Multi-laboratory comparison of eight commercially available Helicobacter pylori serology kits. Helicobacter pylori Serology Study Group

Mucosal patterns change after Helicobacter pylori eradication: Evaluation using blue laser imaging in patients with atrophic gastritis

BACKGROUND

Mucosal patterns (MPs) observed on blue laser imaging in patients with atrophic gastritis can be classified as spotty, cracked, and mottled. Furthermore, we hypothesized that the spotty pattern may change to the cracked pattern after Helicobacter pylori (H. pylori) eradication.

AIM

To further substantiate and comprehensively investigate MP changes after H. pylori eradication in a larger number of patients.

METHODS

We included 768 patients who were diagnosed with atrophic gastritis with evaluable MP using upper gastrointestinal endoscopy at the Nishikawa Gas-trointestinal Clinic, Japan. Among them, 325 patients were H. pylori-positive, and of them, 101 patients who underwent upper gastrointestinal endoscopy before and after H. pylori eradication were evaluated for post-eradication MP changes. The patients’ MPs were interpreted by three experienced endoscopists who were blinded to their clinical features.

RESULTS

Among 76 patients with the spotty pattern before or after H. pylori eradication, the pattern disappeared or decreased in 67 patients [88.2%, 95% confidence interval (CI): 79.0%-93.6%), appeared or increased in 8 patients (10.5%, 95%CI: 5.4%-19.4%), and showed no change in 1 patient (1.3%, 95%CI: 0.2%-7.1%). In 90 patients with the cracked pattern before or after H. pylori eradication, the pattern disappeared or decreased in 7 patients (7.8%, 95%CI: 3.8%-15.2%), appeared or increased in 79 patients (87.8%, 95%CI: 79.4%-93.0%), and showed no change in 4 patients (4.4%, 95%CI: 1.7%-10.9%). In 70 patients with the mottled pattern before or after H. pylori eradication, the pattern disappeared or decreased in 28 patients (40.0%, 95%CI: 29.3%-51.7%), appeared or increased in 35 patients (50.0%, 95%CI: 38.6%-61.4%), and showed no change in 7 patients (10.0%, 95%CI: 4.9%-19.2%).

CONCLUSION

After H. pylori eradication, MPs changed from spotty to cracked in most patients, which may help endoscopists easily and precisely evaluate H. pylori-related gastritis status.

Hyperemesis Gravidarum in First-Trimester Pregnant Saudi Women: Is Helicobacter pylori a Risk Factor?

Introduction

Hyperemesis gravidarum (HG) is a serious complication of pregnancy involving nausea and vomiting which affects all facets of the lives of many women. Helicobacter pylori infection has been linked to HG in some regions of the world. However, the prevalence of H. pylori in Saudi Arabian pregnant women and its link to HG has not been the subject of previous research. Detecting and treating H. pylori infection in women early in their pregnancies may lower the likelihood of adverse maternal outcomes. This study aims to assess the connection between the pathogenesis of HG and H. pylori infection in this population.

Methods

Forty-five pregnant women with HG were recruited from the outpatient clinic for antenatal care in the Gynecology and Obstetrics Department at King Abdulaziz University Hospital. Forty-five pregnant women without HG were matched as controls. Both groups underwent testing for the H. pylori antigen in stool samples.

Results

A statistically significant difference (P < 0.05) was observed between the cases and controls in terms of the occurrence of H. pylori. Thirty-eight women in the HG group (84.4%) tested positive for H. pylori, while the same was true of only 20 of the controls (44.4%). The mean level of blood hemoglobin in positive cases was significantly lower than that in negative cases (9.56 ± 1.29 vs. 11.90 ± 1.18 g/dl, P = 0.012).

Conclusion

H. pylori may play a contributing role in the presence of HG in the study population. It may be included with other investigations of HG, especially with cases that do not respond to conventional management and continue into the second trimester. Women with H. pylori were also more likely to suffer from anemia compared to those without the infection. For this reason, those working with pregnant women should pay close attention to those infected with H. pylori. Additional large case–control studies are necessary to better understand the part H. pylori plays and the pathogenesis of HG.

Diagnosis of Helicobacter pylori infection : A short review

Helicobacter pylori infections represent an important factor in the pathogenesis of chronic gastritis, peptic ulcer, MALT lymphoma and gastric adenocarcinoma. The recently published Maastricht V/Florence consensus report indicated that the urea breath test using 13 C urea still remains the best non-invasive test to diagnose H. pylori infections with high sensitivity and specificity. Among the stool antigen tests, the ELISA monoclonal antibody test is a rational option. Effective therapy should be based only on susceptibility testing in regions with documented high clarithromycin resistance (>15%). Advanced high-resolution endoscopic technologies enable increased diagnostic accuracy for detection of H. pylori infections.

The diagnosis and management of H. pylori infection in Singapore

Helicobacter pylori (H. pylori) is an infection that has a role in causing dyspepsia and complications such as peptic ulcer disease and gastric malignancies. In the primary care setting, one can adopt a stepwise approach with the 'test-and-treat' strategy to manage H. pylori-associated dyspepsia in young patients without alarm symptoms. Empiric first-line therapies should be for a two-week duration; options include clarithromycin-containing triple therapy alone or with the addition of bismuth, concomitant therapy and bismuth quadruple therapy. Post-treatment carbon urea breath test must be performed at least four weeks after the end of treatment to confirm the cure. Options for empiric second-line treatment include bismuth quadruple therapy and levofloxacin-containing triple therapy. Patients with persistent or alarm symptoms should be referred for further evaluation. Patients with persistent infection should be referred for gastroscopy so that gastric biopsies can be obtained for H. pylori culture and antibiotic susceptibility testing.

Classification of atrophic mucosal patterns on Blue LASER Imaging for endoscopic diagnosis of Helicobacter pylori-related gastritis: A retrospective, observational study

Background

Atrophic gastritis can be classified according to characteristic mucosal patterns observed by Blue LASER Imaging (BLI) in a medium-range to distant view.

Aims

To facilitate the endoscopic diagnosis of Helicobacter pylori (HP)-related gastritis, we investigated whether atrophic mucosal patterns correlated with HP infection based on the image interpretations of three endoscopists blinded to clinical features.

Methods

This study included 441 patients diagnosed as having atrophic gastritis by upper gastrointestinal endoscopy at Nishikawa Gastrointestinal Clinic between April 1, 2015 and March 31, 2016. The presence/absence of HP infection was not taken into consideration. Endoscopy was performed using a Fujifilm EG-L580NW scope. Atrophic mucosal patterns observed by BLI were classified into Spotty, Cracked and Mottled. Image interpretation results were that 89, 122 and 228 patients had the Spotty, Cracked and Mottled patterns, respectively, and 2 patients an undetermined pattern. Further analyses were performed on 439 patients, excluding the 2 with undetermined patterns.

