Highly sensitive urine-based enzyme-linked immunosorbent assay for detection of antibody to Helicobacter pylori

Detection of Urinary Antibodies and Its Application in Epidemiological Studies for Parasitic Diseases

For epidemiological studies of infectious diseases, pathogen-specific antibody levels in an area give us essential and appropriate information. The antibodies against pathogens are usually detected in blood, the drawing of which inconveniences people. Collection of blood increases the risk of accidental infections through blood, and it is difficult to obtain the participation of the target populations, especially the younger generation. On the other hand, urine samples, which contain a high enough level of antibodies for ELISA, can be harmlessly and easily collected and therefore have been used for epidemiological studies for diseases. The antibody examination of urine has been used for the epidemiology of parasitic diseases with a high sensitivity and specificity of serum samples. In this paper, we reviewed antibody assays with urine for seven parasitic diseases that urine diagnostic methods have reported in the past, and these are important infections included in NTDs, caused, for example, by Leishmania donovani, Wuchereria bancrofti, Schistosoma japonicum, Paragonimus westermani, Echinococcus granulosus, Echinococcus multilocularis, Strongyloides stercoralis, and Opisthorchis viverrini. The easy and safe urine surveillance system might be an admirable tool for future epidemiological studies for infectious diseases.

Noninvasive Helicobacter pylori Diagnostic Methods in Indonesia

Although the prevalence of Helicobacter pylori infection in Indonesia is lower than that in other countries, H. pylori is still an essential pathogen associated with severe gastric mucosal damage and dyspeptic symptoms. Invasive diagnostic methods are not ideal due to the lack of endoscopic centers and high costs without full coverage by social insurance. Among the noninvasive methods, the urea breath test is widely available in Indonesia and has been suggested as the primary option to ensure the successful eradication of H. pylori. There has been no local validation for the urea breath test utilizing ¹³C or ¹⁴C. The stool antigen test is inexpensive and suitable for use in active infections before and after eradication; however, customs and habits are obstacles to delivering fresh stool on time. Only polyclonal antibodies and qualitative stool antigen test kits with low sensitivity are available. Serology is a widely validated method and has good accuracy, but it cannot distinguish between active and inactive infections. According to our observations, serology is the main choice of experts and patients, as it is simple, inexpensive and widely known. The urine test is an alternative for reducing costs and endoscopic workload, with high accuracy but low sensitivity. Further studies are necessary to prove the validity of the urine test to be used throughout Indonesia, especially in areas with a low prevalence of H. pylori infection. In conclusion, the validated urea breath test and the stool antigen test are considered noninvasive practical approaches for the detection of H. pylori infection in Indonesia, with serological and urine tests as alternatives.

Are Helicobacter pylori Infection and Fucoidan Consumption Associated with Fucoidan Absorption?

We examined the associations of Helicobacter pylori and mozuku consumption with fucoidan absorption. Overall, 259 Japanese volunteers consumed 3 g fucoidan, and their urine samples were collected to measure fucoidan values and H. pylori titers before and 3, 6, and 9 h after fucoidan ingestion. Compared to the basal levels (3.7 ± 3.4 ng/mL), the urinary fucoidan values significantly increased 3, 6, and 9 h (15.3 ± 18.8, 24.4 ± 35.1, and 24.2 ± 35.2 ng/mL, respectively) after fucoidan ingestion. The basal fucoidan levels were significantly lower in H. pylori-negative subjects who rarely ate mozuku than in those who regularly consumed it. Regarding the ΔMax fucoidan value (highest value − basal value) in H. pylori-positive subjects who ate mozuku at least once a month, those aged ≥40 years exhibited significantly lower values than <40 years old. Among subjects ≥40 years old who regularly consumed mozuku, the ΔMax fucoidan value was significantly lower in H. pylori-positive subjects than in H. pylori-negative ones. In H. pylori-positive subjects who ate mozuku at least once monthly, basal fucoidan values displayed positive correlations with H. pylori titers and ΔMax fucoidan values in subjects <40 years old. No correlations were found in H. pylori-positive subjects who ate mozuku once every 2–3 months or less. Thus, fucoidan absorption is associated with H. pylori infection and frequency of mozuku consumption.

Review of current diagnostic methods and advances in Helicobacter pylori diagnostics in the era of next generation sequencing

Helicobacter pylori (H. pylori) infection is highly prevalent in the human population and may lead to severe gastrointestinal pathology including gastric and duodenal ulcers, mucosa associated tissue lymphoma and gastric adenocarcinoma. In recent years, an alarming increase in antimicrobial resistance and subsequently failing empiric H. pylori eradication therapies have been noted worldwide, also in many European countries. Therefore, rapid and accurate determination of H. pylori’s antibiotic susceptibility prior to the administration of eradication regimens becomes ever more important. Traditionally, detection of H. pylori and its antimicrobial resistance is done by culture and phenotypic drug susceptibility testing that are cumbersome with a long turn-around-time. Recent advances in diagnostics provide new tools, like real-time polymerase chain reaction (PCR) and line probe assays, to diagnose H. pylori infection and antimicrobial resistance to certain antibiotics, directly from clinical specimens. Moreover, high-throughput whole genome sequencing technologies allow the rapid analysis of the pathogen’s genome, thereby allowing identification of resistance mutations and associated antibiotic resistance. In the first part of this review, we will give an overview on currently available diagnostic methods for detection of H. pylori and its drug resistance and their implementation in H. pylori management. The second part of the review focusses on the use of next generation sequencing technology in H. pylori research. To this end, we conducted a literature search for original research articles in English using the terms “Helicobacter”, “transcriptomic”, “transcriptome”, “next generation sequencing” and “whole genome sequencing”. This review is aimed to bridge the gap between current diagnostic practice (histology, rapid urease test, H. pylori culture, PCR and line probe assays) and new sequencing technologies and their potential implementation in diagnostic laboratory settings in order to complement the currently recommended H. pylori management guidelines and subsequently improve public health.

High Efficacy of Rapid Urine Test for Diagnosis of Helicobacter pylori Infection in Thai People

Background:

Accurate diagnosis of Helicobacter pylori (H. pylori) infection plays an important role in further effective treatment. Rapid urine test (RAPIRUN) is a test developed for qualitative detection of urine H. Pylori antibody and use for determine the sensitivity, specificity and accuracy. However, the test needs validation in Thai population before using in clinical practice.

Objective:

This study aimed to compare performance of different diagnostic tests on H. pylori detection in Thai population.

Methods:

Total of 94 patients with dyspepsia who referred to Thammasat University Hospital, Pathumthani, Thailand, between December 2012 and April 2013 were enrolled in this study. All patients underwent gastroscopy. Then, 3 biopsies at antrum were taken for H. pylori diagnosis. including rapid urease test (Pronto Dry, Eisai, Thailand), H. pylori culture, and histopathology. Urine samples were also collected at the same time for rapid urine test (RAPIRUN H. pylori Antibody, Otsuka Pharmaceutical Co., Ltd.). Patients were diagnosed with H. pylori-positive if their culture or rapid urease tests plus histopathology yielded positive results.

Results:

Total of 29 patients (30.9%) were infected with H. pylori. Prevalence of H. pylori infection by rapid urease test, histopathology, culture and rapid urine test were 25.5%, 28.7%, 29.8%, and 32.9% respectively. We observed that rapid urease test, histopathology, culture, and rapid urine test had sensitivity of 82.8%, 93.1%, 93.1% and 86.2%; specificity of 100%, 100%, 100%, and 90.8%; and accuracy of 95.7%, 97.9%, 97.9%, and 89.4%, respectively.

Conclusion:

Rapid urine test (RAPIRUN) provided a reliable result for diagnosis of H. pylori infection. Furthermore, this rapid urine test demonstrated high accuracy, reliable, safe handle and easy to use. We suggested rapid urine test for diagnosis of H. pylori infection in Thai population since we found it less invasive and with higher reliable efficacy.

