Search

Background: To prevent gastric cancer, a test-and-treat strategy for Helicobacter pylori has been proposed. This retrospective study assessed the clinical features, efficacy and safety of treatment for H. pylori infection in children and adolescents., Methods: Questionnaires concerning the clinical features and treatment of H. pylori in children and adolescents were sent to doctors in 2013. It included questions on patient background, H. pylori-associated disease, first- and second-line treatment, success or failure of eradication, resistance to antibiotics, and occurrence of adverse events. In 2014, serious adverse events associated with treatment were analyzed., Results: Invitation letters and questionnaires were sent to 1097 doctors, of whom 409 (37.3%) participated. Finally, 332 patients (mean age, 11.6 ± 3.4 years; male, n = 200) treated from 1997 to 2013 were analyzed. H. pylori-associated gastritis, iron deficiency anemia, and duodenal ulcer occurred most frequently. Success rates for first- and second-line treatments were 73.1% and 79.6%, respectively. Seventy-six H. pylori strains were analyzed for resistance to amoxicillin (AMPC) and clarithromycin (CAM), and 64 were analyzed for resistance to metronidazole (MNZ). CAM resistance was most frequent, occurring in 43.4% of patients; that of MNZ was 21.9%. Adverse events were observed in 13.8% of cases. In total, 587 cases of H. pylori infection were analyzed and no serious adverse events were observed., Conclusions: Treatment for H. pylori in children and adolescents is safe, but further studies on treatment regimens should be conducted to improve eradication rates and monitor increasing CAM resistance., (© 2016 Japan Pediatric Society.)

Background: Infection of Helicobacter pylori mainly occurs in childhood. In Japan, incidence of gastric cancer is still high in the senior citizen population, but little is known about the current H. pylori infection status among children or their family members., Methods: As a population-based study, the prevalence of H. pylori infection and change in infection status over a 1-year interval in children were determined. Family members of some participants were also invited to participate in the study to determine their infection status. All children of specific ages attending 16 schools in Sasayama, Hyogo Prefecture, were invited to participate. H. pylori infection was determined by the stool antigen test and diagnosis confirmed by polymerase chain reaction and the urea breath test., Results: Helicobacter pylori prevalence was 1.9% among 689 children aged 0-8 years in 2010 and 1.8% among 835 children aged 0-11 in 2011. No feco-conversion was observed in 430 children aged 0-8 years (170 were aged 0-4 years) who provided follow-up stool samples after 1 year. The prevalence of infection was 6% (2 of 33) and 38% (6 of 16) in mothers of negative and positive probands (p = .04), respectively, and 12% (3 of 25) and 50% (8 of 16) (p = .01), respectively, in fathers., Conclusion: Helicobacter pylori prevalence in Japanese children is approximately 1.8%, which is much lower than that reported in Japanese adults. New infection may be rare. Parent-to-child infection is thought to be the main infection route of the infrequent infection for children in Japan., (© 2014 John Wiley & Sons Ltd.)

Non-invasive diagnosis of Helicobacter pylori infection is important not only for screening of infection but also for epidemiological studies. Stool antigen tests are non-invasive and are convenient to identify H. pylori infection, particularly in children. We evaluated the stool antigen test, which uses a mAb for native catalase of H. pylori developed in Japan. A total of 151 stool samples were collected from participants (52 children and 99 adults) of the Sasayama Cohort Study and stored between -30 and -80 °C. The stool antigen test used was Testmate pylori antigen (TPAg), and was performed according to the manufacturer's instructions. Furthermore, we conducted a quantitative real-time PCR test and compared the PCR results with those of the TPAg test. When compared with the results in real-time PCR, the sensitivity of TPAg was 89.5 % overall, 82.7 % for children and 92.4 % for adults, and the specificity was 100 %. The accuracy was 93.4 % overall, 90.4 % for children and 94.9 % for adults, and there was no significant difference in the accuracy of TPAg between children and adults. Five of 28 children (18 %) and five of 38 adults (13 %) were PCR positive with negative TPAg results. Four of five children with positive PCR and negative TPAg results were given a (13)C-urea breath test and all four children tested negative. No significant correlation was observed between the TPAg results and DNA numbers of H. pylori in faeces among children or adults. A stool antigen test (TPAg) using a mAb for native catalase is useful for diagnosis of H. pylori in children and adults. Additionally, this test has particularly high specificity., (© 2014 The Authors.)

Serum antibodies against pathogenic bacteria play immunologically protective roles, and can be utilized as diagnostic markers of infection. This study focused on Japanese child serum antibodies against Helicobacter pylori, a chronically-infected gastric bacterium which causes gastric cancer in adults. Serological diagnosis for H. pylori infection is well established for adults, but it needs to be improved for children. Serum samples from 24 children, 22 H. pylori (Hp)-positive and 2 Hp-negative children, were used to catalogue antigenic proteins of a Japanese strain CPY2052 by two-dimensional electrophoresis followed by immunoblot and LC-MS/MS analysis. In total, 24 proteins were identified as candidate antigen proteins. Among these, the major virulence factor, cytotoxin-associated gene A protein (CagA) was the most reactive antigen recognized by all the Hp-positive sera even from children under the age of 3 years. The major antigenic part of CagA was identified in the middle region, and two peptides containing CagA epitopes were identified using a newly developed peptide/protein-combined array chip method, modified from our previous protein chip method. Each of the epitopes was found to contain amino acid residue(s) unique to East Asian CagA. Epitope analysis of CagA indicated importance of the regional CagA antigens for serodiagnosis of H. pylori infection in children.

