Pyloric campylobacter serology

Circulating ghrelin levels in patients with gastric cancer: a systematic review and meta-analysis

Background

Ghrelin plays a critical role in regulating energy metabolism and homeostasis. The association between circulating ghrelin levels and gastric cancer has not been systematically analyzed.

Objective

This work explored the association between circulating ghrelin levels and gastric cancer.

Methods

The literature search for relevant articles published until November 2022 was performed using PubMed, Cochrane Library, EMBASE, and Web of Science with the keywords "ghrelin" and "gastric cancer". Standardized mean differences (SMD) with 95% confidence intervals were used to measure the effectiveness. We assessed pooled data by use of a random-effects model.

Results

Of 5,302 identified studies, nine were included (N=3,196 participants). Circulating ghrelin levels were lower in gastric cancer patients (SMD=-0.255, 95%CI: -0.528 to 0.017, P < 0.00001), but with high heterogeneity (I2 = 88.8%).

Conclusion

The circulating ghrelin levels in patients with gastric cancer were lower than in controls. However, there was heterogeneity among results; therefore, studies with larger sample sizes are recommended.

CagA of Helicobacter pylori interacts with and inhibits the serine-threonine kinase PRK2

CagA is a multifunctional toxin of Helicobacter pylori that is secreted into host epithelial cells by a type IV secretion system. Following host cell translocation, CagA interferes with various host-cell signalling pathways. Most notably this toxin is involved in the disruption of apical-basolateral cell polarity and cell adhesion, as well as in the induction of cell proliferation, migration and cell morphological changes. These are processes that also play an important role in epithelial-to-mesenchymal transition and cancer cell invasion. In fact, CagA is considered as the only known bacterial oncoprotein. The cellular effects are triggered by a variety of CagA activities including the inhibition of serine-threonine kinase Par1b/MARK2 and the activation of tyrosine phosphatase SHP-2. Additionally, CagA was described to affect the activity of Src family kinases and C-terminal Src kinase (Csk) suggesting that interference with multiple cellular kinase- and phosphatase-associated signalling pathways is a major function of CagA. Here, we describe the effect of CagA on protein kinase C-related kinase 2 (PRK2), which acts downstream of Rho GTPases and is known to affect cytoskeletal rearrangements and cell polarity. CagA interacts with PRK2 and inhibits its kinase activity. Because PRK2 has been linked to cytoskeletal rearrangements and establishment of cell polarity, we suggest that CagA may hijack PRK2 to further manipulate cancer-related signalling pathways.

Helicobacter pylori CagA: From Pathogenic Mechanisms to Its Use as an Anti-Cancer Vaccine

Helicobacter pylori colonizes the gastric mucosa of more than 50% of the human population, causing chronic inflammation, which however is largely asymptomatic. Nevertheless, H. pylori-infected subjects can develop chronic gastritis, peptic ulcer, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Chronic exposure to the pathogen and its ability to induce epithelial to mesenchymal transition (EMT) through the injection of cytotoxin-associated gene A into gastric epithelial cells may be key triggers of carcinogenesis. By deregulating cell-cell and cell-matrix interactions as well as DNA methylation, histone modifications, expression of micro RNAs, and resistance to apoptosis, EMT can actively contribute to early stages of the cancer formation. Host response to the infection significantly contributes to disease development and the concomitance of particular genotypes of both pathogen and host may turn into the most severe outcomes. T regulatory cells (Treg) have been recently demonstrated to play an important role in H. pylori-related disease development and at the same time the Treg-induced tolerance has been proposed as a possible mechanism that leads to less severe disease. Efficacy of antibiotic therapies of H. pylori infection has significantly dropped. Unfortunately, no vaccine against H. pylori is currently licensed, and protective immunity mechanisms against H. pylori are only partially understood. In spite of promising results obtained in animal models of infection with a number of vaccine candidates, few clinical trials have been conducted so far and with no satisfactory outcomes. However, prophylactic vaccination may be the only means to efficiently prevent H. pylori-associated cancers.

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.

Deciphering host migrations and origins by means of their microbes

Mitochondrial DNA and microsatellite sequences are powerful genetic markers for inferring the genealogy and the population genetic structure of animals but they have only limited resolution for organisms that display low genetic variability due to recent strong bottlenecks. An alternative source of data for deciphering migrations and origins in genetically uniform hosts can be provided by some of their microbes, if their evolutionary history correlates closely with that of the host. In this review, we first discuss how a variety of viruses, and the bacterium Helicobacter pylori, can be used as genetic tracers for one of the most intensively studied species, Homo sapiens. Then, we review statistical problems and limitations that affect the calculation of particular population genetic parameters for these microbes, such as mutation rates, with particular emphasis on the effects of recombination, selection and mode of transmission. Finally, we extend the discussion to other host-parasite systems and advocate the adoption of an integrative approach to both sampling and analysis.

Effect of Helicobacter pylori infection on ghrelin expression in human gastric mucosa

OBJECTIVES

One of the counter-effects of Helicobacter pylori eradication therapy is subsequent obesity. Ghrelin is a recently discovered growth hormone releasing peptide. This endogenous secretagogue increases appetite and facilitates fat storage. The majority of circulating ghrelin is produced in the gastric mucosa. Therefore, we aimed at investigating changes in ghrelin immunoreactivity in gastric mucosa tissues of patients infected with H. pylori.

