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Background: European and North-American guidelines on management of H. pylori infection in children provide the option not to treat even if the infection is endoscopically confirmed. We used data from the EuroPedHp Registry to identify factors associated with therapy decisions., Methods: We included treatment-naïve patients reported between 2017 and 2020 from 30 centers in 17 European countries. Multivariable logistic regression identified factors including comorbidities within and outside the gastrointestinal (GI) tract influencing the decision for or against therapy., Results: Of 1165 patients (52% females, median age 12.8), 28% (321/1165) reported any alarm symptom, 26% (307/1165) comorbidities, and 16% (192/1165) did not receive eradication treatment. Therapy was initiated less often in children having any GI comorbidity (57%, n = 181), particularly in those with eosinophilic esophagitis (60%, n = 35), inflammatory bowel disease (54%, n = 28), and celiac disease (43%, n = 58), compared to those with non-GI (86%, n = 126) or no comorbidity (89%, n = 858), despite similar frequencies of alarm and non-alarm symptoms, ulcers, erosions, and nodular gastritis. Patients with GI and without comorbidities remained more likely untreated in high versus low H. pylori prevalence countries (p < 0.0001). In children without comorbidities, factors favoring therapy included older age, being overweight, having symptoms, erosions, antral nodularity, and available antibiotic susceptibility results., Conclusion: In this cohort, H. pylori-infected children with GI comorbidities compared to no comorbidity showed 75% reduced chance of receiving eradication therapy. We found no evidence supporting different management strategies in infected patients with GI comorbidities compared to all pediatric patients with endoscopically proven H. pylori infection., (© 2024 The Author(s). Helicobacter published by John Wiley & Sons Ltd.)

Competing Interests: The authors declare that they have no conflict of interest.

Purpose: The EuroPedHp-registry aims to monitor guideline-conform management, antibiotic resistance, and eradication success of 2-week triple therapy tailored to antibiotic susceptibility (TTT) in Helicobacter pylori-infected children., Methods: From 2017 to 2020, 30 centres from 17 European countries reported anonymized demographic, clinical, antibiotic susceptibility, treatment, and follow-up data. Multivariable logistic regression identified factors associated with treatment failure., Results: Of 1605 patients, 873 had follow-up data (53.2% female, median age 13.0 years, 7.5% with ulcer), thereof 741 (85%) treatment naïve (group A) and 132 (15%) after failed therapy (group B). Resistance to metronidazole was present in 21% (A: 17.7%, B: 40.2%), clarithromycin in 28.8% (A: 25%, B: 51.4%), and both in 7.1% (A: 3.8%, B: 26.5%). The majority received 2-week tailored triple therapy combining proton pump inhibitor (PPI), amoxicillin with clarithromycin (PAC) or metronidazole (PAM). Dosing was lower than recommended for PPI (A: 49%, B: 41%) and amoxicillin (A: 6%, B: 56%). In treatment naïve patients, eradication reached 90% (n = 503, 95% CI 87-93%) and 93% in compliant children (n = 447, 95% CI 90-95%). Tailored triple therapy cured 59% patients after failed therapy (n = 69, 95% CI 48-71%). Treatment failure was associated with PAM in single clarithromycin resistance (OR = 2.47, 95% CI 1.10-5.53), with PAC in single metronidazole resistance (OR = 3.44, 95% CI 1.47-8.08), and with low compliance (OR = 5.89, 95% CI 2.49-13.95)., Conclusions: Guideline-conform 2-weeks therapy with PPI, amoxicillin, clarithromycin or metronidazole tailored to antibiotic susceptibility achieves primary eradication of ≥ 90%. Higher failure rates in single-resistant strains despite tailored treatment indicate missed resistance by sampling error., (© 2022. The Author(s).)