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

Rapid urine antibody test for Helicobacter pylori infection in adolescents

BACKGROUND

Helicobacter pylori infection is associated with gastric cancer; thus, early diagnosis and treatment are crucial. Given that H. pylori infection in adolescents or young adults has few symptoms, screening tests are necessary for this population. In this study, the accuracy of the rapid urine H. pylori antibody (u-HpAb) test was evaluated and compared with that of urine and serum H. pylori enzyme-linked immunosorbent assay (u-HpELISA and s-HpELISA, respectively) in junior high school students.

METHODS

All 1,225 students attending the junior high schools in Sasayama City were invited to participate in this study. Urine and blood samples were assayed for anti-H. pylori immunoglobulin G antibodies, and rapid u-HpAb was performed by three investigators independently. When all investigators were in agreement, the test was confirmed as positive or negative. Non-concordance was defined as undetermined.

RESULTS

In total, 187 students participated in this study and provided both urine and blood samples. Three students had undetermined rapid u-HpAb. Excluding these results, the positivity rate of rapid u-HpAb was 3.3% (6/184), whereas that for u-HpELISA and s-HpELISA was 4.8% (10/187) and 5.9% (11/187), respectively. Using s-HpELISA and u-HpELISA as the standards, the sensitivity, specificity, positive predictive value, and negative predictive value of rapid u-HpAb were 85.7%, 100%, 100%, and 99.4%, respectively, excluding the undetermined rapid u-HpAb results.

CONCLUSIONS

Rapid urine-HpAb test had excellent specificity but relatively low sensitivity.

Accuracy of testing for anti-Helicobacter pylori IgG in urine for H. pylori infection diagnosis: a systematic review and meta-analysis

OBJECTIVES

This meta-analysis aims to systematically measure the potential diagnostic value of anti-Helicobacter pylori IgG in urine for infection diagnosis, using all eligible studies published in English and Chinese languages.

DESIGN

The random effect model was used to analyse the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative LR (NLR), diagnostic OR (DOR), together with the summary receiver operator characteristic curve.

SETTING

Literature searches of databases including PubMed, EMBASE, MEDLINE, Web of Science, Chinese National Knowledge Infrastructure and Wanfang databases were performed to retrieve studies evaluating the diagnostic value of urine IgG antibody for H.pylori infection.

PRIMARY OUTCOME MEASURE

Twenty-three studies with 4963 subjects were included in the current meta-analysis.

RESULTS

The pooled sensitivity, specificity, PLR, NLR, DOR and area under the curve (AUC) were 0.83 (95% CI 0.82 to 0.85), 0.89 (95% CI 0.88 to 0.90), 8.81 (95% CI 6.37 to 12.2), 0.13 (95% CI 0.09 to 0.2), 73 (95% CI 46.45 to 114.74) and 0.9551, respectively. Subgroup analyses showed that diagnostic accuracy of the urine IgG assay was no different in age, region, study population and assay method.

CONCLUSIONS

Anti-H. pylori antibody in urine might serve as a good marker in diagnosing H. pylori infection. However, further validation based on a larger sample is still required.

Diagnostic accuracy of urine Helicobacter pylori antibody test in junior and senior high school students in Japan

BACKGROUND

To prevent gastric cancer, a Helicobacter pylori test-and-treat strategy has been proposed. In Japan, routine urine examinations are performed to screen for kidney diseases; it is therefore convenient to screen for H. pylori infection via urine antibody (u-Ab) testing.

AIM

To evaluate the diagnostic accuracy of u-Ab testing in students using ¹³ C-urea breath testing (UBT) as a standard.

METHODS

The study population included 806 junior or senior high school students in Japan who provided urine samples and/or underwent UBT. Students with a positive u-Ab test or discrepant results between the u-Ab test and UBT were asked to provide additional stool and/or blood samples or to repeat the UBT. Urinary protein was detected using a urine test strip.

RESULTS

The positive rates for the u-Ab test and UBT were 8.9% (71/795) and 5.5% (44/801), respectively. The u-Ab test showed 88.4% sensitivity and 95.7% specificity using UBT as a standard. In the final diagnoses, the u-Ab test showed 97.6% sensitivity, 96.5% specificity, 61.2% positive predictive value (PPV), and 99.9% negative predictive value (NPV). Of the 508 samples tested using a urine test strip, negative results were obtained for 450 subjects with a sensitivity of 90%, specificity of 97.9%, PPV of 66.7%, and NPV of 99.5%. Proteinuria was detected in 58 samples, with a sensitivity of 100%, specificity of 88.9%, PPV of 40%, and NPV of 100%.

CONCLUSIONS

The u-Ab test is highly accurate and suitable for detecting H. pylori infection. However, the occurrence of proteinuria may yield false-positive results.

Diagnostic Methods of Helicobacter pylori Infection for Epidemiological Studies: Critical Importance of Indirect Test Validation

Among the methods developed to detect H. pylori infection, determining the gold standard remains debatable, especially for epidemiological studies. Due to the decreasing sensitivity of direct diagnostic tests (histopathology and/or immunohistochemistry [IHC], rapid urease test [RUT], and culture), several indirect tests, including antibody-based tests (serology and urine test), urea breath test (UBT), and stool antigen test (SAT) have been developed to diagnose H. pylori infection. Among the indirect tests, UBT and SAT became the best methods to determine active infection. While antibody-based tests, especially serology, are widely available and relatively sensitive, their specificity is low. Guidelines indicated that no single test can be considered as the gold standard for the diagnosis of H. pylori infection and that one should consider the method's advantages and disadvantages. Based on four epidemiological studies, culture and RUT present a sensitivity of 74.2–90.8% and 83.3–86.9% and a specificity of 97.7–98.8% and 95.1–97.2%, respectively, when using IHC as a gold standard. The sensitivity of serology is quite high, but that of the urine test was lower compared with that of the other methods. Thus, indirect test validation is important although some commercial kits propose universal cut-off values.

Validation of Urine Test for Detection of Helicobacter pylori Infection in Indonesian Population

We measured the accuracy of the urine test (RAPIRUN) for detection of Helicobacter pylori infection in Indonesia (Jakarta, Pontianak, and Jayapura) using histology confirmed by immunohistochemistry and/or culture as gold standards. We also used immunohistochemistry to identify CagA phenotype and analyzed H. pylori CagA diversity in Indonesia. The overall prevalence of H. pylori infection in 88 consecutive dyspeptic patients based on the urine test was 15.9% (14/88), 38.1% for patients in Jayapura that had higher prevalence of H. pylori infection than that in Jakarta (9.7%, P = 0.02) and Pontianak (8.3%, P = 0.006). Overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of RAPIRUN were 83.3%, 94.7%, 71.4%, 97.3%, and 93.2%, respectively. All of the H. pylori-positive patients were immunoreactive for anti-CagA antibody but not immunoreactive for East Asian specific anti-CagA antibody in all H. pylori-positive subjects. We confirmed the high accuracy of RAPIRUN in Indonesian population. In general, we found less virulent type of H. pylori in Indonesia, which partly explained the low incidence gastric cancer in Indonesia.

Biomarkers for Helicobacter pylori infection and gastroduodenal diseases

Helicobacter pylori infection is a major cause of gastric cancer. Although identifying H. pylori infected subjects is the first approach for delineating the high-risk population for gastric cancer, the presence of H. pylori antibodies is not sufficient for gastric cancer screening. Among H. pylori infected subjects, only a minority of infected individuals develop gastric cancer. Serologic markers of H. pylori infection can serve as potential predictors for the development of gastric cancer. Serum or urinary H. pylori antibodies, cytotoxin-associated gene A antibodies, pepsinogen and microRNAs were reported to be associated with precancerous lesions or gastric cancer. In this review, we summarized the utilities and limitations of each strategy.

