Validity of a modified 13C-urea breath test for pre- and posttreatment diagnosis of Helicobacter pylori infection in the routine clinical setting

OBJECTIVE: Citric acid meets the criteria of an optimal test drink for the 13C-urea breath test (13C-UBT) because it permits rapid, high level recovery of the 13C administered. In a previous study we reported that administration of 13C-urea dissolved in a citric acid solution provides results similar to those obtained with standard administration of the substrate 10 min after the test drink. The aim of this study was to evaluate the accuracy of this modified 13C-UBT for both primary and posttreatment diagnosis of Helicobacter pylori (H. pylori) infection in a large patient population in clinical practice. METHODS: The 13C-UBT was performed in 553 patients with dyspeptic symptoms by giving them 75 mg of 13C-urea either 10 min after administration of 200 ml of a test drink comprising 0.1 mol/L citric acid solution (protocol 1, n = 320) or dissolved in the same amount of this test drink (protocol 2, n = 233). All patients underwent an upper gastrointestinal endoscopy and the H. pylori-status was assessed by histology, rapid urease test, and culture. Sixty patients with proven H. pylori infection were reinvestigated by both endoscopy and 13C-UBT (protocol 2) 4 wk after completing eradication therapy. RESULTS: The accuracy of the two test protocols in the pretreatment diagnosis of H. pylori infection (95.6% and 96.6%), as well as of the modified 13C-UBT in the posttreatment evaluation of the infection (98.3%) was similar. More meaningful are the high PPV (>96%) and NPV (>93%) of the 13C-UBT under pre- and posttreatment conditions. CONCLUSIONS: The administration of 13C-urea dissolved in a citric acid solution simplifies the 13C-UBT, while preserving the high accuracy in the diagnosis of H. pylori infection. This modified 13C-UBT has equal accuracy in the pre- and the posttreatment situations.     

A test-and-treat policy does not save endoscopy workload in a non-referral hospital

AIM : To assess the impact that a test-and-treat policy with open-access urea breath testing (UBT) has had on the referral rates for endoscopy in a district hospital. Additionally, we examined for any change in the proportion of serious pathology detected endoscopically after adopting the policy. METHODS : Analysis of data on all open-access endoscopy referrals in a 12-month period before (October 1994 to September 1995) and 2 years after (October 1997 to September 1998) the introduction of the UBT service. This was compared with the same service in our sister hospital, which had not provided a UBT service. Results of patients attending the UBT service during the period of study were also examined. RESULTS : A total of 798 patients attended for endoscopy (18% aged < 40 years, 82% aged > 40 years) in the pre-UBT year compared with 1905 patients (16% aged < 40 years, 84% aged > 40 years) in the post-UBT year. The standardized referral ratios were significantly higher for both age groups in the post-UBT year: 210 in the < 40 years group (95% CI 187 to 235) and 244 in the > 40 years group (95% CI 233 to 257). Six per cent of the < 40 years group in the post-UBT year had serious pathology compared with 7% pre-UBT (P < 0.1). However, the proportion of serious pathology decreased from 37 to 27% in the > 40 years group (P < 0.01). The total number of open-access endoscopies had increased steadily over the 3 years, despite the introduction of the UBT service. This trend was mirrored in our sister hospital. A total of 457 patients attended the UBT service during the 12 months. Of these, 24.5% were Helicobacter pylori positive, with a 66.3% eradication rate. CONCLUSIONS : A test-and-treat policy has not saved endoscopy workload in this non-referral hospital. We feel that results from centres with an H. pylori interest cannot be generalized for the vast majority.     

Prevention of overuse: A view on upper gastrointestinal endoscopy

Many upper gastrointestinal(GI) endoscopies worldwide are performed for inappropriate indications. This overuse of healthcare negatively affects healthcare quality and puts pressure on endoscopy services. Dyspepsia is one of the most common inappropriate indications for upper GI endoscopy as diagnostic yield is low. Reasons for untimely referral are: unfamiliarity with dyspepsia guidelines,uncertainty about etiology of symptoms, and therapy failure. Unfiltered openaccess referrals feed upper GI endoscopy overuse. This review highlights strategies applied to diminish use of upper GI endoscopies for dyspepsia. First,we describe the impact of active guideline implementation. We found improved guideline adherence, but resistance was encountered in the process. Secondly, we show several forms of clinical assessment. While algorithm use reduced upper GI endoscopy volume, effects of referral assessment of individual patients were minor. A third strategy proposed Helicobacter pylori test and treat for all dyspeptic patients. Many upper GI endoscopies can be avoided using this strategy, but outcomes may be prevalence dependent. Lastly, empirical treatment with Proton pump inhibitors achieved symptom relief for dyspepsia and avoided upper GI endoscopies in about two thirds of patients. Changing referral behavior is complex as contributing factors are manifold. A collaboration of multiple strategies is most likely to succeed.     