Objectives: The aim of the study was to assess clinical presentation, endoscopic findings, antibiotic susceptibility and treatment success of Helicobacter pylori (H. pylori) infected pediatric patients., Methods: Between 2013 and 2016, 23 pediatric hospitals from 17 countries prospectively submitted data on consecutive H. pylori-infected (culture positive) patients to the EuroPedHP-Registry., Results: Of 1333 patients recruited (55.1% girls, median age 12.6 years), 1168 (87.6%) were therapy naïve (group A) and 165 (12.4%) had failed treatment (group B). Patients resided in North/Western (29.6%), Southern (34.1%) and Eastern Europe (23.0%), or Israel/Turkey (13.4%). Main indications for endoscopy were abdominal pain or dyspepsia (81.2%, 1078/1328). Antral nodularity was reported in 77.8% (1031/1326) of patients, gastric or duodenal ulcers and erosions in 5.1% and 12.8%, respectively. Primary resistance to clarithromycin (CLA) and metronidazole (MET) occurred in 25% and 21%, respectively, and increased after failed therapy. Bacterial strains were fully susceptible in 60.5% of group A, but in only 27.4% of group B. Primary CLA resistance was higher in Southern and Eastern Europe (adjusted odds ratio [ORadj] = 3.44, 95% confidence interval [CI] 2.22-5.32, P < 0.001 and 2.62, 95% CI: 1.63-4.22, P < 0.001, respectively) compared with Northern/Western Europe. Children born outside Europe showed higher primary MET resistance (ORadj = 3.81, 95% CI: 2.25-6.45, P < 0.001). Treatment success in group A reached only 79.8% (568/712) with 7 to 14 days triple therapy tailored to antibiotic susceptibility., Conclusions: Peptic ulcers are rare in dyspeptic H. pylori-infected children. Primary resistance to CLA and MET is markedly dependent on geographical regions of birth and residence. The ongoing survey will show whether implementation of the updated ESPGHAN/NASPGHAN guidelines will improve the eradication success.

Background: Because of the changing epidemiology of Helicobacter pylori infection and low efficacy of currently recommended therapies, an update of the European Society for Paediatric Gastroenterology Hepatology and Nutrition/North American Society for Pediatric Gastroenterology, Hepatology and Nutrition recommendations for the diagnosis and management of H pylori infection in children and adolescents is required., Methods: A systematic review of the literature (time period: 2009-2014) was performed. Representatives of both societies evaluated the quality of evidence using GRADE (Grading of Recommendation Assessment, Development, and Evaluation) to formulate recommendations, which were voted upon and finalized using a Delphi process and face-to-face meeting., Results: The consensus group recommended that invasive diagnostic testing for H pylori be performed only when treatment will be offered if tests are positive. To reach the aim of a 90% eradication rate with initial therapy, antibiotics should be tailored according to susceptibility testing. Therapy should be administered for 14 days, emphasizing strict adherence. Clarithromycin-containing regimens should be restricted to children infected with susceptible strains. When antibiotic susceptibility profiles are not known, high-dose triple therapy with proton pump inhibitor, amoxicillin, and metronidazole for 14 days or bismuth-based quadruple therapy is recommended. Success of therapy should be monitored after 4 to 8 weeks by reliable noninvasive tests., Conclusions: The primary goal of clinical investigation is to identify the cause of upper gastrointestinal symptoms rather than H pylori infection. Therefore, we recommend against a test and treat strategy. Decreasing eradication rates with previously recommended treatments call for changes to first-line therapies and broader availability of culture or molecular-based testing to tailor treatment to the individual child.

Unlabelled: The goal of first-line Helicobacter pylori therapy is to reach an eradication rate of 90% to avoid further investigations, antibiotic use, and spreading of resistant strains., Aim: To evaluate the eradication rate of high-dose sequential therapy in treatment-naïve children and to assess factors associated with failure., Methods: Prospective data assessed in a registry from nine European centers between October 2009 and December 2011. Children with biopsy-proven Helicobacter pylori infection were prescribed 5 days of esomeprazole and amoxicillin, followed by 5 days of esomeprazole, clarithromycin, and metronidazole according to bodyweight. Eradication was assessed after 8-12 weeks. Primary endpoint was the eradication rate in children who received at least one dose and had follow-up data. Multivariate analysis evaluated potential factors for treatment success including sex, age, center, migrant status, antibiotic resistance, and adherence to therapy., Results: Follow-up was available in 209 of 232 patients (age range 3.1-17.9 years, 118 females). Primary resistance occurred for clarithromycin in 30 of 209 (14.4%), for metronidazole in 32 (15.3%), for both antibiotics in 7 (3.3%), and culture failed in 6 (2.9%). Eradication was achieved in 168 of 209 children (80.4%, 95% CI 75.02-85.78), in 85.8% with no resistance, 72.6% with single resistance, and 28.6% with double resistance. Independent factors affecting eradication rate included resistance to clarithromycin (adjusted ORs 0.27 (0.09-0.84), p = .024), to metronidazole (0.25 (0.009-0.72), p = .010) or to both (0.04 (0.01-0.35), p = .004), and intake of ≤ 90% of prescribed drugs (0.03 (0.01-0.18), p < .001)., Conclusion: A high-dose 10-day sequential therapy cannot be recommended in treatment-naïve children., (© 2015 John Wiley & Sons Ltd.)

