Accuracy of Stool Antigen Test in Posteradication Assessment of Helicobacter pylori Infection

Our aim was to evaluate the accuracy of HpSA test in the diagnosis of Helicobacter pylori infection after the end of eradication therapy. In all 106 H. pylori-positive patients (55 men and 51 women, mean age 51 years, range 19–82) were treated with a course of eradicating regimen. [¹³C]Urea breath test (UBT) and HpSA were performed four weeks after stopping the treatment. The diagnostic accuracy of HpSA was evaluated in comparison with the results of [¹³C]UBT. In 90 patients (85%) H. pylori was eradicated according to [¹³C]urea breath test. After eradication, sensitivity of HpSA was 87.5%, specificity 95.5%, positive predictive value 77.8%, negative predictive value 97.7%, and diagnostic accuracy 94.3%. HpSA is a valuable test in the posteradication assessment of H. pylori infection.     

Accuracy of a monoclonal antibody-based stool antigen test in the diagnosis of Helicobacter pylori infection

Background: Recent availability of tests for Helicobacter pylori antigens in stool samples has provided potentially useful tools for epidemiological studies and clinical settings. The aim of this study was to evaluate a monoclonal antibody-based H. pylori antigen stool test in the primary diagnosis of H. pylori infection, and to study the test performance after patients were treated with lanzoprazole, and after eradication therapy. Methods: The study included 122 dyspeptic patients. At gastroscopy, biopsy specimens were obtained for culture and histology. Stool antigen and [[Formula: See Text]C]-urea breath tests were performed concurrently. Positive culture alone or a positive [[Formula: See Text]C]-urea breath test in combination with positive histology defined the reference standard. Forty-three Hp +ve patients were treated with lanzoprazole for 2 to 4 weeks, and stool antigen tests were performed on days 1 and 7 post-treatment. After eradication therapy, 32 patients were re-examined for H. pylori infection. Results: Prevalence of H. pylori was 44.3%. Sensitivity and specificity for the stool antigen test in the primary diagnosis of H. pylori infection were 98% and 94%, with positive and negative likelihood ratios of 16.7 and 0.02, respectively. All patients had positive stool tests immediately after lanzoprazole treatment, whereas 2 patients had negative stool tests after 7 days. Triple therapy rendered all patients stool test negative. Conclusions: The monoclonal antibody-based stool antigen test is an accurate tool in the primary diagnosis of H. pylori infection and after eradication therapy. Lanzoprazole treatment does not influence the clinical performance of the test.     

Comparison between the <Superscript>13</Superscript>C-urea breath test and stool antigen test for the diagnosis of childhood <Emphasis Type="Italic">Helicobacter pylori</Emphasis> infection

Background As noninvasive tests for Helicobacter pylori infection, the ¹³C-urea breath test (UBT) and stool antigen test have been widely used. In children, however, there are few studies reporting which test shows superior performance. The purpose of this study was to compare the ¹³C-UBT and stool antigen test for their accuracy in diagnosing H. pylori infection in children.Methods A total of 123 Japanese children, ages 2 to 17 years (mean, 12 years) who underwent gastric biopsies for H. pylori infection were studied. The diagnoses included gastritis (n = 55), gastric ulcer (n = 5), duodenal ulcer (n = 20), iron-deficiency anemia (n = 7), and other conditions (n = 36). The cutoff value of the ¹³C-UBT was defined to be 3.5. The stool antigen test was performed using the HpSA enzyme-linked immunosorbent assay (ELISA) (Premier Platinum HpSA). In 16 patients who received eradication therapy, the ¹³C-UBT and HpSA were repeated 2 months after treatment.Results Based on biopsy tests, 60 children were infected with H. pylori and 63 children were not. For the ¹³C-UBT, the sensitivity, specificity, and accuracy were 95.0% (95% confidence interval [CI], 86.1%–99.0%), 98.4% (95% CI, 91.5%–100%), and 96.4% (95% CI, 93.6%–99.9%), respectively. For the HpSA, the sensitivity, specificity, and accuracy were 98.3% (95% CI, 90.8%–100%), 98.4% (95% CI, 91.2%–100%), and 98.3% (95% CI, 96.0%–100%), respectively. There were no significant differences between the performance of these two tests. In the assessment of H. pylori eradication, the results of ¹³C-UBT and HpSA agreed with those of biopsy tests.Conclusions The ¹³C-UBT and the HpSA are equally accurate for the diagnosis of active H. pylori infection in Japanese children.Kazuie Iinuma, for the Japanese Pediatric Helicobacter study Group     

