) were cagA-negative. However, all H. pylori from gastric cancer patients possessed Western-type CagA. Histological analyses showed that East-Asian-type CagA was the most virulent strains, followed by Western-type and cagA-negative strains. This finding agreed with the current consensus. CagA-positive strains were the most virulent type. However, the fact that different CagA types can explain the high incidence of gastric cancer might be inapplicable in Mongolia.

Initial Trials With Susceptibility-Based and Empiric Anti-H. pylori Therapies in Mongolia.

Background: Mongolia has a high prevalence of Helicobacter pylori infection and gastric cancer. We conducted a prospective, randomized, single-blind study to evaluate the efficacy of common regimens in Mongolia and to obtain specimens for susceptibility testing. Methods: Empiric treatments: 270 patients with confirmed H. pylori infection were randomized to receive 10 days clarithromycin-triple therapy (Clari-TT) (n = 90), modified bismuth quadruple therapy (M-BQT) (n = 90), or sequential therapy (ST) (n = 90). A second group of 46 patients received susceptibility-based Clari-TT. H. pylori was cultured from 131 patients and susceptibility testing was performed. H. pylori eradication was confirmed by stool antigen 4 weeks after the therapy. Results: Intention-to-treat (ITT) analysis cure rates were 71.1% (95% CI = 61.7-80.5%) for Clari-TT, 87.8% (95% CI = 81-94.6%) for M-BQT, 67.8% (95% CI = 58.1-77.5%) for ST vs. 89.1% (95% CI = 86-98.2%) for susceptibility-based Clari-TT. Per-protocol (PP) analysis results for these therapies were 72.7% (63.4-82%), 89.8% (83.5-96.1%), 68.5% (58.8-78.2%), and 97.6% (89.5-99.8%), respectively. Among 131 cultured H. pylori, resistance rates to amoxicillin, clarithromycin, and metronidazole were 8.4, 37.4, and 74%, respectively. Conclusion: In Mongolia, the prevalence of H. pylori resistance is high requiring bismuth quadruple therapy or susceptibility-based therapy to obtain acceptable cure rates.

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

BACKGROUND: The environment surrounding Helicobacter pylori eradication treatment is dramatically changing. Recently, vonoprazan, a first-in-class potassium-competitive acid blocker (P-CAB), was introduced onto the market in 2015. The aging of Japan's demographic structure is becoming pronounced. In this study, we examined the trend of the eradication rate of H. pylori in the metropolitan area and examined factors concerning successful eradication. METHODS: We collected data from 20 hospitals in the Tokyo metropolitan area on patients who received first-line eradication therapy with a proton-pump inhibitor (PPI)/P-CAB, amoxicillin, and clarithromycin for 1 week and second-line eradication therapy with a PPI/P-CAB, amoxicillin, and metronidazole for 1 week from 2013 to 2018. The annual eradication rate and associated factors for successful eradication were analyzed. RESULTS: We collected data of 4097 and 3572 patients in the first- and second-line eradication therapies, respectively. The eradication rate decreased from 2013 to 2014 and increased again from 2015 to 2018 with the first-line therapy [the eradication rates in 2013, 2014, 2015, 2016, 2017 and 2018 were 71.8%, 63.7%, 78.5%, 84.6%, 89.7 and 90.1%, respectively, in the per protocol (PP)]. The second-line eradication rates were 90.0%, 82.6%, 88.8%, 87.5%, 91.8% and 90.1% in 2013, 2014, 2015, 2016, 2017 and 2018, respectively, in PP. Vonoprazan was an independent factor for successful eradication in not only first-line, but also second-line eradication. Age over 75 years was an independent factor for eradication failure in both first- and second-line eradication therapies. CONCLUSION: The eradication rate improved from 2015 to 2018 with the first-line therapy because of the introduction of vonoprazan in the market. The eradication rates with first- and second-line regimens in elderly patients were lower than those in younger patients.

The prevalence of Helicobacter pylori infection and other risk factors among Mongolian dyspeptic patients who have a high incidence and mortality rate of gastric cancer.

BACKGROUND: Mongolia has not only the second highest incidence rate but also the highest mortality rate for gastric cancer globally. In addition to gastric cancer, ulcerative disease complications are also life threatening; thus, investigating Helicobacter pylori infection and other risk factors is essential. RESULTS: H.pylori infection was high in tested dyspeptic patients from all parts of Mongolia, with an overall infection rate of 80.0%. Logistic regression analysis showed that H. pylori infection was associated with gastritis (odds ratio; 9.0 ([95% confidence interval 5.0-16.2]); p < 0.0001). H. pylori infection (3.3 [2.0-5.4]; p < 0.0001) and > 40 years old (1.5 [1.0-2.0]; p < 0.02) were both associated with atrophy. However, > 40 years old (3.8 [2.4-6.0]; p < 0.0001) and high salt intakes (1.6 [1.0-2.3]; p < 0.02), but not H. pylori infection, were associated with intestinal metaplasia. Excessive amount of salt usage was dramatically higher in northern and western parts of Mongolia, where precancerous diseases, such as erosive esophagitis (for cardia cancer), severe atrophy, and intestinal metaplasia (for non-cardia cancer), were highly prevalent. CONCLUSIONS: H. pylori infection was the major gastric health problem among the Mongolian population. In addition, environmental factors such as high salt intake worsened the clinical outcome. Therefore, a nationwide screening and eradication of H. pylori infection as well as salt-reducing measures should be implemented.