Background: To analyze risk factors associated with gastro-duodenal ulcers and erosions in children., Methods: Open, prospective, multicenter, case-control study carried out in 11 European countries in patients with gastric or duodenal ulcers/erosions and 2 age-matched controls each. Possible risk factors were recorded. Logistic regression models were performed with adjustment for centers and age groups., Results: Seven-hundred thirty-two patients (244 cases, 153 with erosions only and 91 with ulcers, and 488 controls) were recruited. Children receiving antimicrobials or acid suppressive drugs before endoscopy were excluded (202 cases/390 controls remained for risk factor analysis). Helicobacter pylori was detected more frequently in cases than controls but only in 32.0% versus 20.1% in controls (P = 0.001). Independent exposure factors for gastric ulcers were male gender (P = 0.001), chronic neurologic disease (P = 0.015), chronic renal disease (P < 0.001) and nonsteroidal anti-inflammatory drug consumption (P = 0.035). Exposure factors for duodenal ulcers were H. pylori infection (P < 0.001) and steroid consumption (P = 0.031). Chronic renal disease was the only independent factor associated with gastric erosions (P = 0.026), those associated with duodenal erosions being H. pylori infection (P = 0.023), active smoking (P = 0.006) and chronic arthritis (P = 0.008). No risk factor was identified in 97/202 (48.0%) cases., Conclusions: H. pylori remains a risk factor for duodenal, but not for gastric lesions in children in countries with low prevalence of infection. No risk factor could be identified in half of the children with gastro-duodenal ulcers/erosions.

Objective: As the clinical implications of Helicobacter pylori infection in children and adolescents continue to evolve, ESPGHAN and NASPGHAN jointly renewed clinical guidelines using a standardized evidence-based approach to develop updated recommendations for children and adolescents in North America and Europe., Methods: An international panel of 11 pediatric gastroenterologists, 2 epidemiologists, 1 microbiologist, and 1 pathologist was selected by societies that developed evidence-based guidelines based on the Delphi process with anonymous voting in a final face-to-face meeting. A systematic literature search was performed on 8 databases of relevance including publications from January 2000 to December 2009. After excluding nonrelevant publications, tables of evidence were constructed for different focus areas according to the Oxford classification. Statements and recommendations were formulated in the following areas: whom to test, how to test, whom to treat, and how to treat. Grades of evidence were assigned to each recommendation based on the GRADE system., Results: A total of 2290 publications were identified, from which 738 were finally reviewed. A total of 21 recommendations were generated, and an algorithm was proposed by the joint committee providing evidence-based guidelines on the diagnostic workup and treatment of children with H pylori infection., Conclusions: These clinical practice guidelines represent updated, best-available evidence and are meant for children and adolescents living in Europe and North America, but they may not apply to those living on other continents, particularly in developing countries with a high H pylori infection rate and limited health care resources.

