PCR detection of Helicobacter pylori in string-absorbed gastric juice

Molecular methods for detection of Helicobacter pylori infection have been shown to be highly sensitive in gastric biopsies and cultures. The objective of this work was to compare PCR detection of H. pylori DNA in string-absorbed gastric juice and in gastric biopsies. The study was performed in 47 dyspeptic adult patients undergoing endoscopy, and infection was detected by amplification of a segment of H. pylori ureA gene. Of the 29 patients positive in biopsy analysis, 23 (79%) were also positive in the gastric string. PCR analysis of gastric strings is a sensitive and safe procedure to detect H. pylori when endoscopy is not indicated, and may be of great clinical and epidemiological usefulness in determining effectiveness of eradication therapies, typing virulence genes and detecting antibiotic resistance mutations.     

Comparison of five detection methods for Helicobacter pylori

OBJECTIVE: To evaluate which diagnostic test is preferable for the diagnosis of Helicobacter pylori in patients with gastroduodenal disease. STUDY DESIGN: H pylori infection was diagnosed prospectively in 101 patients. Diagnosis of H pylori was made by tests based on five different principles: (1) culture, (2) direct histologic demonstration, (3) imprint cytology, (4) brushing cytology, and (5) gram staining of H pylori. Efficacy of each test was compared. RESULTS: All the tests were reliable for diagnosing H pylori infection; 73.3% of patients showed concordance in at least two tests. All the tests were positive in > 50% of patients. Significant concordance between brushing and imprint cytology was also determined. These two tests have almost similar specificity when compared to other tests. CONCLUSION: When patients undergo upper endoscopy, we recommend taking biopsy specimens for culture and histology. H pylori can be assessed equally well with all the tests, but imprint and brushing cytology have the advantage of rapid response, specificity, much lower cost and reproducibility.     

Eradicating Helicobacter pylori and symptoms of non-ulcer dyspepsia.

OBJECTIVE--To examine the effect of eradication of Helicobacter pylori on symptoms of non-ulcer dyspepsia. DESIGN--Four week prospective study. SETTING--One hospital outpatient and endoscopy department. PATIENTS--90 adults with persistent symptoms typical of non-ulcer dyspepsia but no clinical or endoscopic evidence of other peptic, biliary, pancreatic, or malignant disease; all had histological and microbiological evidence of infection with H pylori. 83 patients completed the treatment regimen. INTERVENTION--Colloidal bismuth subcitrate 120 mg four times a day for four weeks (27 patients); metronidazole 400 mg and amoxycillin 500 mg each three times a day for one week (27); and bismuth subcitrate 120 mg four times a day for four weeks, metronidazole 400 mg three times a day for one week, plus amoxycillin 500 mg three times a day for the first week (29). MAIN OUTCOME MEASURES--Change in symptom scores determined with questionnaire; histological evidence of gastritis and microbiological evidence of presence of H pylori in biopsy specimens. RESULTS--Overall, H pylori was eradicated in 41 (49%) patients. Although gastritis scores improved significantly in only patients in whom H pylori had been eradicated (from 1.56 to 0.61, p less than 0.01 v from 1.83 to 1.07, p = 0.52) mean symptom scores after treatment were similar in patients in whom H pylori had or had not been eradicated (3.0 v 2.3, NS). Similarly the mean symptom score improved whether or not gastritis improved (2.8 v 3.1 respectively, p = 0.72). The observations were similar for treatment groups analysed individually. CONCLUSION--Antral infection with the organism does not seem to have an important aetiological role in non-ulcer dyspepsia short term.     