Results

The numbers of patients testing negative/positive for HP infection in the Spotty, Cracked and Mottled pattern groups were 12/77, 105/17, and 138/90, respectively. The specificity, positive predictive value and positive likelihood ratio for endoscopic diagnosis with positive HP infection based on the Spotty pattern were 95.3%, 86.5% and 8.9, respectively. In all patients with the Spotty pattern before HP eradication, the Cracked pattern was observed on subsequent post-eradication endoscopy.

Conclusions

The Spotty pattern may represent the presence of HP infection, the Cracked pattern, a post-inflammatory change as seen after HP eradication, and the Mottled pattern, intestinal metaplasia.

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.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Comparative evaluation of 29 commercial Helicobacter pylori serological kits

BACKGROUND

Serology is a noninvasive diagnostic method for the detection of Helicobacter pylori infection. Many commercial kits are now on the market. It is necessary to assess their performances to help the user to choose the most appropriate.

MATERIAL AND METHODS

The performances of 29 commercial serological tests detecting antibodies to Helicobacter pylori (17 enzyme-linked immunosorbent assay and 12 near-patient tests) were evaluated using sera from 108 patients prospectively selected from gastroenterology departments of five French hospital centers. These patients were infected (45) or uninfected (47) by H. pylori, or had doubtful results (16), according to the gold standard (culture or histology plus rapid urease test or urea breath test). The tests were evaluated by determining the usual parameters of performance: sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Two analyzes were performed including or not the 16 patients with doubtful infection as uninfected or not analyzed.

RESULTS

Depending on the type of analysis, four or two of the 17 enzyme-linked immunosorbent assay tests presented excellent results with the five performance parameters >90%. Calculation of the Youden index allowed to show significantly better performances for one of the 4. Performances of the 12 near-patient tests were lower with accuracies <90% for all except one test.

CONCLUSION

These data should help the users to choose the kit the most appropriate to their goals.

Helicobacter Pylori "Test-and-Treat" Strategy for Management of Dyspepsia: A Comprehensive Review

OBJECTIVES:

Deciding on whether the Helicobacter pylori test-and-treat strategy is an appropriate diagnostic–therapeutic approach for patients with dyspepsia invites a series of questions. The aim present article addresses the test-and-treat strategy and attempts to provide practical conclusions for the clinician who diagnoses and treats patients with dyspepsia.

METHODS:

Bibliographical searches were performed in MEDLINE using the keywords Helicobacter pylori, test-and-treat, and dyspepsia. We focused mainly on data from randomized controlled trials (RCTs), systematic reviews, meta-analyses, cost-effectiveness analyses, and decision analyses.

RESULTS:

Several prospective studies and decision analyses support the use of the test-and-treat strategy, although we must be cautious when extrapolating the results from one geographical area to another. Many factors determine whether this strategy is appropriate in each particular area. The test-and-treat strategy will cure most cases of underlying peptic ulcer disease, prevent most potential cases of gastroduodenal disease, and yield symptomatic benefit in a minority of patients with functional dyspepsia. Future studies should be able to stratify dyspeptic patients according to their likelihood of improving after treatment of infection by H. pylori.

CONCLUSIONS:

The test-and-treat strategy will cure most cases of underlying peptic ulcer disease and prevent most potential cases of gastroduodenal disease. In addition, a minority of infected patients with functional dyspepsia will gain symptomatic benefit. Several prospective studies and decision analyses support the use of the test-and-treat strategy. The test-and-treat strategy is being reinforced by the accumulating data that support the increasingly accepted idea that “the only good H. pylori is a dead H. pylori”.

Serologic and stool antigen assay of Helicobacter pylori infection in hyperemesis gravidarum: which test is useful during early pregnancy?

OBJECTIVE

To investigate the relationship between Helicobacter pylori infection and hyperemesis gravidarum (HG) during early pregnancy by using serologic and stool antigen tests in developing South Anatolia region of Turkey.

MATERIALS AND METHODS

A prospective cross-sectional study was performed on 40 pregnant women with HG and 40 asymptomatic controls without gastric problems at 7-12 weeks of gestation. The sociodemographic characteristics were recorded. The presence of H pylori was analyzed in the sera of the study-group patients by serology-specific IgG test in serum and by a stool antigen test in fecal samples.

RESULTS

The rates of serology-specific H pylori IgG positivity were 80% (32 of 40) in patients with HG and 35% (14 of 40) in control group. The difference between the two groups was significant [odds ratio: 6.9 (confidence interval: 2.2-22.1); p<0.01]. The rates of H pylori stool antigen test positivity were 87.5% (35 of 40) in patients with HG and 62.5% (25 of 40) in control groups. The difference between the two groups was significant (odds ratio: 4.5, confidence interval: 1.09-18.5); p=0.028.

CONCLUSION

Both serology-specific IgG and stool antigen tests seem to be good screening methods to identify H pylori in our pregnant patient population with HG during early pregnancy.

Detection of Helicobacter pylori in adenotonsillar tissue of children with chronic adenotonsillitis using rapid urease test, PCR and blood serology: a prospective study

OBJECTIVE

Contradictory results have been reported regarding Helicobacter pylori (H. pylori) detection in adenotonsillar tissue. The aims of this study were to investigate whether adenotonsillar tissue of symptomatic children with chronic adenotonsillitis harbors the H. pylori organism, using two biopsy-based invasive methods namely; rapid urease test (RUT) and polymerase chain reaction (PCR) as well as blood serology and to compare the results obtained from each of these methods to the "gold standard".

METHODS

This prospective clinical study was carried out on 20 children aged between 2 and 10 years scheduled for tonsillectomy +/- adenoidectomy in a tertiary referral center. Exclusion criteria included: use of antacids, H(2) blockers or antibiotics during the previous month before surgery and adenotonsillectomy for obstructive sleep apnea. Core biopsy samples from resected adenotonsillar tissue was tested for H. pylori detection using both RUT and PCR assay for the ureC gene. Preoperative patient venous blood samples were also tested for H. pylori IgG antibodies. As a "gold standard", examined tissue was considered to be H. pylori infected if the two biopsy specimen-based methods (RUT and PCR) yielded positive results.