A better method for confirming <Emphasis Type="Italic">Helicobacter pylori</Emphasis> infection in Mongolian gerbils

Background. Our aim was to evaluate the accuracy of the stool antigen test and the optimal time point for detecting Helicobacter pylori infection in a Mongolian gerbil model. Methods. We inoculated 8-week-old Mongolian gerbils with H. pylori (Vac A (+)/CagA(+)). The gerbil-infected model was developed as follows: H. pylori was put into broth (about 10⁹ CFU/ml), and 50 gerbils were then fed with 1 ml intragastrically twice within a 3-day interval. Another ten gerbils were fed broth only. Twenty-six weeks after the inoculation, the gerbils were killed. The gastric mucosa was sampled for a series of examinations including culture, histology, rapid urease test, and polymerase chain reaction. Stool samples for a stool antigen test, H. pylori-specific stool antigen assay (HpSA), were collected during weeks 4, 6, 8, 12, and 26 after inoculation. Of the 50 gerbils inoculated with H. pylori, the inoculation was successful in 88%. Severe active gastritis, ulceration, and intestinal metaplasia were obvious. Results. The HpSA test results were sensitivity, 88.6%; specificity, 100%; positive predictive value (PPV), 100%; negative predictive value (NPV), 54.5%, and accuracy, 90%. The HpSA test began to be more sensitive and accurate (P < 0.05) beginning during week 6 after inoculation. We also found that H. pylori could be detected earlier and more easily in the group with high H. pylori density. Conclusions. HpSA seems to be suitable for confirming colonization of gerbils with H. pylori. The optimal testing time point is around 6 weeks after inoculation. This test is a good choice for long-term observation of H. pylori infection in Mongolian gerbils.     

Simple and accurate 13C-urea breath test for detection of Helicobacter pylori in the remnant stomach after surgery

Background The efficacy of the ¹³C-urea breath test (UBT) for diagnosis of Helicobacter pylori (H. pylori) infection in the remnant stomach after surgery is a matter of controversy. We report a simple and accurate method of ¹³C-UBT for diagnosis of H. pylori infection in the remnant stomach after gastrectomy. Methods Eighty patients who had undergone gastrectomy with or without subsequent H. pylori eradication therapy were examined a total of 134 times for H. pylori infection by the ¹³C-UBT. ¹³C-Urea, 10mg per test, was used in powdered form or in the form of film-coated tablets. Breath samples were collected before and 10, 20, and 3min after ingestion. Mucosal biopsy specimens for bacterial culture and histological examination of the remnant stomach were collected endoscopically after each ¹³C-UBT test. Results Factors that confounded the ¹³C-UBT results in the remnant stomach were oral bacteria, posture, and residual food. Lying horizontally on the left side was the best position, and film-coated tablets indicated no necessity for use of mouthwash. The method of anastomosis had no significant effect on the results of the ¹³C-UBT. Thirty minutes and a cutoff of 4.5‰ were optimal conditions for detection of H. pylori in the remnant stomach. Under these conditions, sensitivity, specificity, and accuracy were 79.4% (27/34 cases), 95.7% (44/46 cases), and 88.8% (71/80 cases), respectively, in ordinary H. pylori diagnosis, and 100% (2/2 cases), 93.3% (14/15 cases), and 94.1% (16/17 cases), respectively, in evaluating eradication at 4 weeks after treatment of H. pylori. Conclusions Having the patient lie horizontally on the left side, using a film-coated ¹³C-urea tablet without using mouthwash, and measurement at 3min provided a simple and accurate method of ¹³C-urea breath test for detection of H. pylori in the remnant stomach after gastrectomy.     

