A combination of the Helicobacter pylori stool antigen test and urea breath test is useful for clinical evaluation of eradication therapy: a multicenter study

BACKGROUND: Helicobacter pylori stool antigen (HpSA) test is a new tool for evaluating the H. pylori infection. The present study was carried out to investigate the clinical usefulness of the HpSA test in the evaluation of eradication therapy by comparing it with the (13)C-urea breath test (UBT). METHODS: One hundred and five patients received eradication therapy for H. pylori. After more than 8 weeks, the success of the therapy was evaluated by the HpSA test and the UBT. Concordant results were regarded as a final diagnosis, but when the results were discordant, histological examination was carried out. RESULTS: Of the 105 patients receiving eradication therapy for H. pylori, 25 patients were regarded as H. pylori positive by the UBT and and 20 patients were regarded as H. pylori positive by the the HpSA test. Nine patients (8.6%) showed discordant results (seven cases with UBT(+) and HpSA(-), and two with UBT(-) and HpSA(+)). Five cases out of nine were ultimately judged as having a false-positive result of the UBT, and in these cases the UBT values were relatively low (below 10 per thousand). The final diagnostic accuracies of the UBT and the HpSA test were 94.3% (88.0-97.9%; 95% CI) and 97.1% (91.9-99.4%), respectively. When we used the HpSA test in cases with weakly positive UBT values, we were able to diagnose the correct status of H. pylori infection after eradication in 99% of all patients (94.8-100.0%). CONCLUSION: The HpSA test is a useful tool for the evaluation of eradication therapy and a combination of the HpSA test and UBT is clinically recommended.     

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.     

Comparison of two enzyme immunoassays for the assessment of Helicobacter pylori status in stool specimens after eradication therapy

OBJECTIVES: Assessment of Helicobacter pylori antigen in stool specimens has recently been proposed as a valid method for the noninvasive detection of H. pylori infection, especially as posttreatment control. After the development of an enzyme immunoassay based on polyclonal antibodies (Premier Platinum HpSA) a monoclonally based test has recently been developed (FemtoLab H. pylori). The aim of the present study was to assess the diagnostic accuracy of both tests in adult patients undergoing H. pylori eradication therapy. METHODS: Stool samples were collected and the 13C-urea breath test performed in 148 patients (79 females and 69 males aged 21-75 yr) 4-6 wk after eradication therapy. The FemtoLab H. pylori and Premier Platinum HpSA tests were performed in accordance with the manufacturers' protocols. A receiver operator characteristics analysis was performed to define the optimal cutoff value on the basis of the results of the 13C-urea breath test. RESULTS: H. pylori eradication was successful in 113 of the 148 patients (76%). After adjusting the cutoff, the sensitivity of FemtoLab H. pylori was found to be higher than that of the Premier Platinum HpSA (94.3% vs 80.0%, ns). Specificity, positive predictive value, and negative predictive value of the two tests were comparable (93.8% vs 95.6%, 82.8% vs 85.2%, and 98.1% vs 93.8%, respectively). CONCLUSIONS: The new stool antigen test (FemtoLab H. pylori) is an excellent tool for diagnosing H. pylori infection after eradication therapy, and its accuracy is comparable with that of the Premier Platinum HpSA. Adjustment of the cutoff after H. pylori eradication therapy increases the overall accuracy.     

Accuracy of the stool antigen test for the diagnosis of childhood Helicobacter pylori infection: a multicenter Japanese study