RESULTS

Thirty adenotonsillectomy specimens were tested (20 tonsils and 10 adenoids). RUT was positive in 16 (53.3%) specimens (12 tonsils and 4 adenoids). According to the "gold standard", 11/16 were considered false-positive, yielding this test sensitivity 100% and specificity 56%. The ureC gene sequence was detected by PCR in 5 (16.6%) specimens (3 tonsils and 2 adenoids), all of which were also positive by RUT, thus were considered H. pylori infected. Accordingly, PCR had a 100% sensitivity and specificity. Serology testing was positive for H. pylori IgG antibodies in 4/20 patients (20%), only two of them were found to have H. pylori infected adenotonsillar tissue.

CONCLUSIONS

Based on our findings it seems that adenotonsillar tissue may constitute an extra-gastric reservoir for H. pylori in symptomatic children with chronic adenotonsillitis. RUT was found to be of less accuracy than PCR in H. pylori detection in an extra-gastric location, thus results of previous studies using this test alone for detection of oral H. pylori should be treated with caution.

Concurrent overexpression of serum p53 mutation related with Helicobacter pylori infection

Background & Aims

In the province of Cadiz (Spain), the adjusted mortality rate for gastric cancer in the coastal town of Barbate is 10/100.000 inhabitants, whereas in the inland town of Ubrique, the rate is twice as high. The rate of Helicobacter pylori (H. pylori) infection (H. pylori antibodies) in the normal population was 54% in Ubrique, but only 32% in Barbate. In the two decades since its original discovery, p53 has found a singularly prominent place in our understanding of human gastric cancer and H. pylori cause accumulation of reactive oxygen species in the mucosa compartment. This study was designed to compare serum levels of p53 in a population characterized by high mortality due to stomach cancer and a high prevalence of H. pylori infection and another population in which mortality from this cause and the prevalence of H. pylori infection are low.

Materials and methods

319 subjects from the low mortality population and 308 from the high mortality population were studied, as were 71 patients with stomach cancer. We measured serum immunoglobulin G antibody to H. pylori and serum mutant p53 protein and ceruloplasmin.

Results

The difference between the two populations in the prevalence of H. pylori infection was significant (p < 0.001). Of the seropositive, 81% had elevated values of mutant p53, in comparison with 11% of the seronegative (p < 0.0001). Serum concentration of ceruloplasmin was significantly higher in seropositive with elevated mutant p53 protein than in seronegative with normal levels of p53 (p < 0.05).

Conclusions

There is a significant association between infection with H. pylori, elevated titers of H. pylori antibodies, and positivity for serum mutant p53 protein. Such information can significantly increase our basic knowledge in molecular pathology of gastric cancer and protection against H. pylori infection.

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.

Association of autoimmune type atrophic corpus gastritis with Helicobacter pylori infection

AIM: To study the association between Helicobacter pylori (H. pylori) infection and autoimmune type atrophic gastritis.

METHODS: Twenty-three patients with different grades of atrophic gastritis were analysed using enzyme immunoassay-based serology, immunoblot-based serology, and histology to reveal a past or a present H. pylori infection. In addition, serum markers for gastric atrophy (pepsinogen I, pepsinogen I/II and gastrin) and autoimmunity [parietal cell antibodies (PCA), and intrinsic factor (IF), antibodies] were determined.

RESULTS: Of the 14 patients with severe gastric atrophy, as demonstrated by histology and serum markers, and no evidence for an ongoing H. pylori infection, eight showed H. pylori antibodies by immunoblotting. All eight had elevated PCA and 4/8 also had IF antibodies. Of the six immunoblot-negative patients with severe corpus atrophy, PCA and IF antibodies were detected in four. Among the patients with low to moderate grade atrophic gastritis (all except one with an ongoing H. pylori infection), serum markers for gastric atrophy and autoimmunity were seldom detected. However, one H. pylori negative patient with mild atrophic gastritis had PCA and IF antibodies suggestive of a pre-atrophic autoimmune gastritis.

CONCLUSION: Signs of H. pylori infection in autoimmune gastritis, and positive autoimmune serum markers in H. pylori gastritis suggest an etiological role for H. pylori in autoimmune gastritis.

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.

Relationship between the severity of hepatitis C virus-related liver disease and the presence of Helicobacter species in the liver: A prospective study

AIM: To determine the presence of Helicobacter species DNA in the liver of chronic hepatitis C (CHC) patients with and without cirrhosis as compared to controls, and to identify the bacterial species involved.

METHODS: Seventy-nine consecutive patients (HBV and HIV negative) with a liver sample obtained after liver biopsy or hepatic resection were studied: 41 with CHC without cirrhosis, 12 with CHC and cirrhosis, and 26 controls (HCV negative). Polymerase chain reactions (PCRs) targeting Helicobacter 16S rDNA and species-specific were performed on DNA extracted from the liver. A gastric infection with H pylori was determined by serology and confirmed by ¹³C-urea breath test.

RESULTS: Overall, Helicobacter 16S rDNA was found in 16 patients (20.2%). Although positive cases tended to be higher in CHC patients with cirrhosis (41.6%) than in those without cirrhosis (17.0%) or in controls (15.4%), the difference was not statistically significant (P = 0.08). H pylori-like DNA was identified in 12 cases and H. pullorum DNA in 2, while 2 cases remained unidenti-fied. Gastric infection with H pylori was found in only 2 of these patients.

CONCLUSION: Our results do not confirm the associ-ation of Helicobacter species DNA in the liver of CHC patients with advanced liver disease. The lack of correlation between positive H pylori serology and the presence of H pylori-like DNA in the liver may indicate the presence of a variant of this species.

Association of Helicobacter pylori IgA antibodies with the risk of peptic ulcer disease and gastric cancer

AIM

To compare the prevalence of Helicobacter pylori (H pylori) IgG and IgA antibodies between adult subjects, with defined gastric diseases, non-defined gastric disorders and those representing the population.

METHODS

Data on H pylori IgG and IgA antibodies, determined by enzyme immunoassay, were analyzed in 3,252 subjects with DGD including 482 patients with gastric ulcer, 882 patients with duodenal ulcer, 1,525 patients with chronic gastritis only and 363 subjects with subsequent gastric cancer, 19,145 patients with NoDg and 4,854 POPUL subjects. The age-adjusted prevalences were calculated for 1- and 20-year age cohorts.

RESULTS

The prevalences of IgG antibodies were equally high (89-96%) in all 20-year age cohorts of the DGD groups, whereas the prevalences of IgG antibodies were lower and increased by age in the POPUL and NoDg groups. The prevalences of IgA antibodies were also higher in the DGD groups; among them CA (84-89%) and GU groups (78-91%) showed significantly higher prevalences than DU (68-77%) and CG patients (59-74%) (OR 2.49, 95%CI 1.86-3.34 between the GU and DU groups). In the CA, GU, and DU groups, the IgA prevalences showed only minor variation according to age, while they increased by age in the CG, POPUL, and NoDg groups (P<=0.0001). The IgA response, but not the IgG response, was associated with an increased risk of CA (OR 2.41, 95%CI 1.79-3.53) and GU (OR 2.57, 95%CI 1.95-3.39) in comparison with CG patients.

