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

Association between dental caries and Helicobacter pylori infection in Japanese adults: A cross-sectional study

Helicobacter pylori (H. pylori) is widely known as a cause of gastric disorders. Presence of H. pylori in dental pulp has been reported. Dental caries may influence the presence or absence of systemic H. pylori infection by serving as a source of H. pylori. In this cross-sectional study, we examined whether H. pylori infection in blood were associated with dental caries in Japanese adults. The participants were 752 individuals (513 males and 239 females, mean age 53.8 years) who underwent both H. pylori testing (H. pylori antibody test and pepsinogen test) and dental checkups at the Asahi University Hospital Human Health Center between April 2018 and March 2019. Those diagnosed as positive for H. pylori antibody test or positive for serum pepsinogen test as H. pylori test in the human health checkup were judged as those with H. pylori infection in the blood. In our study, 83 participants (11%) were determined to be infected with H. pylori in the blood. The proportion of those with decayed teeth was higher in participants with H. pylori infection in blood than in those without H. pylori infection in blood (p< 0.001). The logistic analysis showed that presence of H. pylori infection in blood was positively associated with those with decayed teeth (OR, 5.656; 95% CI, 3.374 to 9.479) after adjusting for age, gender, gastric disease, regular dental checkups, antibiotic medication history, and decayed teeth. Furthermore, the proportion of H. pylori infection in blood increased according to number of decayed teeth (p< 0.001). The results indicate that H. pylori infection in blood were associated with decayed teeth. Untreated dental caries may have an impact on systemic H. pylori infection.

<p>Observation of Changes in <em>Helicobacter pylori</em> Antigen and Antibody Positivity According to Non-Invasive Tests Before and After <em>Helicobacter pylori</em> Eradication Therapy in Symptomatic Patients</p>

Background

Non-invasive tests can help with the diagnosis of Helicobacter pylori (H. pylori) infection and in determining patient prognosis following H. pylori eradication therapy. The aim of the study was to detect H. pylori antigens in the stool in symptomatic patients and to observe changes in the antigen test results following H. pylori eradication therapy.

Methods

A prospective study was conducted. Blood, urine and stool samples were collected from 62 dyspeptic patients. Anti-H. pylori IgM and IgG antibodies were detected in the serum by ELISA, anti-H. pylori IgG antibodies were detected in the urine by ICT and H. pylori antigens were detected in the stool by ELISA. Among the 62 patients, 39 (62.90%) were positive with all three methods. These 39 patients were asked to complete a 2-week course of medication and return after 6 weeks following completion of therapy to undergo repeated tests. In total, 3 dropped out of the study.

Results

Among the 62 dyspeptic patients, 41 (66.13%) were positive for serum IgG according to ELISA, 39 (62.90%) were positive for urine IgG according to ICT, 8 (12.90%) were positive for serum IgM according to ELISA, and 42 (67.74%) were positive for HpSA according to ELISA. After eradication therapy, 18 (50.00%) patients were positive for serum IgG, 19 (52.78%) were positive for urine IgG, 4 (11.11%) were positive for serum IgM and 5 (13.88%) were positive for HpSA. The difference in HpSA positivity before and after eradication therapy was statistically significant (P <0.05).

Conclusion

This study involved non-invasive procedures that can be used as first-line screening tools for the detection of active H. pylori infection to observe the role of HpSA test in diagnosis and assessment of prognosis following eradication therapy for H. pylori.

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.

Guidelines for the management of Helicobacter pylori infection in Japan: 2016 Revised Edition

BACKGROUND

Since "Helicobacter pylori (H. pylori) infection" was set as the indication in the Japanese Society for Helicobacter Research (JSHR) Guidelines 2009, eradication treatment for H. pylori gastritis is covered under insurance since 2013 in Japan, and the number of H. pylori eradication has rapidly increased. Under such circumstances, JSHR has made the third revision to the "Guidelines for diagnosis and treatment of H. pylori infection" for the first time in 7 years.

METHODS

The Guideline Committee held 10 meetings. Articles published between the establishment of the 2009 Guidelines and March 2016 were reviewed and classified according to the evidence level; the statements were revised on the basis of this review. After inviting public comments, the revised statements were finalized using the Delphi method.

RESULTS

There was no change in the basic policy that H. pylori infectious disease is an indication for eradication. Other diseases presumed to be associated with H. pylori infection were added as indications. Serum pepsinogen level, endoscopic examination, and X-ray examination were added to the diagnostic methods. The effects of 1-week triple therapy consisting of potassium-competitive acid blocker (P-CAB), amoxicillin, and clarithromycin have improved, and high eradication rates can also be expected with proton pump inhibitors (PPI) or P-CAB combined with amoxicillin and metronidazole. If the susceptibility test is not performed, the triple PPI or P-CAB/amoxicillin/metronidazole therapy should be chosen, because the PPI/amoxicillin/metronidazole combination demonstrated a significantly higher eradication rate than PPI/amoxicillin/clarithromycin. In the proposal for gastric cancer prevention, we divided gastric cancer prevention measures by age from adolescent to elderly, who are at an increased gastric cancer risk, and presented measures for gastric cancer prevention primarily based on H. pylori eradication.