Unlabelled: There are no solid figures of the frequency of ulcer disease during childhood in Europe. We assessed its frequency and analyzed known risk factors., Patients and Methods: Ulcers, erosions, indications, and risk factors were recorded in all children undergoing an upper gastrointestinal endoscopy in a prospective study carried out during 1-month simultaneously in 19 centers among 14 European countries., Results: Ulcers and/or erosions were observed in 56 out of 694 children. Children with ulcers/erosions were significantly older than those without lesions (10.3+/-5.5 vs. 8.1+/-5.7 years, P=0.002). Helicobacter pylori infection was present in 15 of 56 children (27%) where NSAIDs were used in eight, steroids in five, immune-suppressive drugs in five, antibiotics in six, antacids in one, H2-blockers in six and proton pump inhibitors in eight children (more than one risk factor was detected in 32 of 56 children). No risk factors were observed in 24 of 56 children (43%). The main indications for endoscopy were epigastric or abdominal pain (24%) and suspicion of gastroesophageal reflux disease (15%). Similarly, epigastric tenderness, hematemesis, melena, and weight stagnation were significantly associated with ulcers/erosions, whereas sex, H. pylori infection, socioeconomic and lifestyle factors were equally distributed., Conclusion: Although limited by the short-time duration and the heterogeneity of the patients included throughout the 19 centers, our study shows a frequency of 8.1% of ulcers and/or erosions in children, occurring mainly in the second decade of life. H. pylori infection and gastrotoxic medications were less frequently implicated than expected.

The array of tests that can be used for diagnosis of Helicobacter pylori infection is large, and it can be confusing to define which test to use particularly in children where results may not be comparable to those obtained in adult patients. Using PubMed, we reviewed the English literature from January 1999 to May 2009 to identify articles that determined sensitivity and specificity of H. pylori invasive and non-invasive diagnostic tests in children. We excluded articles that presented a review of the literature, abstracts, case reports, or series where children's results could not be separated from adult populations. Of the tissue based methods, rapid urease tests have better sensitivity than histology to detect presence of H. pylori; however, histology can detect the pathology associated with disease including gastritis, intestinal metaplasia, and other conditions that could be the cause of the child's symptoms. Culture of gastric tissues or stool has 100% specificity but sensitivity is low. Of the serologic tests, immunoblot has the best sensitivity. The urea breath tests have >75% sensitivity for detection of H. pylori before and after treatment. Immunoassays in stool using monoclonal antibodies have >95% sensitivity for detection of H. pylori before and after treatment. PCR testing can be performed in tissue and stool samples and can detect genes associated to antibiotic resistance. In summary, the current commercial non-invasive tests have adequate sensitivity and specificity for detecting the presence of H. pylori; however, endoscopy with histopathology is the only method that can detect H. pylori and lesions associated with the infection.

Background: Helicobacter pylori-associated diseases and gastroduodenal ulcer disease are common conditions of major clinical and economic importance. There is thus a need for a guideline that incorporates the scientific knowledge gained in recent years and that takes specific aspects of the situation in Germany into account with regard to epidemiology, resistance status, diagnostic evaluation, and treatment., Methods: This level-S3 consensus guideline was developed in accordance with the recommendations of the Association of Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF). It was commissioned by the German Association for Digestive and Metabolic Diseases (Deutsche Gesellschaft für Verdauungs- und Stoffwechselkrankheiten, DGVS) and prepared in cooperation with other scientific societies. After search terms were compiled, a systematic, IT-supported literature search was performed in the PubMed and Cochrane databases. The search was restricted to articles that appeared in German or English from 2000 onward., Results: H. pylori infection can be accurately diagnosed either non-invasively (with a (13)C-urea breath test or a stool antigen test) or invasively (with a rapid urease test, by histology, or by culture). Gastric and duodenal ulcer and gastric MALT lymphoma are absolute indications for eradication therapy; relative indications include functional dyspepsia, the prevention of gastric cancer in persons at risk, the initiation of long-term treatment with non-steroidal anti-inflammatory drugs (NSAID), and the prior occurrence of gastroduodenal complications with the use of either NSAID or acetylsalicylic acid (ASA). First-line therapy consists of a proton-pump inhibitor (PPI) and clarithromycin combined with either metronidazole or amoxicillin, given for at least one week., Conclusion: This guideline enables the structured, evidence-based diagnosis and treatment of H. pylori infection and associated conditions, as well as of gastroduodenal ulcer disease.