CONCLUSION

An IgA antibody response during H pylori infection is significantly more common in CA and GU patients as compared with CG patients.

Lack of correlation between Helicobacter pylori infection and autologous serum skin test in chronic idiopathic urticaria

BACKGROUND

There are controversial reports about the direct role of Helicobacterpylori infection in chronic idiopathic urticaria. The indirect role of H. pylori infection in the induction of pathogenetic antibodies is not fully elucidated either. This study aims to reveal the association of H. pylori infection with autologous serum skin test positivity in chronic idiopathic urticaria (CIU) patients.

METHODS

A total of 47 patients (35 women, 12 men, age range 17-65 years) diagnosed as CIU were included in the study. Autologous serum skin test was performed on all patients. The patients were examined with a commercially available ELISA test for H. pylori-specific antibodies. Gastroscopy with mucosal biopsy and rapid urease tests were proposed to verify the presence of H. pylori infection.

RESULTS

Helicobacter pylori infection was detected in 33 of the 47 patients (70%). No significant relation was found between the autologous serum skin test positivity and the serological and histopathological presence of H. pylori infection.

CONCLUSION

The results of our study suggest that chronic H. pylori infection does not appear to have a role in the induction of autoantibodies in CIU.

Is Helicobacter pylori infection a risk factor for acute coronary syndromes?

OBJECTIVES

To elucidate risk factors for acute coronary syndromes (ACS), the present study examined whether Helicobacter pylori infection is a risk factor for patients with ACS.

METHODS

We studied 33 male patients with acute coronary syndromes (ACS). All patients were incidence cases of ACS that they did not have a past history of IHD and were at the first onset of ACS. A control group was consisted of 66 males. Controls were at random selected from outpatients. All controls had normal resting electrocardiogram and had no history of IHD. H. pylori seropositivity was determined by an IgG-specific enzyme linked immunosorbent assay (ELISA). We serologically confirmed the presence of antibodies specific to the antigen CagA of H. pylori, using CagA ELISA.

RESULTS

Seropositive rate of IgG antibodies in patients with ACS was 87.9%. A rate of in controls was 66.7%. After adjustment for age, a statistically significant association was found in H. pylori seropositivity between ACS and controls (OR, 3.74; 95% CI, 1.15-12.13). This relation was also significant after adjusted for potential confounding factors (OR, 4.09; 95% CI, 1.10-15.17). Anti-CagA positive H. pylori were significantly recognized in ACS (adjusted OR, 3.58; 95% CI, 1.08-11.82). However, this significant association was disappeared after adjusted for potential confounding factors (P=0.054).

CONCLUSIONS

We confirmed a significant link between H. pylori infection and ACS. H. pylori infection is likely to be a risk factor for ACS.

Helicobacter pylori serology in a birth cohort of New Zealanders from age 11 to 26

AIM

To determine seroprevalence of Helicobacter pylori (H pylori) in the Dunedin Multidisciplinary Health and Development Study (DMHDS) at age 26 in order to investigate seroconversion and seroreversion from age 11 to 26 and the association of seropositivity with risk factors for H pylori infection.

METHODS

Participants in the DMHDS at age 26 and retrospectively at age 21 were tested for H pylori antibodies using two commercially available ELISA kits. Gender, socioeconomic status (SES), smoking, educational attainment and employment at age 26 were tested for association with H pylori seropositivity.

RESULTS

At ages 21 and 26, seroprevalence of H pylori using one or other kit was 4.2% (n = 795) and 6.3% (n = 871) respectively. Seroreversion rate was lower than seroconversion rate (0.11% vs 0.53% per person-year) in contrast to the period from age 11 to 21 when seroreversion rate exceeded seroconversion rate (0.35% vs 0.11% per person-year). Serology in those tested at ages 11, 21, and 26 remained unchanged in 93.6% of the sample. Seroprevalence at age 26 was lower among those with a secondary school qualification (P = 0.042) but was not associated with gender, SES, smoking or employment status.

CONCLUSION

H pylori seroprevalence in a New Zealand birth cohort remains low between ages 11 and 26. H pylori infection remains stable from childhood to adulthood although seroreversion seems to be more common in the adolescent years than in young adults.

Age-dependent accuracy of Helicobacter pylori antibody assays for adults, with special emphasis on atrophic gastritis

The accuracy of Helicobacter pylori antibody assays for 561 consecutive adult outpatients who had undergone gastroscopy was studied. The sensitivity of an immunoglobulin G test was 99 to 100% for all age groups, but the specificity declined by age group, from 99% for those aged 15 to 49 years to 75% for those aged > or =65 years. The exclusion of false-positive results for patients with atrophic gastritis improved the specificity to 93 to 97% for the older age groups.

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.

Comparison of two different stool antigen tests for the primary diagnosis of Helicobacter pylori infection in turkish patients with dyspepsia

AIM

To assess the reliability of two different enzyme immunoassays in detecting the Helicobacter pylori status in stool specimens of Turkish patients with dyspepsia.

MATERIALS AND METHODS

One hundred and fifty-one patients [74 with nonulcer dyspepsia (NUD), 64 with duodenal ulcer (DU) and 13 with gastric cancer] who were admitted to the endoscopy unit of Istanbul University, Cerrahpasa Medical Faculty for upper gastrointestinal endoscopy because of dyspepsia were enrolled in the study. Helicobacter pylori infection was confirmed in all patients by histology, rapid urease test and culture. A patient was classified as being H. pylori-positive if the culture alone or both the histology and the rapid urease test were positive and as negative only if all of these tests remained negative. Stool samples were obtained from patients to assess the reliability of a monoclonal (FemtoLab H. pylori) and a polyclonal (Premier Platinum HpSA) stool antigen test and to compare the diagnostic accuracies of these two tests. A chi2 test was used for statistical comparisons.

RESULTS

Using cut-off values of 0.19 for FemtoLab H. pylori and 0.16 for Premier Platinum HpSA, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 93%, 90%, 98%, 68% and 93% for the monoclonal test and 84%, 67%, 94%, 40% and 81% for the polyclonal test, respectively. The sensitivity, specificity, negative predictive value and diagnostic accuracy of the monoclonal test were significantly greater than those of the polyclonal test (chi2 = 3.98; p < .05 for sensitivity and chi2 = 15.67; p = .000 for specificity, chi2 = 15.78; p = .000 for negative predictive value and chi2 = 6.37; p = .012 for diagnostic accuracy). The bacterial load did not affect the sensitivity of either test.