Delta (13)C-urea breath test value is a useful indicator for Helicobacter pylori eradication in patients with functional dyspepsia

BACKGROUND: Eradication of Helicobacter pylori is not routinely recommended for the symptomatic relief and the prevention of gastric cancer in patients with functional dyspepsia. The present study investigated a useful indicator of H. pylori eradication in such patients by determining the optimal cutoff value of a 13C-urea breath test (UBT). METHODS: One hundred dyspeptic patients participated in the study. Dyspepsia was scored, and a 13C-UBT administered. A level of delta 13C-UBT of>4 per thousand was diagnosed as H. pylori-positive. After the stomach was endoscopically sprayed with phenol red, biopsy specimens were taken from the antrum, body and cardia of the stomach for the assessment of H. pylori density, and activity (neutrophil infiltration) and degree (lymphocyte infiltration) of gastritis. RESULTS: Correlation between delta 13C-UBT and dyspepsia score was not found. Delta 13C-UBT significantly correlated with H. pylori density score in the total stomach (r = 0.53, P < 0.0001), neutrophil (r = 0.34, P = 0.0005) and lymphocyte score (r = 0.69, P < 0.0001). Twenty-six of the 100 subjects had a neutrophil score of >or=4, lymphocyte score of >or=4, and H. pylori score of >or=4. Their 95% confidence interval of mean was 58.2 per thousand, which reflects moderate to marked acute and chronic gastritis, and dense H. pylori colonization. CONCLUSIONS: The 13C-UBT is a reliable semiquantitative test to assess H. pylori density and the activity and degree of gastritis. It is proposed that H. pylori eradication therapy might be beneficial for patients with functional dyspepsia with a delta 13C-UBT of >58.2 per thousand.     

Use of open access in GI endoscopy at an academic medical center.

BACKGROUND: Open access endoscopy systems (those in which endoscopy is performed without prior gastroenterology consultation) are becoming more common in the current cost-conscious environment. The aim of this study was to compare appropriateness and yield of endoscopy for patients referred for open access endoscopy with those for patients who had prior contact with a gastroenterologist. We also evaluated patients' preference for undergoing open access endoscopy as opposed to having prior consultation with a gastroenterologist and compared preparedness for endoscopic procedures between the two groups. METHODS: The cases of all outpatients referred for upper endoscopy and colonoscopy were assessed prospectively over a 5-month period. American Society for Gastrointestinal Endoscopy (ASGE) guidelines for indications for gastrointestinal endoscopy were used to determine appropriateness of referrals. Significant pathologic findings were rated independently by two investigators using defined criteria. Patients' opinions regarding preparedness for endoscopy and referral preference were measured by means of questionnaires administered before endoscopy. RESULTS: Eighty-six percent of endoscopies after consultation with gastroenterologists were performed for accepted indications compared with 65% of open access procedures (p < 0.01). Significant pathologic findings were present in 40% of the former group compared with 28% of those undergoing open access endoscopy (p < 0.01). Significant pathologic findings were found in 37% of endoscopies performed for indications listed in the ASGE guidelines compared with 20% for unlisted indications (p < 0.01). Forty percent of patients referred for open access endoscopy would have preferred prior consultation with a gastroenterologist. CONCLUSION: Patients initially seen by a gastroenterologist are more likely to undergo endoscopy for accepted indications, and the yield of endoscopy is higher than among patients referred through an open access system. The system of open access endoscopy as currently practiced may have to be reassessed.     

One week's anti-Helicobacter pylori treatment for duodenal ulcer.