Triple Therapy with Lansoprazole, Clarithromycin, and Amoxicillin for the Cure of Helicobacter pylori Infection: A Short Report

Background Given the therapeutic potential of proton pump inhibitor-based triple therapy for successful cure of Helicobacter pylori infection, we evaluated the efficacy and safety of lansoprazole with clarithromycin and amoxicillin in an open-label, single-center study.
Materials and Methods. H. pylori -positive patients self-administered lansoprazole, 30 mg; clarithromycin, 500 mg; and amoxicillin, 1 gm bid for 14 days. Patients were assessed pretreatment, at which time the presence of H. pylori was documented by rapid urease test, culture, or histology, following study drug administration (week 2) for a brief evaluation only, and at least 4 weeks posttreatment (week 6), which included endoscopy with collection of biopsy specimens for culture and histology testing.
Results. Primary clarithromycin and metronidazole resistance were observed in 6% (2 of 30) and 43% (13 of 30) of study patients, respectively. One month after the end of therapy, H. pylori infection was cured in 23 of 25 patients (92%; 95% confidence interval, 74%-99%). The triple-therapy regimen was well-tolerated; 17% of patients (5 of 30) reported mild to moderate adverse effects during the treatment period.
Conclusion. A 2-week, triple-drug combination of lansoprazole, clarithromycin, and amoxicillin is highly effective for cure of H. pylori infection. Additionally, the triple-drug combination was well-tolerated by patients infected with H. pylori.     

Seven-Day Triple Therapy with Lansoprazole, Clarithromycin, and Metronidazole for the Cure of Helicobacter pylori Infection: A Short Report

Background To refine our understanding of anti- Helicobacter pylori treatment regimens further, we evaluated the efficacy and safety of lansoprazole given in combination with clarithromycin and metronidazole for 7 days in an open-label, multicenter study.
Materials and Methods. H. pylori -positive patients self-administered lansoprazole, 30 mg; clarithromycin, 500 mg; and metronidazole, 500 mg bid for 7 days. Patients were assessed at pretreatment, at which time the presence of H. pylori was documented by rapid urease test or histology and culture, following study drug administration (week 1) for a brief evaluation only, and at least 4 weeks posttreatment (week 5), including endoscopy with collection of biopsy specimens for culture and histology testing.
Results. Of the 60 patients enrolled in the study, 59 had confirmed H. pylori infection, and 51 were included in an intent-to-treat analysis of efficacy. Primary metronidazole and clarithromycin resistance were observed in 84% and 8% of study patients, respectively. One month after the end of therapy, H. pylori infection was cured in 40 of 51 patients (78%); 95% confidence interval, 65%–89%). The triple-therapy regimen was well-tolerated, with only 2 patients (4%) requiring premature withdrawal from the study due to treatment-related adverse events. Taste perversion (15.0%) and diarrhea (11.7%) were the most frequently reported adverse events possibly or probably related to study medication during the treatment period.
Conclusion. Despite a high prevalence of metronidazole resistance, a 1-week, triple-drug combination of lansoprazole, clarithromycin, and metronidazole is effective treatment for and well-tolerated by patients with H. pylori infection.     

The results of Helicobacter pylori eradication on repeated bleeding in patients with stomach ulcer

The triple therapy of Helicobacter pylori eradication prevents repeated bleeding from stomach ulcer. The aim of this one-way blind prospective study was to evaluate the efficiency of the two-week triple therapy for Helicobacter pylori eradication in preventing renewed bleeding in patients with stomach ulcer within one year. This research included 60 hospitalized patients with bleeding stomach ulcer and positive Helicobacter pylori infection, 34 men and 26 women (average age 59.7 years). The patients were given therapeutic scheme of omeprazol--amoxicilin--metrodinazol (OAM) eradication for 14 days. Eradication of H. pylori infection was defined as lack of proof of the infection one month or several months after therapy suspension. By applying triple OAM therapy within two weeks the eradication was successful in 72%. In the group of 17 H. pylori positive patients there were 8 patients (47.6%) with repeated stomach ulcer and 3 patients (18%) with bleeding. Within the group of 43 H. pylori negative patients there were only 2 patients (4.65%) with repeated stomach ulcer and 1 patient (2%) with bleeding, during the observed period of 12 months. This research confirms the hypothesis about the necessity of eradication of Helicobacter pylori infection in patients with bleeding stomach ulcer as prevention of repeated bleeding.     

Immediate endoscopy or initial Helicobacter pylori serological testing for suspected peptic ulcer disease: estimating cost-effectiveness using decision analysis.