CONCLUSIONS

The monoclonal FemtoLab H pylori test, using a cut-off 0.19, is a very sensitive, specific and easy to perform diagnostic tool for the primary diagnosis of H. pylori infection in Turkish patients with dyspepsia.

Association Between Cerebral Ischemia and Cytotoxin-Associated Gene-A–Bearing Strains ofHelicobacter pylori

BACKGROUND AND PURPOSE

Studies on Helicobacter pylori infection and risk of ischemic stroke yielded variable results. Infection with more virulent H. pylori strains, such as cytotoxin-associated gene-A (CagA)-bearing strains, may be of particular relevance for ischemic diseases. We investigated whether H. pylori and CagA seropositivity are independent risk factors for cerebral ischemia or its etiologic subtypes.

METHODS

We determined IgG antibodies against H. pylori and CagA protein (enzyme immunoassays) in 190 patients with acute cerebral ischemia and in 229 age- and sex-matched control subjects selected randomly from the general population.

RESULTS

CagA seropositivity was more common in patients (114/190; 60.0%) than in control subjects (99/229; 43.2%; odds ratio, 1.97; 95% CI, 1.33 to 2.91; P<0.001). This result remained significant after adjustment for age, sex, vascular risk factors and diseases, and childhood and adult social status (odds ratio, 1.84; 95% CI, 1.13 to 3.00; P=0.015). Subgroup analyses yielded similar results in all etiologic stroke subtypes. In contrast, H. pylori seropositivity in general was not associated with increased risk of stroke or its etiologic subtypes.

CONCLUSIONS

Our results support the hypothesis of an association between infection with CagA-positive H. pylori strains and acute cerebral ischemia.

Helicobacter pylori infection in patients with autoimmune thrombocytopenic purpura

AIM: To compare the prevalence of Helicobacter pylori (H pylori) infection in autoimmune thrombocytopenic purpura (AITP) patients with that of nonthrombocytopenic controls, and to evaluate the efficacy of the treatment in H pylori(+) and H pylori(-) AITP patients.

METHODS: The prevalence of gastric H pylori infection in 38 adult AITP patients (29 female and 9 male; median age 27 years; range 18-39 years) who consecutively admitted to our clinic was investagated.

RESULTS: H pylori infection was found in 26 of 38 AITP patients (68.5%). H pylori infection was found in 15 of 23 control subjects (65.2%). The difference in H pylori infection between the 2 groups was not significant. Thrombocyte count of H pylori-positive AITP patients was significantly lower than that of H pylori-negative AITP patients (P < 0.05). Thrombocyte recovery of H pylori-positive group was less than that of H pylori-negative group (P < 0.05).

CONCLUSION: H pylori infection should be considerecd in the treatment of AITP patients with H pylori infection.

Biopsy specimen acquisition in patients with newly diagnosed peptic ulcer disease as determined from a national endoscopic database

BACKGROUND

Eradication of Helicobacter pylori infection decreases peptic ulcer recurrence. Therefore, assessment of Helicobacter pylori status is recommended for patients with newly diagnosed peptic ulcer disease.

METHODS

Data obtained from the Clinical Outcomes Research Initiative's national endoscopic database were analyzed to characterize the acquisition of biopsy specimens in patients with a non-bleeding gastric or duodenal ulcer newly diagnosed by EGD.

RESULTS

Between January 2000 and June 2003, 8299 patients underwent EGD with identification of non-bleeding peptic ulcer disease in the stomach (5390) or the duodenum (2909). Overall, biopsy specimens were obtained from the gastric or duodenal ulcer in 5578 (67%) of these patients. Multivariate analysis identified male gender (odds ratio [OR] 0.75, 95% confidence interval (CI) [0.66-0.85] vs. female), age greater than 75 years (OR 0.67, 95% CI [0.57-0.77] vs. age <55 years), ulcer location (OR 0.53, 95% CI [0.48-0.59] for duodenal vs. gastric ulcers) and endoscopy setting (OR 0.35, 95% CI [0.31-0.39] for academic vs. community; OR 0.36, 95% CI [0.32-0.41] for Veterans Affairs medical centers vs. community) as independent predictors for the acquisition of biopsy specimens (p < 0.001 for all).

CONCLUSIONS

The findings of this study suggest that there is variation in the rates of biopsy specimen acquisition among patients with ulcers who may be at risk for Helicobacter pylori infection. Given the established benefit of Helicobacter pylori eradication, further study is needed to determine whether physicians are diagnosing and treating Helicobacter pylori infection adequately in patients with peptic ulcer.

Are tonsils a reservoir for Helicobacter pylori infection in children?

OBJECTIVE

Helicobacter pylori (H. Pylori) has been associated with the development of gastritis, peptic ulcer and gastric cancer. Although H. pylori infects up to more than half of the world's population, to date the precise modes of transmission has not been fully understood yet. Therefore a study was planned to investigate whether the tonsils and the adenoid tissue were the reservoir or the gate for the entrance of H. pylori.

METHODS

The adenotonsillectomy specimens obtained from 50 children, between two and 10 years of age were examined for H. Pylori colonization by the CLO-test method. Before tonsillectomy, anti-H. pylori IgG antibody titers were detected by commercial enzyme immunoassay method in venous blood and H. pylori antigen enzyme immunoassay for detection of H. pylori in stool was used to define current infection status.

RESULTS

The stool antigen was positive in 25 (50%) of 50 children. Serum IgG antibody was positive in 28 (56%) patients and both tests were positive in 21 (42%) patients. H. pylori positivity was not detected in any one of the adenotonsillectomy specimens with the CLO-test method.

CONCLUSION

In this study although H. pylori was detected in stools of children, it was not detected in adenotonsillectomy specimens with CLO-test method. The results may indicate that H. pylori does not colonize in either adenoid or tonsils and that these tissues do not constitute a reservoir for H. pylori infection.

Does seropositivity for Helicobacter pylori antibodies increase outpatient costs for gastric and duodenal ulcer or inflammation?

BACKGROUND

Helicobacter pylori is regarded as an important cause of both peptic ulcer and chronic gastritis. In particular, seropositivity is highest in patients with duodenal ulcer. No studies have determined whether there are differences in the direct medical costs associated with gastric/duodenal ulcer or inflammation, between seropositive and seronegative patients.

OBJECTIVE

To examine the relationship between seropositivity for H. pylori and outpatient visits and direct medical costs for gastric/duodenal ulcer or inflammation in Japan from the perspective of the payor and patients.

