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.     

Clinical value of Helicobacter pylori stool antigen test,ImmunoCard STAT HpSA，for detecting Hpylori infection

AIM: To evaluate the reliability of the Helicobacter pylori stool antigen test, ImmunoCard STAT HpSA, for detecting H pylori infection. METHODS: Stool specimens were collected from 53 patients who received upper endoscopy examination due to gastrointestinal symptoms. ImmunoCard STAT HpSA was used to detect H pylori stool antigens. H pylori infection was detected based on three different tests: the urease test, Warthin-Starry staining and culture. H pylori status was defined as positive when both the urease test and histology or culture alone was positive. RESULTS: Sensitivity, specificity, positive predictive and negative predictive values and the total accuracy of ImmunoCard STAT HpSA for the diagnosis of H pylori infection were 92.6% (25/27), 88.5% (23/26), 89.3% (25/28), 92% (23/25) and 90.6% (48/53), respectively.CONCLUSION: The stool antigen test, ImmunoCard STAT HpSA, is a simple noninvasive and accurate test for the diagnosis of H pylori infection.     

Usefulness of the Helicobacter pylori stool antigen test for detection Helicobacter pylori infection

Several diagnostic tests are available for evaluating Helicobacter pylori (H. pylori) infection: histological examination, culture of gastric biopsy specimens, rapid urease test, urea breath test and serology. In this study, we assessed the reliability of a newly developed enzyme immunoassay HpSA (H. pylori Stool Antigen) kit for detecting H. pylori antigen in stool. Eighty-five patients (50 males, 35 females; mean age 41.6 +/- 9.8 years) with dyspeptic symptoms who were examined by upper gastrointestinal endoscopy. The patients with a history of previous treatment with proton pump inhibitors, bismuth compounds or antibiotics were excluded. During the endoscopic examination biopsies were taken from antrum and corpus for rapid urease test and histological examination. Stool specimens were submitted to the laboratory and HpSA test was performed. H. pylori was considered in condition with rapid urease test and histopathological examination for H. pylori positive. Forty-six of 85 patients were positive and remaining 39 patients were negative for H. pylori with the rapid urease test and pathologic evaluation. When 0.160 was adopted as the cut-off value, in accordance with the manufacturer's recommendations; stool antigen has been detected in 45 of the 46 H. pylori positive patients. The sensitivity and specificity of HpSA test were 97.8%, 94.9% respectively. These results indicate that HpSA is a highly reliable diagnostic method for H. pylori infection.     

Evaluation of the Helicobacter pylori stool antigen test (HpSA) for detection of Helicobacter pylori infection in children

OBJECTIVE: Helicobacter pylori (H. pylori) infection is usually acquired in early childhood. Noninvasive methods for detection of H. pylori infection are required to study its incidence, transmission, and clearance. They should be easy to perform, inexpensive, and have a high diagnostic accuracy, especially in infants and toddlers. Both serology and the 13C-urea breath test (13C-UBT) do not fulfill all these requirements. The aim of this study was to evaluate a new enzyme immunoassay for detection of H. pylori antigen in stool (Premier Platinum HpSA, Meridian Diagnostics, Cincinnati, OH) in a large cohort of children and to compare it to invasive techniques and the 13C-UBT. METHODS: HpSA was performed in 310 stool samples of 274 children divided into three groups. Group A consisted of 145 children and adolescents (0.5-19.8 yr, 66/145 <6 yr) who underwent upper endoscopy for various gastrointestinal symptoms. H. pylori status was defined by histology, culture, and rapid urease test from biopsies of the antrum and corpus. A 13C-UBT was performed in 133 of 145 children. Group B consisted of 22 patients (5.7-16.1 yr) who were retested with both noninvasive tests 8 wk after anti-H. pylori triple therapy. Group C consisted of 129 healthy infants and toddlers (0.9-3.1 yr) who were tested with the 13C-UBT. Children with discrepant or positive test results were retested after 2 and 12 months. Results of the HpSA were read at 450/620 nm by spectrophotometry. An optical density <0.100 was defined as negative, >0.120 as positive, and values between 0.100 and 0.120 were considered as equivocal. RESULTS: In Group A, the HpSA gave false-negative results in five of 45 infected children and false-positive results in four of 100 noninfected children, whereas four patients (2.8%) showed equivocal results. In both infected and noninfected children, no relation between the optical density values and age was found. The 13C-UBT was correct in 132 of 133 children tested. In Group B, there was complete concordance between the HpSA and 13C-UBT: 19 children tested negative and three positive. In Group C, concordant results between the two noninvasive methods were found in 124 of 129 (96%) toddlers (122 negative and two positive). Retesting of five children with discrepant results revealed that, on initial testing, the HpSA was incorrect in two (one false-positive, one false-negative), and the 13C-UBT was incorrect in three (always false-positive). CONCLUSIONS: In symptomatic children, the HpSA revealed a sensitivity of 88.9% (95% CI 77.3-96.3) and a specificity of 94.0% (88.1-97.7) compared to the 13C-UBT, 100% (94.0-100) and 98.9% (94.7-100), respectively. However, in healthy toddlers, the HpSA performed as well as the 13C-UBT with excellent concordance between the two noninvasive tests. There was no age dependency of the stool test results, and changing the cutoff would not have improved accuracy. Thus, the HpSA test seems suitable to monitor the success of anti-H. pylori therapy.     