We analyzed the ratio of positive test results in various diagnostic methods for Helicobacter pylori infection and the clinical presentations in six cases of acute gastric mucosal lesions (AGML) caused by acute H. pylori. At onset, five cases tested negative for serum antibodies; one had a positive result, but the antibody titer increased with time. Some false negative results were obtained with the following tests: urea breath test, rapid urease test, microscopy, culture, and immunostaining; however, the feces antigen test gave positive results in all five cases. These data suggest that feces antigen test should be performed in all cases suspected of acute H. pylori infection. Where progress was monitored without eradication therapy, subjective symptoms were exacerbated in some patients, and one patient developed a persistent infection. Consequently, eradication therapy should be performed at an early stage of AGML.

Background: A number of noninvasive diagnostic tests are available to detect Helicobacter pylori infection. Data on serologic testing of children are lacking, however, and thus it remains unclear whether the serology cutoff points used for adults are appropriate for children., Methods: Serum and stool samples were obtained from 73 children who visited 5 hospitals in Japan between March 1993 and December 2009. Analysis of stool samples was carried out using an H pylori stool antigen enzyme-linked immunosorbent assay (HpSA ELISA), and serum antibodies to H pylori were examined using an antibody determination kit (E-Plate Eiken H pylori antibody). The validity of the serologic test was evaluated based on its sensitivity, specificity, and receiver operating characteristics curve., Results: Of the 73 children included in this study, 34 were HpSA-positive and 39 were negative. Among the 34 HpSA-positive patients, 32 were IgG-positive and 2 were IgG-negative. Of the 39 patients who were HpSA-negative, 38 were IgG-negative and 1 was IgG-positive. The sensitivity, specificity, and positive likelihood ratio for IgG antibody testing were 91.2%, 97.4%, and 35.6, respectively, based on the recommended adult cutoff point of 10 U/ml. Among children, use of cutoff points in the range of 7 to 9 U/ml yielded optimal values for sensitivity and specificity, as well as a positive likelihood ratio., Conclusions: The performance of the E-plate anti-H pylori IgG antibody test was comparable to that of the stool antigen test and is therefore suitable for epidemiologic studies of H pylori infection in large samples.

The incidence of Helicobacter pylori (H. pylori) infection is rapidly decreased in Japan. H. pylori infection is mainly acquired in the first 2 years life and the risk of infection declines rapidly after 5 years of age. Person-to-person transmission in the family appears to be the predominant and in the population with low prevalence, several studies showed the infected mother is likely to be the main source of the infection. H. pylori can be detected from vomitus, saliva and cathartic stools and the possibility of source of infection. Waterborne infection is unlikely in the developed countries.

Background: Rapid urine-HpAb is reported to be a reliable test of Helicobacter pylori infection in adults, but there are no data on the application of the test in children. The aim of this study was to evaluate the accuracy of a urine-based enzyme-linked immunosorbent assay (urine-HpELISA) and immunochromatography (rapid urine-HpAb) kit for anti-H. pylori immunoglobulin G antibody in children. We compared its sensitivity and specificity in reference to the (13) C-urea-breath test (UBT) and H. pylori stool antigen test (HpSA)., Methods: In total, 101 Japanese children without significant upper-abdominal symptoms were included (mean age, 7.1 years; range 2-15 years). Their sensitivity and specificity were evaluated in reference to the UBT and HpSA., Results: Thirty-seven children were judged H. pylori-positive and 64 negative by the UBT and HpSA. No discrepancy in the results was observed between UBT and HpSA. Urine-HpELISA showed 91.9% sensitivity and 96.9% specificity with an accuracy of 95.0%. Rapid urine-HpAb showed 78.4% sensitivity and 100% specificity with an accuracy of 92.1%. Seven false negative results for rapid urine-HpAb were from children aged younger than 10 years, and their antibody titers of urine-HpELISA were lower than true positives., Conclusions: For the diagnosis of H. pylori infection in Japanese children, both tests are non-invasive, inexpensive, reliable and easy-to-perform methods giving satisfactory accuracy, although the sensitivity of the rapid urine-HpAb kit was inferior to that of the urine-HpELISA kit, especially in children aged younger than 10 years, showing relatively low titer of H. pylori antibody., (© 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.)

This study used multilocus sequence typing (MLST) of total DNA extracted from faecal specimens to genotype Helicobacter pylori to analyse intra-familial transmission. Faecal DNA was extracted and amplified by nested PCR. The products were analysed by direct sequencing and the allele type was determined using an MLST website. Mother-to-child transmission was suspected in at least two of three families, and father-to-child transmission was suspected in one family.

Background and Aim: Two types of stool antigen tests have been used in the management of Helicobacter pylori infection. Testmate Pylori Antigen enzyme immunoassay (TPAg EIA) is a direct sandwich enzyme immunoassay (EIA) while Testmate Rapid Pylori Antigen (Rapid TPAg) is performed using immunochromatography. The aim of this study was to study the characterization and usefulness of these tests., Methods: Accuracy of both tests was studied using 111 fecal samples obtained from H. pylori-positive or -negative patients. Cross-reactivity was examined with four other Helicobacter spp. and five fecal bacteria in humans. To estimate the sensitivity of both kits, we tested H. pylori clinical strains. We also examined the diagnostic performances of both tests after the storage for 12 months., Results: The accuracy of both Testmate kits was 100% in fecal samples from 111 patients. No cross-reactivity was observed in both Testmate kits in five fecal bacteria and four other Helicobacter spp. TPAg EIA and Rapid TPAg showed positive results in 1342 of 1344, and 483 of 485 clinical strains, respectively. Diagnostic performances was maintained for 12 months when TPAg EIA was stored at 4°C and Rapid TPAg at 30°C., Conclusions: We examined the details of high accuracy of TPAg EIA and Rapid TPAg. The diagnostic performance of both kits was maintained after storage for up to 1 year. The two types of tests would be useful in the management of H. pylori infection., (© 2012 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.)