METHODS

Participants were males (n = 653) who worked for an agricultural co-operative in Fukuoka Prefecture, attended an annual health examination (including a written lifestyle and medical survey), belonged to the same health insurance society consistently for 4 years from April 1996 to March 2000, and provided a blood sample. The survey asked about lifestyle, including smoking and drinking, and past medical history. We retrospectively analysed the annual number of outpatient visits per person and outpatient medical cost (Yen, 2000 values) per person for visits relating to gastric or duodenal ulcer or inflammation using International Classification of Diseases (9th edition) -- Clinical Modification codes. We assessed for potential confounding factors using analysis of covariance and the chi-square test.

RESULTS

The annual outpatient incidence of disease, the number of visits to physicians, and the medical costs for gastric or duodenal ulcer or inflammation were about 2-fold greater in individuals with antibodies to H. pylori compared with those without antibodies.

CONCLUSION

Population-based studies and/or randomised controlled clinical trials that target high-risk groups and account for the unique way in which data are collected in Japan are needed to determine whether medical costs for gastric and duodenal ulcer might be reduced by treating asymptomatic patients who have antibodies to H. pylori.

Diagnosis of Helicobacter pylori infection

Numerous studies are still published on diagnostic tests for Helicobacter pylori, essentially for noninvasive tests. The urea breath test is applied in different types of patients, and there are attempts to have quicker and simpler protocols. Stool tests using monoclonal antibodies are now evaluated while serology is still a subject of interest. The progress in PCR (multiplex PCR, real-time PCR) has also stimulated the research in this area of invasive tests, in order to get insight into virulence factors, macrolide susceptibility and to detect H. pylori in nonconventional specimens.

What is the role of serology in assessing Helicobacter pylori eradication?

AIM

To assess the decline in Helicobacter pylori antibodies after eradication of infection.

METHODS

The H. pylori status was determined at entry (D0) by culture and histology performed on antral biopsies and after eradication treatment at day 42 (day 42) and after 6 months (M6) by the 13C-urea breath test. The EIA kits used to determine the anti-H. pylori antibody titre were HM-CAP (immunoglobulin-G) and PP-CAP (immunoglobulin-A) kits (Enteric Products, Inc.) and Pyloriset EIA-G (Orion Diagnostica).

RESULTS

Ninety-three patients were included. For 82 patients who were successfully treated, no kit was sufficiently accurate at D42 to show eradication. The antibody titre decreased for HM-CAP, PP-CAP and Pyloriset EIA-G by a mean of 35.6%, 41.2% and 64.7% between D0 and M6, respectively. According to the cut-off values defined by the manufacturers, 8.5% (PP-CAP, Pyloriset EIA-G) and 9.7% (HM-CAP) of the patients became H. pylori negative at M6. Using a 25% decrease in antibody titre between D0 and M6 as a threshold for H. pylori eradication, specificity was 100% for HM-CAP, 89.9% for Pyloriset EIA-G and 100% for PP-CAP, whereas the sensitivity was 76.8%, 98.8% and 72%, respectively.

CONCLUSION

An antibody titre decrease of 25% at M6 was found to be accurate in confirming H. pylori eradication.

What is the long-term outcome of the different subgroups of functional dyspepsia?

BACKGROUND

Functional dyspepsia is often a long-lasting disorder that accounts for substantial healthcare costs. It has been classified into subgroups assuming that it can guide management of dyspepsia.

AIM

To evaluate the clinical significance of subgrouping functional dyspepsia in a long-term perspective study.

METHODS

Consecutive patients with dyspepsia identified by general practitioners were investigated. Those patients with functional dyspepsia (n=201) were enrolled in this study. Initially, patients were divided into five subgroups (ulcer-like, dysmotility-like, reflux-like, unspecified, and irritable bowel syndrome-like). Patients' medical histories were reviewed after 6-7 years, and the number and outcome of repeated investigations were analysed. At the end of follow-up, patients filled in a questionnaire similar to that at baseline, and were invited for gastroscopy.

RESULTS

Only 2% of patients developed peptic ulcer during follow-up, none of them were in the ulcer-like subgroup. When referrals to hospital and examinations during follow-up were registered, no statistically significant differences existed between subgroups. Patients with reflux-like dyspepsia made fewer revisits than others (P=0.02), but had used antidyspepsia drugs during the previous year more often (P=0.036). Stability of the subgroups over time was poor.

CONCLUSIONS

Functional dyspepsia is a long-lasting disorder with a very good prognosis. Subgroups of functional dyspepsia play only a minor role in prediction of the long-term outcome, and their usefulness in clinical practice is also hampered by subgroup instability over time.

[Helicobacter pylori infection: prospective study for asymptomatic Tunisian children]

The aim of this study was to specify epidemiologic particularities of Helicobacter pylori infection among asymptomatic Tunisian children.

POPULATION AND METHODS

A sample of 191 Tunisian healthy children studied for a two-month-period of time in protection center for mothers and children in a Tunis area. The children had benefited of an oriented questionnaire and a serological study of Helicobacter pylori.

RESULTS

The prevalence of Helicobacter pylori infection was 30.4% (58 of 191). This prevalence increased with age (21% < 5 years vs 69% > 6 years: p < 0.04). The low socio-economic level and the familial antecedents of peptic illness constitute the main risk factors of Helicobacter pylori infection (p < 0.05). Both ways of transmission: oro-oral and fecal-oral seem to coexist among children.

Which test to use to detect Helicobacter pylori infection in patients with low-grade gastric mucosa-associated lymphoid tissue lymphoma?

Helicobacter pylori is involved in the pathogenesis of lymphoma of the gastric mucosa-associated lymphoid tissue (MALT). Because gastric MALT lymphoma is a rare disease, few studies comparing the accuracy of diagnostic tests in this group of patients have been carried out, and only a limited number of tests (essentially histological) were performed. The aim of our study was to compare the results of four different diagnostic methods used to detect H. pylori (histology, culture, polymerase chain reaction, and serology) in a prospective multicenter study. A patient was considered to be H. pylori positive if culture or histology was positive. During the period 1995-2000, a total of 90 patients with low-grade gastric MALT lymphoma were enrolled. Results for the four tests were available for 56 patients (62.2%). Among these patients, the four tests were concordant in 35 cases (62.5%), i.e., were positive in 19 cases (33.9%) and negative in 16 patients (17.8%). Histology (39/40 positive, 97.5%) and serology (38/40 positive, 95.0%) were the most sensitive tests. Polymerase chain reaction (PCR) and culture were positive in 52.5% and 50%, respectively. The cagA gene was detected in 47.4% of the strains.

