Comparison of biopsy and serological methods of diagnosis of Helicobacter pylori infection and the potential role of antibiotics

Helicobacter Pylori Infection Is Associated with Neurodegeneration in Cognitively Normal Men

BACKGROUND

An association between Helicobacter pylori (H. pylori) infection and dementia was reported in previous studies; however, the evidence is inconsistent.

OBJECTIVE

In the present study, the association between H. pylori infection and brain cortical thickness as a biomarker of neurodegeneration was investigated.

METHODS

A cross-sectional study of 822 men who underwent a medical health check-up, including an esophagogastroduodenoscopy and 3.0 T magnetic resonance imaging, was performed. H. pylori infection status was assessed based on histology. Multiple linear regression analyses were conducted to evaluate the relationship between H. pylori infection and brain cortical thickness.

RESULTS

Men with H. pylori infection exhibited overall brain cortical thinning (p = 0.022), especially in the parietal (p = 0.008) and occipital lobes (p = 0.050) compared with non-infected men after adjusting for age, educational level, alcohol intake, smoking status, and intracranial volume. 3-dimentional topographical analysis showed that H. pylori infected men had cortical thinning in the bilateral lateral temporal, lateral frontal, and right occipital areas compared with non-infected men with the same adjustments (false discovery rate corrected, Q < 0.050). The association remained significant after further adjusting for inflammatory marker (C-reactive protein) and metabolic factors (obesity, dyslipidemia, fasting glucose, and blood pressure).

CONCLUSION

Our results indicate H. pylori infection is associated with neurodegenerative changes in cognitive normal men. H. pylori infection may play a pathophysiologic role in the neurodegeneration and further studies are needed to validate this association.

Helicobacter pylori Infection and the Development of Advanced Colorectal Neoplasia

BACKGROUND

An association between Helicobacter pylori infection and colorectal neoplasia has been reported in cross-sectional studies.

GOALS

We examined the association between H. pylori infection and the development of advanced colorectal neoplasia (AN) in a screening cohort.

STUDY

We identified 3753 adults, who underwent screening and subsequent surveillance colonoscopies. The primary outcome was the development of metachronous AN, as confirmed by surveillance colonoscopy. H. pylori infection status was assessed by an H. pylori-specific immunoglobulin G antibody test. Sensitivity analysis was also performed by H. pylori infection status on the basis of histology.

RESULTS

During a median follow-up of 41 months, the incidence of AN was 3.2% and 1.7% in participants with and without H. pylori infection, respectively. In multivariable analysis adjusted for age, body mass index, smoking status, alcohol intake, family history of colorectal cancer, and baseline adenoma characteristics, the hazard ratio [95% confidence interval (CI)] for metachronous AN was 1.74 (1.11-2.73) in participants with H. pylori seropositivity, compared with those without H. pylori seropositivity. The association was consistent with H. pylori infection status on the basis of histology (adjusted hazard ratio, 3.51; 95% CI, 1.64-7.51). In the subgroup analysis, the positive association was observed in both no-adenoma and adenoma removal subgroups.

CONCLUSIONS

In a cohort study, H. pylori infection was associated with an increased risk of AN development. This association was consistent in both the serological and histologic assessment of H. pylori infection. Prospective studies are necessary to determine whether H. pylori eradication can reduce the risk of colorectal neoplasia.

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.

A multicenter prospective study on the prevalence of Helicobacter pylori-negative and nonsteroidal anti-inflammatory drugs-negative idiopathic peptic ulcers in Japan

BACKGROUND AND AIM

The prevalence of Helicobacter pylori-negative and nonsteroidal anti-inflammatory drug-negative peptic ulcers, commonly known as idiopathic peptic ulcers (IPUs), has been reported to be very low (0.9-2.6%) in Japan based on data from the 1990s. However, recent trends have yet to be been reported. Herein, we present a multicenter prospective analysis between 2012 and 2013 investigating current trends in the prevalence and characteristics of IPUs in Japan.

METHODS

Clinical data of all peptic ulcer subjects detected via endoscopy at four participating hospitals were prospectively collected between April 2012 and March 2013. Enrolled subjects were classified according to H. pylori infection status and intake of nonsteroidal anti-inflammatory drugs. Multiple logistic regression analyses were used to determine the risk factors for IPUs.