Background and Aim: Ecabet sodium is reported to have a bactericidal effect on Helicobacter pylori and inhibit urease activity in vitro., Methods: Seven male volunteers (mean age, 51.3 years; range, 45-55 years) with H. pylori infection were medicated with 1 g ecabet sodium t.i.d. for 4 weeks. The urea breath test (UBT) was performed 10 times per person: before medication, seven times in 2 weeks, and once in the third and fourth weeks. Stool antigen tests (HpSA PLUS and Testmate pylori antigen) were performed five times per person: before medication and weekly during medication., Results: The premedication UBT value ranged from 4.9 ‰ to 77.4 ‰ and from 2.9 ‰ to 44 ‰ at the end of the treatment period. Not one of the subjects had a negative UBT result during medication. The optical densities of the HpSA and Testmate pylori antigen tests ranged from 0.4 to > 3.0 premedication and from 0.0 to > 3.0 at the end of treatment. HpSA and Testmate pylori antigen were negative in two cases., Conclusions: In this study, ecabet sodium did not effect the results of UBT in volunteers with H. pylori infection. Ecabet sodium may influence stool antigens because in two of seven cases the H. pylori stool antigen tests returned negative results., (© 2012 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.)

Aim: To investigate the effects of proton pump inhibitor (PPI) treatment on stool antigen test using the TestMate pylori enzyme immunoassay., Methods: This study assessed 28 patients [16 men and 12 women; mean age (63.1 ± 5.9) years; range, 25-84 years] who underwent stool antigen test and urea breath test (UBT) before and after PPI administration., Results: Using the UBT as the standard, the sensitivity, specificity and agreement of the stool antigen test in all 28 patients were 95.2%, 71.4%, and 89.3%, respectively, before PPI administration, and 88.9%, 90.9%, and 89.3%, respectively, after PPI treatment. Mean UBT values were 23.98% ± 5.33% before and 16.19% ± 4.75% after PPI treatment and, in 15 patients treated for ≥ 4 wk, were significantly lower after than before 4 wk of PPI treatment (12.58% ± 4.49% vs 24.53% ± 8.53%, P = 0.048). The mean optical density (A(450/630)) ratios on the stool antigen test were 1.16 ± 0.20 before and 1.17 ± 0.24 after PPI treatment (P = 0.989), and were 1.02 ± 0.26 and 0.69 ± 0.28, respectively, in the group treated for > 4 wk (P = 0.099)., Conclusion: The stool antigen test was equally sensitive to the UBT, making it a useful and reliable diagnostic method, even during PPI administration.

Background: A number of noninvasive tests have been developed to establish the presence of Helicobacter pylori infection. However, thus far these tests have only been capable of detecting its presence. An increasing number of antibiotic-resistant H. pylori infections have been reported and they are known to be correlated with 23S rRNA single nucleotide polymorphisms (SNPs). We hypothesized that genomic analysis of H. pylori recovered from gastric washes could not only be less invasive, but also useful as a screening test and for assessing the outcome of eradication therapy., Methods: Biopsy specimens and gastric washes were collected from 100 patients during endoscopic examination. Then we analyzed 23S rRNA, ureA, and cagA genes using PCR and high-throughput pyrosequencing analysis., Results: Forty-five percent (44/97) of patients tested positive for ureA and 42.3% (41/97) tested positive by a rapid urease test. One hundred percent (35/35) of patients who tested positive by both methods were observed to have the cagA gene. Among these 35 patients, 23S rRNA SNPs were present in 34.3% (12/35)., Conclusions: Gastric wash-based PCR and a pyrosequencing assay were used to rapidly detect and estimate the number of 23S rRNA SNPs in clinical isolates of H. pylori. Not only is this a less invasive technique, but it can also diagnose drug resistance., (Copyright © 2011 S. Karger AG, Basel.)

Objective: Stool antigen tests using monoclonal antibody are used to test the results of eradication therapy of Helicobacter pylori. A newly developed test using multiple monoclonal antibodies is considered to have higher sensitivity. The aim of this study was to examine whether monoclonal antibody-based stool antigen tests are equally applicable to determine the results of eradication therapy., Materials and Methods: Stool specimens obtained from patients infected with H. pylori were diluted by human stool and tested by both Testmate pylori antigen enzyme immunoassay (TPAg EIA) and Premier Platinum HpSA PLUS (HpSA ELISA II). A total of 239 patients infected with H. pylori received eradication therapy and 5-8 weeks after finishing the treatment, stool samples were tested by TPAg EIA and HpSA ELISA II. On the same day of stool collection, all the patients received (13)C-urea breath test (UBT)., Results: After 5× dilution, optical density (OD) values of TPAg EIA were significantly reduced and three out of four stool specimens were tested negative after 10× dilution. By contrast, three specimens were tested positive even after 100× dilution by HpSA ELISA II. In the determination of eradication therapy, accordance between the two tests was 95.8%. Among 199 patients who tested negative by both stool antigen tests, 10 patients were positive by UBT. Overall accordance of TPAg EIA and HPSA ELISA II to UBT was 91.2% and 95.4%, respectively (NS)., Conclusions: Although reduction of OD values was seen in TPAg EIA, it did not seem to cause false negative results in stool samples after eradication therapy. Both TPAg EIA and HpSA ELISA II were equally useful to determine the results of eradication therapy comparing with UBT.