OBJECTIVE: The (13)C-urea breath test (UBT) has been accepted as a reliable noninvasive test for detecting Helicobacter pylori infection. Recently, another noninvasive test, a new enzyme immunoassay for H. pylori antigens in stool, has been widely investigated for its clinical usefulness. The purpose of this multicenter study was to evaluate the diagnostic accuracy of the stool antigen test in Japanese children. METHODS: A total of 264 children (148 male and 116 female; mean age 9.2 yr, range 2-17 yr) who underwent (13)C-UBT and the stool antigen test were studied. The diagnosis in these patients was gastritis (n = 49), gastric ulcer (n = 4), duodenal ulcer (n = 24), recurrent abdominal pain (n = 43), and other conditions (n = 144). The stool antigen test was performed using the HpSA ELISA (Premier Platinum HpSA, Meridian Diagnostics). According to manufacturer's instructions, an absorbance at 450/630 nm of <0.100, > or =0.120, and 0.100-0.119 was defined as negative, positive, and indeterminate, respectively. Based on the (13)C-UBT with a cutoff value of 3.5 per mil, the performance of HpSA was studied. In 21 patients who received eradication therapy, the HpSA was performed at baseline and at 1, 2, and 6 months after completion of therapy. Eradication of H. pylori was confirmed by (13)C-UBT at 2 or 3 months of follow-up. RESULTS: (13)C-UBT showed that 76 children were infected with H. pylori and 188 were not infected. In these same children, HpSA results were positive in 77 children, negative in 183, and indeterminate in four. The overall sensitivity, specificity, and accuracy of the test were 96.0% (95% CI = 88.6-99.2%), 96.8% (95% CI = 94.2-99.3%), and 96.5% (95% CI = 94.3-98.8%), respectively. There were no significant differences in these results among age groups of < or =5, 6-10, and > or =11 yr. Receiver operating characteristic curve analysis demonstrated that the best cutoff value of absorbance at 450/630 nm was 0.110. When a single cutoff value of 0.110 without indeterminate results was used, the sensitivity, specificity, and accuracy were 96.1% (95% CI = 90.8-99.7%), 96.3% (95% CI = 93.6-99.0%), and 96.2% (95% CI = 93.9-98.5%), respectively. In 19 patients in whom H. pylori was successfully eradicated, HpSA results were negative at 1 month of follow-up and remained negative through 6 months. CONCLUSIONS: The HpSA is an accurate test for the detection of H. pylori infection in all age groups of children.     

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.     

Noninvasive antigen-based assay for assessing Helicobacter pylori eradication: a European multicenter study. The European Helicobacter pylori HpSA Study Group

OBJECTIVE: In a recently published multicenter study involving 501 patients undergoing esophagogastroduodenoscopy (EGD) throughout Europe, we showed the high accuracy of a recently developed simple test (HpSA) to detect Helicobacter pylori (H. pylori) antigens in stools of untreated patients. The aim of this study was to assess the diagnostic usefulness of HpSA compared with 13C UBT shortly after H. pylori eradication treatment. METHODS: Of the 501 patients enrolled in the validation study, 279 were found to be H. pylori-positive. These patients were given H. pylori eradicating regimen and asked to return for follow-up EGD with biopsies, 13C UBT and HpSA testing 4 wk after therapy. Follow-up results were available for 235 patients. Of these, 162 consented to all testing and 73 consented only to 13C UBT and HpSA testing. We assessed sensitivity and specificity of both HpSA and 13C UBT compared with biopsy-based methods in the 162 patients, who accepted follow-up EGD. We also assessed sensitivity and specificity of HpSA compared with 13C UBT, arbitrarily chosen as the gold standard, in the whole population of 235 patients. RESULTS: Sensitivity and specificity in 162 patients who consented to a second EGD were 93.8% (CI: 85.4-100%) and 96.9% (CI: 93.9-99.9%) for HpSA, and 90.6% (CI: 80.5-100%) and 99.2% (CI: 97.7-100%) for UBT. Using EGD-based methods as the gold standard, 130 of the 162 treated patients' H. pylori infection were eradicated (125 HpSA-negative, one borderline, and four false-positive; 129 13C UBT-negative, one false-positive), and 32 remained H. pylori-infected (30 HpSA-positive, two false-negative, 29 13C UBT-positive, three false negative). The overall eradication rate was 80.2%. The sensitivity and specificity of HpSA relative to UBT as the gold standard in the overall population (n = 235) were 95.6% (CI: 89.6-100%) and 94.7% (CI: 91.5-97.9%), respectively. CONCLUSIONS: HpSA has proven to be a useful method in posttreatment eradication testing for H. pylori. Its ease of use, speed, and noninvasive nature make HpSA testing an ideal method for post-treatment monitoring where a second EGD may not be justified.     