METHODS

Sixty-one patients with H. pylori infection (25 cases each of duodenal and gastric ulcer, and 11 cases of gastritis) and 22 healthy controls without H. pylori infection were included in the study. H. pylori-infected patients received standard proton pump-based triple therapy followed by histological examination and (13)C-urea breath test to confirm H. pylori eradication. H. pylori was eradicated in 50 out of 61 patients. Biopsy specimens were obtained from antrum and corpus before and 3 months following eradication. Ghrelin expression was evaluated immunohistochemically with an anti-ghrelin antibody, and the number of ghrelin-positive cells determined per 1 mm(2) of the lamina propria mucosa.

RESULTS

There was no relationship between ghrelin immunoreactivity and body weight or body mass index for healthy controls. The number of ghrelin-positive cells was significantly lower for H. pylori-infected patients than for healthy controls. However, the ghrelin-positive cell number increased significantly following H. pylori eradication without significant change in severity of atrophy.

CONCLUSIONS

These data indicated that H. pylori infection affected ghrelin expression. After H. pylori eradication, gastric tissue ghrelin concentration increased significantly. This could lead to the increased appetite and weight gain seen following H. pylori eradication.

Correlation between Helicobacter pylori infection and vitamin C levels in whole blood, plasma, and gastric juice, and the pH of gastric juice in Korean children

BACKGROUND

It is well known that chronic gastritis induced by Helicobacter pylori may be associated with hypochlorhydria and may also be accompanied by low levels of vitamin C in plasma and gastric juice in adults. This study investigates the relationship between H. pylori infection and vitamin C levels in the blood, plasma and gastric juice and the gastric juice pH of Korean children.

METHODS

During a 5-year period, multiple gastric antral biopsies were taken from 452 children who underwent gastroduodenoscopy. The biopsy specimen was inoculated into phenol red buffered urea broth and incubated for 48 hours to detect color changes. The histopathologic findings were evaluated using the Sydney System. Concentrations of vitamin C in whole blood, plasma, and gastric juice aspirate were measured using the 2,4-dinitrophenylhydrazine method.

RESULTS

Four hundred fifty-two patients (228 boys, 224 girls) aged 1 to 15 years were enrolled in this study. H. pylori was detected in 112 patients (24.8%) using histology, whereas it was found in 204 patients (45.1%) using the urease test. One hundred seven patients (23.7%) had active gastritis, and 421 patients (93.1%) had chronic gastritis. Vitamin C levels in whole blood, plasma, and gastric juice exhibited significant negative correlation with the age of patients, the histologic density of H. pylori, the degree of active and chronic gastritis, and the severity of H. pylori infection (based on urease positivity and histologic density of H. pylori). Gastric juice pH was correlated with the degree of chronic gastritis and was significantly higher in urease-positive patients.

CONCLUSIONS

The data demonstrate that vitamin C levels in whole blood, plasma, and gastric juice and the gastric juice pH in Korean children are closely related to the severity of H. pylori infection and the histologic changes in the stomach. These data suggest that vitamin C may play a role in determining infection and progression, and vitamin C supplementation may be an important axis for the management of H. pylori infection in children.

Helicobacter pylori infection in the Australian community: current prevalence and lack of association with ABO blood groups

AIMS

To assess the current prevalence of Helicobacter pylori infection in an Australian urban population sample and to relate this to age, gender and ABO and Rhesus blood groups.

METHODS

We performed a prospective epidemiological survey of H. pylori serological status in 500 consecutive voluntary blood donors who presented for the purpose of blood donation at the central -Melbourne branch of the Australian Red Cross Blood Service, Victoria, Australia, and gave a Melbourne suburban home address.

RESULTS

The overall prevalence of specific anti-H. pylori IgG antibodies in this cohort was 32% (95% confidence interval = 28-36%) and H. pylori sero-positivity increased with age. The rate of H. pylori infection was not significantly different in men and women, with anti-H. pylori IgG anti-bodies detected in 35% (97/277) of men compared with 28% (63/233) of women (P = 0.12). Similarly, H. pylori serological status was not significantly different between subjects of different ABO (P = 0.18) or Rhesus blood groups (P = 0.55).

CONCLUSION

This study showed that, contrary to expectation, the updated prevalence of H. pylori seropositivity (32%) in this Melbourne sample is at least as high as that found in previous Australian studies over the past 19 years. Seropositivity increased with age, and was not related to gender, confirming the infection pattern seen in other developed nations. Despite epidemiological evidence of increased peptic ulcer disease in ABO blood group O subjects, and recent evidence that H. pylori adhesion to gastric epithelial cells is mediated by blood group epitopes, no significant association between blood groups and H. pylori serological status was detected.

[Evaluation of enzyme-linked immunosorbent assay for the diagnosis of Helicobacter pylori infection in children and adolescents]

BACKGROUND

Helicobacter pylori infection is recognized as the most frequent cause of chronic gastritis in adults and children. The diagnosis is accomplished with invasive methods in fragments of endoscopic gastric biopsies and non-invasive methods. The enzyme-linked immunosorbent assay constitutes a simple, fast exam and of low cost with high sensibility in adult patients.