RESULTS

Of 382 enrolled patients with peptic ulcers, 46 (12%) were judged to have IPUs. Compared with those with simple H. pylori-positive ulcers, patients with IPUs were significantly older (P < 0.02) and more often had underlying comorbidities such as hypertension (P < 0.02) and hyperlipidemia (P < 0.05). Multivariate regression analysis indicated that the presence of multiple underlying diseases was the only significant risk factor for IPUs, with an odds ratio of 3.8 (95% confidence interval, 1.3-11.1).

CONCLUSIONS

This study revealed that the prevalence of IPUs in patients with peptic ulcers in Japan is 12%, much higher than previously reported. Presence of multiple underlying comorbid diseases, rather than aging itself, is an important risk factor for IPUs.

Non-Invasive Diagnosis of Helicobacter pylori: Evaluation of Two Enzyme Immunoassays, Testing Serum IgG and IgA Response in the Anand District of Central Gujarat,India

CONTEXT

Validation of an accurate and less cumbersome noninvasive method to detect current Helicobacter pylori infection is a requisite for any laboratory.

OBJECTIVES

The purpose of this study is to corroborate the usefulness of two commercially available kits NovaTec ELISA-A and ELISA-G, in the detection of ongoing H.pylori infection.

MATERIALS AND METHODS

Two hundred and twenty eight consecutive serum samples of symptomatic patients who attended the endoscopy unit of "Deep" surgical hospital, Anand, which were collected during the period from 27th February 2008 to 31st august 2011, were studied. The sera were processed and tested for the detection of the H.pylori IgG and IgA antibody by using a solid phase; capture micro well ELISA, procured from Nova Tec immunodiagnostica GmbH Germany.

RESULTS

IgG ELISA showed 100% sensitivity and Negative predictive value (NPV), while IgA ELISA was better in terms of specificity (61.4%) and accuracy (63%) as compared to IgG ELISA. We found 7% (16/228) of IgA positive cases with IgG negative response. IgG response was more common in reflux esophagitis patients (OR 1.451, 95%CI-0.850-2.477) and then in gastritis (OR 0.962, 95%CI-0.570-1.621) and duodenitis(OR-0.806, 95%CI-0.112-5.827), while IgA positive response was more common in duodenitis patients (OR-1.383, 95%CI-0.191-9.995) and reflux esophagitis patients (OR 1.289, 95% CI-0.756-2.197) and least in duodenal ulcer patients (OR 0.670, 95%CI-0.222-2.029).

CONCLUSION

IgG update is reliable and accurate test and can be expedient as a screening test and thus serve as an alternative to endoscopy. For the purpose of excluding infection with H.pylori, the performance of IgG is moderate (low specificity) but can be improved by conjunctional IgA testing which will offer some additional diagnostic value.

Helicobacter pylori-negative, non-steroidal anti-inflammatory drug: Negative idiopathic ulcers in Asia

Since the discovery of Helicobacter pylori (H. pylori) infection in the stomach, the bacteria infection and non-steroidal anti-inflammatory drugs (NSAIDs) use had been considered to be the 2 main causes of peptic ulcers. However, there have been recent reports of an increase in the proportion of peptic ulcers without these known risk factors; these are termed idiopathic peptic ulcers. Such trend was firstly indicated in 1990s from some reports in North America. In Asia, numerous studies reported that idiopathic ulcers accounted for a small percentage of all ulcers in the 1990s, but in the 2000s, multiple studies reported that the proportion of idiopathic ulcers had reached 10%-30%, indicating that the incidence of idiopathic ulcers in Asia has also been rising in recent years. While a decline in H. pylori infection rates of general population in Asia is seen as the main reason for the increased incidence of idiopathic ulcers, it is also possible that the absolute number of idiopathic ulcer cases has increased. Advanced age, serious systemic complication, and psychological stress are considered to be the potential risk factors for idiopathic ulcers. Management of idiopathic ulcers is challenging, at present, because there is no effective preventative measure against recurrence in contrast with cases of H. pylori-positive ulcers and NSAIDs-induced ulcers. As it is expected that H. pylori infection rates in Asia will decline further in the future, measures to treat idiopathic ulcers will also likely become more important.

Association between metabolic syndrome and Helicobacter pylori infection diagnosed by histologic status and serological status

GOALS

We aimed to simultaneously evaluate the association between metabolic syndrome and Helicobacter pylori (HP) infection diagnosed histologically and serologically in a large number of healthy Korean adults.

BACKGROUND

Serological positivity for HP does not necessarily indicate current infection. No study to date has compared the association between metabolic syndrome and HP infection diagnosed by histologic and serological status.