OBJECTIVE: To compare the clinical and economic effects of a strategy using immediate endoscopy to a non-invasive strategy utilizing a serologic test for Helicobacter pylori infection for individuals with symptoms suggestive of peptic ulcer disease. DESIGN: Cost-effectiveness analysis evaluating the clinical and economic effects of alternative management strategies of hypothetical patients with suspected peptic ulcer disease in a computer simulation model. INTERVENTION: Two strategies for hypothetical patients with suspected ulcer disease were evaluated: 1) Immediate endoscopy and biopsy for H. pylori, using antisecretory treatment in all patients with documented ulcers and adding antibiotic eradication therapy for those patients with ulcers whose biopsies were positive for H. pylori. 2) Empiric treatment with antisecretory therapy and serologic testing for H. pylori for all patients, using antibiotic eradication therapy only in patients testing positive for H. pylori. MEASUREMENTS: Cost per ulcer cured over a one-year study period. RESULTS: The more cost-effective strategy was the test-and-treat strategy (Strategy 2) with $4481 cost per ulcer cured. The immediate endoscopy strategy resulted in $8045 cost per ulcer cured. The cost-effectiveness advantage of the non-invasive strategy diminished as the cost of endoscopy fell or as the probability of recurrent symptoms rose in patients initially managed without endoscopy. CONCLUSION: Endoscopy, though costly, precisely guided diagnosis and treatment and, thus, potentially reduced the number of patients inappropriately treated. However, cost-effectiveness analysis supports the continued practice of initial non-invasive management of patients with symptoms suggestive of peptic ulcer disease, achieving the benefits of H. pylori eradication through the use of serologic testing to guide antibiotic use.     

Comparison of two different stool antigen tests for the primary diagnosis of Helicobacter pylori infection in turkish patients with dyspepsia

AIM: To assess the reliability of two different enzyme immunoassays in detecting the Helicobacter pylori status in stool specimens of Turkish patients with dyspepsia. MATERIALS AND METHODS: One hundred and fifty-one patients [74 with nonulcer dyspepsia (NUD), 64 with duodenal ulcer (DU) and 13 with gastric cancer] who were admitted to the endoscopy unit of Istanbul University, Cerrahpasa Medical Faculty for upper gastrointestinal endoscopy because of dyspepsia were enrolled in the study. Helicobacter pylori infection was confirmed in all patients by histology, rapid urease test and culture. A patient was classified as being H. pylori-positive if the culture alone or both the histology and the rapid urease test were positive and as negative only if all of these tests remained negative. Stool samples were obtained from patients to assess the reliability of a monoclonal (FemtoLab H. pylori) and a polyclonal (Premier Platinum HpSA) stool antigen test and to compare the diagnostic accuracies of these two tests. A chi2 test was used for statistical comparisons. RESULTS: Using cut-off values of 0.19 for FemtoLab H. pylori and 0.16 for Premier Platinum HpSA, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 93%, 90%, 98%, 68% and 93% for the monoclonal test and 84%, 67%, 94%, 40% and 81% for the polyclonal test, respectively. The sensitivity, specificity, negative predictive value and diagnostic accuracy of the monoclonal test were significantly greater than those of the polyclonal test (chi2 = 3.98; p < .05 for sensitivity and chi2 = 15.67; p = .000 for specificity, chi2 = 15.78; p = .000 for negative predictive value and chi2 = 6.37; p = .012 for diagnostic accuracy). The bacterial load did not affect the sensitivity of either test. CONCLUSIONS: The monoclonal FemtoLab H pylori test, using a cut-off 0.19, is a very sensitive, specific and easy to perform diagnostic tool for the primary diagnosis of H. pylori infection in Turkish patients with dyspepsia.     