Value of a new stick-type rapid urine test for the diagnosis of Helicobacter pylori infection in the Vietnamese population

AIM: To assess the value of a new test for the diagnosis of Helicobacter pylori (H. pylori) infection, Rapirun^®H. pylori Antibody Stick (Rapirun^® Stick), in a Vietnamese population.

METHODS: Eligible patients without previous history of H. pylori eradication were recruited. Rapid urease test (RUT) and histologic examination were used to diagnose the H. pylori infection. Patients were considered H. pylori positive when the RUT results were positive and/or the bacteria were detected histologically. Rapirun^® Stick tests were performed using urine samples, and the results were compared with the other 2 methods.

RESULTS: We enrolled 200 patients with a mean age of 36 (range, 18-76) years. There were 116 females and 84 males. Of the 200 patients, 111 (55.5%) were diagnosed as being H. pylori positive. The sensitivity, specificity, and accuracy of the Stick test were 84.7%, 89.9%, and 87.0%, respectively. There were 17 (8.5%) false-negative patients and 9 (4.5%) false-positive patients.

CONCLUSION: The Rapirun^® Stick test has high sensitivity, specificity, and accuracy for the diagnosis of H. pylori infection in the Vietnamese population. The test can be clinically applied in Vietnamese populations.

Diagnostic accuracy of urine-based kits for detection of Helicobacter pylori antibody in children

BACKGROUND

Rapid urine-HpAb is reported to be a reliable test of Helicobacter pylori infection in adults, but there are no data on the application of the test in children. The aim of this study was to evaluate the accuracy of a urine-based enzyme-linked immunosorbent assay (urine-HpELISA) and immunochromatography (rapid urine-HpAb) kit for anti-H. pylori immunoglobulin G antibody in children. We compared its sensitivity and specificity in reference to the (13) C-urea-breath test (UBT) and H. pylori stool antigen test (HpSA).

METHODS

In total, 101 Japanese children without significant upper-abdominal symptoms were included (mean age, 7.1 years; range 2-15 years). Their sensitivity and specificity were evaluated in reference to the UBT and HpSA.

RESULTS

Thirty-seven children were judged H. pylori-positive and 64 negative by the UBT and HpSA. No discrepancy in the results was observed between UBT and HpSA. Urine-HpELISA showed 91.9% sensitivity and 96.9% specificity with an accuracy of 95.0%. Rapid urine-HpAb showed 78.4% sensitivity and 100% specificity with an accuracy of 92.1%. Seven false negative results for rapid urine-HpAb were from children aged younger than 10 years, and their antibody titers of urine-HpELISA were lower than true positives.

CONCLUSIONS

For the diagnosis of H. pylori infection in Japanese children, both tests are non-invasive, inexpensive, reliable and easy-to-perform methods giving satisfactory accuracy, although the sensitivity of the rapid urine-HpAb kit was inferior to that of the urine-HpELISA kit, especially in children aged younger than 10 years, showing relatively low titer of H. pylori antibody.

Prevalence of gastroduodenal ulcers/erosions in patients taking low-dose aspirin with either 15 mg/day of lansoprazole or 40 mg/day of famotidine: the OITA-GF study 2

Background

The preventive effects of histamine 2 receptor antagonists vs. proton pump inhibitors on low-dose aspirin (LDA)-related gastroduodenal mucosal injury have not been fully investigated. We conducted a cross-sectional study to compare the prevalence of gastroduodenal ulcers or erosions in patients taking LDA with either 40 mg/day of famotidine or 15 mg/day of lansoprazole for at least three months.

Methods

Of 84 eligible patients, two taking 40 mg/day of famotidine and four taking 15 mg/day of lansoprazole refused to undergo upper gastrointestinal endoscopy. Ultimately, we performed upper gastrointestinal endoscopy in 78 patients taking either 40 mg/day of famotidine (group F, n = 31) or 15 mg/day of lansoprazole (group L, n = 47). The prevalence of gastroduodenal ulcers or erosions and the magnitude of gastric mucosal injury evaluated using modified Lanza scores were compared between the two groups.

Results

No patients in either group had gastroduodenal ulcers. Gastroduodenal erosions were more prevalent in group F than in group L (48.4% vs. 17.0%, p = 0.005). The modified Lanza scores (mean ± SD) were significantly higher in group F than in group L (0.9 ± 1.3 vs. 0.3 ± 0.7, p = 0.007). A multivariate logistic regression analysis showed that the use of lansoprazole was negatively associated with gastroduodenal erosions.

Conclusions

This study suggests that 15 mg/day of lansoprazole may be more effective in preventing the development of LDA-related gastroduodenal erosions than 40 mg/day of famotidine. The preventive effects of these two regimens on the development of LDA-related gastroduodenal ulcers require further investigation.

Prevalence and independent factors for gastroduodenal ulcers/erosions in asymptomatic patients taking low-dose aspirin and gastroprotective agents: the OITA-GF study

BACKGROUND

Although it is well known that aspirin causes gastroduodenal mucosal injury and that aspirin-induced gastroduodenal mucosal injury is often asymptomatic, the prevalence and independent factors for gastroduodenal mucosal injury have not been clarified in asymptomatic patients taking low-dose aspirin and gastroprotective agents.

AIM

To clarify the prevalence and independent factors for gastroduodenal ulcers/erosions in asymptomatic patients taking low-dose aspirin and gastroprotective agents.

DESIGN

Prospective observational study.

METHODS

We performed endoscopy in 150 asymptomatic patients taking low-dose aspirin and gastroprotective agents for at least 3 months.

RESULTS

Gastroduodenal ulcers/erosions were observed in 37.3% [ulcers (4.0%); erosions (34.0%)]. Univariate logistic regression analyses showed that proton-pump inhibitor (PPI) use was negatively associated with gastroduodenal ulcers/erosions [odds ratio (OR) 0.35, 95% confidence interval (95% CI) 0.17-0.75, P=0.007]. A multivariate logistic regression analysis selected PPI use as the only independent factor for gastroduodenal ulcers/erosions (OR 0.35, 95% CI 0.14-0.86, P=0.02). None of the 53 patients with PPI use had any gastroduodenal ulcers, and 11 with standard-dose PPI use tended to have a lower prevalence of gastroduodenal erosions than 42 with low-dose PPI use (0% vs. 28.6%, P=0.052).

CONCLUSION

Gastroduodenal ulcers/erosions were observed in about one-third of asymptomatic patients taking low-dose aspirin and gastroprotective agents, and PPI use was a negative independent factor for gastroduodenal ulcers/erosions in those patients. In addition, standard-dose PPI therapy might be more effective in the prevention of aspirin-induced gastroduodenal mucosal injury than low-dose PPI therapy.

Dual specimens increase the diagnostic accuracy and reduce the reaction duration of rapid urease test

AIM: To evaluate the influence of multiple samplings during esophagogastroduodenoscopy (EGD) on the accuracy of the rapid urease test, and the validity of newly developed rapid urease tests, HelicotecUT plus test and HelicotecUT test, CLO test and ProntoDry test.

METHODS: A total of 355 patients undergoing EGD for dyspepsia were included. Their Helicobacter pylori (H. pylori) treatment status was either naïve or eradicated. Six biopsy specimens from antrum and gastric body, respectively, were obtained during EGD. Single antral specimens and dual (antrum + body) specimens were compared. Infection status of H. pylori was evaluated by three different tests: culture, histology, and four different commercially available rapid urease tests (RUTs)-including the newly developed HelicotecUT plus test and HelicotecUT test, and established CLO test and ProntoDry test. H. pylori status was defined as positive when the culture was positive or if there were concordant positive results among histology, CLO test and ProntoDry test.