STUDY

HP status was ascertained histologically and serologically in healthy Korean adults who underwent comprehensive health screening in a private health screening center in Korea. Metabolic syndrome was defined according to the International Diabetes Federation definition. Multivariate logistic analyses were performed, after adjusting for potential confounders, including age, sex, smoking, alcohol consumption, and income level.

RESULTS

A total of 5889 subjects were included in the analysis. The metabolic syndrome was more strongly associated with histologic positivity for HP [adjusted odds ratio (aOR)=1.26; 95% confidence interval (CI), 1.08-1.48] than serologic positivity (aOR=1.12, 95% CI, 0.95-1.32), after adjusting for age, sex, smoking status, alcohol consumption, and economic status.

CONCLUSIONS

The stronger association between metabolic syndrome and histologic positivity than serological positivity suggests that the effects of HP infection on the pathogenesis of cardiometabolic outcomes may be reversible. Further prospective studies are needed.

Non-invasive testing for Helicobacter pylori in patients hospitalized with peptic ulcer hemorrhage: a cost-effectiveness analysis

PURPOSE

Guidelines recommend routine invasive screening for Helicobacter pylori in patients with peptic ulcer hemorrhage (PUH). However, compliance with screening remains suboptimal. The aim of this study was to determine if a simplified approach based on noninvasive screening is cost effective in PUH.

RESULTS

In the base case, post-endoscopy urea breath test (UBT) dominated the invasive testing with 34 fewer hemorrhages and cost savings of $406,600 in a cohort of 10,000 patients. When compliance with invasive testing decreases to 60%, post-endoscopy UBT leads to 109 fewer hemorrhages and cost savings of $1,089,600. The invasive strategy becomes the preferred choice if the sensitivity of UBT reduces to <75%, such as in patients taking proton-pump inhibitors (PPI) before hospitalization.

CONCLUSIONS

Post-endoscopy UBT is cost effective in PPI-naïve patients presenting with PUH. This strategy, once prospectively validated, can prove to be a preferred approach in institutions where compliance with invasive testing is suboptimal.

Review article: Helicobacter pylori-negative duodenal ulcer disease

BACKGROUND

Helicobacter pylori infection rates in duodenal ulcer (DU) patients may be lower than previously estimated.

AIM

To review the real prevalence of H. pylori-negative DUs and its possible causes.

METHODS

Bibliographical searches in MEDLINE looking for the terms 'H. pylori' and 'duodenal ulcer'.

RESULTS

Mean prevalence of H. pylori infection in DU disease, calculated from studies published during the last 10 years including a total of 16 080 patients, was 81%, and this figure was lower (77%) when only the last 5 years were considered. Associations with H. pylori-negative DU were: (1) False negative results of diagnostic methods, (2) NSAID use (21% in studies with <90% infection rate), (3) Complicated DU (bleeding, obstruction, perforation), (4) Smoking, (5) Isolated H. pylori duodenal colonization, (6) Older age, (7) Gastric hypersecretion, (8) Diseases of the duodenal mucosa, (9) Helicobacter'heilmanii' infection and (10) Concomitant diseases.

CONCLUSION

In patients with H. pylori-negative DU disease, one should carefully confirm that the assessment of H. pylori status is reliable. In truly H. pylori-negative patients, the most common single cause of DU is, by far, the use of NSAIDs. Ulcers not associated with H. pylori, NSAIDs or other obvious causes should, for the present, be viewed as 'idiopathic'. True idiopathic DU disease only exceptionally exists.

Evaluation of a commercial immunoblot, Helicoblot 2.1, for diagnosis of Helicobacter pylori infection

The best method to diagnose Helicobacter pylori infection in different clinical situations is controversial. The aim of the study was to assess the performance of a commercial immunoblot, Helicoblot 2.1. The study comprised 215 patients, who were grouped according to the presence of H. pylori infection (assessed by two gastroscopies including histology with a median interval of 7.1 years, enzyme immunoassay [EIA]-based serology, and history of previous H. pylori infections and eradication therapies) into four categories: no H. pylori infection ever, previous infection, ongoing infection, and EIA seropositivity as the only marker of a possible previous infection. The sensitivity of Helicoblot 2.1 to show an ongoing or previous H. pylori infection was 100% and 92%, respectively. Helicoblot 2.1 was negative in only 80% of individuals with no evidence of present or previous infection but in 96% of patients 50 years of age or younger. The current infection marker of the immunoblot was positive in 49% of patients with successful H. pylori eradication therapy. After successful eradication therapy, Helicoblot 2.1 sustained positive results in 87% of patients, and CagA positivity was detected in 87% of patients with follow-up samples for more than 10 years after therapy. Helicoblot 2.1 is a sensitive and, among patients of ages 50 years or younger, a specific test in the primary diagnosis of H. pylori infection. However, it does not discriminate between past and current infections. It can be used in epidemiological studies assessing the role of H. pylori in different late sequelae.