This open study tested whether eradication of Helicobacter pylori (H pylori) heals duodenal ulcers as well as decreasing recurrence. H pylori was detected in patients with endoscopic duodenal ulcers by histology, CLO-test, culture, and 13C-urea breath test (13C-UBT). Tripotassium dicitrato bismuthate (120 mg) and amoxycillin (500 mg) each four times daily, were given for seven days, with 400 mg metronidazole five times a day on days 5-7. The 13C-UBT was repeated immediately after treatment and endoscopy repeated within 21 days. After treatment unhealed ulcers were reinspected one month later and healed ulcers followed up by 13C-UBT alone for 12 months. Of 45 patients, 44 were available for follow up. Mean pretreatment excess delta 13CO2 excretion was 25.6 per mil, which fell to 2.4 per mil immediately after finishing treatment, indicating clearance of H pylori in every patient. At the second endoscopy (median interval 20 days from start of treatment) 33 of 44 (75%) duodenal ulcers had healed. Ten of the remaining 11 duodenal ulcers were smaller and those 10 healed in the next two weeks with no further treatment. Two patients' ulcers that initially healed with clearance of H pylori recurred three weeks later (both had metronidazole resistant H pylori). H pylori was eradicated in 28 of 44 (64%) patients (13C-UBT negative for median follow up 10.2 months). Overall 41 of 43 (93%, 95% confidence intervals 81%-99%) duodenal ulcers were healed at one month. This study suggests that one week of anti-H pylori triple treatment is effective in healing duodenal ulcers.     

Recurrence of Helicobacter pylori infection 1 year after successful treatment: prospective cohort study in the Republic of Yemen

OBJECTIVES: To investigate the prevalence of Helicobacter pylori infection in dyspeptic patients in the Republic of Yemen and the recurrence rate 1 year after apparently successful eradication. METHODS: A total of 275 patients with chronic dyspepsia seen in one clinic were enrolled. Gastric biopsies were obtained at endoscopy and H. pylori infection was diagnosed using the rapid urease test. Patients with H. pylori infection were given either clarithromycin or metronidazole-based triple therapy. Six weeks later H. pylori status was assessed using the C-urea breath test (C-UBT). Those who were negative for H. pylori had a further C-UBT after 1 year to establish the recurrence rate. RESULTS: The prevalence of H. pylori infection at entry to the study was 82.2% [95% confidence interval (CI) 78-87%]. The overall eradication rate 6 weeks after treatment was 49.1% (95% CI 42.6-55.6%) by intention-to-treat analysis, and 60% (95% CI 53-67%) by per-protocol analysis. Recurrence rate of H. pylori infection at 1 year was 34% (95% CI 14-45%) and the only predictor of recurrence was an excess delta C-UBT value less than 3.5 per million but equal to or greater than 2.5 per million at 6 weeks after treatment (odds ratio 2.28; 95% CI 1.17-4.44; P = 0.028). CONCLUSION: The prevalence of H. pylori infection in dyspeptic patients in Yemen is very high, the eradication rate with standard triple therapy was unsatisfactory probably because of widespread bacterial resistance due to unrestricted antibiotic use. The recurrence rate of infection at 1 year was high, as a result of recrudescence of incompletely eradicated organisms rather than reinfection.     

Simplified single sample 13Carbon urea breath test for Helicobacter pylori: comparison with histology, culture, and ELISA serology.

There is no ideal method for detecting Helicobacter pylori. The 'standard' 13Carbon urea breath test (13C-UBT), which involves collecting eight to 15 breath samples and subsequent costly analysis, was modified by pooling 21 samples of expired breath taken at five minute intervals for 40 minutes into a collecting bag, from which a single 20 ml aliquot was taken and analysed by mass spectrometry. This test was evaluated on 50 patients after routine upper gastrointestinal endoscopy, and results were compared with those from the standard 13C-UBT, bacteriology, ELISA serology, and histology--the latter being taken as the gold standard. H pylori were seen in 34 of 50 (68%) patients (in three it was detected in biopsy specimens from the corpus alone). The modified 13C-UBT was positive (pooled excretion delta 13CO2 greater than 5 per mil) in 31 patients and negative in 19 (three false negative results), specificity was 100% (standard 13C-UBT 94%) and sensitivity 92% (standard 13C-UBT 93%). The modified 13C-UBT had a coefficient of variation within subjects of 3.7%. For the ELISA serology and culture the specificities were both 100%, but the sensitivities were 82% and 68% respectively. The 13C-UBT results correlated with the grade of histological gastritis. The modified 13C-UBT is simpler, cheaper, more reproducible, and provides an easy non-invasive method for the detection of H pylori.     