Helicobacter pylori infection in combination with the serum pepsinogen I/II ratio and interleukin-1beta-511 polymorphisms are independent risk factors for gastric cancer in Thais.

BACKGROUND: Thailand has the lowest incidence of gastric cancer in the world. Helicobacter pylori infection, a low serum pepsinogen I/II ratio, and interleukin (IL)-1beta-511 polymorphisms are suspected to be risk factors for gastric cancer. METHODS: A total of 167 Thais, comprising 56 cancer patients and 111 volunteers without cancer, underwent an esophagogastroduodenoscopic examination and three fixed-point biopsies; a cancer tissue biopsy was also done, and blood samples were collected. The subjects without cancer were divided into normal subjects and chronic gastritis patients. IL-1beta-511 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism, and the serum levels of pepsinogen I and II were determined by a radioimmunoassay. Helicobacter pylori IgG antibody and tissue pathology were tested in all groups. RESULTS: The pepsinogen I/II ratio was significantly lower in the gastric cancer group than in the normal and chronic gastritis groups [odds ratio (OR), 2.3; 95% confidence interval (CI), 1.10-4.80; P = 0.025]. Gastric cancer patients were positive for the H. pylori IgG antibody more frequently than negative (OR, 2.946; 95% CI, 1.4-6.39; P = 0.005). However, only 15 (27%) cancer patients were both positive for H. pylori IgG antibody and had low serum pepsinogen I/II. The C/C genotype was found more frequently in the gastric cancer group than in the group with a normal gastric mucosa (OR, 0.64; 95% CI, 0.50-0.81; P = 0.014). CONCLUSIONS: A low serum pepsinogen I/II ratio combined with positivity for H. pylori IgG, and a IL-1beta-511 C/C genotype may be independent risk factors for gastric cancer in Thais.

Helicobacter pylori infection, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer and early gastric cancer.

AIM: To evaluate the histological features of gastric mucosa, including Helicobacter pylori infection in patients with early gastric cancer and endoscopically found superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer. METHODS: The biopsy specimens were taken from the antrum, corpus and upper angulus of all the patients. Giemsa staining, improved toluidine-blue staining, and H pylori-specific antibody immune staining were performed as appropriate for the histological diagnosis of H pylori infection. Hematoxylin-eosin staining was used for the histological diagnosis of gastric mucosa inflammation, gastric glandular atrophy and intestinal metaplasia and scored into four grades according to the Updated Sydney System. RESULTS: The overall prevalence of H pylori infection in superficial gastritis was 28.7%, in erosive gastritis 57.7%, in gastric erosion 63.3%, in gastric ulcer 80.8%, in early gastric cancer 52.4%. There was significant difference (P<0.05), except for the difference between early gastric cancer and erosive gastritis. H pylori infection rate in antrum, corpus, angulus of patients with superficial gastritis was 25.9%, 26.2%, 25.2%, respectively; in patients with erosive gastritis 46.9%, 53.5%, 49.0%, respectively; in patients with gastric erosion 52.4%, 61.5%, 52.4%, respectively; in patients with gastric ulcer 52.4%, 61.5%, 52.4%, respectively; in patients with early gastric cancer 35.0%, 50.7%, 34.6%, respectively. No significant difference was found among the different site biopsies in superficial gastritis, but in the other diseases the detected rates were higher in corpus biopsy (P<0.05). The grades of mononuclear cell infiltration and polymorphonuclear cell infiltration, in early gastric cancer patients, were significantly higher than that in superficial gastritis patients, lower than that in gastric erosion and gastric ulcer patients (P<0.01); however, there was no significant difference compared with erosive gastritis. The grades of mucosa glandular atrophy and intestinal metaplasia were significantly highest in early gastric cancer, lower in gastric ulcer, the next were erosive gastritis, gastric erosion, the lowest in superficial gastritis (P<0.01). Furthermore, 53.3% and 51.4% showed glandular atrophy and intestinal metaplasia in angular biopsy specimens, respectively; but only 40.3% and 39.9% were identified in antral biopsy, and 14.1% and 13.6% in corpus biopsy; therefore, the angulus was more reliable for the diagnosis of glandular atrophy and intestinal metaplasia compared with antrum and corpus (P<0.01). The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis with H pylori-positivity was 50.7%, 34.1%; of erosive gastritis 76.1%, 63.0%; of gastric erosion 84.8%, 87.8%; of gastric ulcer 80.6%, 90.9%; and of early gastric cancer 85.5%, 85.3%, respectively. The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis with H pylori-negativity was 9.9%, 6.9%; of erosive gastritis 42.5%, 42.1%; of gastric erosion 51.1%, 61.9%; of gastric ulcer 29.8%, 25.5%; and of early gastric cancer 84.0%, 86.0%, respectively. The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis, erosive gastritis, gastric erosion, and gastric ulcer patients with H pylori positivity was significantly higher than those with H pylori negativity (P<0.01); however, there was no significant difference in patients with early gastric cancer with or without H pylori infection. CONCLUSION: The progression of the gastric pre-cancerous lesions, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis and gastric ulcer was strongly related to H pylori infection. In depth studies are needed to evaluate whether eradication of H pylori infection will really diminish the risk of gastric cancer.