Evaluation of the Helicobacter pylori stool antigen test for monitoring eradication therapy

OBJECTIVE: We aimed to clarify the time course of the Helicobacter pylori stool antigen (HpSA) level during and after eradication therapy and to determine the appropriate time of measurement of HpSA to evaluate eradication. METHODS: The subjects were 47 patients who were positive for H. pylori. The patients underwent a 1-wk regimen of triple therapy. The outcome of the eradication therapy was judged by urea breath test, culture, and histology 6 wk after the end of treatment. The HpSA level was serially measured nine times from before therapy until 12 wk after the end of therapy. RESULTS: In the group with successful eradication, HpSA became negative immediately after the end of therapy and the negativity persisted. In contrast, in the noneradication group HpSA became negative immediately after therapy, but became positive again within 2 wk after the end of therapy. The mean absorbance value of the HpSA test on the 4th day after the initiation of eradication therapy was significantly higher in the noneradication group than in the group with successful eradication. The diagnostic accuracy of the HpSA test increased to > or = 90% 2 wk after therapy and thereafter. Comparison of the diagnostic accuracy at 4 wk after the end of therapy showed no significant differences with that at 2, 6, 8, and 12 wk after the end of therapy. CONCLUSIONS: The course of the HpSA levels during and after eradication therapy in patients with successful eradication was quite different from that in noneradication patients. Measurement of HpSA was useful to evaluate eradication, and the appropriate evaluation of the outcome of treatment could be made as early as 2 wk after the end of therapy.     

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.     

Accuracy of a new monoclonal stool antigen test in post-eradication assessment of Helicobacter pylori infection: Comparison with the polyclonal stool antigen test and urea breath test

BACKGROUND AND AIM: The enzyme immunoassay based on polyclonal antibodies (HpSA) represents a valid method for the detection of Helicobacter pylori antigens in stool specimens, but some controversial results were reported in post-eradication setting. A new monoclonal enzyme immunoassay (FemtoLab H. pylori, Connex) has been developed. The present study compares the diagnostic accuracy of the two tests after eradication therapy. PATIENTS AND METHODS: Stool samples were collected and urea breath test and endoscopy performed in 325 patients (161 F, 164 M, age 17-78 years), 4-8 weeks after standard triple eradication therapy. The FemtoLab and HpSA tests were performed in accordance with the manufacturer's protocol. H. pylori infection was confirmed if culture alone or both urease test and histology were positive and was considered absent if all three tests were negative. RESULTS: H. pylori was eradicated in 231 patients (71.1%). Urea breath test showed the best performances with sensitivity 98.9% and specificity 99.5%. The sensitivity of FemtoLab was 88.3%, specificity 94.8%, positive and negative predictive values 87.4% and 95.2%. Corresponding HpSA values were 73.4%, 97.8%, 93.2% and 90%. Sensitivity and negative predictive value of FemtoLab were significantly better than HpSA. Adjusting the cut-offs according to a ROC curve improved not significantly the sensitivity of the two tests. CONCLUSIONS: Urea breath test shows the best accuracy in the assessment of H. pylori infection. Between the stool tests, the FemtoLab due to its higher sensitivity is to prefer in the post-eradication assessment of H. pylori infection.     

The diagnostic validity of Helicobacter pylori stool antigen test in the pre- and post-eradication]

BACKGROUND/AIMS: The efficacy of a new enzyme immunoassay designed to detect H. pylori antigens in stool (HpSA) was evaluated before and after the eradication therapy. METHODS: HpSA test was performed in 75 patients whose H. pylori status was defined on the basis of concordant results of the 13C-urea breath test (13C-UBT), rapid urease test and histology. Fifty-one H. pylori-positive patients were treated with a week regimen of triple therapy (amoxicillin 1.0 g b.d., clarithromycin 500 mg b.d., rabeprazole 10 mg b.d). Four weeks after the completion of therapy, previous tests including HpSA were repeated on 29 of 51 patients. Six weeks after the completion of therapy, HpSA test was repeated on 10 of 29 patients. RESULTS: Before the eradication, the sensitivity, specificity, and accuracy of HpSA test was 80.4%, 95.2% and 84.7%, respectively. When the cut-off value of 0.12 was adopted on the basis of our receiver operation characteristics (ROC) curve, the sensitivity and specificity improved as 90.0% and 95.2%. Four weeks after the completion of therapy, the sensitivity, specificity and accuracy of HpSA test was 50.0%, 88.9% and 86.2%, respectively. In 3 patients, false positive results at 4th week were converted to true negative at 6 weeks. CONCLUSIONS: The HpSA test is a useful diagnostic method for H. pylori in pre-eradication stage. The specificity of HpSA test in the post-eradication was similar to other studies. For the velue of HpSA test in the post-eradication period, further studies about the cut-off value and the guideline of optimal time after the eradication may be needed.     