Objective: A higher incidence of infectious disease has been documented in U.S. regions bordering Mexico compared with non-border areas. We assessed the prevalence of important gastrointestinal infections in Ciudad Juarez, Mexico, and El Paso, Texas, the largest binational community along the U.S.-Mexico border., Methods: Fecal specimens from a sample of the asymptomatic population representing all ages were tested for Helicobacter pylori (H. pylori), Cryptosporidium spp., Giardia spp., and other intestinal parasitic pathogens using flotation, immunoassays, and/or polymerase chain reaction. We also measured indicators of microbiological contamination of drinking water, hands of food preparers, and kitchen surfaces., Results: Overall, of the 386 participants, H. pylori was present in 38.2%, Taenia spp. in 3.3%, Giardia spp. in 2.7%, Cryptosporidium spp. in 1.9%, Entamoeba dispar in 1.3%, and Ascaris lumbricoides and Necator americanus in 0.3% of the study subjects; Cyclospora spp. and Entamoeba histolytica were not found. H. pylori infection was associated with handwashing (prevalence ratio [PR] = 1.3, 95% confidence interval [CI] 1.0, 1.8). Taenia spp. was found more often on the U.S. side (PR=8.6, 95% CI 2.3, 30.8). We did not find an association between these infections and the occurrence of total coliforms or fecal coliforms on kitchen surfaces. In addition, Escherichia coli was not found in any drinking water sample., Conclusion: The study results indicated that H. pylori and Taenia spp. infections may be highly prevalent along the U.S.-Mexico border. Additional research is necessary to adequately characterize the prevalence, as well as determine whether interventions that reduce these infections are warranted.

Background: Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan., Materials and Methods: Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines., Results: Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori-associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy., Conclusion: The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions.

Helicobacter pylori (H. pylori) infection is mainly acquired in the first 2 or 3 years and the risk of infection declines rapidly after 5 years of age. In developing countries, acquisition age of the infection is probably lower than in developed countries. In Japan, main transmission route is intrafamilial and mother to children infection is most important. But in developing countries, some reports suggest that extrafamilial infection is more important. The famous paper revealed that H. pylori can be cultivated from vomitus, saliva and cathartic stools and the possibility of source of H. pylori infection. Bed sharing, large number of family members, delayed weaning from a feeding bottle, regurgitated gastric juice in the mother's mouth are reported as risk factors of the infection.

The (13)C-urea breath test (UBT) is widely used to examine the results of eradication therapy for Helicobacter pylori. We examined whether a stool antigen test can be used as efficiently as UBT. (i) Ninety-four patients infected with H. pylori underwent eradication therapy. Six or eight weeks after the completion of treatment, the results were evaluated by UBT and a stool antigen test (TPAg). In 77 out of 78 patients who had negative UBT results, the TPAg results were also negative. Among the 16 UBT-positive patients, 12 were also positive by TPAg. Agreement of UBT and TPAg was 94.7%. (ii) Twenty-two patients with peptic ulcers in the active stage also received eradication therapy followed by proton pump inhibitor (PPI) administration. TPAg and UBT were performed to examine the results of eradication therapy at the end of PPI administration and at least 7 days after its discontinuation. Of the 22 patients taking PPIs, TPAg evaluated the results of eradication therapy accurately in 21 patients. TPAg appears to be an accurate test for evaluating the results of H. pylori eradication therapy, and to be as efficient as (13)C-UBT. Use of the stool antigen test should be considered as an alternative, particularly in patients who have to take PPIs in order to avoid the risk of peptic ulcers.

Background and Aims: Infection with Helicobacter hepaticus is suggested to play a role in the pathogenesis of chronic liver disease in humans. However, reactive antigens among Helicobacter species make the development of an H. hepaticus ELISA test with high specificity difficult. A new monoclonal antibody from a hybridoma clone (HRII-51) showed high specificity to H. hepaticus without cross-reaction to other gastrointestinal bacteria., Methods: The molecular weight of HRII-51 immunoreactive antigen was examined by Western blot of H. hepaticus probed with the monoclonal antibody HRII-51. A HRII-51-immunoreactive antigen capture ELISA was prepared in which the specific antigen was anchored by HRII-51-immobilized ELISA plate. Accuracy of HRII-51 antigen capture ELISA was examined using sera obtained from mice inoculated with Helicobacter species. Specificity of HRII-51 antigen capture ELISA was compared to that of H. hepaticus antigen-based ELISA using human sera with absorption by H. pylori cell lysate., Results: HRII-51 immunoreactive antigen had a molecular weight of 15 kDa. Sensitivity and specificity of HRII-51 antigen capture ELISA were 87.0% and 97.6% in mice inoculated with Helicobacter species. In human sera, modification of the results by absorption with H. pylori lysate was smaller in HRII-51 antigen capture ELISA comparing with H. hepaticus-antigen-based ELISA., Conclusion: Use of the HRII-51 antigen capture ELISA would be a useful approach for the serodiagnosis of H. hepaticus infection in both experimental animals and humans.

Rapid immunochromatographic tests for Helicobacter pylori infection have been developed to allow "near-patient" testing. We therefore performed a pilot study to test a rapid immunochromatographic stool antigen test for the diagnosis of H. pylori infection in asymptomatic children. We tested stool specimens collected from children participating in a cohort study in the United States and Mexico. H. pylori-positive status was defined by positivity on at least 2 tests: a commercial H. pylori stool antigen enzyme immunoassay, an immunoglobulin G antibody enzyme immunoassay, and the C-urea breath test. Negative H. pylori status was defined by negative findings of all of these tests. Of 52 children (22 girls, 30 boys) 25 were H. pylori-positive, 19 H. pylori-negative, and 8 uncertain (eg, presumably negative; positive findings on 1 of the 3 noninvasive tests). The sensitivity and specificity of the new stool antigen test for those with definite H. pylori status were 100% (exact 95% CI 86.3%-100% and 82.4%-100%, respectively). This rapid stool antigen test may prove useful for point-of-care testing and epidemiological field studies. Larger prospective studies are needed in symptomatic and asymptomatic children for more precise estimates.