Helicobacter pylori test and eradicate versus prompt endoscopy for management of dyspeptic patients: 6.7 year follow up of a randomised trial

BACKGROUND: Dyspepsia is a chronic disease with significant impact on the use of health care resources. A management strategy based on Helicobacter pylori testing has been recommended but the long term effect is unknown. AIM: To investigate the long term effect of a test and treat strategy compared with prompt endoscopy for management of dyspeptic patients in primary care. PATIENTS: A total of 500 patients presenting in primary care with dyspepsia were randomised to management by H pylori testing plus eradication therapy (n = 250) or by endoscopy (n = 250). Results of 12 month follow up have previously been presented. METHODS: Symptoms, quality of life, and patient satisfaction were recorded during a three month period, a median 6.7 years after randomisation (range 6.1-7.3 years). Number of endoscopies, antisecretory medication, H pylori treatments, and hospital visits were recorded from health care databases for the entire follow up period. RESULTS: Median age was 45 years; 28% were H pylori infected. Use of resources was registered in all 500 patients (3084 person years) of whom 312 completed diaries. We found no difference in symptoms between the two groups. Median proportion of days without symptoms was 0.52 (interquartile range 0.10-0.88) in the test and eradicate group versus 0.64 (0.14-0.90) in the prompt endoscopy group (p = 0.27) (mean difference 0.05 (95% confidence interval (CI) -0.03 to 0.14)). Compared with the prompt endoscopy group, the test and eradicate group underwent fewer endoscopies (mean difference 0.62 endoscopies/person (95% CI 0.38-0.86)) and used less antisecretory medication (mean difference 102 defined daily doses/person (95% CI -1 to 205)). CONCLUSION: On a long term basis, a H pylori test and eradicate strategy is as efficient as prompt endoscopy for management of dyspeptic patients in primary care and reduces the use of endoscopy and antisecretory medication.     

13C-Urea Breath Test for Diagnosis of Helicobacter pylori Infection in the Elderly

Helicobacter pylori infection has a high prevalence in the elderly, but its characteristics and treatment in the geriatric population are not well defined. The aims of the study were to characterize geriatric patients according to referral patterns and results of the 13C-urea breath test (13C-UBT) and to investigate the results of treatment combinations for H. pylori eradiction. The 13C-UBT was performed with 75 mg urea labeled with 13C. Physicians who ordered the test completed a questionnaire covering demographic data, indication for the test, chronic use of a proton pump inhibitor, or nonsteroidal anti-inflammatory drug, and type of eradiction therapy. The study sample consisted of 2128 patients, aged 70-102 years, 958 (45%) men, referred for 13C-UBT. The test was positive on 697 (33%). History of peptic disease was the main indication for referral, following by validation of successful eradication, Israeli origin screening for gastric cancer, treatment with regimen containing metronidazole, history of peptic disease, and recurrence of symptoms were predictive factors for a positive 13C-UBT. Multivariate logistic regression analysis revealed a significant influence of eradication therapy on negative results. History of peptic disease and validation of successful eradication are the main indications for referral of the elderly for 13C-UBT. Our results are in accordance with the increase in metronidazole resistance of H. pylori stains and the cohort effect of H. pylori infection on the elderly Israeli-born population.     

Scintigraphic evaluation of gallbladder motor functions in H pylori positive and negative patients in the stomach with dyspepsia

AIM：To evaluate the relationship between gallbladder （GB） motor function and H pylori infection in the stomach.
METHODS： All cases （86） underwent the 14C urea breath test （UBT）. ^14C-UBT was found as positive in 58 and negative in 28 dyspeptic patients. ^14C- UBT was accepted as a gold standard test. Clo test and histopathologic examination were compared with the results of ^14C-UBT in cases who tolerated upper gastrointestinal endoscopy procedure. Cholescintigraphy with ^99mTc-mebrofenin was used to determine the parameters of GB motor function （GB filling and emptying time, half of the emptying time, ejection fraction at 30th and 60th min） in all patients.
RESULTS： We found the sensitivity and specificity as 88% and 86% for Clo test and as 89% and 80% for histologic evaluation, respectively. The parameters of GB function were not significantly different in H pylori positive and negative patients. The GB emptying was normal in both groups. Minimum GB filling time was 30 min in 34 of 86 cases （39.5%）, filling was not observed in 2 cases. The GB ultrasonography （USG） results were normal for all cases and bile composition abnormality was not determined.
CONCLUSION： Our study showed that ^14C-UBT is highly reliable method to detect the presence of H pylori. The presence of H pylori infection does not directly affect the GB function.     