HpSA试验监测幽门螺杆菌感染根除效果的价值

目的检测粪便幽门螺杆菌抗原(HpSA)水平在根除治疗期间及以后的变化,并评估根除治疗疗效检测的最佳时间。方法受试者为57例Hp阳性的病人,均接受了一周的三联疗法。根除治疗的结果由尿素呼气试验、细菌培养以及治疗结束后6周时的组织检查来判定。HpSA的水平则从治疗前到治疗后的12周,先后共检测9次。结果根除治疗获得成功组病人的HpSA在治疗结束后立即转阴并保持阴性。而治疗失败组的病人HpSA也在治疗结束后立即转阴,但在治疗结束后2周时又转为阳性。治疗失败组在根除治疗开始后第4天HpSA试验的平均吸收值显著高于根治成功组。HpSA试验诊断(根除成功与否)的准确率在治疗2周以后增长到>90%。治疗结束后第2、6、8、12周HpSA的诊断准确率与治疗结束后第4周相比无显著差异。结论根除成功组病人的HpSA水平在治疗后的变化情况同失败组显著不同。HpSA的检测对于评估根治疗效是非常有意义的,且评估治疗效果的适当时机是在根除治疗后2周以后。     

Stool antigen tests in the diagnosis of Helicobacter pylori infection before and after eradication therapy

Aim: To evaluate two enzyme immunoassay-based stool antigen tests, Premier Platinum HpSA and Amplified IDEIA HpStAR, and one rapid test, ImmunoCard STAT! HpSA, in the primary diagnosis of Helicobacter pylori (Hpylori) infection and after eradication therapy. METHODS: Altogether 1 574 adult subjects were screened with a whole-blood H pylori antibody test and positive results were confirmed with locally validated serology and 13C-urea breath test. All 185 subjects, confirmed to be H pylori positive, and 97 H pylorinegative individuals, randomly selected from the screened study population and with negative results in serology and UBT, were enrolled. After eradication therapy the results of 182 subjects were assessed. RESULTS: At baseline, the sensitivity of HpSA and HpStAR was 91.9% and 96.2%, respectively, and specificity was 95.9% for both tests. ImmunoCard had sensitivity of 93.0% but specificity of only 88.7%. After eradication therapy, HpSA and HpStAR had sensitivity of 81.3% and 100%, and specificity of 97.0% and 97.6%, respectively. ImmunoCard had sensitivity of 93.8% and specificity of 97.0%. HpSA, HpStAR, and ImmunoCard had PPV 77%, 80%, and 75%, and NPV 98%, 100%, and 99%, respectively. CONCLUSION: In primary diagnosis, the EIA-based tests performed well. After eradication therapy, negative results were highly accurate for all the three tests. HpStAR had the best overall performance.     

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

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

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.     

Poor efficacy of ranitidine bismuth citrate-based triple therapies for Helicobacter pylori eradication.

BACKGROUND: Helicobacter pylori eradication rates have tended to decrease recently possibly related with increasing antibiotic resistance. The present study investigated the efficacy of three different ranitidine bismuth citrate (RBC) based triple regimens in a population with high prevalence of H. pylori. METHODS: 300 consecutive H. pylori positive patients with non-ulcer dyspepsia were randomized into three regimens: (1) RBC 400 mg, amoxicillin 1000 mg and tetracycline 500 mg [RBC-AT], (2) RBC 400 mg, amoxicillin 1000 mg and clarithromycin 500 mg [RBC-AC], (3) RBC 400 mg, metronidazole 500 mg and tetracycline 500 mg [RBC-MT]. Tetracycline was given q.i.d, all other drugs were given b.i.d. for 14 days. Gastroscopy and (14)C-Urea breath test (UBT) were performed before enrollment and UBT only was repeated 6 weeks after the end of treatment. RESULTS: 274 patients completed the protocols. The overall 'intention to treat' and 'per protocol' H. pylori eradication rates in all subjects were 57.6% (95% CI: 52-63) and 63.1% (95% CI: 57-68), respectively. The eradication rates achieved in the groups (RBC-AT, RBC-AC and RBC-MT) were 64.4% (95% CI: 54-74), 66.2% (95% CI: 56-76), and 58.9% (95% CI: 49-68) on 'per protocol' analyses, respectively. There was no difference in eradication rates, compliance and major side effects between the groups. CONCLUSION: The current RBC-based H. pylori eradication therapy is not adequately effective.     