Surveillance of Helicobacter pylori antimicrobial susceptibility reflecting the general population in Japan is limited. The antimicrobial susceptibilities of 3,707 H. pylori strains isolated from gastric mucosa samples of previously untreated patients diagnosed with gastroduodenal diseases at 36 medical facilities located throughout Japan between October 2002 and September 2005 were evaluated. Using an agar dilution method for antimicrobial susceptibility testing of H. pylori, the MIC distributions and trends during the study period for clarithromycin, amoxicillin, and metronidazole were studied. While the MIC(50) and MIC(90) for clarithromycin did not change during the 3-year period, the MIC(80) showed a 128-fold increase. Furthermore, the rate of resistance increased yearly from 18.9% (2002 to 2003) to 21.1% (2003 to 2004) and 27.7% (2004 to 2005). With a resistance rate of 19.2% among males compared to 27.0% among females, a significant gender difference was observed (P < 0.0001). Our study shows that in Japan, there is an evolving trend towards increased resistance to clarithromycin with geographical and gender differences as well as between clinical disease conditions. No significant changes in resistance were observed for amoxicillin and metronidazole during the period. While the benefit of H. pylori antimicrobial susceptibility testing has been debated in Japan, current empirical regimens are not based on susceptibility data representative of the general population. The development of an effective H. pylori eradication regimen in Japan will require continued resistance surveillance as well as a better understanding of the epidemiology of resistance.

Background: Large-scale studies of rabeprazole-based Helicobacter pylori eradication therapy have not been reported in Japan., Aims: To evaluate H. pylori eradication by rabeprazole-based therapy with reference to antibiotic susceptibility, CYP2C19 genotype, and rabeprazole and clarithromycin dosages., Methods: From 35 centres 479 H. pylori-positive patients with gastric or duodenal ulcer were randomized to four treatment groups: Group 1 (10 mg rabeprazole + 750 mg amoxicillin + 200 mg clarithromycin twice daily for 7 days); Group 2 (10 mg, 750 mg, 400 mg); Group 3 (20 mg, 750 mg, 200 mg) and Group 4 (20 mg, 750 mg, 400 mg)., Results: Eradication rates were 86% (102 of 119), 89% (97 of 109), 91% (106 of 116) and 90% (104 of 115) for Groups 1-4, respectively. The eradication rate was 95% (360 of 379) for clarithromycin-susceptible strains, and 50% (30 of 60) for clarithromycin-resistant strains. The eradication rates were 88% (332 of 379) and 96% (77 of 80) in extensive metabolizers and poor metabolizers, respectively., Conclusions: Rabeprazole-based therapies achieved 50% eradication of clarithromycin-resistant H. pylori, and even achieved good rates in extensive metabolizers. Accordingly, rabeprazole can be recommended as part of a first-line proton pump inhibitor-based triple therapy for H. pylori.

Eradication treatment for Helicobacter pylori is known to cause mild but relatively frequent adverse effects. Some adverse effects such as diarrhoea and soft stools are related to disruption of the composition of the intestinal microflora. This study investigated the microfloral changes resulting from administration of an eradication regimen using proton pump inhibitor (PPI), amoxycillin and clarithromycin. Twenty-eight laboratory-bred Japanese macaques either were administered eradication treatment by this regimen for 7 days or received no medication. Faecal samples were collected for analysis on days 0, 8 and 15, and both aerobic and anaerobic cultures were performed. Among aerobic bacteria, Streptococcus had significantly decreased by day 8, while Enterococcus and Enterobacteriaceae had significantly increased. However, the total number of aerobic bacteria was not significantly decreased from pretreatment levels 1 day after completion of treatment. The number of anaerobic bacteria did not change significantly by day 8. However, the number of Lactobacillus and the detection rate of Bifidobacterium, Peptostreptococcus and Veillonella significantly decreased by day 8, although the number of Bifidobacterium, Peptostreptococcus and Veillonella had almost recovered up to the pretreatment levels 1 week after completion of treatment (day 15). These results suggest that the alterations in the composition of the intestinal microflora caused by the antimicrobial regimen that excludes metronidazole are different from those caused by the regimen including this drug. However, the alterations in bacterial microflora had almost reversed 7 days after completion of treatment in these macaques, which supports clinical findings that diarrhoea or soft stools in humans resolve relatively quickly after a similar treatment.

Objectives: One of the counter-effects of Helicobacter pylori eradication therapy is subsequent obesity. Ghrelin is a recently discovered growth hormone releasing peptide. This endogenous secretagogue increases appetite and facilitates fat storage. The majority of circulating ghrelin is produced in the gastric mucosa. Therefore, we aimed at investigating changes in ghrelin immunoreactivity in gastric mucosa tissues of patients infected with H. pylori., Methods: Sixty-one patients with H. pylori infection (25 cases each of duodenal and gastric ulcer, and 11 cases of gastritis) and 22 healthy controls without H. pylori infection were included in the study. H. pylori-infected patients received standard proton pump-based triple therapy followed by histological examination and (13)C-urea breath test to confirm H. pylori eradication. H. pylori was eradicated in 50 out of 61 patients. Biopsy specimens were obtained from antrum and corpus before and 3 months following eradication. Ghrelin expression was evaluated immunohistochemically with an anti-ghrelin antibody, and the number of ghrelin-positive cells determined per 1 mm(2) of the lamina propria mucosa., Results: There was no relationship between ghrelin immunoreactivity and body weight or body mass index for healthy controls. The number of ghrelin-positive cells was significantly lower for H. pylori-infected patients than for healthy controls. However, the ghrelin-positive cell number increased significantly following H. pylori eradication without significant change in severity of atrophy., Conclusions: These data indicated that H. pylori infection affected ghrelin expression. After H. pylori eradication, gastric tissue ghrelin concentration increased significantly. This could lead to the increased appetite and weight gain seen following H. pylori eradication.