The gram-negative gastric pathogen Helicobacter pylori is equipped with an extraordinarily large set of outer membrane proteins (OMPs), whose role in the infection process is not well understood. The Hop (Helicobacter outer membrane porins) and Hor (Hop-related proteins) groups constitute a large paralogous family consisting of 33 members. The OMPs AlpA, AlpB, BabA, SabA, and HopZ have been identified as adhesins or adherence-associated proteins. To better understand the relevance of these and other OMPs during infection, we analyzed the expression of eight different omp genes (alpA, alpB, babA, babB, babC, sabA, hopM, and oipA) in a set of 200 patient isolates, mostly from symptomatic children or young adults. Virtually all clinical isolates produced the AlpA and AlpB proteins, supporting their essential function. All other OMPs were produced at extremely variable rates, ranging from 35% to 73%, indicating a function in close adaptation to the individual host or gastric niche. In 11% of the isolates, BabA was produced, and SabA was produced in 5% of the isolates, but the strains failed to bind their cognate substrates. Interleukin-8 (IL-8) expression in gastric cells was strictly dependent on the presence of the cag pathogenicity island, whereas the presence of OipA clearly enhanced IL-8 production. The presence of the translocated effector protein CagA correlated well with BabA and OipA production. In conclusion, we found unexpectedly diverse omp expression profiles in individual H. pylori strains and hypothesize that this reflects the selective pressure for adhesion, which may differ across different hosts as well as within an individual over time.

The aim of the present study was to evaluate the Helicobacter pylori ClariRes assay (Ingenetix, Vienna, Austria) for the detection of H. pylori infection and the simultaneous clarithromycin susceptibility testing of the H. pylori isolates in stool samples from 100 symptomatic children. The results obtained by this novel biprobe real-time PCR method were directly compared with the results obtained from histological examination of gastric biopsy specimens, culturing, the [13C]urea breath test, and a monoclonal antibody-based stool antigen enzyme immunoassay (EIA). Fecal specimens from all 54 children who were shown to be noninfected by "gold standard" tests gave true-negative PCR results (specificity, 100%). Of the remaining 46 individuals with a positive H. pylori status, 29 were found to be positive by real-time PCR (sensitivity, 63%). For these 29 cases, the H. pylori ClariRes assay confirmed all results from phenotypic clarithromycin susceptibility testing by Etest. In summary, this investigation demonstrates that detection of Helicobacter DNA in stool samples by real-time PCR is a difficult task and that this method cannot replace the stool antigen EIA (sensitivity, 95.7%) for the accurate diagnosis of H. pylori infection in children.

Background: Poor compliance to therapy and antibiotic resistance are the main causes for failure of anti-Helicobacter pylori therapy., Objective: To evaluate the effectiveness of esomeprazole-based triple therapy directed by susceptibility testing., Methods: Symptomatic children with H. pylori infection, who underwent successful susceptibility testing and were colonized by no double-resistant strain, received 1-week triple therapy with esomeprazole, amoxicillin and either clarithromycin or metronidazole. Success of eradication was investigated by C-urea breath test., Results: Fifty-eight children (median age, 11.4 years; range, 2.2-17.7 years; 81% immigrants) were included. Helicobacter pylori was resistant to clarithromycin in 5 (9%) and to metronidazole in 9 children (16%). Eradication was successful in 49 (92%) of 53 children receiving esomeprazole, amoxicillin and clarithromycin and in all 5 children treated with metronidazole instead of clarithromycin, resulting in an eradication rate of 93% (95% confidence interval, 83%-98%, intention-to-treat analysis). All 4 treatment failures occurred in immigrants with language problems; 2 of them were obviously noncompliant., Conclusion: Esomeprazole-based 1-week triple therapy directed by susceptibility testing is highly effective for eradication of H. pylori infection in children.

Noninvasive tests can be used for the initial diagnosis of Helicobacter pylori infection and to monitor the success of eradication therapy. In populations with a low prevalence of H. pylori infection (children living in North America and Europe), a high sensitivity is required to make the test valuable for clinical practice. The 13C-urea breath test has been validated in children of different age groups in a significant number of infected and noninfected children in several countries and, thus far, is the only noninvasive test that fulfills sensitivity and specificity quality standards. In studies to date, enzyme immunoassays using monoclonal antibodies to detect H. pylori antigen in stool provide excellent results, but the number of children tested, particularly post-treatment, is not sufficient to recommend the test. All other noninvasive stool tests or methods based on the detection of specific antibodies in serum, whole blood, urine or saliva have limited accuracy in comparison with the 13C-urea breath test. Therefore, these tests cannot be recommended for clinical decision making in pediatric patients.