RESULTS: When dual specimens were applied, sensitivity was enhanced and RUT reaction time was significantly reduced, regardless of their treatment status. Thirty minutes were enough to achieve an agreeable positive rate in all the RUTs. Both newly developed RUTs showed comparable sensitivity, specificity and accuracy to the established RUTs, regardless of patient treatment status, RUT reaction duration, and EGD biopsy sites.

CONCLUSION: Combination of antrum and body biopsy specimens greatly enhances the sensitivity of rapid urease test and reduces the reaction duration to 30 min.

Guidelines for the management of Helicobacter pylori infection in Japan: 2009 revised edition

BACKGROUND

Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan.

MATERIALS AND METHODS

Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines.

RESULTS

Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori-associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy.

CONCLUSION

The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions.

Evaluation of rapid urine test for the detection of Helicobacter pylori infection in the Vietnamese population

PURPOSE

This study attempted to assess the value of the RAPIRUN test for the diagnosis of Helicobacter pylori infection in the Vietnamese population.

METHODS

We recruited 148 Vietnamese patients undergoing upper gastrointestinal endoscopy during which five gastric biopsies were taken; blood and urine samples were collected from each patient. Helicobacter pylori infection status was determined by a combination of three different methods, including culture, immunohistochemistry, and serum ELISA. RAPIRUN tests were performed using urine samples.

RESULTS

The sensitivity, specificity, and accuracy of the RAPIRUN test in these Vietnamese patients were 79.5, 90.7, and 84.5%, respectively.

CONCLUSIONS

The RAPIRUN test is useful for the diagnosis of H. pylori infection in the Vietnamese population, showing high specificity, acceptable sensitivity, non-invasiveness, convenience, and rapidity.

Changes in the presence of urine Helicobacter pylori antibody in Japanese children in three different age groups

BACKGROUND

The rates of acquisition and spontaneous eradication of Helicobacter pylori infection in children has yet to be established. To determine these rates in children living in an urban region of Japan, the levels of urine H. pylori antibodies in children of three different age groups were measured.

METHODS

A urine-based enzyme-linked immunosorbent assay (ELISA) was used to detect H. pylori antibodies twice within a 12 month interval over 2 years in 452 healthy children living in Tokyo. The subjects were divided into three groups: ages 4, 7, and 10 years.

RESULTS

The prevalence of H. pylori infection was not different among the groups, being between 4.0% and 6.7%. The rate of turn to positivity for H. pylori infection was 1.5% per year and the rate of turn to negativity was 1.1%, but in the 10 year age group the rates were markedly lower than in the younger children.

CONCLUSION

The prevalence of H. pylori infection in Tokyo was 4.0-6.7% and was not different among 4, 7, and 10 year age groups.

Helicobacter pylori detection and antimicrobial susceptibility testing

The discovery of Helicobacter pylori in 1982 was the starting point of a revolution concerning the concepts and management of gastroduodenal diseases. It is now well accepted that the most common stomach disease, peptic ulcer disease, is an infectious disease, and all consensus conferences agree that the causative agent, H. pylori, must be treated with antibiotics. Furthermore, the concept emerged that this bacterium could be the trigger of various malignant diseases of the stomach, and it is now a model for chronic bacterial infections causing cancer. Most of the many different techniques involved in diagnosis of H. pylori infection are performed in clinical microbiology laboratories. The aim of this article is to review the current status of these methods and their application, highlighting the important progress which has been made in the past decade. Both invasive and noninvasive techniques will be reviewed.

Effect of a gastro-protective agent, rebamipide, on symptom improvement in patients with functional dyspepsia: a double-blind placebo-controlled study in Japan

BACKGROUND AND AIM

Although mucosal protective agents have been used frequently for treatment of symptomatic gastritis, there has been no well-controlled study of functional dyspepsia. The aim of this study was to assess the efficacy of a 4-week treatment with rebamipide for the relief of overall dyspeptic symptoms and the improvement in quality of life from an untreated baseline in Japanese patients with functional dyspepsia.

METHODS

In a double-blinded, randomized, placebo-controlled, single-center study, 81 patients with functional dyspepsia were recruited and treated with rebamipide (100 mg, t.i.d.) or placebo for 4 weeks. Symptoms were assessed at baseline and at the end of the study period by a symptom questionnaire. Quality of life was evaluated by the QPD 32.

RESULTS

Data was analyzed for symptoms from 38 patients who received rebamipide and 33 patients who received placebo treatment. Overall symptoms were significantly improved in both the rebamipide and placebo treatment groups from the untreated baseline after 4 weeks of treatment, and the mean changes in overall symptoms were not significantly different between the groups. However, the improvement in symptom score was significantly greater in the treatment arm than in the placebo arm for three items, which were bloating, belching, and pain or discomfort that was relieved after a meal. Regarding quality of life, social restriction and pain intensity were significantly improved in the rebamipide treatment group in per-protocol analysis (P = 0.048 and P = 0.031, respectively).

CONCLUSIONS

Although rebamipide was not significantly better than placebo in reducing overall symptoms by 4 weeks' treatment, it may partially improve the symptoms. It may also be beneficial in improvement of quality of life in Japanese patients with functional dyspepsia.

Assessing the efficacy of famotidine and rebamipide in the treatment of gastric mucosal lesions in patients receiving long-term NSAID therapy (FORCE--famotidine or rebamipide in comparison by endoscopy)

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori infection are major causes of gastric mucosal lesions. In Japan, histamine-2 receptor antagonists are frequently prescribed, but the literature regarding their efficacy is limited. In this study, we compare the effects of famotidine and rebamipide on NSAID-associated gastric mucosal lesions using upper gastrointestinal endoscopy.

METHODS

This study examined 112 patients taking NSAIDs for either gastric hemorrhage or erosion. Before treatment, the patients were assessed by endoscopy. Using blind randomization, patients were divided into two groups: group F (famotidine, 20 mg/day) and group R (rebamipide, 300 mg/day). Efficacy was examined 4 weeks later using endoscopy.

RESULTS

After treatment, the Lanza score decreased significantly in group F (P < 0.001) but not in group R (P = 0.478). The change in the Lanza score in group F was significantly greater (P = 0.002) than that in group R.

CONCLUSIONS

Famotidine was superior to rebamipide in treating NSAID-associated mucosal lesions.

The clinical applications and accuracy of 2 rapid near-patient tests in detecting Helicobacter pylori infection

Noninvasive methods for assessing Helicobacter pylori infection status are now an integral part of managing patients with upper gastrointestinal complaints. The aim of this study is to evaluate the feasibility and diagnostic accuracy of 2 rapid tests: a urine-based H. pylori antibody detection method (Rapirun) and a stool-based H. pylori antigen detection method (immunocard STAT! HpSA). The combined use of the mentioned 2 tests was also evaluated, which has not been described in previous similar studies. Urine and stool specimens were collected from patients who were arranged for gastroendoscopic examination. The urine and stool specimens were tested with Rapirun and immunocard STAT! HpSA separately. The estimated reaction time was about 15 to 20 min for the former and 5 to 10 min for the latter. H. pylori infection was confirmed with 4 tests: culture, histology, rapid urease test, and the (13)C-urea breath test. Obtained results from both kits were compared with confirmed results. One hundred twenty patients were eligible for analysis. Of them, 62 tested positive for H. pylori infection and 58 were negative by the confirmation criteria. The urine Rapirun test relative to the confirmed results showed sensitivity, specificity, and accuracy as 87.1% (confidence interval [CI] = 81.1-93.1%), 89.7% (CI = 84.2-95.1%), and 88.3%, respectively. The stool immunocard STAT! HpSA test relative to the confirmed results showed sensitivity, specificity, and accuracy as 96.8% (CI = 93.6-99.9%), 82.8% (CI = 76.0-89.5%), and 90%, respectively. The combined-use method of both tests revealed sensitivity, specificity, and accuracy as 98.4% (CI = 96.1-100%), 81.0% (CI = 74.0-88.1%), and 90%, respectively. These 2 urine and stool tests have a satisfactory accuracy around 90% in detecting H. pylori infection. In consideration of the advantages of cheapness, timesaving, and ease of use, both can be used as rapid near-patient tests in general practice. The combined use of both tests was also promising in detecting H. pylori infection.