Helicobacter pylori (H. pylori) infection is the main cause of most gastroduodenal diseases; this discovery has been a major breakthrough in gastroenterology, hematology, dermatology and pediatrics. Triple therapy, including two antibiotics, amoxicillin and clarithromycin, and a proton pump inhibitor given for a week has been recommended as the treatment of choice in guideline for diagnosis and treatment of H. pylori infection in Japanese Journal of Helicobacter Research. However, this treatment may fail for several reasons including bacterial resistance. Our aim to review the problems and cautions in diagnosis and treatment of H. pylori infection.

In Japan, the noninvasive diagnostic tests currently approved for health insurance by the Ministry of Health are the serology test, the 13C-UBT test and the stool antigen test. The serology(antibody detection) test is useful for pretreatment screening, but because it reflects an immunologic response, false negatives are seen in patients with diseases such as rheumatoid arthritis and connective tissue diseases, and in the elderly. Furthermore, the serology test is difficult to use in the clinical setting, because 6 months or more is needed for the antibody titer to fall, after eradication therapy. For UBT, the expensive 13C-UBT is used. In view of the anticipated increase in testing, a test that is relatively inexpensive, simple, accurate and safe is needed. The stool antigen test has become available, and the test has been validated for accuracy. The stool antigen test is useful for the diagnosis of H. pylori infection before and after treatment in Japanese population.

The study aimed to determine the association between cytotoxin-associated gene product (CagA), serum gastrin and pepsinogen levels in Japanese children infected with Helicobacter pylori. Three hundred children were enrolled in the study. H. pylori infection was assessed using an enzyme-linked immunosorbent assay, and CagA status was assessed using immunoblotting. Serum gastrin and pepsinogen concentrations were measured by radioimmunoassay. H. pylori seroprevalence was 12.3% (37/300) and CagA status was identified in 28/37 H. pylori-seropositive children (75.7%). Serum pepsinogen I and II levels were significantly higher in CagA-seropositive than CagA-seronegative children with H. pylori infection. There was no significant relationship between CagA seropositivity and serum gastrin levels. In conclusion, CagA status has a significant impact on serum pepsinogen levels, possibly through enhanced gastric mucosal inflammation.

It has been suggested that enzyme immunoassay (EIA) kits validated in one region may yield variable diagnostic performance results in different regions, possibly due to strain-specific differences in antibody responses in different populations. We tested (13)C-urea breath test-characterized serum samples from 109 U.S. patients and 288 Japanese patients using enzyme immunoassay with different preparations of high-molecular-weight cell-associated (HM-CAP) antigens that are conserved across Helicobacter pylori strains. Replicate antigens were prepared from five H. pylori clinical isolates. Eight antigen preparations were evaluated: two of U.S. origin and six of Japanese origin. The accuracies achieved with the eight antigen preparations ranged from 94.4 to 96.3% with the U.S. samples. With the Japanese samples the accuracies achieved ranged from 92.3 to 97.2%. Use of a pool of HM-CAP antigens prepared from isolates from Japan resulted in a higher median enzyme immunoassay value and slightly fewer samples with indeterminate results compared to the results obtained by use of the U.S. standard HM-CAP antigen for H. pylori-positive patients (accuracies, 97.2 and 92.3%, respectively), suggesting that variations in performance between both antigen source and patient population might be reduced by using antigens pooled from several strains.

Since the eradication therapy of Helicobacter pylori(H. pylori) for peptic ulcer was covered by Japanese health insurance at 2000 November, this therapy has been generalized in Japan. However, some problems have cropped up at the time, for example, emergence of clarithromycin resistant bacterium etc. On the other hand, investigation of relation between H. pylori and gastric cancer is making progress. Uemura, et al. demonstrated H. pylori had an important role for gastric carcinogenesis by the elegant prospective study in 2001. Under the present circumstances, the Japanese society of Helicobacter Research has to reconsider the guideline for eradication therapy. In this paper, we would like to state the present status and problems of eradication therapy of the current guideline for eradication therapy, especially focusing on gastric cancer.

Background: To evaluate histopathological changes and effects on inhibition of ulcer recurrence, a follow-up survey was performed in Japanese patients with Helicobacter pylori-positive active peptic ulcers. These patients had previously participated in a large-scale multicenter trial of triple therapy with lansoprazole (LPZ)/amoxicillin (AMPC)/clarithromycin (CAM) for eradication of H. pylori., Methods: Patients who had been treated with LPZ only or a combination of LPZ, AMPC, and CAM for a period of 7 days and in whom ulcer healing had been confirmed after treatment were grouped according to successful or failed eradication of H. pylori. They were examined endoscopically to determine whether ulcers had recurred. The updated Sydney system was applied to study histological changes after H. pylori eradication therapy, compared with baseline., Results: Twelve months after treatment for H. pylorieradication, gastric ulcers had recurred in 11.4% of those with successful H. pylorieradication and in 64.5% of those with unsuccessful H. pylori eradication. Duodenal ulcers had recurred in 6.8% of patients for whom H. pylori eradication was successful and in 85.3% of patients in whom eradication failed. These findings proved that H. pylori eradication significantly reduced ulcer recurrence ( P < 0.0001 for both types of ulcers). Histopathological findings of inflammation and activity grade in both gastric and duodenal ulcers were more favorable in patients with successful eradication than in those with unsuccessful eradication., Conclusions: H. pylori eradication significantly inhibited ulcer recurrence in Japanese peptic ulcer patients. Histopathological findings were also improved with regard to inflammation and activity (neutrophils) in patients in whom H. pylori eradication was successful.