As an update to previously published recommendations for the management of Helicobacter pylori infection, an evidence-based appraisal of 14 topics was undertaken in a consensus conference sponsored by the Canadian Helicobacter Study Group. The goal was to update guidelines based on the best available evidence using an established and uniform methodology to address and formulate recommendations for each topic. The degree of consensus for each recommendation is also presented. The clinical issues addressed and recommendations made were: population-based screening for H. pylori in asymptomatic children to prevent gastric cancer is not warranted; testing for H. pylori in children should be considered if there is a family history of gastric cancer; the goal of diagnostic interventions should be to determine the cause of presenting gastrointestinal symptoms and not the presence of H. pylori infection; recurrent abdominal pain of childhood is not an indication to test for H. pylori infection; H. pylori testing is not required in patients with newly diagnosed gastroesophageal reflux disease; H. pylori testing may be considered before the use of long-term proton pump inhibitor therapy; testing for H. pylori infection should be considered in children with refractory iron deficiency anemia when no other cause has been found; when investigation of pediatric patients with persistent or severe upper abdominal symptoms is indicated, upper endoscopy with biopsy is the investigation of choice; the 13C-urea breath test is currently the best noninvasive diagnostic test for H. pylori infection in children; there is currently insufficient evidence to recommend stool antigen tests as acceptable diagnostic tools for H. pylori infection; serological antibody tests are not recommended as diagnostic tools for H. pylori infection in children; first-line therapy for H. pylori infection in children is a twice-daily, triple-drug regimen comprised of a proton pump inhibitor plus two antibiotics (clarithromycin plus amoxicillin or metronidazole); the optimal treatment period for H. pylori infection in children is 14 days; and H. pylori culture and antibiotic sensitivity testing should be made available to monitor population antibiotic resistance and manage treatment failures.

Background: Infection with Helicobacter pylori leads to an increase of T cells in the gastric mucosa of children. In contrast to peripheral blood, where monocytes are the most abundant antigen-presenting cells, CD14+ macrophages are very rare in infected gastric mucosa. We postulated that other types of antigen-presenting cells must be present in infected gastric mucosa., Material and Methods: Antral biopsies were obtained from 56 children. The cellular expression of major histocompatibility complex (MHC) class II molecules, CD1a/b, and CD23, which are involved in antigen presentation were analyzed by immunohistochemistry. In addition, T cells (CD4, CD8, CD25, and gamma/delta-TCR), B cells (anti-IgM), macrophages (CD14) and granulocytes (CD15) were quantified., Results: Twenty-eight children were H. pylori-infected. Thirteen children were healthy, 15 had other gastric pathologies. T cells (p<.0001), B cells (p<.0001), CD23+ (p<.0001), and CD1a/b+ (p<.005) cells were significantly increased in the lamina propria of H. pylori-infected children, whereas macrophages were rare without significant differences among the groups. Within the epithelium, CD8+ T lymphocytes predominated clearly over CD4+ cells. H. pylori-negative children had only few MHC class II-positive cells within the gastric epithelium, whereas MHC class II antigens were strongly expressed on epithelial cells (p<.0001) of all H. pylori-infected children., Conclusion: Helicobacter pylori infection leads to an enhanced expression of antigen-presenting molecules together with a parallel rise of T cells in the lamina propria. This may represent an effort of the immune system to optimize local immune responses against H. pylori. We speculate that the epithelium participates in the initiation of a local immune response against H. pylori.