A simulation to evaluate screening for Helicobacter pylori infection in the prevention of peptic ulcers and gastric cancers

A discrete event simulation model has evaluated a screening programme for Helicobacter pylori infection (H. pylori) in which individuals under the age of 50 years would be screened once. Eradication of H. pylori would reduce the peptic ulcer risk immediately and the gastric cancer risk after a fixed delay. The data were derived from published databases and peer reviewed papers. The simulation model, using variance reduction techniques, predicted that a screening programme would reduce morbidity and deaths but could cost around 19 million pounds for England and Wales in the first year of screening. A factorial design analysis showed the sensitivity of key variables. An increase in the opportunistic testing was found significantly to reduce the impact of screening.

Seroepidemiology of Helicobacter pylori infection in Guadeloupe

854 sera collected from blood donors in Guadeloupe were screened for Helicobacter pylori immunoglobulin G antibodies by a commercial enzyme-linked immunosorbent assay kit. The overall prevalence was 55.2%; it increased significantly with age from 36.1% at 18-19 years to 63.7% at 50-59 years (P = 0.003).

Intrafamilial transmission of Helicobacter pylori: the association between a parent and an offspring with respect to the presence of anti-CagA antibody

In this study, we examined whether the transmission of Helicobacter pylori occurred in married couples. We also examined whether a correlation existed between H. pylori seropositivity in a parent and an offspring, which may be related to H. pylori transmission. A cross-sectional study of residents living in a rural area in Japan was conducted in 1998. The study population consisted of 1910 volunteers, aged from 22 to 79 years, residing in this area. We serologically confirmed the presence of the antigen, CagA (cytotoxin-associated gene A), of H. pylori, using a recombinant CagA antigen, in addition to examining for antibodies to H. pylori, as determined by an IgG-specific enzyme immunoassay. The data were analyzed using logistic regression models. A significant association of H. pylori seropositivity was observed ( P < 0.001) in married couples, but no significant difference with respect to the presence of anti-CagA antibodies was observed in the married couples with H. pylori seropositive results ( P = 0.053). The odds ratio was 8.08 (95% confidence interval [CI], 1.39-40.05) for infection in offspring with seropositive mothers and 2.93 (95% CI, 0.25-33.85) for infection in offspring with seropositive fathers when compared with seronegative fathers or mothers as the reference. There was a concordance between the presence or absence of anti-CagA antibodies in 11 of 13 groups of mothers and offspring (84.6%) compared with concordance in 6 of 14 groups of fathers and offspring (42.9%; P < 0.05). Our results suggest that maternal influence is likely to be more powerful than paternal influence in the transmission of H. pylori.

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.

Identification of novel immunogenic proteins of Helicobacter pylori by proteome technology

Cell surface proteins of the human gastric pathogen Helicobacter pylori, reference strain CCUG 17874, were extracted with acid glycine and fractionated by heparin affinity chromatography. The extracts were subsequently analysed using high-resolution two-dimensional gel electrophoresis (2-DE) and immunoblotting. Four proteins of low molecular masses (25-30 kDa) stained by Coomassie R-350, were identified by peptide ESI-MS/MS sequencing after in-gel tryptic digestion. The identified proteins were recognised by sera from H. pylori-infected patients. Two of them are now described for the first time as immunogenic proteins of which one protein was determined to be distinct from all H. pylori proteins previously described. In addition, the specificity of the identified peptides was evaluated using both 1-D and 2-D immunoblotting against a panel of sera from patients with various bacterial infections. The present identification of highly specific antigens of H. pylori will encourage the improvement of serological diagnostic tests to diagnose and monitor H. pylori infection.

Evaluation of two commercial enzyme immunoassays, testing immunoglobulin G (IgG) and IgA responses, for diagnosis of Helicobacter pylori infection in children

Serological testing to diagnose Helicobacter pylori infection in children is still controversial, although commonly used in clinical practice. We compared the immunoglobulin G (IgG) and IgA results of two commercially available enzyme immunoassays (EIAs) (Pyloriset IgG and IgA and Enzygnost II IgG and IgA) for 175 children with abdominal symptoms divided into three age groups (0 to < or =6 years, n = 47; >6 to < or =12 years, n = 77; >12 years, n = 51). A child was considered H. pylori infected if at least two of three tests (histology, rapid urease test, 13C-urea breath test) or culture were positive and noninfected if all results were concordantly negative. Of 175 children, 93 (53%) were H. pylori negative and 82 were H. pylori positive. With the recommended cutoff values, the overall specificity was excellent for all four EIAs (95.7 to 97.8%) regardless of age. Sensitivity varied markedly between tests and was 92.7, 70.7, 47.5, and 24.4% for Enzygnost II IgG, Pyloriset IgG, Enzygnost II IgA, and Pyloriset IgA, respectively. Sensitivity was low in the youngest age group (25 to 33.3%), except for Enzygnost II IgG (91.6%). Receiver-operating curve analyses revealed that lower cutoff values would improve the accuracy of all of the tests except Enzygnost II IgG. Measurement of specific IgA, in addition to IgG, antibodies hardly improved the sensitivity. The specificity of commercial serological tests is high in children when the cutoff values obtained from adults are used. In contrast, sensitivity is variable, with a strong age dependence in some, but not all, tests. We speculate that young children may have a different immune response to H. pylori, with preferable responses to certain antigens, as well as lower titers than adults. The Pyloriset test may fail to recognize these specific antibodies.

Guidelines in the management of Helicobacter pylori infection in Japan

BACKGROUND

In preparation of the approval of Helicobacter pylori therapy by the Japanese national health system, the board of directors of the Japanese Society for Helicobacter Research decided to prepare guidelines on the diagnosis and treatment of H. pylori infection for physicians in routine medical practice.

METHODS

A guidelines preparation committee was formed and six meetings were held. Then, in December 1999, a consensus meeting was held in Kobe to obtain the opinions of general practitioners as well as experts from Europe, North America, and Asia.

RESULTS

Helicobacter pylori eradication therapy is recommended in gastric or duodenal ulcer patients. Helicobacter pylori eradication therapy is recommended or gastric mucosa associated lymphoid tissue (MALT) lymphoma but it should be done at specialist institutions. The significance of H. pylori eradication therapy is still under evaluation in patients with hyperplastic polyps, chronic atrophic gastritis, non-ulcer dyspepsia and in patients after endoscopic mucosal resection of gastric cancer and after gastrectomy for gastric cancer. When diagnosing H. pylori infection, at least one of the tests requiring endoscopic biopsy (e.g. rapid urease test, histology, or culture) and tests not requiring biopsy (e.g. measurement of H. pylori antibody or urea breath test) should be used. Multiple tests are recommended to increase the accuracy. The drugs of first choice currently covered by the national health insurance system in Japan are: lansoprazole (30 mg) 1 capsule twice daily, amoxicillin (250 mg) 3 capsules twice daily, and clarithromycin (200 mg) 1-2 tablets twice daily. These three drugs should be administered after breakfast and dinner for 1 week.