Toll-like receptor (TLR2, TLR4 and TLR5) gene polymorphisms and Helicobacter pylori infection in children with and without duodenal ulcer

Helicobacter pylori infection is mainly acquired in childhood, and polymorphisms in the host genes coding for Toll-like receptors (TLRs) may influence the innate and adaptive immune response to the infection, affecting the susceptibility to H. pylori or the disease outcomes. Our aim was to investigate whether TLR4, TLR2, and TLR5 polymorphisms were associated with H. pylori susceptibility and risk for duodenal ulcer in children. Gastric biopsy specimens were obtained at endoscopy for evaluation of H. pylori status, TLR4, TLR2 and TLR5 polymorphisms from 486 children (254 H. pylori-negative and 232 H. pylori-positive: 72 with and 160 without duodenal ulcer). cagA status of H. pylori infection was investigated by PCR. The levels of gastric cytokines were detected by ELISA. H. pylori-positivity or duodenal ulcer were not associated with TLR2, TLR4 or TLR5 polymorphisms. Otherwise, the presence of TLR4 polymorphic allele was associated with infection by cagA-positive strains and with increased gastric levels of interleukin-8 and interleukin-10. TLR4 polymorphism might ultimately contribute to more severe consequences of the infection in adulthood since it was associated with susceptibility to cagA-positive H. pylori infection early in life.     

Co-culture of human gastric endoscopic biopsies with Helicobacter pylori: a simple method for studying early phases of bacteria-host interaction

Gastric biopsies obtained through endoscopy from patients uninfected by Helicobacter pylori were co-cultured with an H. pylori strain. According to tissue and H. pylori viability, interleukin 8 was increased in biopsy homogenate and supernatant after 12-36h culture. This simple method is suitable to investigate early phases of bacteria-host interaction.     

Double-Blind, Multicenter Evaluation of Lansoprazole and Amoxicillin Dual Therapy for the Cure of Helicobacter pylori Infection

Background Treatment with amoxicillin plus omeprazole results in disappointing cure rates of Helicobacter pylori infection. The minimal inhibitory concentration of lansoprazole for H. pylori in vitro is lower than that for omeprazole, prompting interest in treatment with amoxicillin plus lansoprazole.
Materials and Methods. H. pylori -infected patients with endoscopically documented duodenal ulcer either currently or within the past year were randomized to 14 days of (1) lansoprazole, 30 mg bid, plus amoxicillin, 1 gm tid; (2) lansoprazole, 30 mg tid, plus amoxicillin, 1 gm tid; (3) lansoprazole, 30 mg tid alone; or (4) amoxicillin, 1 gm tid alone. Endoscopy was done at enrollment and at 4 to 6 weeks after completion of treatment or for recurrent symptoms. H. pylori status was assessed by culture and histology. Ulcer prevalence was evaluated at follow-up endoscopy.
Results. Two hundred sixty-two patients met enrollment criteria and were treated. By per-protocol analysis, H. pylori infection was cured in 57% of those treated with lansoprazole twice daily plus amoxicillin and in 67% of those treated with lansoprazole three times daily plus amoxicillin, compared with 0% treated with lansoprazole alone or amoxicillin alone ( p < .001 for dual therapy versus either monotherapy). Amoxicillin resistance was not observed. At follow-up endoscopy, ulcer prevalence was 17% in patients treated with lansoprazole twice daily plus amoxicillin, 23% in those treated with lansoprazole three times daily plus amoxicillin, 33% in those treated with lansoprazole alone, and 35% in those treated with amoxicillin alone ( p = .024; lansoprazole twice daily plus amoxicillin versus amoxicillin alone).
Conclusions. Treatment with amoxicillin plus lansoprazole, 30 mg tid, led to cure of H. pylori infection in 67% of patients with active or recently healed duodenal ulcer.     

Evaluation of stool antigen test, PCR on ORAL samples and serology for the noninvasive detection of Helicobacter pylori infection in children