Comparison of a monoclonal with a polyclonal antibody-based enzyme immunoassay stool test in diagnosing Helicobacter pylori infection after eradication therapy

Background  Recently, a novel Helicobacter pylori stool antigen test (Testmate pylori antigen EIA) using monoclonal antibodies against H. pylori catalase has been developed commercially. This study assessed the diagnostic usefulness of the stool antigen test compared with a polyclonal enzyme immunoassay (HpSA test) after H. pylori eradication. Methods  A total of 150 patients with H. pylori infection were treated by triple therapy with PPI and amoxicillin with either clarithromycin or metronidazole. H. pylori stool antigen was tested 4 and 8 weeks after eradication. The outcome of H. pylori eradication was assessed by urea breath test (UBT) 8 weeks after the end of therapy. Discordant results were followed by endoscopic examination. Results  Of 150 patients enrolled, H. pylori status was negative in 122 cases and positive in 28 cases, assessed by the ¹³C-UBT. On the other hand, the monoclonal stool antigen test results were negative in 126 cases and positive in 24. The polyclonal stool test results were negative in 126 cases and positive in 22. The overall sensitivity and specificity of the monoclonal stool antigen test were 91.6% (95% CI 85.9–97.3%) and 98.4% (95% CI 97.3–99.5%). The overall sensitivity and specificity of the polyclonal stool antigen test were 87.0% (95% CI 86.9–94.0%) and 97.5% (95% CI 96.1–98.9%). Conclusion  The new stool antigen test using monoclonal antibody is useful for the diagnosis of H. pylori eradication 4 weeks after the end of treatment.     

Five‐year follow‐up study after Helicobacter pylori eradication: Reinfection and peptic ulcer status

OBJECTIVE: To investigate the prevalence of peptic ulcers and Helicobactor pylori reinfection 5 years after H. pylori eradication. METHODS: One thousand and six adults were randomly sampled from the general population in a high‐incidence region of gastric cancer. Of these, 552 subjects were confirmed to be H. pylori‐positive by using both the rapid urease test and the Warthin?Starry stain. All H. pylori‐positive subjects were randomly divided into two groups: (i) the eradication group, who received 1 week of omeprazole‐based triple therapy; and (ii) the control group, who received placebo tablets. Four weeks after the cessation of treatment, ¹³C‐urea breath tests demonstrated that H. pylori had been successfully eradicated in 88.9% of patients in the eradication group, whereas 96.4% of patients remained H. pylori positive in the control group. Subjects in both groups were followed up using endoscopy at the end of the first and fifth year after treatment. The H. pylori infection status was determined by using the rapid urease test and Warthin?Starry staining. RESULTS: The response rates to endoscopy at the end of the first and fifth year were 89.3 and 83.11%, respectively. The prevalence of peptic ulcers in the eradication group and control group were 9.87 and 7.61% before treatment, 3.70 and 12.58% 1 year after treatment (P < 0.05), and 5.86 and 14.93% 5 years after treatment (P < 0.05), respectively. The recurrence rates of peptic ulcers in the eradication group and the control group were 3.70 and 38.10% 1 year after treatment, and 14.81 and 42.86% 5 years after treatment, respectively. The rates of H. pylori infection 1 and 5 years after treatment in the eradication group were 13.58, and 19.82%, respectively. In the control group, the rates of H. pylori infection were 91.97 and 83.26% 1 and 5 years after treatment, respectively. CONCLUSIONS: The prevalence of peptic ulcers decreased significantly after the eradication of H. pylori. The reinfection rate after H. pylori eradication was 4?5% per year. Helicobacter pylori infection status remained constant in almost 85% of cases.     