CONCLUSION

We expect the revised guidelines to facilitate appropriate interventions for patients with H. pylori infection and accomplish its eradication and prevention of gastric cancer.

Application of convolutional neural networks for evaluating Helicobacter pylori infection status on the basis of endoscopic images

BACKGROUND AND AIM

We recently reported the role of artificial intelligence in the diagnosis of Helicobacter pylori (H. pylori) gastritis on the basis of endoscopic images. However, that study included only H. pylori-positive and -negative patients, excluding patients after H. pylori-eradication. In this study, we constructed a convolutional neural network (CNN) and evaluated its ability to ascertain all H. pylori infection statuses.

METHODS

A deep CNN was pre-trained and fine-tuned on a dataset of 98,564 endoscopic images from 5236 patients (742 H. pylori-positive, 3649 -negative, and 845 -eradicated). A separate test data set (23,699 images from 847 patients; 70 positive, 493 negative, and 284 eradicated) was evaluated by the CNN.

RESULTS

The trained CNN outputs a continuous number between 0 and 1 as the probability index for H. pylori infection status per image (Pp, H. pylori-positive; Pn, negative; Pe, eradicated). The most probable (largest number) of the three infectious statuses was selected as the 'CNN diagnosis'. Among 23,699 images, the CNN diagnosed 418 images as positive, 23,034 as negative, and 247 as eradicated. Because of the large number of H. pylori negative findings, the probability of H. pylori-negative was artificially re-defined as Pn -0.9, after which 80% (465/582) of negative diagnoses were accurate, 84% (147/174) eradicated, and 48% (44/91) positive. The time needed to diagnose 23,699 images was 261 seconds.

CONCLUSION

We used a novel algorithm to construct a CNN for diagnosing H. pylori infection status on the basis of endoscopic images very quickly.

ABBREVIATIONS

H. pylori: Helicobacter pylori; CNN: convolutional neural network; AI: artificial intelligence; EGD: esophagogastroduodenoscopies.

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.

Deep learning analyzes Helicobacter pylori infection by upper gastrointestinal endoscopy images

BACKGROUND AND STUDY AIMS

Helicobacter pylori (HP)-associated chronic gastritis can cause mucosal atrophy and intestinal metaplasia, both of which increase the risk of gastric cancer. The accurate diagnosis of HP infection during routine medical checks is important. We aimed to develop a convolutional neural network (CNN), which is a machine-learning algorithm similar to deep learning, capable of recognizing specific features of gastric endoscopy images. The goal behind developing such a system was to detect HP infection early, thus preventing gastric cancer.

PATIENTS AND METHODS

 For the development of the CNN, we used 179 upper gastrointestinal endoscopy images obtained from 139 patients (65 were HP-positive: ≥ 10 U/mL and 74 were HP-negative: < 3 U/mL on HP IgG antibody assessment). Of the 179 images, 149 were used as training images, and the remaining 30 (15 from HP-negative patients and 15 from HP-positive patients) were set aside to be used as test images. The 149 training images were subjected to data augmentation, which yielded 596 images. We used the CNN to create a learning tool that would recognize HP infection and assessed the decision accuracy of the CNN with the 30 test images by calculating the sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve (AUC).

RESULTS

 The sensitivity and specificity of the CNN for the detection of HP infection were 86.7 % and 86.7 %, respectively, and the AUC was 0.956.

CONCLUSIONS

 CNN-aided diagnosis of HP infection seems feasible and is expected to facilitate and improve diagnosis during health check-ups.

Application of Convolutional Neural Networks in the Diagnosis of Helicobacter pylori Infection Based on Endoscopic Images

BACKGROUND AND AIMS

The role of artificial intelligence in the diagnosis of Helicobacter pylori gastritis based on endoscopic images has not been evaluated. We constructed a convolutional neural network (CNN), and evaluated its ability to diagnose H. pylori infection.

METHODS

A 22-layer, deep CNN was pre-trained and fine-tuned on a dataset of 32,208 images either positive or negative for H. pylori (first CNN). Another CNN was trained using images classified according to 8 anatomical locations (secondary CNN). A separate test data set (11,481 images from 397 patients) was evaluated by the CNN, and 23 endoscopists, independently.