老年人幽门螺杆菌粪便抗原检测的价值

目的 评价一种新的酶联免疫法检测老年人粪便中幽门螺杆菌（helicobacter pylori,Hp）特异抗原的可靠性和临床应用价值。方法 因上消化道症状行胃镜检查的老年患者共199例，其中既往无胃手术史者151例，胃大部切除术后者48例。均行胃粘膜活检，作快速尿素酶试验（RUT）和组织学检查（W－S染色），以RUT和W－S染色为金标准，两项均阳性（或阴性）诊断为Hp阳性（或阴性）。所有患者均检查幽门螺杆菌粪便抗原（HpSA）和^13C－尿素呼气试验（^13C-UBT），分别与金标准比较，计算其敏感性和特异性。结果 经金标准诊断，无胃手术史患者中Hp阳性81例，阴性70例。HpSA检测的敏感性和特异性分别为96.3%和90.0%，^13C-UBT为92.6%和92.9%，两种方法的敏感性和特异性差异无显著性。胃大部切除术后患者中Hp阳性23例，阴性25例，HpSA检测的敏感性和特异性分别为91.3%和88.0%，^13C-UBT为65.2%和92.0%，两种方法敏感性差异有显著性（P＜0.05）。结论 HpSA在诊断老年人Hp感染方面准确、快速、简便，值得推广。对于胃大部切除术后的老年患者，其诊断Hp的敏感性明显优于^13C-UBT。     

Lack of accuracy of the noninvasive Helicobacter pylori stool antigen test in patients with gastroduodenal ulcer bleeding

OBJECTIVE: Oral presentation at Digestive Diseases Week, San Francisco, California, May 2002. The antigen-based stool assay has proven to be accurate in diagnosing Helicobacter pylori infection in dyspeptic patients. We evaluated the H. pylori antigen-based stool assay (HpSA) in patients with peptic ulcer bleeding (PUB). METHODS: Thirty-six patients with PUB were endoscoped, and antral and corpus biopsy specimens were taken for rapid urease test (RUT), histology, and culture. The first stool sample after admission was collected for the HpSA test. The gold standard was defined as either positive culture or positive RUT and histology. If only RUT or histology was positive, this was defined as indeterminate. To evaluate cross-reaction with blood constituents, citrated blood samples from 10 healthy volunteers (nine H. pylori serology negative and one H. pylori serology positive) were assessed by the HpSA test. RESULTS:A total of 36 consecutive patients with PUB (21 male) with a mean age of 69.5 yr were included in the study. Using the gold standard, the sensitivity and specificity of the HpSA test were 100% and 52%, respectively. Citrated blood samples of three H. pylori negative and one H. pylori positive volunteer gave a positive result in the HpSA test, suggesting cross-reaction with blood con stituents. CONCLUSIONS: The HpSA test gave a high number of false- positive results in patients with PUB, probably because of blood constituents cross-reacting in the enzyme immunoassay. The HpSA test is not accurate for testing H. pylori infection in patients with PUB.     