CONCLUSION

These guidelines are intended for utilization in routine medical practice after the Japanese national health system begins to cover the management of H. pylori infection.

Prevalence of gastric metaplasia in the duodenal bulb is low in Helicobacter pylori positive non-ulcer dyspepsia patients

BACKGROUND

Gastric metaplasia in duodenum is a common phenomena in duodenal ulcer patients. However, the role of gastric metaplasia in patients with non-ulcer dyspepsia is not clear. It is not known either whether Helicobacter pylori infected non-ulcer patients who are CagA-seropositive have gastric metaplasia in duodenum more often than CagA-negative patients.

AIMS

To compare prevalence of gastric metaplasia in duodenum in non-ulcer dyspepsia patients according to Helicobacter pylori status.

PATIENTS AND METHODS

A series of 400 unselected dyspeptic patients in primary care were investigated. Patients with no endoscopic evidence of organic disease (n=236) were enrolled in the study. Duodenal bulb and gastric biopsies were collected, as well as blood samples for Helicobacter pylori determination.

RESULTS

There were no differences between CagA-seropositive and -seronegative Helicobacter pylori infected patients as far as concerns gastric metaplasia in duodenal bulb (20% vs 25%). Helicobacter pylori negative non-ulcer patients more often had gastric metaplastic changes (46%, p<0.0001) in duodenum.

CONCLUSION

Helicobacter pylori infection has no major role in development of gastric metaplasia in duodenal bulb in non-ulcer dyspeptic patients. Furthermore, it does not result in positive CagA-serology, an increased risk for gastric metaplasia compared with CagA-seronegative cases.

Helicobacter pylori infection as an independent risk factor for cerebral ischemia of atherothrombotic origin

Chronic infection may increase the risk for ischemic stroke. Presently, it is insufficiently established whether Helicobacter pylori infection represents a risk factor for ischemic stroke. We analyzed IgG antibodies against H. pylori in 109 patients with acute cerebral ischemia and 82 age- and sex-matched control patients with non-vascular and non-inflammatory neurological diseases. Antibody titers were significantly higher in patients than in control subjects (p=0.007). H. pylori seropositivity tended to be more common in patients (odds ratio (OR) 1.55, 95% confidence interval (ci) 0.87-2.76), but this trend was further attenuated in multivariate analysis (OR 1.42; 95% 0.75-2.67) with hypertension, diabetes mellitus, current or previous smoking, previous cerebral ischemia and low socioeconomic status. H. pylori seropositivity increased the odds for cerebral ischemia of atherothrombotic origin in univariate (OR 3.63; 95% ci 1.37-9.65) and multivariate analysis (OR 3.53; 95% ci 1.09-11.4). H. pylori seropositivity may be an independent risk factor for stroke of atherothrombotic origin.

Helicobacter spp. infection in cats: evaluation of the humoral immune response and prevalence of gastric Helicobacter spp

The principal aims of this study were to evaluate the humoral immune response (IgG) of cats with gastric Helicobacter spp. infection, and to determine the prevalence of different types of Helicobacter spp. in the stomachs of cats. The Helicobacter infection status of 45 cats (12 healthy spay/neuter cats, 9 sick cats, 24 colony cats) was determined by evaluating endoscopic gastric biopsies for urease activity, presence of Helicobacter-like organisms (HLO) on histopathology, and genus and species-specific PCR. Serum samples were evaluated with a kinetic enzyme linked immunosorbent assay (ELISA) utilizing the high molecular cell-associated protein (HM-CAP) fraction of H. felis ATCC 49179.Seventeen of 45 cats were infected with Helicobacter spp.: "H. heilmannii" 9/17, H. felis 4/17, mixed "H. heilmannii" and H. felis 3/17, unclassified-Helicobacter spp. 7/17. H. pylori was not detected in any cat. Kinetic ELISA results were significantly higher for infected cats, than for uninfected cats. Cats infected with different Helicobacter spp. showed similar distribution of OD/min values. There were no effects of age or clinical signs on the results of kinetic ELISA. No correlation between colonization density and seroconversion was observed. There were statistically significant, but weak correlations between the degree of seroconversion and the degree of inflammation, and the number of lymphoid follicles. Infected cats had more severe inflammation in the pylorus and fundus than uninfected cats. Infected sick cats had a higher degree of pyloric, but not fundic inflammation, than healthy infected cats and uninfected sick cats. The results indicate that naturally acquired infection with gastric Helicobacter spp. is associated with seroconversion (IgG) in cats. The similar ELISA values in cats infected with a variety of Helicobacter spp. suggests substantial antigenic homology between different Helicobacter spp. The higher degree of inflammation in infected than uninfected cats, supports a role for Helicobacter as a cause of gastritis in cats.

Diagnosis of Helicobacter pylori infection: noninvasive methods compared to invasive methods and evaluation of two new tests

OBJECTIVES

Current guidelines recommending Helicobacter pylori eradication treatment without performing endoscopy in certain patients highlight the importance of noninvasive tests. Our aim was to determine the accuracy of two new tests: the antigen stool test and Helicoblot 2.1 (an immunoblot used on serum) as well as the 13C urea breath test and ELISA serology in comparison to invasive tests for the pretreatment diagnosis of H. pylori infection.

METHODS

Helicobacter pylori infection was diagnosed prospectively in 104 untreated patients using eight different tests. Invasive tests included culture, urease test (CLOtest), histology, and PCR; noninvasive tests included the 13C urea breath test, IgG serology (Pyloriset EIA-G), immunoblot (Helicoblot 2.1), and antigen stool detection (Premier Platinum HpSA). A predefined gold standard based on biopsy tests was used to define H. pylori status, as well as an empirical approach.

RESULTS

There was no statistically significant difference between the different tests. The sensitivity of the noninvasive tests ranged between 88.9% and 95.6% (stool test: 88.9%, 95% CI: 82.7-95.1, and Helicoblot 2.1: 95.6%, 95% CI: 91.5-99.6) and the specificity ranged between 92.6 and 98.1% (stool test: 94.4%, 95% CI: 84.6-98.8, and Helicoblot 2.1: 92.6%, 95% CI: 91.5-96.2) when a predefined gold standard was used.

CONCLUSIONS

Most tests had sensitivities, specificities, and predictive values >90%. The noninvasive tests are accurate for the diagnosis of H. pylori infection. Helicoblot 2.1 performed as well as the best ELISA kit. The HpSA is a promising direct noninvasive test that can be applied easily to evaluate H. pylori status.