RESULTS

The sensitivity, specificity, accuracy, and diagnostic time were 81.9%, 83.4%, 83.1%, and 198s, respectively, for the first CNN, and 88.9%, 87.4%, 87.7%, and 194s, respectively, for the secondary CNN. These values for the 23 endoscopists were 79.0%, 83.2%, 82.4%, and 230±65min (85.2%, 89.3%, 88.6%, and 253±92min by 6 board-certified endoscopists), respectively. The secondary CNN had a significantly higher accuracy than endoscopists (by 5.3%; 95% CI, 0.3-10.2).

CONCLUSION

H. pylori gastritis could be diagnosed based on endoscopic images using CNN with higher accuracy and in a considerably shorter time compared to manual diagnosis by endoscopists.

A significant increase in the pepsinogen I/II ratio is a reliable biomarker for successful Helicobacter pylori eradication

Background

Helicobacter pylori (H. pylori) eradication is usually assessed using the ¹³C-urea breath test (UBT), anti-H. pylori antibody and the H. pylori stool antigen test. However, a few reports have used pepsinogen (PG), in particular, the percentage change in the PG I/II ratio. Here, we evaluated the usefulness of the percentage changes in serum PG I/II ratios for determining the success of eradication therapy for H. pylori.

Materials and methods

In total, 650 patients received eradication therapy from October 2008 to March 2013 in our Cancer Institute Hospital. We evaluated the relationship between H. pylori eradication and percentage changes in serum PG I/II ratios before and 3 months after treatment with CLEIA^® (FUJIREBIO Inc, Tokyo, Japan). The gold standard of H. pylori eradication was defined as negative by the UBT performed 3 months after completion of eradication treatment. Cut-off values for percentage changes in serum PG I/II ratios were set as +40, +25 and +10% when the serum PG I/II ratio before treatment was below 3.0, above 3.0 but below 5.0 and 5.0 or above, respectively.

Results

Serum PG I and PG II levels were measured in 562 patients with H. pylori infection before and after eradication therapy. Eradication of H. pylori was achieved in 433 patients studied (77.0%). The ratios of first, second, third-line and penicillin allergy eradication treatment were 73.8% (317/429), 88.3% (99/112), 75% (12/16) and 100% (5/5), respectively. An increasing percentage in the serum levels of the PG I/II ratios after treatment compared with the values before treatment clearly distinguished success from failure of eradication (108.2±57.2 vs. 6.8±30.7, p<0.05). Using the above cut-off values, the sensitivity, specificity and validity for determination of H. pylori were 93.1, 93.8 and 93.2%, respectively.

Conclusion

In conclusion, the percentage changes in serum PG I/II ratios are useful as evaluation criteria for assessing the success of eradication therapy for H. pylori.

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.

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.

Assessment of methods for detection of Helicobacter pylori in animal models

Helicobacter pylori (H. pylori) is a major risk factor for chronic gastritis and peptic ulcer and is closely related to the occurrence of gastric cancer and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Rational use of animal models is very helpful for the clinical and preclinical investigation of H. pylori. However, the methods for detection of H. pylori in animal models were less reported. Most of the reported methods require the animal to be executed, and those not requiring killing the animal were less developed. This review will introduce seven methods for detection of H. pylori in animal models. These methods can meet the requirements for appropriate and accurate detection of H. pylori in different investigation conditions.

Introduction of an examination and treatment for Helicobacter pylori infection in high school health screening

BACKGROUND

Recently, a significant relationship between gastric cancer and Helicobacter pylori infection has been proven. The purpose of this study was to elucidate the actual conditions of H. pylori infection in Japanese teenagers.

METHODS

The study subjects were students at a certain high school between 2007 and 2009. They were first examined with a urinary rapid test kit based on immunochromatographic technology [corrected] for detection of the antibody to H. pylori (RAPIRAN®). [corrected]. Students who tested positive on this screening examination visited Shinshu University Hospital and received esophagogastroduodenoscopy, and biopsy samples were taken to examine their H. pylori status. The resolution of H. pylori infection was assessed by urea breath test.

RESULTS

For 3 years, 1,224 of 1,232 students (99.4%) received a screening examination for H. pylori infection. Sixty-four of these 1,224 students (5.2%) were found to be positive for H. pylori. Thirty of these 64 H. pylori-positive students visited our hospital, and 24 of them (80%) were confirmed to be infected by H. pylori. The most common endoscopic findings for students with H. pylori infection were nodular gastritis (58.3%) and closed-type atrophic gastritis (45.8%). Histological findings showed no evidence of intestinal metaplasia, except in one of the students. All 24 students were successfully cured of H. pylori infection. If this procedure were to be introduced into the nationwide health screening at Japanese high schools, we calculated that the cost of the prevention of a gastric cancer would be 454,073 yen for each person.

CONCLUSIONS

The low rate of prevalence of H. pylori infection in Japanese teenagers would make it possible to perform examinations and carry out treatment for this infection in high school health screenings from the standpoint of medical economy.

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.

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.

