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 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.     

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.     

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.     

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。     

Validity of a Helicobacter pylori stool antigen assay for the assessment of H. pylori status following eradication therapy.

BACKGROUND: A Helicobacter pylori stool antigen (HpSA) test has been proposed as a valid alternative to the 13C-urea breath test (13C-UBT) for the non-invasive detection of H. pylori infection in primary diagnosis. Published reports show conflicting results with regard to the test's diagnostic accuracy after eradication therapy. The aim of the present study was to assess the diagnostic value of the HpSA test and to determine the optimal discriminating cut-off value in patients following H. pylori eradication therapy. METHOD: Stool samples were collected and the 13C-UBT was performed in 113 patients 4-6 weeks after eradication therapy. A validated test protocol for the 13C-UBT was used. Stool specimens were analysed with the Premier Platinum HpSA enzyme immunoassay (EIA). A receiver operator characteristics (ROC) analysis was performed to define the optimal cut-off value on the basis of the results of the 13C-UBT. RESULTS: The results of the 13C-UBT showed that H. pylori eradication was successful in 83/113 (73%) patients. According to the manufacturer, the cut-off value for the HpSA test is 0.14 optical density, but this does not appear to be valid after eradication therapy (sensitivity 76.7%, specificity 98.8%). On the basis of ROC analysis, the optimal cut-off value after therapy was determined to be 0.11 optical density, giving a sensitivity of 93.3% and a specificity of 93.9%. CONCLUSION: The HpSA test is a valid test for the assessment of H. pylori status after eradication therapy, provided an adjusted cut-off value is applied.     

Evaluation of Helicobacter pylori with a stool antigen assay in frail, elderly patients

OBJECTIVE: Helicobacter pylori infection has not been studied thoroughly in elderly patients. The aim of this study was to evaluate the reliability of stool antigen assay (HpSA) in the assessment of H. pylori infection in hospitalized, frail, elderly patients. MATERIALS AND METHODS: The study population consisted of 85 consecutively recruited elderly patients (> or =65 years old) hospitalized between May 1999 and December 2001 with diagnostic indications for upper gastrointestinal endoscopy. Twenty-nine subjects had been receiving treatment with proton-pump inhibitors (PPIs), such as omeprazole (10-20 mg/day) for 2-15 days, and 56 were not receiving treatment. HpSA was evaluated versus UBT (urea breath test), serology and histology: patients with at least two positive results out of the latter three tests were considered positive for H. pylori infection, while patients with at least two negative tests out of three were considered negative. RESULTS: The sensitivity and specificity of HpSA in the 56 untreated patients were, respectively, 76% (true positives TP = 22; false negatives FN = 7) and 93% (true negatives TN = 25; false positives FP = 2). The sensitivity and specificity of HpSA in the 29 patients on PPI treatment were, respectively, 82% (TP = 9; FN = 2) and 83% (TN = 15; FP = 3). CONCLUSIONS: HpSA is an accurate, non-invasive and easy method for diagnosing H. pylori infection in elderly patients.     

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。     

Five methods for detection of Helicobacter pylori in the Turkish population

AIM: To compare culture analysis, Helicobacter pylori (H. pylori) stool antigen (HpSA) test, polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) for H. pylori detection. METHODS: One hundred and thirty-two consecutive adult dyspeptic patients receiving diagnostic endoscopy at the department of gastroenterology were enrolled in this study. Culture and histological examination were performed on biopsy specimens. PCR and FISH tests were applied to histopathological samples. Stool samp...     

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.     

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.     

Evaluation of Helicobacter pylori stool antigen test before and after eradication therapy

BACKGROUND AND AIM: The Helicobacter pylori stool antigen (HpSA) test is useful for initial diagnosis of H. pylori infection, but there is disagreement regarding its diagnostic accuracy after eradication therapy. The aim of the present study was to evaluate the diagnostic accuracy of the HpSA test before and after eradication therapy. METHODS: One hundred and thirty-six patients underwent upper gastrointestinal endoscopy with biopsies for the diagnosis of H. pylori infection using culture, histology and the rapid urease test. Fifty-four H. pylori-positive patients were treated with 1-week triple therapy. Six to 10 weeks after the end of therapy, the patients underwent re-endoscopy and received the same biopsy-based methods. In addition, the 13C-urea breath test was performed. The HpSA test was performed before and 6-10 weeks after the end of therapy. In 23 patients, the HpSA test was also performed at the end of therapy. RESULTS: Before therapy, the sensitivity and specificity of the HpSA test was 98.3% (95% confidence interval (CI): 95.9-100%) and 95.0% (95% CI: 75.1-99.9%), respectively. At the end of therapy, the HpSA tests were all negative both for eradication and non-eradication patients. The sensitivity and specificity of the HpSA test after eradication therapy were 90% (95% CI: 55.5-99.7%) and 97.7% (95% CI: 93.3-100%), respectively. CONCLUSIONS: The HpSA test is a useful method for the diagnosis of H. pylori infection before and after eradication therapy.     