Comparison of Helicobacter pylori infection and gastric mucosal histological features of gastric ulcer patients with chronic gastritis patients.

AIM: To compare Helicobacter pylori infection and gastric mucosal histological features of gastric ulcer patients with chronic gastritis patients in different age groups and from different biopsy sites. METHODS: The biopsy specimens were taken from the antrum, corpus and upper angulus of gastric ulcer and chronic gastritis patients. Giemsa staining, improved Toluidine-blue staining and H pylori-specific antibody immune staining were performed as appropriate for the histological diagnosis of H pylori infection. Hematoxylin-eosin staining was used for the histological diagnosis of activity of H pylori infection, mucosal inflammation, glandular atrophy and intestinal metaplasia and scored into four grades according to the Updated Sydney System. RESULTS: Total rate of H pylori infection, mucosal inflammation, activity of H pylori infection, glandular atrophy and intestinal metaplasia in 3 839 gastric ulcer patients (78.5%, 97.4%, 82.1%, 61.1% and 64.2%, respectively) were significantly higher than those in 4 102 chronic gastritis patients (55.0%, 90.3%, 56.2%, 36.8%, and 37.0%, respectively, P<0.05). The rate of H pylori colonization of chronic gastritis in <30 years, 31-40 years, 41-50 years, 51-60 years, 61-70 years and >70 years age groups in antrum was 33.3%, 41.7%, 53.6%, 57.3%, 50.7%, 43.5%, respectively; in corpus, it was 32.6%, 41.9%, 53.8%, 60.2%, 58.0%, 54.8%, respectively; in angulus, it was 32.4%, 42.1%, 51.6%, 54.5%, 49.7%, 43.5%, respectively. The rate of H pylori colonization of gastric ulcer in <30 years, 31-40 years, 41-50 years, 51-60 years, 61-70 years and >70 years age groups in antrum was 60.5%, 79.9%, 80.9%, 66.8%, 59.6%, 45.6%, respectively; in corpus, it was 59.7%, 79.6%, 83.6%, 80.1%, 70.6%, 59.1%, respectively; in angulus, it was 61.3%, 77.8%, 75.3%, 68.8%, 59.7%, 45.8%, respectively. The rate of H pylori colonization at antrum was similar to corpus and angulus in patients, below 50 years, with chronic gastritis and in patients, below 40 years, with gastric ulcer. In the other age- groups, the rate of H pylori colonization was highest in corpus, lower in antrum and lowest in angulus (all P<0.05). The rates of glandular atrophy and intestinal metaplasia were higher and earlier in H pylori-positive patients than those without H pylori infection (both P<0.01). In comparison of gastric ulcer patients with chronic gastritis patients, the rate of glandular atrophy and intestinal metaplasia was higher in H pylori-positive patients with gastric ulcer than in H pylori-positive patients with chronic gastritis (both P<0.01); the rate of glandular atrophy and intestinal metaplasia were also higher in H pylori-negative patients with gastric ulcer than in H pylori-negative patients with chronic gastritis (both P<0.01). Both glandular atrophy and intestinal metaplasia were much more commonly identified in the angulus than in the antrum, lowest in corpus (all P<0.01). CONCLUSION: Rate of H pylori infection, glandular atrophy and intestinal metaplasia in gastric ulcer were higher than in chronic gastritis in all-different age -groups. Distribution of H pylori colonization is pangastric in the younger patients. It is highest in corpus, lower in antrum and lowest in angulus in the older age groups. Progression of glandular atrophy and intestinal metaplasia seem to have a key role in the distribution of H pylori colonization. H pylori appears to be the most important risk factor for the development of glandular atrophy and intestinal metaplasia, but it is not the only risk.