Helicobacter pylori "test-and-treat" strategy is not suitable for the management of patients with uninvestigated dyspepsia in Shanghai

OBJECTIVE: The safety of Helicobacter pylori "test-and-treat" and "test-and-endoscopy" strategies for the management of young patients with uninvestigated dyspepsia has not been evaluated in Shanghai. MATERIAL AND METHODS: A total of 14,101 consecutive patients with dyspepsia receiving endoscopy in our hospital from October 2002 to December 2003 were retrospectively studied. The detection rates of esophageal or gastroduodenal malignancies and alarm symptoms were investigated, and H. pylori status was assessed. RESULTS: A total of 202 (1.4%) gastrointestinal (GI) malignancies were found, including 162 cases (1.15%) of gastric cancer, 4 of gastric lymphoma, 35 (0.25%) of esophageal cancer and 1 case of duodenal cancer. Among those patients with GI malignancies, 99 (49.0%) were infected with H. pylori and 108 (53.5%) presented with alarm symptoms. Eighteen patients (0.46%, 18/3952) under 45 years of age were diagnosed as having gastric cancer. Of these patients, 5 (27.8%) presented with alarm symptoms and 13 (72.2%) were infected with H. pylori. If the H. pylori "test-and-treat" strategy were used in dyspeptic patients under the age of 45 years without alarm symptoms in the Shanghai region, then 13 cases (72.2%) of gastric cancer would be missed. If the H. pylori "test-and-endoscopy" strategy were applied, then 3 cases (16.7%) of gastric cancer would be missed. CONCLUSIONS: H. pylori "test-and-treat" and "test-and-endoscopy" strategies are both not suitable for the management of patients with uninvestigated dyspepsia in Shanghai. For most Shanghai dyspeptic patients, prompt endoscopy should be recommended as the first-line initial management option.     

A prospective randomised trial of a "test and treat" policy versus endoscopy based management in young Helicobacter pylori positive patients with ulcer-like dyspepsia, referred to a hospital clinic.

BACKGROUND: Management of dyspepsia remains a controversial area. Although the European Helicobacter pylori study group has advised empirical eradication therapy without oesophagogastroduodenoscopy (OGD) in young H pylori positive dyspeptic patients who do not exhibit alarm symptoms, this strategy has not been subjected to clinical trial. AIMS: To compare a "test and treat" eradication policy against management by OGD. PATIENTS: Consecutive subjects were prospectively recruited from open access OGD and outpatient referrals. METHODS: H pylori status was assessed using the carbon-13 urea breath test. H pylori positive patients were randomised to either empirical eradication or OGD. Symptoms and quality of life scores were assessed at baseline and subsequent reviews over a 12 month period. RESULTS: A total of 104 H pylori positive patients aged under 45 years were recruited. Fifty two were randomised to receive empirical eradication therapy and 52 to OGD. Results were analysed using an intention to treat policy. Dyspepsia scores significantly improved in both groups over 12 months compared with baseline; however, dyspepsia scores were significantly better in the empirical eradication group. Quality of life showed significant improvements in both groups at 12 months; however, physical role functioning was significantly improved in the empirical eradication group. Fourteen (27%) in the empirical eradication group subsequently proceeded to OGD because of no improvement in dyspepsia. CONCLUSIONS: This randomised study strongly supports the use of empirical H pylori eradication in patients referred to secondary practice; it is estimated that 73% of OGDs in this group would have been avoided with no detriment to clinical outcome.     

Helicobacter pylori “test-and-scope” strategy for dyspeptic patients. Is it useful and safe?

AIM: To evaluate outcome of test-and-scope strategy using 13C-urea breath test, Helicobacter pylori IgG serology, and CagA serology. PATIENTS AND METHODS: A series of 100 dyspeptic patients were studied. Biopsies were obtained for histology and rapid urease test (gold standard). Serum samples were obtained for Helicobacter pylori IgG and CagA serology, and 13C-urea breath test was carried out. RESULTS: If endoscopy had not been performed in Helicobacter pylori patients based on 13C-urea breath test, <45 years, without alarm symptoms, and without non-steroidal anti-inflammatory drug use, 15% of endoscopies would have been saved, and one gastric ulcer and two oesophagitis would have been missed. Based on Helicobacter pylori IgG serology, 21% of endoscopies would have been saved. Finally, if endoscopy had been performed only in CagA+ patients, 31% of endoscopies would have been saved, missing one gastric ulcer and two cases of oesophagitis. CONCLUSIONS: In our geographical area, the test-and-scope strategy based on 13C-urea breath test or Helicobacter pylori IgG serology would have saved only 15-20% of endoscopies. Although some relevant pathology would have been missed, it is not of a malignant type. 13C-urea breath test is the preferred non-invasive method to be used in this strategy, while Helicobacter pylori IgG serology is of limited value due to its low accuracy. With the use of CagA serology a larger number of unnecessary endoscopic examinations can be avoided.     