Comparative evaluation of urine-based and other minimally invasive methods for the diagnosis of Helicobacter pylori infection

Background: Diagnostic methods have recently been developed for detecting anti-Helicobacter pylori antibody in urine and H. pylori antigen in stool samples. Our aim was to evaluate the usefulness of noninvasive urine-based methods for the diagnosis of H. pylori infection. Methods: The study subjects were 100 asymptomatic Japanese volunteers. We investigated the diagnostic efficacy of various noninvasive diagnostic methods; five serological tests (Immunis anti-pylori, HM-CAP, EIAgen Helicobacter pylori IgG, Helico G, and GAP-IgG), one test for antigen in stool (HpSA enzyme immunoassay [EIA]), and two tests for antibody in urine (Urinelisa and Rapirun) by using the urea breath test (UBT) as the gold standard. Results: Fifty subjects were diagnosed as positive for H. pylori infection by the UBT. The serological tests showed good sensitivity, specificity, and accuracy. The diagnostic values of the feces-based test (HpSA EIA) were lower than that of the serological tests. The sensitivities of the two urine-based methods in frozen urine samples were markedly lower than those of the other tests. However, the use of unfrozen samples markedly improved the diagnostic accuracy of these urine-based tests, which was then superior to that of the feces-based method. Conclusions: This study clearly showed that urine-based tests were useful for the diagnosis of H. pylori infection. However, the use of frozen urine samples was not appropriate for the detection of anti-H. pylori antibody. Received: November 5, 2001 / Accepted: February 22, 2002 Acknowledgments. We wish to thank Ms. Rika Tohma, Ms. Shiho Yamamoto, Ms. Yukiko Inoue, Mr. Masahiro Ishibashi, and Mr. Nobuo Sasaki for their technical supports. This work was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan. Reprint requests to: K. Adachi     

A 13C-urea breath test in children with helicobacter pylori infection: assessment of eradication therapy and follow-up after treatment

Purpose. Our aim was to evaluate the usefulness of the ¹³C-urea breath test (UBT) for the diagnosis of Helicobacter pylori infection, for assessment of the efficacy of eradication therapy, and for post-treatment follow-up in children. Methods. Seventy-two patients who underwent endoscopy for symptoms related to the upper gastrointestinal tract were examined by rapid urease test, histology, and culture. The patients were also studied with serology and UBT. Results. Forty-seven of the 72 patients were diagnosed with H. pylori infection, based on the results of biopsy-based tests and serology. As an initial diagnostic test to detect H. pylori infection, the sensitivity of the UBT was 95%, which was comparable with that of histology (94%), rapid urease test (96%), and serology (91%) and was greater than that of culture (79%). The specificity of the UBT was 100%, which was comparable with that of the other four tests. The efficacy of eradication therapy was assessed by biopsy-based tests and the UBT in 24 H. pylori-positive patients. For this purpose, the sensitivities of UBT and histology were 100%, while the sensitivities of culture and the rapid urease test were 88%. The specificity was 100% for all of these tests. Eleven patients were assessed by biopsy-based tests and UBT after more than 6 months of post-treatment follow-up. There were no discordances between the results of the UBT and those of the biopsy-based tests in any of the patients. Conclusions. The UBT may be useful for detecting H. pylori infection in children with upper gastrointestinal tract symptoms, for assessment of the efficacy of eradication therapy, and for the follow-up evaluation of patients after the therapy. Received: November 24, 2000 / Accepted: March 30, 2001     

Bacterial density of Helicobacter pylori predicts the success of triple therapy in bleeding duodenal ulcer