Diagnosis of Helicobacter pylori infection in patients with atrophic gastritis: comparison of histology, 13C-urea breath test, and serology

BACKGROUND: Atrophic gastritis, a risk factor for gastric cancer, is a late consequence of Helicobacter pylori infection in approximately one-third of the infected patients. It has been suggested that gastric cancer would develop less frequently if H. pylori were eradicated. However, the prevalence of H. pylori infection may be underestimated in patients with atrophic gastritis and intestinal metaplasia if only biopsy-based diagnostic methods are used. METHODS: We compared histology, 13C-urea breath test (13C-UBT), and serology in H. pylori diagnostics in 50 male patients with atrophic corpus gastritis. RESULTS: H. pylori was detected in 15 (30%) patients by histology and in 14 (28%) by 13C-UBT, whereas increased serum antibody levels indicating H. pylori infection were found in 41 (82%) patients (P < 0.0001 between serology and both histology and 13C-UBT). H. pylori infection was associated with atrophic corpus gastritis in 84% of the present patients (in one patient with normal antibody titres H. pylori was defined histologically). CONCLUSIONS: H. pylori infection would have been missed in most patients with atrophic gastritis without the analysis of H. pylori antibodies. Therefore, in patients with atrophic gastritis, the use of serology is encouraged in diagnosing H. pylori infection.     

Helicobacter pylori Stool Antigen test: a reliable non-invasive test for the diagnosis of Helicobacter pylori infection in children

OBJECTIVE: To evaluate the Helicobacter pylori Stool Antigen (HpSA) test for the diagnosis of H. pylori infection in children. DESIGN AND SETTING: Prospective cohort study in an academic medical centre. PATIENTS AND METHODS: A total of 106 consecutive children who underwent gastroscopy were included. Biopsy specimens were sampled from the gastric antrum and corpus for the assessment of H. pylori infection by culture and histology. A patient was defined to be H. pylori positive if the results of culture and/or histology proved to be H. pylori positive; a patient was defined to be negative if both test results were negative. All children provided a stool sample within 2 days of gastroscopy. H. pylori antigens in faeces were assessed by an enzyme immunoassay (Premier HpSA, Meridian Diagnostics, Inc., Cincinnati, OH, USA). RESULTS: The mean age of included patients was 8.5 years (range 1-18.5). Thirty patients were H. pylori positive and 76 patients were H. pylori negative. Using the recommended cut-off values of 0.140 optical density (OD) and 0.159 OD, sensitivity and specificity of 100% and 92% were found. The positive and negative predicting values were 83% (30/36) and 100% (70/70), respectively. CONCLUSION: The HpSA test is an accurate test for the diagnosis of H. pylori infection in children, and might therefore be a good alternative for diagnostic tests such as the 13C-urea breath test (UBT).     

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.     

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.     

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.     

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.     

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.     

The importance of corpus biopsies for the determination of Helicobacter pylori infection

BACKGROUND: The aim of this study was to determine whether an antral biopsy alone represents an adequate tissue sample to diagnose the presence of Helicobacter pylori on the mucosa. Furthermore, we explored the conditions associated with the presence of H. pylori in the corpus. METHODS: Consecutive patients who underwent an upper gastrointestinal endoscopy at a single centre between January 1995 and May 1997 were studied. Biopsies were taken at each endoscopy to assess the presence of H. pylori: two antral and two corpus biopsies for histological examination and one antral and one corpus biopsy for the CLO test. RESULTS: A total of 620 patients underwent an upper gastrointestinal endoscopy, 307 (50%) were H. pylori infected. In 80% of the endoscopies there was total agreement between the performed biopsy tests. The addition of corpus biopsies increases the diagnostic yield by 10% in H. pylori-positive patients. Patients with only corpus infection more often showed atrophy and intestinal metaplasia compared with patients with both antral and corpus infection, 37 vs 20%, respectively (OR 2.2, 95% CI 1.1-4.4). CONCLUSION: One biopsy from the antrum or corpus seems to be inadequate to diagnose the presence of H. pylori on the mucosa. Patients with an infection exclusively in the corpus more often had worse mucosa pathology.