Association between Helicobacter pylori concentration and the combining frequency of histopathological findings in gastric biopsies specimens

BACKGROUND: Helicobacter pylori is the most prevalent infectious agent worldwide. About 90% of patients with chronic gastritis are infected with this bacterium. Some studies have shown a association between the H. pylori concentration and the scores of gastritis activity and severity. AIM: To evaluate the association between H. pylori concentration and the combining frequency of findings on histopathological examination. METHODS: Two hundred consecutive gastric endoscopic biopsies diagnosed as chronic gastritis were retrospectively investigated. The Warthin-Starry silver stain was used to study H. pylori and the following parameters were assessed (according to the Sydney system): 1. infiltration by polymorphonuclear cells in chorio and epithelium (activity) graded as mild, moderate and marked; 2. presence of lymphoid follicles; 3. presence of intestinal metaplasia; 4. presence of regenerative cell atypias, graded as mild, moderate and marked; and 5. H. pylori concentration on the mucous covering the foveolar epithelium. RESULTS: The most frequent association was chronic gastritis and activity, regardless of H. pylori concentration. The association of five histopathological findings in the same biopsy has not occurred in the cases of higher concentration of H. pylori. CONCLUSION: Our study has not revealed any association between H. pylori concentration and an increasing in the number of histopathological findings found in the gastric mucosa. Since referring to its presence is much more important than to its concentration.

Helicobacter pylori infection induces oxidative stress and programmed cell death in human gastric epithelial cells

Helicobacter pylori infection is associated with altered gastric epithelial cell turnover. To evaluate the role of oxidative stress in cell death, gastric epithelial cells were exposed to various strains of H. pylori, inflammatory cytokines, and hydrogen peroxide in the absence or presence of antioxidant agents. Increased intracellular reactive oxygen species (ROS) were detected using a redox-sensitive fluorescent dye, a cytochrome c reduction assay, and measurements of glutathione. Apoptosis was evaluated by detecting DNA fragmentation and caspase activation. Infection with H. pylori or exposure of epithelial cells to hydrogen peroxide resulted in apoptosis and a dose-dependent increase in ROS generation that was enhanced by pretreatment with inflammatory cytokines. Basal levels of ROS were greater in epithelial cells isolated from gastric mucosal biopsy specimens from H. pylori-infected subjects than in cells from uninfected individuals. H. pylori strains bearing the cag pathogenicity island (PAI) induced higher levels of intracellular oxygen metabolites than isogenic cag PAI-deficient mutants. H. pylori infection and hydrogen peroxide exposure resulted in similar patterns of caspase 3 and 8 activation. Antioxidants inhibited both ROS generation and DNA fragmentation by H. pylori. These results indicate that bacterial factors and the host inflammatory response confer oxidative stress to the gastric epithelium during H. pylori infection that may lead to apoptosis.

New approaches to Helicobacter pylori infection in children

Helicobacter pylori infection is usually acquired during childhood, and evidence-based guidelines regarding diagnosis and treatment of infected children have been recently published. Diseases associated with H. pylori infection are gastritis, duodenal ulcers, mucosal-associated lymphoid-type (MALT) lymphoma, and gastric adenocarcinoma. The association of specific symptoms with H. pylori infection in children and adults (ie, recurrent abdominal pain and nonulcer dyspepsia) remains controversial. Additionally, the role of H. pylori in gastroesophageal reflux disease or in extra-gastrointestinal diseases (ie, coronary artery disease) lacks sufficient evidence to demonstrate causality. The diagnosis of H. pylori-associated diseases in children can reliably be made through gastroduodenal endoscopy with biopsies. Clinical trials are underway for the validation of noninvasive diagnostic tests for the H. pylori-infected child, and current guidelines recommend eradication therapy for infected children with duodenal and gastric ulcer, gastric lymphoma, and atrophic gastritis with intestinal metaplasia. The natural history of childhood H. pylori infection is poorly described. Moreover, rational approaches to the prevention and control of childhood H. pylori infection are critically needed, requiring characterization of the determinants for acquisition and persistence and the disease outcomes following eradication.