Background: We studied whether different initial bacterial densities of Helicobacter pylori would alter the eradication rate of H. pylori by triple therapy (amoxicillin 500 mg t.i.d. and metronidazole 500 mg t.i.d. for 14 days; bismuth subcitrate 120 mg t.i.d. for 28 days) in patients with duodenal ulcer bleeding. Method: One hundred thirty-six cases with duodenal ulcer bleeding and H. pylori infection (proved by rapid urease test and histology during emergency endoscopy) were studied. One hundred twenty-seven of these patients completed a course of triple therapy. In each case, anti-H. pylori IgG titer, gastric biopsies for H. pylori density (score 1 to 5), and evaluation of severity of gastritis were collected at the first endoscopy and 1 month after completion of the triple therapy. Results: The ulcer healing rate was 84.3% (107 of 127) at the time of the second evaluation. The eradication rate of H. pylori was 76.4% (97 of 127). Eradication for H. pylori failed in 30 cases. In these eradication failure cases, initial serologic titer and density of H. pylori were higher than those of eradication success cases. The eradication rate of H. pylori decreased as the initial density of H. pylori increased (density of H. pylori: 1, 88.3%; 2, 83.8%; 3, 74.2%; 4, 68%; 5, 50%). At the second evaluation, the serologic titer was lower and continued to decline in eradication success cases whose mean residual titer ratio (100% × follow-up titer / initial titer) was lower than that of eradication failure cases (57.1% ± 14.6% vs 107.1% ± 24.1%, p < 0.001). The mean residual titer ratio also disclosed an upward trend as the density of H. pylori increased (density of H. pylori 1 to 5: 57.5%, 66.6%, 73.5%, 75.3%, 81.8%, respectively). Conclusions: We suggest routine gastric biopsy to detect both the presence of H. pylori and its density inasmuch as quantitative results may predict the usefulness of triple therapy. The higher the H. pylori density, the less effective triple therapy will be at successful eradication of H. pylori. (Gastrointest Endosc 1996;44:683-8.)     

Comparison of two invasive diagnostic tests for Helicobacter pylori after antimicrobial therapy

Objective. To compare the accuracy of two invasive tests, the rapid urease test and histology, one month after antimicrobial treatment of Helicobacter pylori. Material and methods. In the present study the rapid urease test was compared with histology in a group of 232 patients who fulfilled the Maastricht criteria for eradication of H. pylori infection. All patients had one week of triple therapy which included omeprazole b.i.d. and two of three antibiotics (metronidazole, chlarythromycin and amoxicillin) b.i.d. One month after antimicrobial therapy, all the patients underwent upper gastrointestinal endoscopy. Two biopsy samples were taken from the antrum and corpus for each test. We used the office rapid urease test, which was previously evaluated, and histology with Giemsa stain. Results. Concordance between both methods was 94% for antrum biopsies, 97% for corpus biopsies and 96% for pooled data. Kappa values were 0.81 for antrum (95% CI: 0.77–0.85%), 0.87 for corpus (95% CI: 0.83–0.91%) and 0.84 for pooled data (95% CI: 0.80–0.88%). Specificity of the rapid urease test is very high (over 98%), sensitivity is lower, but can be improved, if biopsy specimens are taken from both the corpus and the antrum (to 83.6%). Conclusions. The rapid urease test with two biopsies from the antrum and corpus of the stomach is a reliable diagnostic method for evaluation of the success of H. pylori eradication one month after antimicrobial therapy.     

Clinical characteristics and treatment outcomes in patients with Helicobacter pylori-positive chronic immune thrombocytopenic purpura

Abstract

Immune thrombocytopenic purpura (ITP) is the condition caused by increased platelet destruction and or decreased platelet production. Previous studies have demonstrated the association and efficacy of Helicobacter pylori (H. pylori) eradication therapy in patients with chronic ITP. Data in Thai patients, however, are limited. A prospective cross-sectional analytic study was conducted in adult patients with chronic ITP to determine the prevalence and clinical predictive factors of H. pylori infection and evaluate the efficacy of H. pylori eradication therapy. H. pylori-infected patients received eradication therapy (omeprazole 40?mg/day, clarithromycin 1000?mg/day, amoxicillin 2000?mg/day) for 2 weeks. The platelet counts at baseline and monthly for 6 months after the end of treatment were evaluated. Of the 25 patients, 9 patients (36%) had H.pylori infection. H. pylori infection is higher among women than men. There were two clinical factors included 1) relapsed ITP 2) response after the first-line treatment statistically proven to be associated with H. pylori infection with an odds ratio and p value of 7.7, p?=?0.035 and ND (not determined due to small sample size), p?<?0.001. Nearly 80% of infected patients had the platelet count response after eradication therapy with the median time to response of 4 months. The prevalence of H. pylori infection is modest in Thai adult patients with chronic ITP. A history of relapsed ITP and high quality of response after first-line treatment indicated H. pylori infection. Therefore, the urea breath test should be recommended in patients who have a relapsed ITP condition with a history of good response after first-line therapy.     