How to determine the diagnosis of Helicobacter pylori infection in the elderly?

PURPOSE: The real prevalence of Helicobacter pylori (H. pylori) infection is difficult to determine in the elderly because of the frequency of drug intake (antibiotics or anti-secretory drugs). The aim of this study was to evaluate the diagnostic performance of five tests in the elderly. METHODS: The study population consisted of consecutive patients undergoing a routine endoscopy between August 1998 and December 1999. We evaluated the diagnostic performance of four tests in all of the included patients: culture and histology of biopsy specimens, serology (ELISA) and urea breath test (13C-UBT). Detection of H. pylori antigens in stool samples (HpSA) was realized in a subgroup. Patients were considered H. pylori + when result for culture was positive or when two tests were positive. RESULTS: One hundred and sixty-seven patients were included in this study (55 men, 112 women; mean age: 85.6 +/- 5.1 years). Only 38 (22.8%) patients were H. pylori+. Test performances showed the following results: serology sensitivity: 90.9% (IC 95%: 75.6-98.1) versus 86.9% (IC 95%: 63.6-96.9) for culture versus 77.8% (IC 95%: 60.8-89.9) for histology and 74.3% (IC 95%: 56.7-87.5) for 13C-UBT. Eighty-nine (53.3%) took antibiotics or anti-secretory drugs, only 13C-UBT performances decreased significantly (sensitivity: 94.4% [72.7-99.8] versus 52.9% [27.8-77]; P < 10(-6)). When gastric or duodenal ulcer were endoscopically diagnosed in older patients, both histology and 13C-UBT could not improve the diagnosis of H. pylori infection. HpSA was realized in 107 patients (sensitivity: 74.1%, specificity: 98.7%). We showed no statistical difference between HpSA performances and drug intake. CONCLUSION: Diagnostic performances decreased in older patients especially because of drug intake.     

The clinical utility of string-PCR test in diagnosing Helicobacter pylori infection

BACKGROUND/AIMS: Non-invasive string test has been reported as being convenient and capable of yielding bacteria by means of gastric juice sampling in the diagnosis of Helicobacter pylori infection. Molecular methods, such as polymerase chain reaction for the amplification of DNA, are desirable for the detection of minute quantities of H. pylori. We planned to evaluate the diagnostic efficiency of the combination of the string test and polymerase chain reaction and determine whether the string polymerase chain reaction test could obtain more information in conditions where the bacterial load is so low that other diagnostic tests fail to confirm the presence of H. pylori. METHODOLOGY: We enrolled 48 dyspeptic patients, including 29 males and 19 females, with a mean age of 52.5 years. Each patient received endoscopy and biopsy-based tests, including RUT (rapid urease test), cultures, and histology, followed by 13C-UBT (13Carbon urea breath test). We used the string test, (Entero-Test H. pylori, HDC Corporation, CA, US), for gastric juice sampling. The specimen was further analyzed by polymerase chain reaction for the presence of H. pylori with the primer for cagA gene, which is highly prevalent in Taiwan. H. pylori infection was considered as positive when either culture yield was positive, or when two of the other three tests, including RUT, histology, and 13C-UBT, were positive. RESULTS: Of the total 48 patients, 34 patients were H. pylori-positive, and 14 were H. pylori-negative. A fragment of 349 bp of polymerase chain reaction products was detected by agarose gel electrophoresis in 32 out of 34 patients who was classified as H. pylori-positive. The sensitivity, specificity, positive predictive value, and negative predictive value of the string polymerase chain reaction test were 94.12%, 96.97%, 92.86%, and 86.67%, respectively. These results are comparable to 13C-UBT and RUT, and better than histology and culture. One subject, who tested as H. pylori-negative according to the diagnostic criteria, had positive 13C-UBT and string polymerase chain reaction test results. Further sequencing of the DNA obtained from the results of polymerase chain reaction product was performed and it showed 98% identities with the known sequence of cagA strain H. pylori (GenBank accession number: AF249275). CONCLUSIONS: The string polymerase chain reaction test is non-invasive and provides direct bacterial yields. Its diagnostic efficiency is comparable with 13C-UBT and RUT in detecting H. pylori infection. Also, with the assistance of polymerase chain reaction and DNA sequencing, we can diagnose H. pylori infection even when the bacterial load is low. Further application of string polymerase chain reaction test in the genetic analysis of virulent and resistant strains seems promising.     