Urease test, histology, culture, urea breath test(UBT) and stool antigen test are accurate tests for Helicobacter pylori diagnosis. General practitioners are now going to test peptic ulcer disease patients with these tests before and after in Japan. To test with high accuracy after eradication therapy, it is important that examination should be done over 4 weeks after cessation of treatment with PPI and antibiotics. UBT and stool antigen test are suitable tests for diagnosis of Helicobacter pylori infection after treatment.

Peptic ulcer in elderly patients may be associated with Helicobacter pylori infection. Diagnosis for H. pylori infection should be needed in these patients. The test may be resulted in false negative in case of invasive diagnostic methods based gastric biopsy, because atrophic gastritis and intestinal metaplasia developed in patients may not be able to detect scarce infection of the bacterium. Urea breath test or stool antigen test are recommended for diagnosis of H. pylori infection in patients. It is suitable for patients, because of the non invasive nature of these diagnostic tests.

Recently, we reported the production of three new monoclonal antibodies with high specificity for a Helicobacter pylori antigen suitable for diagnosis of H. pylori infection. The aim of the present study was to identify the antigen recognized by these monoclonal antibodies concerning both H. pylori and the feces of human subjects infected with H. pylori. The cellular antigen was purified from an H. pylori cell extract by immunoaffinity column chromatography with the monoclonal antibody as a ligand. The amino-terminal amino acid sequences (eight residues) of the purified antigen and H. pylori catalase were the same. The molecular weights of native and subunit, specific catalase activity, and UV and visible spectra of the purified antigen were in good agreement with those of H. pylori catalase. The human fecal antigens were purified from two fecal samples of two H. pylori-positive subjects by ammonium sulfate precipitation, CM-Sephadex C(50) chromatography, and the same immunoaffinity chromatography used for the H. pylori cellular antigen. The fecal antigens had catalase activity. The amino-terminal amino acid sequences (five residues) of the human fecal antigen and H. pylori catalase were the same. The monoclonal antibodies reacted with the native cellular antigen, but did not react with the denatured antigen, human catalase, and bovine catalase. The results show that the target antigen of the monoclonal antibodies is native H. pylori catalase and that the monoclonal antibodies are able to specifically detect the antigen, which exists in an intact form, retaining the catalase activity in human feces.

Background: The NIH consensus conference in 1994 recommended that all patients with peptic ulcers should be tested and treated for Helicobacter pylori. Recent studies have shown that the eradication of H. pylori is associated with a significant reduction in the relapse rate of peptic ulcers, but there are few reports about long-term outcome., Aims: To evaluate the relapse rate of peptic ulcer in the long-term follow-up of patients after H. pylori eradication therapy., Patients and Methods: Patients infected with H. pylori (445; 88 duodenal ulcer, 357 gastric ulcer) were randomly divided into three groups. In group A, patients received 'conventional treatment' including acid decreasing therapy with a histamine H2-receptor antagonist or proton pump inhibitor (PPI). In group B, patients received 'dual therapy' including one antibiotic plus acid-decreasing therapy. In group C, patients received 'triple therapy' with PPI plus amoxicillin and clarithromycin. Eradication of H. pylori infection was assessed by histology of biopsy specimens from both the antrum and body corpus at 4 weeks, and 6 and 12 months after stopping therapy. Endoscopy was performed at intervals of 6 months for 5 years., Results: Intention-to-treat eradication rates for the duodenal ulcer patients were 0% for group A, 46% for group B and 80% for group C; eradication rates for the gastric ulcer patients were 0%, 33% and 83% respectively. No recurrence was noted in the duodenal ulcer patients and only 4% of gastric ulcers recurred after successful eradication during follow-up for 5 years. In contrast, in patients with persistent H. pylori infection all DU and 92% of gastric ulcers recurred., Conclusion: Eradication of H. pylori infection changes the natural course of peptic ulcer.

Helicobacter pylori (H. pylori) infection has been acknowledged as a promoter and an initiator for gastric carcinogenesis in experimental models using Mongolian gerbils with H. pylori strains TN2GF4 and ATCC 43504, which have + ve cagA and vacA phenotype s1 / m1. To get more insight into the role of H. pylori in gastric carcinogenesis, we studied the effect of H. pylori SS1, which has + ve cagA and vacA phenotype s2 / m2, on N-methyl-N-nitrosourea (MNU)-induced chemical gastric carcinogenesis using SPF C57BL / 6 mice. Thus, H. pylori SS1 was inoculated 1 week after the completion of MNU treatment to examine the promoting effect of this bacterium. The incidences of polypoid lesions, differentiated adenocarcinomas, and adenomatous hyperplasias were 67% (10 / 15), 47% (7 / 15) and 80% (12 / 15), respectively, in the MNU-alone group. The corresponding figures were 31% (8 / 26), 23% (6 / 26) and 35% (9 / 26) in the MNU + H. pylori group. The incidences of polypoid lesions and adenomatous hyperplasia were significantly different between the groups. Thus, the results indicate that H. pylori SS1 infection reduced susceptibility to chemical gastric carcinogenesis in this model. The discrepancy between the present result and previous results is likely to have been caused by differences in host factors and bacterial factors. Further study of the relationship between gastric carcinogenesis and H. pylori infection is needed.

Background: Previous studies have shown that gastric acid suppression worsens corpus gastritis in Helicobacter pylori (H. pylori)-positive patients. We evaluated the effect of acid-suppressive therapy and vitamin C on H. pylori-associated gastritis., Methods: Forty patients with reflux esophagitis were divided into three groups by the status of H. pylori and therapy: group A (n=15), H. pylori (+) and omeprazole 20 mg; group B (n=15), H. pylori (+) and omeprazole 20 mg + vitamin C 1200 mg; and group C (n=10), H. pylori (-) and omeprazole 20 mg. In all three groups, the mucosal interleukin (IL)-8 contents, H. pylori colonization density, neutrophil infiltration in the corpus, and serum gastrin were evaluated at entry and 2 weeks after starting therapy; in group B, serum vitamin C levels were also measured., Results: In group A, the IL-8 contents and the degree of neutrophil infiltration during therapy exceeded those at entry, whereas in groups B and C, these values did not change significantly with treatment. Helicobacter pylori colonization density during therapy was similar to that at entry in all three groups. The serum gastrin (in all groups) and vitamin C levels (in group B) during therapy exceeded those at entry., Conclusions: Potent acid suppression worsens H. pylori-associated corpus gastritis, although such worsening gastritis may be inhibited by vitamin C.