BACKGROUND: Endoscopy represents the gold standard for the diagnosis of Helicobacter pylori infection. We evaluated three noninvasive tests in a group of children: the immunoassay for detection of H. pylori stool antigen, the polimerase chain reaction for identification of bacterial DNA on the oral cavity and the serum specific antibodies. MATERIALS AND METHODS: One hundred and ninety children underwent endoscopy for various gastrointestinal symptoms. H. pylori stool antigen and anti-H. pylori antibodies were assayed by commercial kits. The bacterial DNA on saliva and oral plaque was detected by a seminested PCR. RESULTS: Based on the positivity of culture or urease rapid test and histology, infection was detected in 47 patients. The statistical analysis showed that, for the detection of the infection, stool antigen assay is more effective in sensitivity and negative predictive value (91.5% and 96.5%), whereas specificity and positive predictive values appear slightly better in serology (89.6% and 76.0%). Correlations between serum IgG both with patients' age (r = 0.21, p < .05) and H. pylori stool antigen (r = 0.47, p < .01) were found. The search for bacterial DNA on oral samples proved to be very specific (99.1% on saliva and 98.2% on plaque), but insensitive (22.2% and 25.7%). CONCLUSIONS. In children H. pylori stool antigen represents a sensitive test, suitable for detecting H. pylori infection. Serum IgG proved to be more specific; the PCR on the oral cavity resulted as being a very specific, but insensitive test.     

Rabeprazole- versus esomeprazole-based eradication regimens for H. pylori infection

BACKGROUND: Different kinds of proton pump inhibitor-based triple therapies could result in different Helicobacter pylori eradication rates. AIM: The aims of this study were to compare the efficacy and safety of rabeprazole- and esomeprazole-based triple therapy in primary treatment of H. pylori infection in Taiwan. PATIENTS AND METHODS: From June 2005 to March 2007, 420 H. pylori-infected patients were randomly assigned to receive a 7-day eradication therapy with either esomeprazole 40 mg daily (EAC group, n = 209) or rabeprazole 20 mg b.i.d. (RAC group, n = 211) in combination with amoxicillin 1 g b.i.d. and clarithromycin 500 mg b.i.d.. Follow-up endoscopy with biopsy was done 12-16 weeks after completion of eradication therapy. Those who refused endoscopic exams underwent (13)C-urea breath test to assess the treatment response. RESULTS: Intention-to-treat analysis revealed that the eradication rate was 89.4% in the EAC group and 90.5% in RAC groups (p-value = .72). All of the subjects returned for assessment of compliance (100% in EAC group vs. 99.5% in RAC group, p-value = .32) and adverse events (3.83% in EAC group vs. 6.16% in RAC group, p-value = .27). Sixty (28.7%) and 37 (17.6%) patients in EAC and RAC group, respectively, refused endoscopy and underwent a (13)C-urea breath test to determine the treatment effect. CONCLUSION: In conclusion, rabeprazole- and esomeprazole-based primary therapies for H. pylori infection are comparable in efficacy and safety.     

Imprint cytology in the diagnosis of Helicobacter pylori. Does imprinting damage the biopsy specimen?

OBJECTIVE: To investigate the efficacy of imprint cytology in the diagnosis of Helicobacter pylori infection and whether it damages the biopsy specimen for subsequent histologic examination. STUDY DESIGN: Two antral biopsies were taken from 76 patients with dyspeptic symptoms undergoing upper gastrointestinal endoscopy. Imprint cytology was made from the first specimen. This specimen was fixed in 10% formalin and sent for histopathologic examination. The second specimen was directly fixed in 10% formalin for routine histopathologic examination without being used for an imprint. The imprint smears were examined by cytopathologists. The biopsy specimens were examined by pathologists who did not know which specimens were used for the imprints. RESULTS: H pylori was seen in smears from 55 (72%) patients and in both biopsy specimens from the same patients. The pathologists could not recognize the biopsy specimens from which the imprints were made. Concordance between imprint cytology and histopathology was 100%. CONCLUSION: Imprint cytology is a suitable test for H pylori diagnosis, and imprints do not adversely affect the quality of the biopsy specimen.     