Preoperative versus postoperative Helicobacter pylori eradication therapy in gastric cancer patients: a randomized trial

OBJECTIVES: Helicobacter pylori (H. pylori) eradication is strongly recommended for gastric cancer patients who undergo subtotal gastrectomy. The efficacy of proton pump inhibitor-based triple therapy for H. pylori eradication has not been adequately assessed in the gastric remnant. The aim of this study was to compare the efficacy of postoperative versus preoperative H. pylori eradication therapy. METHODS: A total of 138 distal gastric cancer patients with H. pylori infection were randomized to receive either preoperative (preop, N = 68) or postoperative (postop, N = 70) proton pump inhibitor-based triple therapy for H. pylori eradication. The regimen consisted of rabeprazole 10 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily for 7 days. Eradication was assessed by rapid urease test and histology 12 wk after surgery. RESULTS: By intention-to-treat (ITT) analysis, H. pylori eradication rates were 84.6% (95% CI 73.5-92.4) in the preop group and 83.1% (95% CI 71.7-91.2) in the postop group (P= 0.99). By per protocol (PP) analysis, the rates were 87.3% (95% CI 76.5-94.4) in the preop group and 86.9% (95% CI 75.8-94.2) in the postop group (P= 0.99). In the postop group, eradication rates did not differ with reconstruction method (Billroth I vs II, 80.4%[95% CI 66.1-90.6]vs 89.5%[95% CI 66.9-98.7] by ITT analysis (P= 0.49), and 85.7%[95% CI 71.5-94.6]vs 89.5% (95% CI 66.9-98.7) by PP analysis, P= 0.99). CONCLUSIONS: In distal gastric cancer patients, the effect of proton pump inhibitor-based triple therapy for H. pylori eradication was not different whether given postoperatively or preoperatively.     

<Emphasis Type="Italic">Helicobacter pylori</Emphasis> Stool Antigen (HpSA) Tests in Children Before and After Eradication Therapy: Comparison of Rapid Immunochromatographic Assay and HpSA ELISA

The rapid immunochromatography for Helicobacter pylori (H. pylori) stool antigen (rapid HpSA) test is a recently-developed method for detection of H. pylori infection. The objective of this study was to assess the pre and post-eradication diagnostic accuracy of the rapid HpSA test compared with the conventional HpSA immunoassay (HpSA ELISA) in children. Sensitivity, specificity, positive predictive value, and negative predictive value for the rapid HpSA test were 94.6, 98.4, 94.6, and 98.4%, respectively, and those for the HpSA ELISA were 94.6, 96.1, 87.5, and 98.4%, respectively. No significant difference was observed between the sensitivity and specificity of the two HpSA tests in children (P = 1.000 and P = 0.250) or the sensitivity and specificity of the two HpSA tests pre and post-eradication therapy (P = 1.000 and P = 1.000). The rapid HpSA and HpSA ELISA are reliable methods of detection of H. pylori infection in the pediatric population before and after eradication therapy.     

Accuracy of Helicobacter pylori stool antigen for the detection of Helicobacter pylori infection in dyspeptic patients

AIM: The premier platinum Helicobacter pylori (H pylori) stool antigen (HpSA) test is an enzyme immunoassay (EIA) that detects an H pylori antigen present in human stools. However, at present there is no uniformity about the cut off level required to consider the test as positive or negative. So we need the cut off level for our local population. The aim of this study was to evaluate the HpSA for the detection of H pylori infection in dyspeptic patients and to determine the sensitivity, specificity of the HpSA test in the diagnosis of H pylori infection, as compared to other standardized diagnostic techniques. METHODS: Sixty-three dyspeptic patients were selected from patients who came to the Division of Gastrointestinal Clinic in Cipto Mangunkusumo Hospital, Jakarta, Indonesia. H pylori infection was confirmed in all patients by histology and rapid urease test (CLO test). Positive results for H pylori were based on positive results from both rapid urea test and microscopic detection of H pylori. Stool specimens were analyzed for H pylori antigen using HpSA immunoassay. RESULTS: A total 63 patients consisted of 31 (49.2%) males and 32 (50.8%) females ranging in ages between 16 and 73 years with a mean age of 42.4+/-15 years. The mean age of men was 43.2+/-15.7 years and women was 41.6+/-14.4 years. Endoscopic findings in this study included gastric cancer 1.6%, peptic ulcer 4.8%, duodenal ulcer 7.9%, esophagitis 6.3%, gastritis 77.7%, and gastroduodenitis 4.8%. According to the predefined study criteria, 6 (9.5%) of 63 patients were positive for H pylori. In the diagnosis of infection, the area under the receiver operating characteristic (ROC) curve for the HpSA test was 0.722 (95% CI, 0.518-0.927). Using a cut-off value of 0.274 instead of 0.16 (as recommended by the manufacturer) the sensitivity and the specificity were 66.7% and 78.9% respectively. CONCLUSION: The HpSA stool test, using a cut-off value of 0.274, may be useful for the primary diagnosis of H pylori infection, its specificity is similar to other standard tests but its sensitivity was lower.     