Presence and gradual disappearance of filaria-specific urinary IgG4 in babies born to antibody-positive mothers: a 2-year follow-up study

A total of 14 Sri Lankan pregnant women, who were anti-Brugia pahangi urinary IgG4 positive, and their 14 newborn babies were followed up for the urinary antibody for 2 years by enzyme-linked immunosorbent assay. Eight babies showed positive IgG4 reaction, at least once within 4 months after birth. Urinary antibody titers of mothers and their babies measured around the perinatal period showed a significant positive correlation, suggesting that baby's IgG4 was transferred from the mother through the placenta. The IgG4 decreased gradually and became negative in all positive babies by day 339.3 after birth. The present result provides a basis to judge if a positive urine ELISA test among babies is due to a new filarial infection.

Utility of diagnostic tests for detection of Helicobacter pylori in children in northeastern Mexico

BACKGROUND

The presence of Helicobacter pylori in pediatric population has been associated with recurrent abdominal pain (RAP), although this association is unclear. One of the major problems in studying the role of H. pylori in RAP is that methods used to detect the bacteria in children have poor sensitivity and specificity. The aims of the present study were to determine the prevalence of H. pylori in pediatric patients with RAP in northeastern Mexico and to assess the diagnostic utility of invasive tests and serology in this population.

METHODS

A total of 40 patients (mean age, 7.9 years; range 2-16 years; F: M, 0.81), who underwent an endoscopy procedure for RAP, were studied. The presence of H. pylori was assessed using invasive diagnostic tests (culture, rapid urease test, polymerase chain reaction and histology) and one non-invasive test: determination of IgG antibodies. The prevalence of H. pylori in the present group and the diagnostic utility for each test were evaluated.

RESULTS

The prevalence of H. pylori in the present pediatric group with RAP was 12.5-42.5% depending on the criteria of positivity used. The non-invasive methods (serology) had acceptable values in sensitivity and specificity in comparison with invasive tests.

CONCLUSIONS

This is the first report on prevalence of H. pylori in pediatric patients with RAP from the northeastern region of Mexico. The prevalence of H. pylori was low compared with the adult population in the same geographic region. Serology had the best diagnostic utility.

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.

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.

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.

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.

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.

Immunological rapid urease test using monoclonal antibody for Helicobacter pylori

BACKGROUND AND AIM

The current diagnostic methods for detecting Helicobacter pylori infection include rapid urease test (RUT), urea breath test (UBT), histology, culture, and serum antibody detection. The present study evaluated the efficacy of a novel highly specific test, an immunological RUT (IRUT), that uses a monoclonal antibody against H. pylori urease.

METHODS

The clinical evaluation of the IRUT was performed in 100 subjects. Each gastric mucus sample obtained during endoscopic examination was incubated for 15 min with a solid tip coated with monoclonal antibody for H. pylori urease, and then the tip was introduced into a pH-monitoring cell containing urea solution. The change in pH of the solution after the enzymatic reaction (delta pH) was measured. The performance of the IRUT was compared with culture, histology, RUT, and UBT.

RESULTS

Of the 47 H. pylori-positive subjects, 43 were IRUT positive (sensitivity, 91.5%), and of the 53 H. pylori-negative subjects, 52 were negative (specificity, 98.1%). Compared with the usual diagnostic methods, IRUT had high sensitivity and specificity for the detection of H. pylori and was no less efficient.

CONCLUSIONS

IRUT is a sensitive, specific and very rapid (within 20 min) method of detecting H. pylori infection.

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.

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.

Pathogenesis and therapy of gastric and duodenal ulcer disease

Despite the decreasing frequency of Helicobacter pylori-induced peptic ulcers, peptic ulcer disease remains a major clinical problem partly because nonsteroidal anti-inflammatory drug ulcers have increased in frequency. The reduction in nonsteroidal anti-inflammatory drug ulcers by use of selective cyclooxygenase-2 inhibitors will not eliminate the problem because of increased use of aspirin for cardiovascular prophylaxis. This article reviews current concepts of peptic ulcer pathogenesis and therapy according to ulcer etiology; discusses potential interactions between etiologies; and considers the therapy for H pylori infection including the effects of antimicrobial resistance, and the role of bismuth quadruple therapy or furazolidone salvage therapy.

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.

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.

Shared antigenicity between Helicobacter pylori and periodontopathic Campylobacter rectus strains

Periodontopathic Campylobacter rectus strains possess 41- and 68-kDa proteinaceous antigens which share antigenicity with antigens of Helicobacter pylori strains. H. pylori strains have a 54-kDa antigen which reacts with C. rectus strains. We found that the salivary IgA levels against H. pylori were correlated with those against C. rectus. These cross-reactive antigens of C. rectus may affect the serological diagnosis of H. pylori infections, especially when saliva is used. It is possible that these cross-reacting antigens may relate to the induction of immunopathological responses against both microorganisms.