Evaluation of a urine-based enzyme-linked immunosorbent assay test for the detection of Helicobacter pylori infection among 3- to 5-year-old Israeli Arab healthy children

We conducted a community-based study among 159 healthy Israeli Arab children aged 3 to 5 years old to examine the validity of the HpELISA kit (URINELISA, Otuska Phamaceuticals Co, Ltd, Tokyo, Japan) for detection Helicobacter pylori IgG antibodies in urine. The polyclonal H. pylori stool antigen test (Premier HpSA) served as the gold standard. The sensitivity, specificity, positive and negative predictive values of the URINELISA kit were 34.2%, 96.3%, 90% and 60%, respectively. Using a cutoff value calculated based on the receiver operating characteristic curve (0.066), the corresponding figures were 65.8%, 87.5%, 83% and 72%, respectively. These data indicate that the usefulness of the URINELISA test in epidemiological studies in healthy young children is limited.

Case-control study on the association of upper gastrointestinal bleeding and nonsteroidal anti-inflammatory drugs in Japan

OBJECTIVE

Studies in Western populations have shown the association of nonsteroidal anti-inflammatory drugs (NSAIDs) and upper gastrointestinal bleeding (UGIB). The role of Helicobacter pylori infection in NSAIDs-related UGIB remains to be studied. We conducted a case-control study in Japan to investigate these related topics.

METHODS

Cases of UGIB due to duodenal or gastric ulcer, or gastritis were identified in 14 study hospitals in various areas of Japan. For each case, two controls were identified from population registries in the same district. Information on drugs and other risk factors was obtained from 175 cases and 347 controls by telephone interviews. Anti-H. pylori antibody in the urine was measured in a single laboratory for all the cases and 225 controls.

RESULTS

The odds ratio (OR) of UGIB was 5.5 for aspirin and 6.1 for other NSAIDs (NANSAIDs) (p<0.01). The OR for regular use was higher than for occasional use both for aspirin (7.7 vs 2.0) and NANSAIDs (7.3 vs 4.1). Loxoprofen (5.9), frequently used in Japan as a safe 'prodrug', was significantly associated with UGIB. The odds ratio for H. pylori infection was 4.9 and the relative excess risk due to the interaction between H. pylori and the use of NSAID was 1.2 (95% CI: -5.8-8.1).

CONCLUSION

NSAIDs including loxoprofen increase the risk of UGIB in Japan as in Western countries, with a similar magnitude of association. There was no evidence of biological interaction between NSAIDs and H. pylori infection.

Point-of-care Helicobacter pylori urine antibody detection in a multi-ethnic adult population in the United States

A need exists for accurate point-of-care tests for diagnosis of Helicobacter pylori (H. pylori) infection to evaluate a rapid urine-H. pylori antibody test device for detection of H. pylori infection in a point-of-care setting in the United States. A multi-center study in a multi-ethnic population compared the RAPIRUN urine antibody test with the (13)C-urea breath test (C-UBT) and a traditional serologic test, the high-molecular-weight cell-associated protein enzyme immunoassay (HM-CAP EIA). The primary comparator was with "definite positive" and "definite negative" patients defined as a concordance of combined results of the UBT and the HM-CAP IgG EIA. Overall, 188 eligible patients were enrolled (61 men, age range: 18-73 years, including 84 Hispanics, 73 Asian-Pacific Americans, 22 Black African-Americans, 6 non-Hispanic Caucasians, and 3 of "other" ethnicity). Compared with "definite positive" and "definite negative" results, the sensitivity and specificity of the urine antibody test were 0.9 and 1.0, respectively. The urine antibody test proved suitable for point-of-care rapid diagnosis of anti-H. pylori antibodies indicative of active or past H. pylori infection.

Reliability of rapid urinary test for antibody to Helicobacter pylori in adult patients with proteinuria

A urinary test for detecting the anti-H. pylori antibody using immunochromatography (RAPIRAN) is considered suitable for the screening purpose. However, this may yield spurious results in the presence of proteinuria. The present study was conducted to evaluate the diagnostic performance of RAPIRAN in patients with proteinuria. Urine and serum samples of adult inpatients with proteinuria were used for analyses. The diagnosis of H. pylori infection was made based on the seropositivity of anti-H. pylori antibody using 2 different serum tests. Fifty-one subjects were eligible for analyses. The serum tests showed negative and positive in 25 and 26 patients, respectively. Two of 25 seropositive patients had a negative result in RAPIRAN, and 1 provided invalid data. All of seronegative patients showed negative in RAPIRAN. The overall accuracy was 95.0%. The present study showed that RAPIRAN has diagnostic quality enough to use clinically also in patients with proteinuria.

Evaluation of urine ELISA test for detecting Helicobacter pylori infection in Taiwan: A prospective study

AIM: To evaluate the diagnostic accuracy and clinical utility of a new ELISA (URINELISA) test for detecting Helicobacter pylori (H pylori) antibody in the urine of Taiwanese population.

METHODS: In this prospective study, 317 consecutive dyspeptic patients (171 men, 146 women; mean age, 51.0 years) were included. They underwent gastroendoscopy for evaluation. Invasive tests, including culture, histology, and rapid urease test (RUT), and non-invasive 13C-urea breath test were preformed. At the same time, urine specimens were collected for URINELISA. The status of H pylori infection was considered as positive when either culture was positive, or when two of the other, RUT, histology or 13C-UBT, were positive.

RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of URINELISA are 91.7% (211/230), 90.8% (79/87), 96.3% (211/219), and 80.6% (79/98) respectively.

CONCLUSION: This URINELISA test is reliable, inexpensive and easy-to-use. The high diagnostic accuracy warrants the use of URINELISA as a first-line screening tool for diagnosis of H pylori infection in untreated patients.

Helicobacter heilmannii infection: clinical, endoscopic and histopathological features in Japanese patients

Gastric biopsy materials of 4074 consecutive Japanese patients undergoing esophagogastroduodenoscopy were reviewed, along with those of 15 patients with Helicobacter heilmannii infection (11, chronic gastritis; four, mucosa-associated lymphoid tissue (MALT) lymphoma). In four patients with H. heilmannii infection, the materials were examined by transmission electronmicroscopy. Urea breath test (three patients) and antibody test (five patients) were performed in patients with H. heilmannii infection. In two patients with MALT lymphoma, H. heilmannii was eradicated. The prevalence of H. heilmannii was 0.1% in the consecutive series. In chronic gastritis, the gastric mucosa was endoscopically normal (13.3%), had erythema (33.3%), or had erosions (53.3%); histologically, it showed no epithelial change, mild mononuclear cell infiltration, and slight and focal neutrophil infiltration; Helicobacter heilmannii was positive with anti-H. pylori antibody, and was detected in the mucous gel layer and in foveolae. In MALT lymphoma, the gastric mucosa was coarsely granular with enlarged mucosal folds without ulcers (two cases), with small ulcers (one case), or with multiple erosions (one case). Urea breath test and antibody test were both negative. Eradication of H. heilmannii resulted in remission of MALT lymphoma. Helicobacter heilmannii infection is therefore uncommon in Japanese adults, but is associated with chronic gastritis and gastric MALT lymphoma.