Safety of first-line triple therapy with a potassium-competitive acid blocker for Helicobacter pylori eradication in children

Background

Helicobacter pylori infection is a risk factor for gastric cancer, and it has been reported that eradication of H. pylori is effective for preventing such cancer. Recently, H. pylori eradication has been performed in children as first-line therapy against gastric cancer. Here, we report use of triple therapy with a potassium-competitive acid blocker (P-CAB) for H. pylori eradication in children.

Methods

H. pylori infection testing and eradication therapy began in fiscal year 2015 in junior high school students located in Yurihonjo city and Nikaho city, Akita prefecture, Japan. Urine-based immunochromatography, stool antigen enzyme-linked immunosorbent assay tests, and serum antibody tests were performed as the initial screening examination. Those who tested positive on one of the three examinations then underwent a urea breath test (¹³C-UBT). Those who tested positive on ¹³C-UBT and expressed the desire to undergo H. pylori eradication then received eradication therapy comprising 20 mg P-CAB, 750 mg amoxicillin, and 200 mg clarithromycin twice a day for 7 days. At least 8 weeks after treatment, eradication success was evaluated using ¹³C-UBT.

Results

A total of 118 students received eradication therapy. Eradication rates were 81.3% (95% confidence interval: 74.3–88.4, 96/118) in ITT analysis and 85.7% (95% confidence interval: 79.1–92.9 96/112) in PP analysis. Adverse effects associated with eradication therapy were observed in 25 of 118 subjects (21.1%), seven of whom required hospital treatment (rash in five, vomiting in two). All seven subjects either discontinued therapy or were administered anti-allergy drugs, which resulted in swift alleviation of symptoms.

Conclusions

First-line triple therapy with a P-CAB for H. pylori eradication in children was found to be safe.

     

Long-term effects of Helicobacter pylori eradication in Mongolian gerbils

Background: In this study, to clarify whether Helicobacter pylori eradication alters the course of the development of gastric mucosal changes in the stomach, we examined the long-term effects of H. pylori eradication on H. pylori-inoculated gerbils. Methods: A total of 40 H. pylori-inoculated gerbils were randomized and subjected, at 22 months after inoculation, to eradication treatment with dual therapy of omeprazole plus clarithromycin, or with therapy with a novel quinolone compound, Y-34867, alone. The animals were killed at the start of administration (control group) or at 8 months after the completion of therapy (vehicle or eradication-treatment groups). Results: Severe histopathological changes in the gastric mucosa were observed in all H. pylori-inoculated gerbils at the start of administration. At 8 months after completion of therapy, the frequency of gastritis, erosion, intestinal metaplasia, and gastric carcinoid in the eradication therapy groups was markedly reduced compared with that in the control and vehicle groups. Values for anti-H. pylori IgG titer, bacterial counts, and gastrin also decreased significantly. Conclusions: These results suggest that H. pylori eradication may have had a therapeutic effect not only on gastritis, erosion, and gastric ulcer but also on glandular atrophy, intestinal metaplasia, and gastric carcinoid. Received: November 8, 2001 / Accepted: May 31, 2002 Reprint requests to: F. Hirayama     

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.     