A new rapid one-step immunochromatographic test using monoclonal antibodies for detection of Helicobacter pylori antigen in stool in children was evaluated on coded stool samples from 159 children (mean age, 9.7 +/- 5.0 years; 118 from Munich, 41 from Vienna): 86 children were H. pylori infected defined by positive culture and/or > or =2 other positive tests ([13C]urea breath test, histology, rapid urease test), and 73 children showed concordant negative results. Seventy-nine patients (12.1 +/- 3.8 years; 42 from Munich; 37 from Vienna) were tested 6 to 8 weeks after anti-Helicobacter pylori therapy with urea breath test and stool test. In Munich, all 160 tests (118 pre- and 42 posttreatment) were independently read by two observers. Equivocal results were excluded for calculation of sensitivity and specificity but were considered as false to assess accuracy. The two observers in Munich agreed in 63 out of 65 positive and 89 out of 95 negative results, while eight times (5.0%) they judged the test as equivocal. Pretreatment and posttreatment results for sensitivity were 88.1% (79.2 to 94.1) and 88.9% (51.8 to 99.7), specificity 88.1% (77.8 to 94.1) and 93.9% (85.2 to 98.3), and accuracy 83.5% and 81.5%, respectively. We conclude that the new monoclonal immunochromatographic quick test shows a good interobserver agreement, but equivocal results occur in 5%. Performance is comparable before and after therapy. The test may become a good alternative in children in settings where a [13C]urea breath test or a reliable enzyme immunoassay stool test are not available.

We investigated whether a novel monoclonal stool antigen test for detection of Helicobacter pylori performs with the same accuracy as the (13)C-urea breath test (UBT) for adult outpatients in the setting of a private office. The two tests showed identical levels of sensitivity when used to identify H. pylori-infected patients before and after eradication therapy.

We report on the successful application of fluorescent in situ hybridization for detection of Helicobacter pylori and determination of its clarithromycin susceptibility in formalin-fixed and paraffin-embedded gastric biopsy specimens that had been prepared for pathological examination. This method is useful when results from conventional culturing with antibiotic susceptibility testing are not available.

Objectives: This study was performed to determine the rate of Helicobacter pylori reinfection after its successful eradication in children living in Germany., Design: A total of 102 children (48 boys; 31 German and 71 other nationalities; age 1.8-18 years) with a negative (13)C-urea breath test 8 weeks after triple therapy were followed up by a (13)C-urea breath test every 6 months. The cohort included 11 children aged <6 years, 58 children aged > or =6 to 12 years, and 33 children > or =12 years., Results: The mean duration (+/- standard deviation) of follow-up was 15.5 +/- 11.9 months with a maximum of 4.9 years, representing 132 patient years. Only three children (aged 9.7-14.9 years, one German, two Turkish) tested positive at 6, 12, and 18 months, respectively. The calculated reinfection rate was 2.3% per person per year., Conclusion: The risk of reinfection with H. pylori is low in children living in Germany. There is no evidence that the reinfection rate depends on the age, sex, or nationality of the child. The low reinfection rate indicates that it is unnecessary to screen or treat asymptomatic family members in order to prevent reinfection.

Infection withHelicobacter pylorileads to an increase of T cells in the gastric mucosa of children. In contrast to peripheral blood, where monocytes are the most abundant antigen-presenting cells, CD14+ macrophages are very rare in infected gastric mucosa. We postulated that other types of antigen-presenting cells must be present in infected gastric mucosa.Antral biopsies were obtained from 56 children. The cellular expression of major histocompatibility complex (MHC) class II molecules, CD1a/b, and CD23, which are involved in antigen presentation were analyzed by immunohistochemistry. In addition, T cells (CD4, CD8, CD25, andγ/δ-TCR), B cells (anti-IgM), macrophages (CD14) and granulocytes (CD15) were quantified.Twenty-eight children wereH. pylori-infected. Thirteen children were healthy, 15 had other gastric pathologies. T cells (p < .0001), B cells (p < .0001), CD23+ (p < .0001), and CD1a/b+ (p < .005) cells were significantly increased in the lamina propria ofH. pylori-infected children, whereas macrophages were rare without significant differences among the groups. Within the epithelium, CD8+ T lymphocytes predominated clearly over CD4+ cells.H. pylori-negative children had only few MHC class II-positive cells within the gastric epithelium, whereas MHC class II antigens were strongly expressed on epithelial cells (p < .0001) of allH.pylori-infected children.Helicobacter pyloriinfection leads to an enhanced expression of antigen-presenting molecules together with a parallel rise of T cells in the lamina propria. This may represent an effort of the immune system to optimize local immune responses againstH. pylori. We speculate that the epithelium participates in the initiation of a local immune response againstH. pylori. [ABSTRACT FROM AUTHOR]