Serum and urine Helicobacter pylori antibody titer after intravenous gamma-globulin treatment for Kawasaki disease and its clearance

BACKGROUND

It is not clear the effect of gamma-globulin therapy on results of enzyme-linked immunosorbent assays (ELISA) based on serum and urine for detection of Helicobacter pylori (H. pylori) antibodies, although the therapy can cause false-positive results in those assays.

METHODS

To examine the effect of intravenous gamma-globulin (IVIG) treatment on the results of ELISA based on serum and urine, levels of H. pylori IgG were measured in the serum and urine before and after IVIG therapy in 18 children with Kawasaki disease (KD) uninfected with H. pylori.

RESULTS

The serum and urine H. pylori IgG levels decreased time-dependently after the IVIG therapy and there were significant differences (P < 0.01) in the levels prior to therapy and at 7 days and 1 month after the therapy. The significant difference in the H. pylori IgG levels prior to therapy and 3 months after the therapy was observed in the serum but not in the urine.

CONCLUSION

The results suggest that gamma-globulin administration can cause false-positive results in ELISA based both on serum and urine for detection of H. pylori antibodies, and that the H. pylori antibodies cleared much more quickly from the urine than from the serum.

Comparison of non-invasive tests to detect Helicobacter pylori infection in children and adolescents: results of a multicenter European study

OBJECTIVE

To compare the current non-invasive tests for Helicobacter pylori infection in children and adolescents.

STUDY DESIGN

This multicenter, multinational study investigated the sensitivity, specificity, and positive and negative predictive values of four non-invasive tests: urea breath test (UBT), stool antigen test, and antibody detection in serum and urine, in comparison with biopsy-based tests.

RESULTS

Of 503 patients included pre-treatment, 473 fulfilled the definition of H pylori status and among those 316 had results available for the four non-invasive tests (including 133 H pylori -positive patients). The specificity was excellent for all tests. The UBT had the best sensitivity in all age groups, followed by serology, stool test, and antibody detection in urine. A trend for better sensitivity with an increase in age was observed except for the stool test. The receiver operating characteristics (ROC) curves showed that sensitivity of serology, stool test, and urinelisa could be improved by changing the cutoff value. An inadequate storage of the specimens may explain the poor results of the stool test.

CONCLUSION

The UBT appears to be an excellent test for diagnosis of H pylori infection for children and adolescents.

Reliability of urinary tests for antibody to Helicobacter pylori in patients with pulmonary tuberculosis

AIM: Although the quality of currently available urinary tests for detecting antibody to Helicobacter pylori (H pylori) have been proved in some populations, the accuracy has not been studied regarding patients who suffer from pulmonary tuberculosis with multi-drug treatments. The present study was conducted to evaluate the accuracy of these urinary tests for antibody to H pylori in these patients.

METHODS: Serum samples from 61 inpatients with pulmonary tuberculosis were tested using enzyme immunoassay, and urine samples were assayed by enzyme-linked immunosorbent assay method (URINELISA) and immunochromatography method (RAPIRAN). Medicines prescribed to the patients were recorded for medical charts, to evaluate the influences on the results of urinary tests.

RESULTS: The sensitivity, specificity, and consistency of URINELISA against the serum test were 93.1%, 65.6%, and 78.6% respectively, and those of RAPIRAN were 86.2%, 93.7%, and 90.1% respectively, which were almost equal to the data previously reported. Prescribed medicines had little influence on the results.

CONCLUSION: The two urinary tests for detecting H pylori antibody have a diagnostic accuracy in patients with pulmonary tuberculosis given multiple anti-tuberculosis drugs.

Evaluation of a urine antibody test for Helicobacter pylori in Japanese children

OBJECTIVE

To evaluate the accuracy of a urine-based enzyme-linked immunosorbent assay (ELISA) kit for anti-Helicobacter pylori immunoglobulin G antibody (urine-HpELISA) in children, we compared its sensitivity and specificity in reference to (13)C-urea-breath test (UBT) and H pylori stool antigen test (HpSA).

STUDY DESIGN

Japanese children without significant upper abdominal symptoms were included (n=100; mean age, 7.0 years; range, 2 to 15). UBT, HpSA, and urine-HpELISA were performed.

RESULTS

Of 100 children, 36 and 64 were judged H pylori-positive and H pylori-negative, respectively, by UBT and HpSA. Thirty-four of 36 positive children were positive by urine-HpELISA, and 62 out of 64 negative children were negative by urine-HpELISA. Thus, the urine-HpELISA had 94.4% sensitivity and 96.9% specificity, with accuracy of 96.0%.

CONCLUSIONS

The urine-HpELISA is a rapid, inexpensive, reliable, and easy-to-perform method for the diagnosis of H pylori infection in children. It may be useful not only for diagnosis but also for mass screening for epidemiological studies in pediatric population.

Urine-based enzyme-linked immunosorbent assay for the detection of Helicobacter pylori antibodies in children

OBJECTIVE

Recent studies of urine-based enzyme-linked immunosorbent assays (ELISA) for detection of antibody to Helicobacter pylori (H. pylori) have already shown high sensitivity and specificity in adults. The diagnostic accuracy of these assays in children was investigated.

METHODS

The results of serum and urine-based ELISAs were compared with those of 13C-urea breath tests (13C-UBT) and/or detection of faecal H. pylori antigen in 68 children. The effect of urine total immunoglobulin G (IgG) levels on the ELISA results for anti-H. pylori antibodies in urine was also examined.

RESULTS

The sensitivity, specificity and accuracy of the serum ELISA were 72.7%, 96.3%, and 92.3% respectively, while those of the urine-based ELISA were 92.3%, 76.4%, and 79.4% respectively. The level of urine total IgG in children with false-positive results in the urine-based ELISA, was significantly higher than that in children who showed negative results in both the urine-based ELISA and the 13C-UBT and/or faecal H. pylori antigen tests. Human gamma-globulin affected the urine-based ELISA results at final concentrations of 2.0 mg/dL, 3.0 mg/dL, and 4.0 mg/dL; the anti-H. pylori antibody values were significantly higher than the ELISA values without the addition of human gamma-globulin.

CONCLUSION

The findings suggested that the specificity of urine-based ELISA for detection of H. pylori antibodies is low in children, since high urinary levels of total IgG increase the likelihood of false-positive results.

European multicentre validation trial of two new non-invasive tests for the detection of Helicobacter pylori antibodies: urine-based ELISA and rapid urine test

AIM

Non-invasive tests for the assessment of Helicobacter pylori status are now an integral part of the management strategies for patients with dyspepsia. The aim of this study was to evaluate a urine based antibody ELISA and a near patient urine test for the diagnosis of H. pylori infection in a European population.

METHODS

Urine samples were collected from 449 patients (240 females, 209 males, mean age 54 years), with dyspeptic symptoms but no previous H. pylori eradication therapy, at five centres in four European countries. All patients underwent GI endoscopy and biopsies were taken for H. pylori diagnosis. Urine samples were analysed using an IgG ELISA (URINELISA) and a near patient urine test (RAPIRUN). In addition, a serum IgG ELISA (Pyloriset-EIA-GIII), a whole blood test (Pyloriset-Screen) and a 13C-urea breath test were performed.

RESULTS

The sensitivity of the urine based ELISA and the near patient urine test was 90% and 82%, and the specificity 68% and 83%, respectively. The accuracy of the serum ELISA and the whole blood test was comparable with the urine based test.

CONCLUSION

The urine based ELISA and the near patient urine test are just as accurate as the serological tests. This comparable accuracy and complete non-invasiveness of the former gives it an advantage over blood based tests. This limits the application of these tests in general practice.

Novel diagnostic method of testing for Helicobacter pylori infection using the rapid leukocyte strip test, Leukostix

BACKGROUND AND AIM

A characteristic of gastric mucosa infected with Helicobacter pylori is infiltration of inflammatory cells, mainly consisting of neutrophils. The present study aimed to detect neutrophils in homogenates of biopsied gastric mucosa semiquantitatively using the rapid leukocyte strip test, Leukostix. The authors then investigated the association of these results with H. pylori status.