Practical rapid, minimally invasive, reliable nonendoscopic method to obtain Helicobacter pylori for culture

BACKGROUND: Helicobacter pylori culture typically requires endoscopy. AIM: To develop a minimally invasive rapid and reliable method to obtain H. pylori cultures. METHODS: An extendable oro-gastric brush, contained within a plastic over-tube, was constructed (Baylor Brush, US Endoscopy). After topical oral anesthesia, the 5-mm diameter brush assembly was swallowed. The brush was extended in the stomach and the mucosa was brushed three or four times. The brush was then retracted into the protective sleeve and withdrawn from the patient. The brush was either cultured directly or placed in cysteine transport medium with 20% glycerol which was then sampled immediately or after freezing at -70 degrees C. RESULTS: Twenty-five adult H. pylori-infected subjects (13 male, 12 female) were studied. Helicobacter pylori recovery rate was 100% (11 of 11) when cultured immediately or after storage in transport medium at -70 degrees C for 1 or 2 weeks or after storage at 4 degrees C for 24 hours (four of four) or 72 hours (four of four) before being cultured. Freezing on dry ice and air shipment did not reduce recovery. CONCLUSION: Rapid, reliable, nonendoscopic culture of gastric mucus is a practical method to obtain culture of H. pylori for clinical or research purposes. The method is amenable to being performed in a doctor's office or in the field.     

The Influence of Helicobacter pylori Status on Circulating Levels of the Coagulation Factors Fibrinogen, von Willebrand Factor, Factor VII, and Factor VIII

Background. Helicobacter pylori (H. pylori) infection has been associated with an increased risk of developing ischemic heart disease (IHD). It has been suggested that a persisting low-grade acute phase response results from the chronic inflammation caused by H. pylori infection, which may give rise to increased circulating levels of certain coagulation factors.
Materials and Methods. One hundred three (53 male) nonconsecutive, randomly selected white subjects with symptoms of dyspepsia were recruited for study from an outpatient endoscopy clinic at Leeds General Infirmary. The presence of H. pylori was determined by histological and microbiological investigation, a rapid urease test, and a ¹³carbon urea breath test (¹³C-UBT). Fibrinogen was measured by the Clauss method, factor VIII:C (FVIII:C) and factor VII:C (FVII:C) were measured by clotting rate assays, and the von Willebrand factor (vWF) was determined by an enzyme-linked immunosorbent assay.
Results. No difference was found in levels of coagulation factors according to H. pylori status. Multiple regression models were used to account for the effect of covariates and H. pylori status on levels of FVII:C, FVIII:C, vWF, and fibrinogen, and again H. pylori status was not a significant determinant of levels of any of these coagulation factors. No difference occurred in full blood count, platelet count, white cell count, or plasma viscosity in individuals who were H. pylori -positive compared with those who were negative.
Conclusions. H. pylori infection is not associated with increased circulating levels of fibrinogen, FVII:C, vWF.Ag, or FVIII:C or hemorrheology in this patient group.     

Diagnosis of Helicobacter pylori infection and determination of clarithromycin resistance by fluorescence in situ hybridization from formalin-fixed, paraffin-embedded gastric biopsy specimens

A reliable diagnostic test for Helicobacter pylori is important in clinical practice and research. The ideal diagnostic test for H. pylori should be sensitive, specific, and cost-effective. Helicobacter pylori resistance to clarithromycin is a common reason for failure of eradication therapy. The aim of this study was to evaluate the fluorescent in situ hybridization (FISH) method to detect H. pylori and determine clarithromycin resistance in formalin-fixed, paraffin-embedded gastric biopsy specimens. One hundred seventeen gastric biopsy specimens from patients with dyspepsia were examined for the presence of H. pylori by conventional culture, FISH, and histopathological methods. A set of fluorescent-labeled oligonucleotide probes binding to either H. pylori 16S rRNA or 23S rRNA sequences were used for FISH analysis. Phenotypic antibiotic susceptibilities of the isolates were tested using the Epsilometer test method (E test). Helicobacter pylori was detected in 70 of 117 biopsy specimens by histopathological examination and FISH, whereas it was detected in 47 specimens by culturing. Histopathology and FISH techniques failed to identify H. pylori in 1 biopsy sample isolated by culture. Clarithromycin resistance was found in 11 of 46 H. pylori isolates using the E test method. All of the phenotypic resistance measurements of isolates were correlated with genotypic clarithromycin resistance. Eleven clarithromycin-resistant strains were identified by FISH. The diagnosis of H. pylori infection and the determination of clarithromycin resistance in formalin-fixed, paraffin-embedded specimens using FISH is promising because it provides a rapid, reliable, and culture-independent diagnosis.     