Evaluation of the Helicobacter pylori stool antigen test (HpSA) for the detection of Helicobacter pylori infection and comparison with other methods

BACKGROUND/AIMS: Several invasive and non-invasive methods are available for the detection of H. pylori infection. The accuracy of anti-H. pylori antibodies in serum is low. There is a need for a quick, inexpensive and reliable non-invasive test to detect H. pylori. The aim of this study was to evaluate the enzyme immunoassay for the detection of H. pylori antigen in stool in the Turkish population and compare it to other methods. METHODOLOGY: 50 patients who were admitted to Hacettepe University Department of Internal Medicine, Division of Gastroenterology with the symptom of dyspepsia for whom the indication of upper gastrointestinal endoscopy was present were included in the study. With their permission stool samples were taken. The patients were evaluated with histology, culture, serology, rapid urease test and HpSA (Helicobacter pylori Stool Antigen test). Forty-one patients had gastritis and biopsies were taken from those. RESULTS: Excluding HpSA if three of the rest of four methods were positive, patients were accepted as H. pylori positive. Nineteen patients were positive for H. pylori, 22 were negative. HpSA was positive in 16 of 19. The sensitivity and specificity of the methods were as follows: histology 100% sensitive, and 86% specific, culture 63% and 100%, HpIgG 58% and 73%, rapid urease test 89% and 82%, respectively. The results were as 84% and 82% for HpSA. Comparing with the 'Gold Standard' histology using McNemar's test Kappa results were as 0.610, 0.181, 0.610, 0.708 for culture, HpIgG, Rapid Urease Test and HpSA, respectively. CONCLUSIONS: HpSA is a cheap, effective method for the diagnosis of H. pylori infection in the Turkish population.     

幽门螺杆菌粪便抗原试验的多中心研究

目的：评估幽门螺杆菌（H.pylori)粪便抗原（HpSA)试验诊断H.pylori感染的准确性。方法：应用酶免疫反应原理进行HpSA试验，在大样本、多中心研究中进行HpSA试验的评估。995例因消化不良症状接受胃镜检查者纳入本研究，所有患者均以HpSA试验、快速尿素酶试验（RUT）和组织学（或培养）方法检测H.pylori。以RUT和组织学（或培养）联合检测作为“金标准”，两项试验均阳性者定为H.pylori感染。结果：以光密度值≥0.16为阳性，HpSA检测诊断H.pylori感染的敏感性为93.5%(478/511)，特异性为94.2%(456/484)，阳性预测值为94.5%(478/506)，阴性预测值为93.3%(456/489)，总的检测准确性为93.9%(934/995)。结论：HpSA试验是一种简便、准确的非侵入性H.pylori感染检测方法。     

Diagnosis of Helicobacter pylori infection by stool antigen test in southern Taiwan

Helicobacter pylori (H. pylori) has been found to be associated with various gastrointestinal diseases. Confirmation of H. pylori infection includes invasive and non-invasive methods. There has been increasing interest in noninvasive tests recently. However, the geographical differences among H. pylori strains have been emphasized recently and the H. pylori strain in Taiwan showed a high cagA positive result and different vacA subtype when compared with those of Western countries. The aim of this study is to access and compare the reliability and the diagnostic accuracy of the stool H. pylori antigen tests by spectrophotometry and by the visual method, especially in Southern Taiwan. Thirty-two patients (18 men and 14 women; age range: 23-91 y/o, mean: 50.5 y/o) who underwent gastroendoscopy at Kaohsiung Medical University Hospital were enrolled in this study. H. pylori infection status was confirmed by culture or two positive test results on CLO test, histology and 13C-urea breath test (13C-UBT). The exclusion criteria included previous gastrointestinal tract surgery, use of antibiotics, proton pump inhibitor or compounds containing bismuth within 1 month of the study. Among them, 14 patients were with duodenal ulcer (DU), 4 with gastric ulcer (GU), 12 with non-ulcer dyspepsia, and 2 with GU and DU. Those patients had their stool collected for ELISA tests of H. pylori stool antigen (HpSA). The HpSA tests were positive in 16 of 18 patients diagnosed as H. pylori positive, and negative in 13 of 14 patients as H. pylori negative. The sensitivity and specificity were 88.9% and 92.9% respectively. The positive and negative predictive values were 94.1% and 86.7% respectively. The concordance of HpSA accessed by spectrophotometry and visual method is 100%, which makes this test even easier and cheaper. We concluded that stool HpSA test is a noninvasive, accurate, reliable, rapid and easy way to diagnose H. pylori infection in Southern Taiwan, either by spectrophotometry or by visual assessment.     