METHODS

The authors studied 342 patients undergoing endoscopy. Of these, 160 were treated for eradication of H. pylori infection and were reassessed after treatment. For the definitive diagnosis of H. pylori infection, quantitative culture, the rapid urease test and immunohistostaining were performed. Additionally, serum antibody against H. pylori was determined at the initial examination, and the 13C-urea breath test was performed after treatment. With the use of Leukostix, homogenates of biopsied gastric mucosa were spotted onto strips and judged 2 min later.

RESULTS

There was a significant correlation between the positive reaction of Leukostix and the number of neutrophils in gastric tissues determined by microscopic observation. The sensitivity and specificity of Leukostix at the initial examination were 97.9% and 76.9%, respectively, while those after eradication treatment were 100% and 97.2%, respectively. There was a significant positive correlation between the degree of reaction of Leukostix and the amount of H. pylori determined by quantitative culture.

CONCLUSIONS

The Leukostix test, using biopsied samples of gastric mucosa, was excellent for quantitative determination of neutrophils and useful for diagnosis of H. pylori infection and early assessment of treatment efficacy. Positive gradations of Leukostix results corresponded closely with the amount of H. pylori in gastric tissues.

Review article: clinic-based testing for Helicobacter pylori infection by enzyme immunoassay of faeces, urine and saliva

Enzyme immunoassays have been used to detect Helicobacter pylori infection in human body materials such as faeces, urine and saliva. The stool antigen assay (HpSA), which uses polyclonal anti-H. pylori antibody as a capture reagent, has been widely used in the pre-treatment diagnosis of the infection in adults and children. Although the assay has the potential for monitoring eradication therapy, there are controversies over its use, especially at an early stage after treatment. The efficacy of the stool antigen assay can be modified by using monoclonal antibodies towards well characterized H. pylori faecal antigens. Two types of enzyme immunoassays (enzyme-linked immunosorbent assay [ELISA] and immunochromatography) have been used to detect antibodies to H. pylori in urine. Immunochromatography of urine is a rapid assay well suited for epidemiological studies. The salivary ELISA, used in a number of studies, has shown inconsistent results with less than optimum sensitivity and specificity. Urinary and salivary immunoassays may not distinguish between past and present infections, thus limiting their potential to monitor eradication therapy.

Urinary antibody titers to Helicobacter pylori and an impact of clinical characteristics

This study evaluates the clinical usefulness of titers of antibody to Helicobacter pylori (Hp) in a urine-based enzyme-linked immunosorbent assay (URINELISA; Otsuka Pharmaceutical, Tokushima, Japan) by comparing values of serum antibody to Hp in an already commercialized kit in a population of 250 asymptomatic individuals. Influences of physical and laboratory characteristics on the relationship between serum and urinary titers of antibody to Hp were also estimated using simple and multiple regression analyses. Specific urine gravity, urine pH, proteinuria, and age of the subjects were regarded as significant factors relating to urinary titers of the anti-Hp antibody on simple regression analyses. Both the urinary and serum titers strongly correlated on simple regression analysis (r = 0.782, P < 0.0001). On multiple regression analysis, an additional two factors, specific urine gravity and urine pH, were picked up, and the correlation coefficient was improved (r = 0.795, P < 0.0001). The present results indicate that URINELISA had not only qualitative but quantitative accuracy. However, careful attention should be paid to cases with abnormalities in urinalysis when used quantitatively.

An evaluation of a rapid urine test for the diagnosis of Helicobacter pylori infection in the Chinese population

BACKGROUND

A new rapid urine test was developed to detect anti-Helicobacter pylori antibody in urine using the principle of immunochromatography. The accuracy of this test in the Chinese population remains to be defined.

AIM

To evaluate a new rapid urine test for the diagnosis of H. pylori infection in the Chinese population.

METHODS

Eligible patients without previous treatment of H. pylori were recruited. In-house rapid urease test and histology were used as the gold standard. The rapid urine test (RAPIRUN H. pylori antibody) was performed and the results were compared with the gold standard.

RESULTS

One hundred and twenty-three patients were eligible for analysis and 61 (50%) were H. pylori positive by the gold standard. The rapid urine test showed a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 96.7%, 95.2%, 95.2%, 96.7% and 95.9%, respectively. Results were obtained within 20 min and no special laboratory support was required.

CONCLUSIONS

The rapid urine test by immunochromatography is highly accurate for the diagnosis of H. pylori infection in untreated Chinese patients.

Diagnosis of Helicobacter pylori infection

A number of invasive and non-invasive techniques are available for the diagnosis of infection with Helicobacter pylori. These can be used to establish whether infection is present and to confirm that eradication has been achieved after treatment. Invasive techniques require biopsy of the gastric mucosa; such techniques include histology, bacterial culture, the rapid urease test and the polymerase chain reaction (PCR) technique. The principal non-invasive techniques are the 13C-urea breath test and serological assays in serum or saliva samples. Histological examination of gastric biopsy samples should be mandatory at the initial presentation of the patient because it also gives insight on the status of the gastric mucosa. The rapid urease test can be used to give a rapid diagnosis of infection. Eradication should also be confirmed by histological examination, though other sensitive tests such as bacterial culture, PCR or the 13C-urea breath test may also be used.

Urine-based enzyme-linked immunosorbent assay for the detection of Helicobacter pylori infection in children

OBJECTIVE

Serology and (13)C-urea breath test have been widely used as noninvasive tests to detect Helicobacter pylori infection. However, easier collection of samples and lower costs are desirable for diagnosis of the individual patient or for use in epidemiologic studies. Our aim was to study the diagnostic accuracy of a recently developed urine-based enzyme-linked immunosorbent assay (ELISA) kit for the detection of H pylori-specific immunoglobulin G (IgG) antibodies in children.

STUDY DESIGN

Specimens of serum and randomly voided urine were collected from 816 children (0-15 years old) and were analyzed using 2 serum-based ELISA kits and a urine-based ELISA kit, respectively. Based on results of serology, the sensitivity, specificity, and accuracy of the urine-based ELISA kit were evaluated. With regard to false-positive and false-negative results, urinary IgG concentrations and IgG/creatinine levels were studied.

RESULTS

Both serum-based ELISAs were positive in 41 children and were negative in 666, who were enrolled in this study. The remaining 109 children were excluded because of disagreement between the results of the 2 serum-based ELISAs, including indeterminate values. Overall sensitivity, specificity, and accuracy of urine-based ELISA test compared with serology were 85.4%, 95.5%, and 94.9%, respectively. On positivity rates, the urine-based ELISA was closely coincident with the serum-based ELISA in each age group. There was no correlation between antibody levels detected by urine-based ELISA and each serum-based ELISA. Urinary IgG concentrations and IgG/creatinine levels were significantly higher in false-positives and were lower in false-negatives than in true-positives plus true-negatives for serology. Most of those with false-positive results had trace to moderate proteinuria.

CONCLUSIONS

The urine-based ELISA is an alternative to serum-based ELISA for diagnosis of H pylori infection in children and should be suitable for large-scale epidemiologic studies concerning the organism. In children with proteinuria, results of the test should be interpreted with caution. It is possible that the urine-based ELISA method would be applicable to diagnosis of other infectious diseases.

Rapid detection of anti-Helicobacter pylori IgG in urine using immunochromatography

BACKGROUND

Non-invasive methods to detect the presence of H. pylori infection continue to be refined.

AIM

To evaluate a new 20-min immunochromatography method (RAPIRUN H. pylori Antibody) for the presence of anti-H. pylori IgG in urine.