In this paper, we present our research on the lipid A of Helicobacter pylori, an experimental study using the Mongolian gerbil model and experimental carcinogenesis using the mouse model to evaluate roles of host factors and bacterial factors which are related to the pathogenicity of Helicobacter pylori including gastric carcinogenesis. Future study on bacterial factors and host factors may give more insight into the role of Helicobacter pylori in gastric carcinogenesis.

Background: In preparation of the approval of Helicobacter pylori therapy by the Japanese national health system, the board of directors of the Japanese Society for Helicobacter Research decided to prepare guidelines on the diagnosis and treatment of H. pylori infection for physicians in routine medical practice., Methods: A guidelines preparation committee was formed and six meetings were held. Then, in December 1999, a consensus meeting was held in Kobe to obtain the opinions of general practitioners as well as experts from Europe, North America, and Asia., Results: Helicobacter pylori eradication therapy is recommended in gastric or duodenal ulcer patients. Helicobacter pylori eradication therapy is recommended or gastric mucosa associated lymphoid tissue (MALT) lymphoma but it should be done at specialist institutions. The significance of H. pylori eradication therapy is still under evaluation in patients with hyperplastic polyps, chronic atrophic gastritis, non-ulcer dyspepsia and in patients after endoscopic mucosal resection of gastric cancer and after gastrectomy for gastric cancer. When diagnosing H. pylori infection, at least one of the tests requiring endoscopic biopsy (e.g. rapid urease test, histology, or culture) and tests not requiring biopsy (e.g. measurement of H. pylori antibody or urea breath test) should be used. Multiple tests are recommended to increase the accuracy. The drugs of first choice currently covered by the national health insurance system in Japan are: lansoprazole (30 mg) 1 capsule twice daily, amoxicillin (250 mg) 3 capsules twice daily, and clarithromycin (200 mg) 1-2 tablets twice daily. These three drugs should be administered after breakfast and dinner for 1 week., Conclusion: These guidelines are intended for utilization in routine medical practice after the Japanese national health system begins to cover the management of H. pylori infection.

Background: Two triple therapies with lansoprazole (LPZ)/amoxicillin (AMPC)/clarithromycin (CAM) for eradication of Helicobacter pylori were studied in multicenter, double-blind fashion to evaluate the eradication rate of H. pylori and safety of eradiation treatment in Japanese patients with H. pylori-positive active gastric ulcers or duodenal ulcers., Methods: Patients were randomly chosen for the control treatment of LPZ 30 mg twice a day (b.i.d.; Group A-LPZ-only) or the test treatments of LPZ 30 mg plus AMPC 750 mg and CAM 200 mg b.i.d. (Group B-LAC200) and LPZ 30 mg, AMPC 750 mg and CAM 400 mg b.i.d. (Group C-LAC400). All eradication treatments lasted for a period of 7 days. Successful eradication was assessed by culture and gastric histology 1 month after completion of the ulcer treatment., Results: The eradication rates of H. pylori in the full analysis set were 0% in Group A-LPZ-only, 87.5% in Group B-LAC200 and 89.2% in Group C-LAC400 for gastric ulcer and, 4.4% in Group A-LPZ-only, 91.1% in Group B-LAC200 and 83.7% in Group C-LAC400 for duodenal ulcer. The eradication rates of Group B-LAC200 and Group C-LAC400 were 89.2% (95% CI: 84.8-93.7%) and 86.4% (95%CI: 81.5-91.3%) in total in the full analysis set, 89% (95% CI: 84.3-93.7%) and 85.3% (95%CI: 80.1-90.5%) in the per protocol set. The eradication rates in Groups B-LAC200 and group C-LAC400 were statistically significantly higher than the rate in Group A-LPZ-only for both gastric ulcer and duodenal ulcer patients (p <.0001 for both)., Conclusion: A satisfactorily high H. pylori eradication rate was obtained in Japanese ulcer patients with the triple therapy regimen consisting of LPZ 30 mg, AMPC 750 mg, and CAM 200 mg b.i.d.

Background: Lipopolysaccharides of Helicobacter pylori have an antigenic structure that mimics Lewis X occurring in gastric mucosa. The pathogenic role of antigenic mimicry in Helicobacter pylori-induced gastritis has been of recent interest., Aim: To examine whether this molecular mimicry affects gastric mucosal inflammation in patients infected with Helicobacter pylori., Patients: A total of 59 patients (mean age 58.0 years, 35 males, 24 females) were studied., Methods: Serum samples were collected to measure IgG antibodies to Helicobacter pylori and Lewis X. Biopsy specimens were obtained from the antrum and corpus for the grading of gastritis. Correlation coefficients between serum Lewis X antibody titre and histological grades of inflammatory infiltration were determined., Results: There was no significant correlation between anti-Lewis X antibody titre and the grade of mononuclear or polymorphonuclear cell infiltration. High titre of anti-Lewis X antibody was seen only in patients who had increased inflammatory infiltration in the corpus., Conclusions: Serum anti-Lewis X antibody, possibly induced by Helicobacter pylori infection, does not seem to play a major role in gastric mucosal inflammation in patients with Helicobacter pylori infection.