Diagnosis of Helicobacter pylori infection: noninvasive methods compared to invasive methods and evaluation of two new tests

OBJECTIVES: Current guidelines recommending Helicobacter pylori eradication treatment without performing endoscopy in certain patients highlight the importance of noninvasive tests. Our aim was to determine the accuracy of two new tests: the antigen stool test and Helicoblot 2.1 (an immunoblot used on serum) as well as the 13C urea breath test and ELISA serology in comparison to invasive tests for the pretreatment diagnosis of H. pylori infection. METHODS: Helicobacter pylori infection was diagnosed prospectively in 104 untreated patients using eight different tests. Invasive tests included culture, urease test (CLOtest), histology, and PCR; noninvasive tests included the 13C urea breath test, IgG serology (Pyloriset EIA-G), immunoblot (Helicoblot 2.1), and antigen stool detection (Premier Platinum HpSA). A predefined gold standard based on biopsy tests was used to define H. pylori status, as well as an empirical approach. RESULTS: There was no statistically significant difference between the different tests. The sensitivity of the noninvasive tests ranged between 88.9% and 95.6% (stool test: 88.9%, 95% CI: 82.7-95.1, and Helicoblot 2.1: 95.6%, 95% CI: 91.5-99.6) and the specificity ranged between 92.6 and 98.1% (stool test: 94.4%, 95% CI: 84.6-98.8, and Helicoblot 2.1: 92.6%, 95% CI: 91.5-96.2) when a predefined gold standard was used. CONCLUSIONS: Most tests had sensitivities, specificities, and predictive values >90%. The noninvasive tests are accurate for the diagnosis of H. pylori infection. Helicoblot 2.1 performed as well as the best ELISA kit. The HpSA is a promising direct noninvasive test that can be applied easily to evaluate H. pylori status.     

Comparison of three stool antigen tests in confirming Helicobacter pylori eradication in adults

OBJECTIVE: Reliable and readily available non-invasive methods are needed for detection of Helicobacter pylori infection and assessment of eradication therapy. In H. pylori-positive subjects we compared three stool antigen tests (Premier Platinum HpSA, Amplified IDEIA HpStAR and ImmunoCard STAT!HpSA) with invasive tests before their eradication therapy, and with non-invasive diagnostic methods after their therapy. MATERIAL AND METHODS: A total of 82 adults with dyspepsia (aged 24-79 years) with an H. pylori-positive rapid urease test were enrolled in the study. Before therapy, H. pylori status was also confirmed with histology, culture and serology. After eradication, success was assessed with the [13C]-urea breath test (UBT) and usually also with serology. RESULTS: At baseline, sensitivities of these stool antigen tests were 90.2% for HpSA, 97.6% for HpStAR and 96.3% for ImmunoCard. Eradication therapy was successful in 66 patients and unsuccessful in 16. Sensitivity and specificity of the three stool antigen tests in the post-eradication setting were, respectively, 75.0% and 95.5% for HpSA, 93.8% and 98.5% for HpStAR and 87.5% and 95.5% for Immunocard. CONCLUSIONS: The performance of all three stool antigen tests in the post-treatment setting was slightly inferior to that of the UBT test and serology, with monoclonal antibody-based tests showing better results.     