Rhesus monkey (Macaca mulatta) model of Helicobacter pylori: noninvasive detection and derivation of specific-pathogen-free monkeys.

BACKGROUND AND PURPOSE: Development of the rhesus monkey model of Helicobacter pylori has been hampered by problems with serodetection and by the difficulty of identifying specific-pathogen (Helicobacter)-free animals. Our purpose was to determine whether detection could be improved and to determine if pathogen-free monkeys could be derived by nursery rearing. METHODS: An enzyme-linked immunoabsorbent assay (ELISA) and a [14C]urea breath test were compared to endoscopy to determine H. pylori infection status in rhesus macaques; 18 animals were hand raised in the nursery to determine whether pathogen-free animals could be selected. RESULTS: Helicobacter pylori infection was common in colony-raised young rhesus monkeys and was nearly universal by adulthood. Serodetection, using antigen from rhesus-derived H. pylori strains, was 95% sensitive and 94% specific. The [14C]urea breath test was 96% sensitive and 88% specific for detection of chronic Helicobacter infection in rhesus monkeys. Segregation of newborn animals within the first 24 h of life was a reliable method to obtain pathogen-free rhesus monkeys. CONCLUSION: Isolation of specific-pathogen-free animals, together with better detection methods, may improve the value of the rhesus monkey model for the study of H. pylori pathogenesis, immune response, and vaccine development.     

Factors that affect results of the 13C urea breath test in Japanese patients

Background. The ¹³C urea breath test (UBT) is considered to be the most accurate way of diagnosing Helicobacter pylori infection. Our objective was to investigate the accuracy of the UBT in Japanese patients and the association of UBT values with histological findings.
Materials and Methods. A total of 169 consecutive patients were studied by endoscopy with histology, by serology with IgG antibody and test serum pepsinogen (PG), and by UBT. The association between UBT values and histological findings and the PG I / II ratio were analyzed in H. pylori –positive patients.
Results. Of 169 Japanese patients, 135 were H. pylori –positive on both histology and serology analysis, 27 were H. pylori –negative on both histology and serology analysis, and 7 patients showed differing results. Using a cutoff value of 2.5‰, test sensitivity was 100%, while specificity was 96%. Among the 135 H. pylori –positive patients, a significant relation was observed between UBT value and H. pylori colonization density of the corpus and antrum, neutrophil activity of the antrum, atrophy, and intestinal metaplasia of the corpus in the H. pylori –positive patients. Also, UBT values correlated with the PG I /II ratio. In multivariate analysis, the PG I /II ratio was the most important factor related to UBT values (odds ration [OR], 4.99; 95% confidence interval, 1.60–15.55).
Conclusions. The UBT is an accurate method for detecting H. pylori infection in the Japanese population, which shows a high prevalence of atrophic gastritis. Values are affected by H. pylori infection and by the severity of atrophic gastritis.     

13C-urea breath test and gastric mucosal colonization by Helicobacter pylori in children: quantitative relation and usefulness for diagnosis of infection

Objective. Because in children Helicobacter pylori colonization could differ as compared to that in adults, gastric metabolism of urea and the reliability of the breath test must be evaluated. The aim of this study was to quantify the relationship between breath test and colonization.
Methodology. We studied data from 50 endoscopies performed in 39 children and adolescents (20 girls, 19 boys, aged 3–18 years); 28 were infected with H. pylori. Biopsies were analyzed for histological and microbiological diagnosis of infection and for quantitative antral culture of H. pylori. A ¹³C urea breath test was performed on the same day as that of endoscopy ( n = 33) or delayed between 2 and 90 days ( n = 17).
Results. Using a cut-off value of 3 δ‰, sensitivity was 96.5%, and specificity was 91.5%. The three children showing discrepancies between breath test and biopsy results had a δ‰ value close to the cut-off. For the 26 cases with a positive culture, we noted a significant correlation (r = 0.63; p < .001) that was not affected by the delay between breath test and gastroscopy.
Conclusion. This quantitative relation between bacterial density and δ‰ permits increasing the reliability of the test by interpreting carefully those results that approach the cut-off value.