Prospective,study comparing the accuracy of two different stool antigen tests (Premier Platinum HpSA and novel ImmunoCard STAT! rapid test) for the diagnosis of Helicobacter pylori infection

BackgroundAt present only monoclonal EIA (enzyme-immunoassay) stool antigen-tests have obtained optimal accuracy in the diagnosis of Helicobacter pylori. Our aim was to evaluate the accuracy of two stool antigen-tests, the validated Premier Platinum HpSA PLUS (EIA test) and the newly available ImmunoCard STAT! HpSA HD (rapid test) for the initial diagnosis and the confirmation of eradication of H. pylori infection.Patients and methodsPatients with indication of H. pylori diagnosis, or confirmation after treatment were included. Data were coded to protect personal data and ensure blindness between tests. Accuracy was considered as coincident diagnosis with the gold standard (¹³C-urea breath test, UBT). The EIA was used as a bench standard. All stool tests were performed in duplicate.Results264 patients completed the protocol (100 naïve, 164 post-eradication). Average age was 52 years, 61% women, 11% ulcer. Positive diagnoses by UBT were 41% for naïve and 17% for post-eradication. Overall ImmunoCard and EIA accuracies were respectively 91% (95%C.I. = 88–94%) and 89% (86–93%), sensitivities 72% (67–78%) and 72% (67–78%), and specificities 98% (96–100%), and 95% (92–97%). Concordance between ImmunoCard and EIA was 95% (93–98%).DiscussionOur results indicate that the newly available ImmunoCard rapid stool antigen-test achieves 90% accuracy, with high specificity but suboptimal sensitivity. The ImmunoCard attained equivalent accuracies as the EIA bench standard, with 95% concordance.     

Accuracy of an enzyme immunoassay for the detection of Helicobacter pylori in stool specimens in the diagnosis of infection and posttreatment check-up

OBJECTIVE: The aim of this study was to assess the reliability of a newly developed enzyme immunoassay for Helicobacter pylori-specific antigen detection in stools (HpSA) compared to other standardized diagnostic techniques such as histology (H), rapid urease test (RUT) and 13C-urea breath test (UBT) to diagnose H. pylori infection and to evaluate its usefulness in determining H. pylori status after treatment. METHODS: One hundred eighty-eight patients referred to our department for upper gastrointestinal endoscopy were included. H. pylori infection was confirmed in all patients by HpSA test in stools, RUT, UBT, and H. Patients were defined as positive for H. pylori if RUT and UBT or H were positive. A total of 142 symptomatic patients received eradication treatment and were reassessed 6 wk after therapy; for 70 of these patients, stool samples were also collected at 24 h and 6 months after finishing eradication treatment. In the posttreatment follow-up, UBT was used as gold standard. RESULTS: The sensitivity of HpSA test for the diagnosis of H. pylori infection using a cut-off value of 0.130 was 89.5% and its specificity 77.8%. This specificity was lower than that obtained with UBT, H, and RUT. In the early follow-up the sensitivity of HpSA test was null. At 6 weeks and at 6 months post-treatment its sensitivity was 70.4% and 50% and its specificity was 81.6% and 79.3%, respectively. CONCLUSIONS: The HpSA stool test, using a cut-off value of 0.130, may be useful for the primary diagnosis of H. pylori infection, with sensitivity similar to that obtained with other standard tests, but with less specificity. HpSA test is not useful for early monitoring of treatment efficacy. At 6 wk and at 6 months posttreatment, HpSA test lacks accuracy as compared to UBT for evaluating the outcome of the eradication treatment.     

Follow-up survey of a large-scale multicenter,double-blind study of triple therapy with lansoprazole,amoxicillin, and clarithromycin for eradication of Helicobacter pylori in Japanese peptic ulcer patients