Quantitative correlation of Helicobacter pylori stool antigen (HpSA) test with 13C-urea breath test (13C-UBT) by the updated Sydney grading system of gastritis

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) infection has a causative relationship with various gastrointestinal disorders. 13C-urea breath test and H. pylori stool antigen test are two valuable noninvasive tests for detecting H. pylori infection. Since the bacterial load of H. pylori in the stomach and the resulting severity of gastritis are important in validating the status of H. pylori infection, we would like to investigate the relative diagnostic accuracy of 13C-urea breath test and H. pylori stool antigen test with respect to the severity of gastritis. METHODOLOGY: The H. pylori statuses of 62 consecutive patients were evaluated by five tests, i.e., culture, histology, biopsy urease test, 13C-urea breath test, and H. pylori stool antigen test. Gastritis was graded by the updated Sydney system. H. pylori status was defined as positive when the culture was positive or the concordance of positivity of two of the other four tests. RESULTS: Thirty-five patients (56%) were H. pylori positive. The accuracy of H. pylori stool antigen test and 13C-urea breath test were 92.6% and 100%, respectively. There was a positive correlation between the level of delta 13CO2 of the 13C-urea breath test and the optical density value of enzyme immunoassay of the H. pylori stool antigen test (Rho = 0.758, P < 0.001). Both the level of delta 13CO2 of 13C-UBT and the optical density value of enzyme immunoassay of the H. pylori stool antigen test correlated well with the separate score of the density of H. pylori (P < 0.001, each) and the inflammatory activity (each P < 0.001). CONCLUSIONS: Both the 13C-urea breath test and H. pylori stool antigen test are effective non-invasive methods to detect the status of H. pylori infection with respect to correlation with the density of H. pylori and inflammatory activity of gastritis.     

A novel immunoassay based on monoclonal antibodies for the detection of Helicobacter pylori antigens in human stool

BACKGROUND AND AIM: With the Premier Platinum HpSA EIAtrade mark a new enzyme immunoassay was developed for diagnosis of H. pylori infection, using polyclonal antibodies against H. pylori antigens in human stool. Here we evaluated FemtoLab H. pyloritrade mark based on the use of monoclonal antibodies in comparison to established reference methods.METHODS: 53 consecutive patients (27male, 26 female, age: 17-85 years) undergoing routine upper gastrointestinal endoscopy were enrolled in this study. The H. pylori status was determined by 4 reference methods: Histology, rapid urease test (HUT), (13)C-urea breath test ((13)C-UBT) and serology. Patients were considered to be infected with H. pylori if at least 2 of the 4 reference tests were positive. Stool samples were aliquoted after reception and stored frozen (-20 degrees C) until tested. The FemtoLab H. pyloritrade mark (Connex GmbH, Germany) and the Premier Platinum HpSA EIAtrade mark (Meridian, Connecticut, Ohio, USA) were performed according to the manufacturers protocols. RESULTS: 26 of the 53 patients were H. pylori infected. 3 were false-negative by the FemtoLab H. pyloritrade mark and one false-positive result was obtained (sensitivity 88,5 %, specificity 96,3 %). The concordance between the 2 stool tests was 94,3 % (50/53 cases). CONCLUSION: The diagnostic quality of the novel FemtoLab H. pyloritrade mark Enzyme Immunoassay is comparable with the established Premier Platinum HpSA EIAtrade mark. The differences between positive and negative results obtained with the FemtoLab H. pyloritrade mark are greater in comparison to the Premier Platinum HpSA EIAtrade mark and therefore this test system allows a better distinction.     

粪便抗原检测诊断幽门螺杆菌现症感染

目的 评价应用免疫酶联吸附试验(ELISA)检测粪便中幽门螺杆菌(Helicobacter pylori)抗原诊断H.pylori现症感染的敏感性和特异性。方法 应用^14C呼气试验以及幽门螺杆菌粪便抗原(HpSA)试验，对100例因上消化道不适就诊，怀疑有H.pylori感染的患者进行检测，观察两种检查的符合率。结果 ^14C呼气试验和HpSA同时阳性者38例，^14C呼气试验阳性而HpSA阴性者4例；^14C呼气试验和HpSA同时阴性者57例，^14C呼气试验阴性而HpSA阳性1例。以^14C呼气试验作为金标准计算，HpSA检测方法的敏感性为90．48％，特异性为98．28％。结论 幽门螺杆菌抗粪便原检测与^14C呼气试验有较高的符合率，而且简便易行，不需特殊设备，解决了无法进行呼气试验的婴幼儿和有肺部疾患者的非侵人性幽门螺杆菌现症感染诊断问题，是一种非侵入性幽门螺杆菌现症感染诊断的新方法。     