Diagnosis of Helicobacter pylori gastritis in children using the 13C urea breath test

The clinical recognition of Helicobacter pylori gastritis in children with recurrent abdominal pain is difficult. We assessed the value of a simplified 13C urea breath test (13C-UBT) in a selected group of children with nocturnal waking and disruptive recurrent abdominal pain who fulfilled criteria for endoscopy. Gastric antral biopsies were examined histologically and by the quick urease test and were compared with H. pylori serology and the 13C-UBT in a prospective study of 50 children referred to a tertiary center. Thirty-two patients had gastritis and of these, 19 had histologically proven H. pylori gastritis. Seventeen of these 19 patients had a positive 13C-UBT. The sensitivity and specificity of the 13C-UBT compared with the histologic diagnosis of H. pylori was 89 and 90% respectively. The 13C-UBT was more specific than the H. pylori serology. The 13C-UBT using two breath collections is a reliable and noninvasive diagnostic test for H. pylori infection in children.     

Detecting Helicobacter pylori infection in hospitalized frail older patients: the challenge

OBJECTIVES: Helicobacter pylori infection has not been well studied in older people, especially in hospitalized, frail patients. The aim of our study was to evaluate the prevalence of the infection in this population using five H. pylori diagnostic tests. DESIGN: Prospective observational study. SETTING: Geriatric acute care unit of the Department of Geriatrics (H?pital Xavier Arnozan, Pessac, France). PARTICIPANTS: One hundred seven consecutively hospitalized patients with a diagnostic indication for upper gastrointestinal endoscopy. MEASUREMENTS: Geriatric assessment, information on drug intake, indication/results of gastric endoscopy, and results of H. pylori infection diagnostic tests (culture and histological analysis on biopsy specimens, serology, 13carbon-urea breath test (13C-UBT), detection of H. pylori stool antigens (HpSA)) were assessed for each included patient. RESULTS: Fifty-one patients (47.7%) were H. pylori positive with at least one test. 13C-UBT was more frequently positive than the other four tests, with a significant difference from culture, histological analysis, and HpSA (P <.05). Positive 13C-UBT results were significantly associated with H. pylori presence using histological analysis and neutrophil activity of the antrum and corpus. Antibiotic treatments significantly decreased the positivity rate of all of the tests performed, and severe corpus atrophy decreased the positivity rate of culture, histological analysis, and HpSA. CONCLUSIONS: Almost one-third of the H. pylori-positive patients would have remained undetected without performing the 13C-UBT. The low prevalence of H. pylori detection in these hospitalized, frail patients may be explained by the high frequency of current and previous antibiotic treatments.     

Helicobacter pylori stool antigen (HpSA) test--a simple, accurate and non-invasive test for detection of Helicobacter pylori infection

BACKGROUND/AIMS: To access the reliability of a newly developed test, the Helicobacter pylori (H. pylori) stool antigen (HpSA) test was used for detection of H. pylori infection. METHODOLOGY: Stool specimens were collected from 33 consecutive patients (19 males and 14 females, age range: 16-73 years, mean: 49 years) who received upper gastrointestinal endoscopic examination for gastrointestinal symptoms. The H. pylori status was evaluated based on six different tests: culture, histology, biopsy urease test, 13C-urea breath test (13C-UBT), serology, and HpSA test. A commercial kit using an enzyme-linked immunosorbent assay examined HpSA in the stool. H. pylori status was defined as positive when the culture was positive or concordance of three of the other four tests (histology, biopsy urease test, 13C-UBT, and serology) was positive. RESULTS: Twenty patients were diagnosed as H. pylori-positive. The HpSA test was positive in 19 patients and negative in 14 patients. The sensitivity and specificity were 95.0% and 100%, respectively. The overall accuracy rate was 96.3%. CONCLUSIONS: The HpSA test is a new, simple, non-invasive method for accurate diagnosis of H. pylori infection.