Outcomes of furazolidone-and amoxicillin-based quadruple therapy for Helicobacter pylori infection and predictors of failed eradication

AIM To evaluate the outcomes of furazolidone-and amoxicillin-based quadruple therapy for treatment of Helicobacter pylori(H. pylori) infection and identify predictors of failed eradication.METHODS Patients with H. pylori infection treated with furazolidone, amoxicillin, bismuth, and proton pump inhibitor therapy(January 2015 to December 2015) who received the ~(13)C-urea breath test 4 wk after treatment were evaluated. Demographic and clinical data including prior H. pylori treatment attempts, medication adherence, alcohol and cigarette consumption during therapy, and treatment-related adverse events were recorded by reviewing medical records and telephone surveys. H. pylori eradication rates for overall and subgroups were evaluated. Multivariate analysis was performed to identify independent predictors of failed H. pylori eradication.RESULTS Of the 992 patients treated and retested for H. pylori infection, the overall eradication rate was 94.5% [95% confidence interval(CI): 94.1%-95.9%]. H. pylori eradication rate of primary therapy was 95.0%(95%CI: 93.5%-96.5%), while that of rescue therapy was 91.3%(95%CI: 86.8%-95.8%). Among the 859 patients who completed the study protocol, 144(17%) reported treatment-related adverse events including 24(3%) leading to premature discontinuation. On multivariate analysis, poor medication adherence [adjusted odds ratio(AOR) = 6.7, 95%CI: 2.8-15.8], two or more previous H. pylori treatments(AOR = 7.4, 95%CI: 2.2-24.9), alcohol consumption during therapy(AOR = 4.4, 95%CI: 1.5-12.3), and possibly smoking during therapy(AOR = 1.9, 95%CI: 0.9-4.3) were associated with failed H. pylori eradication. CONCLUSION Furazolidone-and amoxicillin-based quadruple therapy for H. pylori infection in an area with a high prevalence of clarithromycin resistance demonstrated high eradication rates as primary and rescue therapies with a favorable safety profile. Patient education targeting abstinence from alcohol during therapy and strict medication adherence may further optimize H. pylori eradication.     

Diagnosis of Helicobacter pylori infection by stool antigen determination: a systematic review

Recently a new, noninvasive diagnostic test based on the detection of Helicobacter pylori stool antigen (SA) has been developed. The aim of this study was to systematically review the experience on H. pylori SA test for the diagnosis of H. pylori infection. Bibliographic searches were performed in the PubMed database and abstracts from several congresses. A total of 43 studies fulfilled the inclusion criteria and evaluated H. pylori SA test accuracy for the diagnosis of H. pylori infection in nontreated patients. Overall, 4769 patients were included. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) (weighted mean) were, respectively: 92.4% (95% CI = 91-93%), 91.9% (91-92%), 92.1% (91-93%), and 90.5% (90-91%). Therefore the SA test can definitively be considered an accurate noninvasive method for the diagnosis of H. pylori infection in untreated patients. A total of 25 studies including 2078 patients evaluated H. pylori SA test for the confirmation of H. pylori eradication > or = 4 wk after completion of therapy. Sensitivity, specificity, PPV and NPV (weighted mean) were: 88.3% (87-90%), 92% (91-93%), 75.1% (73-77%), and 94.8% (94-96%). Although most studies showed that SA test is an accurate method to confirm H. pylori eradication > or = 4 wk after treatment, these favorable results were not confirmed in other studies. Further investigation is necessary to explain these discrepancies, as well as to clarify the precise time for confirmation of eradication after therapy, the appropriate cutoff point for the SA test, and which factors influence it. Proton pump inhibitors seem to affect the accuracy of SA test, but the negative effect disappears 1-2 wk after stopping treatment. The SA test is technically feasible in patients with upper GI bleeding. although the true diagnostic accuracy in this group of patients remains to be more fully assessed. Finally, the SA test seems to be a highly cost-effective method for the diagnosis of H. pylori infection.