Evaluation of 13C-urea breath test to confirm eradication of Helicobacter pylori]

This study aimed to evaluate the effectiveness of the 13C-urea breath test (UBT) for assessment of Helicobacter pylori eradication after treatment. One hundred twenty six patients were enrolled with 85 receiving proton pomp inhibitor based triple therapy. They were underwent upper gastrointestinal endoscopy with biopsies for diagnosis and assessment of H. pylori infection using culture, histology, rapid urease test (RUT) and 13C-UBT. Assessment of eradication needs to be performed 4 weeks or more after completion of treatment. Breath samples were taken 15 minutes after the ingestion of 100 mg 13C-urea. Breath samples were analyzed on a mass spectrometer system. The gold standard for H. pylori infection was a positive culture or positive histology + positive RUT; negative for infection was defined as negative results of all three biopsy tests. Based on ROC curves, the most appropriate cut-off value for diagnosis of H. pylori infection was identified as 2.5/1000, which provided 96.2% sensitivity, 100% specificity, and 96.8% accuracy as judged by the gold standard. However, when confirming the eradication of H. pylori, it was 3.5/1000, which provides for 100%, 95.8%, and 96.5%, respectively. Ten patients (11.8%) had delta13C values that were 2.5-5.0/1000 4-12 weeks after therapy. Eight patients were considered cured of H. pylori infection, and 2 were considered to still have H. pylori infection following 13C-UBT, serology, and H. pylori specific antigen test. The false-positive rate of 13C-UBT was 9.4% (8/85). When the grey zone of 13C-UBT was set at a level of 2.5 to 5.0/1000 (2.5 > : negative, 5.0 < or = : positive) after eradication therapy, the sensitivity and specificity of 13C-UBT was 100% and 98.4% compared to the gold standard. It was concluded that to avoid false-positive results of 13C-UBT, the grey zone of 13C-UBT needs to be set at a level of 2.5 to 5.0/1000; thus improving the accuracy of test for the assessment of eradication of H. pylori infection.     

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.     

Evaluation of an enzyme immunoassay for detecting Helicobacter pylori antigens in human stool samples

BACKGROUND AND AIM: So far, the detection of Helicobacter pylori (Hp) infection by stool analysis appeared to be almost impossible. With the Premier Platinum HpSA EIA a new enzyme immunoassay was developed for diagnosis of Hp infection, using polyclonal antibodies against Hp antigens in human stool. We evaluated this new test in its diagnostic accuracy in comparison to established reference methods. METHODS: From 54 consecutive patients (29 male, 25 female, age: 19 to 85 years) undergoing routine upper gastrointestinal endoscopy antral and corpus biopsies were taken for histology and Helicobacter urease test (HUT). Endoscopy, 13C-urea breath test (13C-UBT), serology, and stool probes sampling were performed within two days. Stool samples were aliquoted after reception and stored frozen (-20 degrees C) until tested. The Premier Platinum HpSA test (Meridian, Connecticut, Ohio, USA) was performed according to the manufactures protocol. Patients were considered to be infected with Hp if two of the four reference tests were positive. RESULTS: 28 of the 54 patients were Hp-infected. Only one of these was found to be false-negative by the HpSA EIA. Two false-positive results were obtained in the noninfected group (sensitivity 96.4%, specificity 92.3%). CONCLUSION: In this group of patients investigated, the novel HpSA Enzyme Immunoassay (EIA) proved to be highly accurate for diagnosis of Hp infection. Collection and testing of stool are noninvasive and easy to perform, therefore this test will become an important tool for diagnosing Hp infection in clinical practice.     