Background: To evaluate histopathological changes and effects on inhibition of ulcer recurrence, a follow-up survey was performed in Japanese patients with Helicobacter pylori-positive active peptic ulcers. These patients had previously participated in a large-scale multicenter trial of triple therapy with lansoprazole (LPZ)/amoxicillin (AMPC)/clarithromycin (CAM) for eradication of H. pylori. Methods: Patients who had been treated with LPZ only or a combination of LPZ, AMPC, and CAM for a period of 7 days and in whom ulcer healing had been confirmed after treatment were grouped according to successful or failed eradication of H. pylori. They were examined endoscopically to determine whether ulcers had recurred. The updated Sydney system was applied to study histological changes after H. pylori eradication therapy, compared with baseline. Results: Twelve months after treatment for H. pylori eradication, gastric ulcers had recurred in 11.4% of those with successful H. pylori eradication and in 64.5% of those with unsuccessful H. pylori eradication. Duodenal ulcers had recurred in 6.8% of patients for whom H. pylori eradication was successful and in 85.3% of patients in whom eradication failed. These findings proved that H. pylori eradication significantly reduced ulcer recurrence (P < 0.0001 for both types of ulcers). Histopathological findings of inflammation and activity grade in both gastric and duodenal ulcers were more favorable in patients with successful eradication than in those with unsuccessful eradication. Conclusions: H. pylori eradication significantly inhibited ulcer recurrence in Japanese peptic ulcer patients. Histopathological findings were also improved with regard to inflammation and activity (neutrophils) in patients in whom H. pylori eradication was successful. Received: May 13, 2002 / Accepted: September 6, 2002 Reprint requests to: M. Asaka Editorial on page 410     

Significant renoprotective effect of telbivudine during preemptive antiviral therapy in advanced liver cancer patients receiving cisplatin-based chemotherapy: a case–control study

Objective. To assess the frequency of gastric cancer patients having received eradication treatment of Helicobacter pylori, and whether this treatment has any influence on the delay in the diagnosis or the stage of the tumours at the time of the operation. Material and methods. A total of 119 consecutive patients with gastric cancer were interviewed preoperatively between 2001 and 2003 at the Department of Surgery, Helsinki University Central Hospital. Abdominal symptoms, previous endoscopies, previous H. pylori testing and eradication therapies were recorded. Results. Of these patients, 112 (94%) had abdominal symptoms before the cancer diagnosis, and in 110 patients (92%) these symptoms were alarming or had changed before the cancer diagnosis. Thirty-five patients (29%) had received H. pylori eradication therapy prior to the diagnosis of gastric cancer (15 after onset or change in symptoms, 10 more than 5 years prior to the cancer diagnosis). The median duration of alarm, new or changed symptoms was longer among patients with H. pylori eradication therapy after the onset or change in their symptoms as compared to other patients (12.0 versus 4.5 months, p=0.001). However, there was no difference in the tumour stages at time of the operation between the eradication and no eradication groups. A previous gastroscopy within 2 years prior to the cancer diagnosis was performed in 17 (14%) patients. Diffuse-type cancers were missed significantly more often in endoscopies than cancers of intestinal type. Conclusion. Previous H. pylori eradication may delay the detection of gastric cancer if it is given during symptoms caused by tumour.     

Discrepancy between Helicobacter pylori stool antigen assay and urea breath test in the detection of Helicobacter pylori infection

Background. The reference diagnostic methods available for detection of Helicobacter pylori infection are either invasive (histology) or expensive and highly sophisticated (Urea Breath Test). A new enzyme immunoassay, which can be easily performed in any laboratory, has been developed to detect Helicobacter pylori in stool specimens (HpSA - Meridian Diagnostics, Cincinnati, USA). Aim of the study was to compare HpSA to Urea Breath Test.Patients and methods. A total of 125 patients (52 never treated for Helicobacter pylori infection and 73 after Helicobacter pylori eradication therapy) referring to our Department, underwent both tests within two weeks.Results. Contrasting results between the two tests were found in 30% of cases: in 19% of the untreated patients and in 37% of the treated patients (p<0.001). The main discrepancy consisted in positive HpSA associated with negative Urea Breath Test. Mean HpSA value in such conditions was 0.273 optical density, while in patients with both positive tests, it was 1.192 optical density. In untreated, but not in treated patients, raising the HpSA cut off value significantly decreased the percentage of conflicting results.Conclusions. Some disagreement was detected between HpSA and Urea Breath Test results, especially in treated patients. Possible explanations for our findings are a low HpSA cut off value together with the identification of Helicobacter pylori coccoid forms by the immunoassay but not by the urease based Urea Breath Test. The higher percentage of discrepancy detected in treated patients might support this hypothesis.