Pediatric disorders of the stomach

Disorders of the stomach represent a significant portion of the practice of pediatric gastroenterology. Controversy still exists in the appropriate management of children with abdominal pain and vomiting and large gaps remain in our understanding of the physiology and pathophysiology of the stomach in children. Nevertheless, we have made significant progress in understanding Helicobacter pylori infection and gastric motility in the pediatric population.

Helicobacter pylori infection in children

A number of scientific breakthroughs since H pylori first became recognized as a human pathogen have increased our understanding of the pathogenesis of gastroduodenal disease. In particular, advances in molecular bacteriology and the complete sequencing of the H pylori genome in 1999, and soon thereafter the human genome, provide tools allowing better delineation of the pathogenesis of disease. These molecular tools for both bacteria and host should now be applied to multicenter pediatric studies that evaluate disease outcome. More recent developments indicate that a better understanding of the microbial-host interaction is critical to furthering knowledge with respect to H pylori-induced diseases. Studies are needed to evaluate either DNA-based or more traditional protein-based vaccines, to evaluate more specific antimicrobials that confer minimal resistance, and to evaluate probiotics for the management of H pylori infection. Multicenter multinational studies of H pylori infection in the pediatric population, which include specific, randomized controlled eradication trials, are essential to extend current knowledge and develop better predictors of disease outcome.

Comparison of PCR and common clinical tests for the diagnosis of H. pylori in dyspeptic patients

Helicobacter pylori has been recognized as a major gastric pathogen. The objective of this study was to assess the diagnostic value of common clinical tests to detect H. pylori infection, by comparison with PCR. Serum and gastric biopsy specimens from 106 dyspeptic patients were examined. Serology was performed with Pyloriset Dry test, and biopsies were examined histologically, for rapid urease activity and PCR amplification of an ureA gene segment of H. pylori. PCR primers were specific for H. pylori and required at least 1.47 pg of H. pylori DNA, corresponding to about 800 bacterial cells. According to serology, histology, rapid urease, and PCR, positive results were respectively found in 56%, 86%, 64%, and 85% of dyspeptic patients, primarily with gastritis. Relative to PCR, the sensitivity (and specificity) was 55% (38%) for serology, 86% (13%) for histology, 70% (69%) for urease. When combining histology and urease, Bayesian analysis of data indicated no advantage of using combined methods over rapid urease test alone. Histology should not any longer be considered a gold standard test for Helicobacter pylori. Urea breath test still seems the first option for non invasive diagnostic. If an invasive diagnostic is justified, highly specific and sensitive molecular methods should be used to examine specimens.

Is gastric nodularity a sign for gastric inflammation associated with Helicobacter pylori infection in children?

The aim of this study was to investigate the accuracy of using gastric nodularity (GN) as a marker for gastric inflammation associated with Helicobacter pylori infection in children. A retrospective analysis of 395 upper endoscopies done in children between 1990-1996 was performed. Demographics, clinical symptoms, endoscopic features, rapid urease test (RUT), and histological results were collected from each report. GN was found in 13 (3.5%) children. GN showed a significant correlation with age but not with gender. Multiple regression analysis showed a significant correlation between GN and gastritis with RUT but not with other histological determinants alone (gastritis, RUT, or H. pylori organisms). Nevertheless, GN had a poor accuracy rate to determine H. pylori-associated gastritis (sensitivity, 61%; positive predictive value, 12%). GN is a poor predictor for gastric inflammation associated with H. pylori infection in children. During endoscopy, gastric biopsies should always be obtained in children to establish the presence of mucosal inflammation.

Helicobacter pylori infection and host cell responses

It is well known that Helicobacter pylori is able to colonize the gastric mucosa, causing a chronic and persistent infection with complications, such as peptic ulcer and gastric cancer. This review places emphasis on some epidemiological aspects of Helicobacter pylori infection and its mode of transmission. At the same time, invasive and non-invasive methods of diagnosis of Helicobacter pylori infection are illustrated. More space is devoted to the host response following invasion of the stomach. In this respect, the role played by different growth factors and polyamines in the course of Helicobacter pylori disease is discussed also in relation to the result of eradicating treatment. On the other hand, an accurate description of the host immune responses against Helicobacter pylori organism and/or their components (e.g. lipopolysaccharides) is reported. Finally, since Helicobacter pylori has been classified as a class I carcinogen, current researches are focussed on the Helicobacter pylori-induced carcinogenesis.