Analysis of eight different methods for the detection of Helicobacter pylori infection in patients with dyspepsia

BACKGROUND: The present study was designed to compare the accuracy of eight different methods for the detection of Helicobacter pylori (H. pylori) infection in patients with dyspepsia. These tests included culture, histology, rapid urease test (CLO test), serology, saliva IgA, gastric juice IgA, and two in-house methods, namely in-house urease test and Gram stain. METHODS: H. pylori infection was diagnosed prospectively in 200 untreated patients who underwent upper gastrointestinal endoscopy at King Chulalongkorn Memorial Hospital, Bangkok, Thailand, between July 1999 and August 2001. The gold standard for H. pylori infection was based on a positive culture or both a positive histological examination and CLO test. RESULTS: The culture provided a sensitivity of 55.9% whereas saliva IgA and gastric juice IgA had a sensitivity of 26.8% and 22.2%, respectively. In contrast, the other tests provided satisfactory sensitivities ranging between 89.3% and 100% (Gram stain 89.3%, histology 93.5%, serology 96.8%, CLO test 99.0%, in-house urease test 100%). The specificities of the tests ranged between 75% and 100% (culture 100%, CLO test 91.9%, histology 90.4%, in-house urease test 88.9%, Gram stain 93.5% serology 96.8%, gastric juice IgA 91.7% and saliva IgA 75%). CONCLUSIONS: Majority of invasive and non-invasive tests in this study were accurate for the diagnosis of H. pylori infection. However, the secretory IgA-based techniques in saliva and gastric juice seem to be inappropriate for determining H. pylori status in our populations due to their low sensitivities.     

Comparison of Diagnostic Methods for Helicobacter pylori Infection in Patients with Upper Gastrointestinal Bleeding

Background: Accuracy of the most frequently used tests for diagnosing Helicobacter pylori infection in patients with upper gastrointestinal bleeding of peptic origin is determined. Methods: Seventy-eight patients with endoscopically-proven upper gastrointestinal bleeding of peptic origin were included. The presence of H. pylori was considered when observed from the histology or, if negative, when serology and breath test were both positive. Accuracy of the rapid urease test was estimated in accordance with results obtained with other diagnostic methods. Results: Lesions causing gastrointestinal bleeding were 56 duodenal ulcers, 13 gastric ulcers, 7 pyloric channel ulcers, 13 acute lesions of the gastric mucosa and 16 erosive duodenitis. H. pylori infection was present in 68 patients (87.2%). Forty-four patients had received non-steroidal anti-inflammatory drugs. The sensitivity/specificity (%) of the diagnostic methods was 48.5/100 for the rapid urease test, 91/77.8 for the breath test, 89.5/80 for serology and 86.3/100 for histology. The prior consumption of proton-pump inhibitors and antibiotics induced false-negative results in the rapid urease test and breath test, with no effect on serology and histology. Conclusions: The prevalence of H. pylori infection in patients with upper gastrointestinal bleeding from peptic lesions is high. Sensitivity of the rapid urease test for diagnosing H. pylori is low in this setting. Cases with negative rapid urease test need the combination of two or more additional tests if diagnosis is to be achieved. Cases with positive rapid urease test do not need further investigation for diagnosis.     

Comparison of diagnostic methods for Helicobacter pylori infection in patients with upper gastrointestinal bleeding.

BACKGROUND: Accuracy of the most frequently used tests for diagnosing Helicobacter pylori infection in patients with upper gastrointestinal bleeding of peptic origin is determined. METHODS: Seventy-eight patients with endoscopically-proven upper gastrointestinal bleeding of peptic origin were included. The presence of H. pylori was considered when observed from the histology or, if negative, when serology and breath test were both positive. Accuracy of the rapid urease test was estimated in accordance with results obtained with other diagnostic methods. RESULTS: Lesions causing gastrointestinal bleeding were 56 duodenal ulcers, 13 gastric ulcers, 7 pyloric channel ulcers, 13 acute lesions of the gastric mucosa and 16 erosive duodenitis. H. pylori infection was present in 68 patients (87.2%). Forty-four patients had received non-steroidal anti-inflammatory drugs. The sensitivity/specificity (%) of the diagnostic methods was 48.5/100 for the rapid urease test, 91/77.8 for the breath test, 89.5/80 for serology and 86.3/100 for histology. The prior consumption of proton-pump inhibitors and antibiotics induced false-negative results in the rapid urease test and breath test, with no effect on serology and histology. CONCLUSIONS: The prevalence of H. pylori infection in patients with upper gastrointestinal bleeding from peptic lesions is high. Sensitivity of the rapid urease test for diagnosing H. pylori is low in this setting. Cases with negative rapid urease test need the combination of two or more additional tests if diagnosis is to be achieved. Cases with positive rapid urease test do not need further investigation for diagnosis.