METHODS

We used the (13)C-urea breath test to establish H. pylori status. We evaluated the urine test among 104 subjects including 43 with H. pylori infection confirmed by repeatedly positive urea breath tests and 61 H. pylori-negative subjects with repeatedly negative urea breath tests. Forty-one of the 43 subjects with H. pylori infection had a positive rapid urine test with two false negative tests. There were two false positive tests among the 61 with repeatedly negative urea breath tests. The sensitivity, specificity, positive and negative predictive values for the rapid urine test were 95.3%, 96.7%, 95.3%, and 96.7%, respectively. The kit was easy to use and required no special equipment.

CONCLUSIONS

The rapid immunochromatography method for determination of anti-H. pylori IgG proved to be reliable with excellent sensitivity and specificity and is likely to be useful for both clinical and epidemiological studies.

On-site diagnosis of H. pylori infection by urine

We have recently developed an on-site diagnostic kit for H. pylori infection using urine (utilizing immunochromatographic method employing a nitrocellulose membrane coated by extracted H. pylori antigen). Accordingly, we investigated its usefulness in 155 consecutive dyspeptic patients using the 13C urea breath test as a gold standard and further compared its performance with two commercially available rapid diagnostic kits that use whole blood (Helisal Rapid Blood, and ImmunoCard H. pylori). As the results, the urine based on-site diagnostic kit provided 95.9% sensitivity and 87.9% specificity with 92.9% accuracy, which were comparable or even better than that of both rapid whole blood tests, suggesting its usefulness in screening of H. pylori infection.

Evaluation of urinary rapid test for Helicobacter pylori in general practice

There is increasing interest in noninvasive tests for the diagnosis of Helicobacter pylori (H. pylori) infection. One such test, a urine-based rapid test kit (RAPIRUN H. pylori Antibody, Otsuka Pharmaceutical Co., Ltd.) for detection of antibody to H. pylori, has been developed and is considered ideal. In addition to its noninvasiveness and safe handling-due to use of urine as a sample-the assay procedure used for the urinary rapid test is very simple. Only 10-20 minutes are required to complete an assay, and no instruments are needed. The aim of this study was to examine the clinical usefulness of this urine-based rapid test. A total of 189 patients, including 76 patients with gastroduodenal disease, were recruited. A pair of random single-void urine and serum samples was collected from each of the 189 patients, and antibody to H. pylori in the urine and serum samples was measured using the urine-based rapid test kit and three commercially available serum-based ELISA kits. For the patients with gastroduodenal disease, invasive diagnostic methods using endoscopic biopsy specimens such as culture, histology, and rapid urease test were also performed. The sensitivity, specificity, and accuracy of the urinary rapid test were evaluated on the basis of the three serum ELISA results or the invasive diagnostic results. In addition, various urinalyses were performed, and the effects of substances existing in urine on the urinary rapid test results were examined. Of the 189 patients, the urinary rapid test was positive for 110 (58.2%), negative for 78 (41.3%), and invalid for only one patient (0.5%). Based on the three serum-based ELISA results, the sensitivity, specificity, and accuracy of the urinary rapid test were 93.7, 88.9, and 92.2%, respectively. On the basis of the biopsy-based test results, the sensitivity of the urinary rapid test was 100% and its accuracy (95.2%) was equivalent or superior to that of each serum-based ELISA. In addition, no significant differences were observed between groups positive and negative on urinary rapid testing in any urinalysis parameter examined. The novel urinary rapid test kit evaluated in this study enables simple, rapid, and accurate diagnosis of H. pylori infection, and is an ideal test method for point-of-care testing.

A new rapid test for detecting anti-Helicobacter pylori antibody excreted into urine

BACKGROUND

Helicobacter pylori infection has been one of the most common infectious diseases in the world, whereas a gold standard for identifying its infection has not yet been established. The specific test will depend on the particular clinical, epidemiological, and scientific requirements. We recently developed a new type of rapid test to detect H. pylori antibody excreted into urine; the test requires only 20 minutes. The purpose of this study was to examine the accuracy of this rapid test.

METHODS

The performance of the rapid test was compared with those of a histological search through Giemsa staining and of an assay for detecting antibodies in serum by a commercially available ELISA kit. The patients, totaling 117 (male, 62, female, 55; average age, 51.6 years), included those with peptic ulcer endoscopically diagnosed and excluded cases that were subjected to eradication therapy in the past.

RESULTS

With respect to the determinations of H. pylori identified by the microscopical test and the serum antibody assay, our kit had a sensitivity of 92. 0% and a specificity of 93.1%, and the agreement of determination of H. pylori infection was as high as 91.5% and 92.3%, respectively.

CONCLUSIONS

The rapid test for antibodies to H. pylori in urine could detect H. pylori infection easily, rapidly, and noninvasively and would be useful in general practice for screening patients with dyspeptic symptoms.

Clinical usefulness of urine-based enzyme-linked immunosorbent assay for detection of antibody to Helicobacter pylori: a collaborative study in nine medical institutions in Japan

BACKGROUND

A urine-based enzyme-linked immunosorbent assay (ELISA) kit for detection of antibody to Helicobacter pylori has been developed in Japan. Urine samples can be obtained noninvasively and are easier and safer to handle than are serum samples. The aim of this study was to examine the clinical usefulness of this urine-based ELISA kit.

MATERIALS AND METHODS

A pair of random, single-void urine and serum samples was collected from each of 1,061 subjects, including 238 patients with gastroduodenal disease. The sensitivity and specificity of the urine-based ELISA was compared with those of three commercially available serum-based ELISA kits. For those patients with gastroduodenal disease, the urine- and serum-based ELISA results were also compared with those for other diagnostic methods using endoscopic biopsy specimens, such as culture, histology, and rapid urease tests.

RESULTS

Based on the three serum-based ELISA results, the sensitivity, specificity, and accuracy of the urine-based ELISA were 97.7%, 95.6%, and 96.8%, respectively. On the basis of the biopsy test results, the sensitivity (96.2%), specificity (78.9%), and accuracy (91.0%) of the urine-based ELISA were almost equivalent or superior to all three serum-based ELISAs tested. In addition, 10 of the 12 false-positive cases for urine-based ELISA were confirmed to be true positives for antibodies to H. pylori by Western blot analysis and inhibition ELISA.

CONCLUSIONS

The urine-based ELISA (URINELISA H. pylori Antibody) is very accurate and should be useful as an alternative to serum-based ELISAs for screening of H. pylori infection.

Testing for rubella-specific IgG antibody in urine

BACKGROUND

In Japan rubella vaccination is generally done once during a lifetime, and the vaccination rate decreased after a revised vaccination law in 1995. History of rubella or vaccination may still be unreliable. Testing for rubella antibody is significant to prevent the occurrence of congenital rubella syndrome. However, the collection of blood samples to detect antibodies from young children is invasive and difficult.

METHODS

For this study we obtained 853 matched serum and urine samples from 904 healthy students 10 or 14 years of age in the Ibara and Yoshii districts of Okayama, Japan, for a comparison of antibodies for rubella in the matched samples. The serum and urine antibodies were measured with hemagglutination-inhibition and enzyme-linked immunosorbent assays, respectively, and with our urine-based antibody test.

RESULTS

The sensitivity, specificity and concordance rates of this urine-based antibody test were 96, 99 and 97% based on the serum antibody results of both assays. The coefficiency was 0.627 between the titers of the urinary and serum antibodies by the enzyme-linked immunosorbent assay. The urinary antibodies were stable for at least 5 months at 4 degrees C and 25 degrees C.

CONCLUSIONS

Urine-based assay methods are helpful not only because they avoid the invasive approach of venipuncture but also because unprocessed urine specimens can be used and urinary antibody is stable for a long period. Therefore this test is suitable for screening. In addition protective amounts of rubella antibody in blood can be reliably assessed by means of urine samples.