AIM

The purpose of this study was to evaluate the ELISA method for the infection diagnosis for Helicobacter pylori in children and adolescents using the Cobas Core II kit (Roche). Helicobacter pylori was positive when the rapid urease test and the histology were both positive or when the culture was positive and Helicobacter pylori negative when all the tests were negative.

PATIENTS/METHODS

Eleven hundred patients were studied, their age ranged from 3 months and 16 years, (mean = 8y 7m +/-; 4.0; median = 9y 5m). Helicobacter pylori infection was diagnosed in 47.7% (53/111).

RESULT

Sensitivity was 83.0% and 86.0%; specificity was 70.6% and 71.0%, using the cutoff of 7 U/mL and 5 U/mL, respectively. When only the positive culture was used as gold standard and the cutoff of 5 U/mL, the sensitivity was 93.3%. In patients older than 10 years, the sensibility was 90.6% and 96.8%; specificity was 71.0% and 61.9%, with the cutoff of 7 U/mL and 5 U/mL, respectively.

CONCLUSION

ELISA method had good sensitivity in children older than 10 years, using the cutoff 5 U/mL, but the specificity was low.

Accurate diagnosis of Helicobacter pylori. Serologic testing

Serologic testing is a useful noninvasive testing strategy for H. pylori. It is particularly useful in areas where the prevalence of H. pylori is high and inexpensive point-of-contact fingerprick tests are used. Sensitive tests are valuable ways of excluding H. pylori infection and can be used in conjunction with a direct test (urease histology culture or breath test) to confirm absence of H. pylori if the two methods are concordant. Serologic testing is more definitive and differentiating if the antigenic epitopes of H. pylori can be differentiated based on the antigenic epitopes that specifically associate with gastric cancer, peptic ulcer, and nonulcer dyspepsia. A study by Kawahara's group reported that Hsp 60 may be involved in the development of mucosa-associated lymphoid tissue based on ELISA. The idea of differentiating antigens for H. pylori may open a new area for use of serologic testing in the diagnostic approach of H. pylori infections.

[14C]-urea breath test to confirm eradication of Helicobacter pylori

BACKGROUND

Treatment for Helicobacter pylori reduces ulcer recurrence. Eradication rates of the organism vary with different drug regimens from 30% to 90%. There is a need to identify patients who have failed treatment. [14C]-Urea breath test (UBT) is non-invasive, sensitive, safe and highly reliable test for diagnosis of H. pylori infection. As there is a paucity of reports on the utility of [14C]-UBT in confirming H. pylori eradication, this study was undertaken.

METHODS

Thirty-eight patients (age 34 +/- 17 years, range 16-84 years, 27 men) with upper gastrointestinal symptoms underwent upper gastrointestinal endoscopy. Baseline H. pylori infection was diagnosed by identification of the organism on antral biopsies and positive rapid urease test (RUT). After 1 month of completion of treatment, repeat RUT and histological examination of antral endoscopic biopsies were performed. Eradication of H. pylori was defined as absence of the organism on histology, and negative RUT. The [14C]-UBT was performed using 185 kBq [14C]-urea dissolved in 300 mL water. Breath samples were collected once before ingestion of [14C]-urea, and subsequently at 5 and 15 min. Results were expressed as 14CO2/mmol CO2 exhaled as per cent of administered urea.

RESULTS

Endoscopy revealed antral gastritis (n = 14), duodenal ulcer (n = 8), duodenitis (n = 2), oesophagitis (n = 1), antral gastritis and duodenal ulcer (n = 3), antral gastritis and duodenitis (n = 7) and normal upper gastrointestinal endoscopy (n = 3). All the 20 patients who were negative for H. pylori on RUT and histology, tested negative for H. pylori on [14C]-UBT. However, of 18 patients shown to have H. pylori infection on RUT and histology, 16 were positive for H. pylori on [14C]-UBT. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of [14C]-UBT were 100, 89, 91, 100 and 95% respectively.

CONCLUSIONS

The [14C]-UBT is a reliable indicator of H. pylori eradication after treatment. It can obviate the need for antral biopsies to confirm eradication of H. pylori after completion of treatment.

Host response and vaccine development to Helicobacter pylori infection

Studies in both humans and animals demonstrate that H. pylori is capable of illiciting an innate response that in part is regulated by the genetic makeup of the host. These innate responses includes stimulating immune effector mechanisms at the cellular and biochemical level resulting in the influx of neutrophils into the lamina propria and have even been shown to modify gastric acid secretion. The availability of good animal models of chronic Helicobacter infection has also allowed investigators to begin to examine how the adaptive host immune response prevents and/or exacerbates Helicobacter-induced gastroduodenal disease. The experimental H. felis/mouse model has been utilized by a number of laboratories to investigate mechanisms of host defense against chronic Helicobacter infection. This model and the more recently developed H. pylori rodent model has not only allowed investigators to confirm the feasibility of immunotherapy to prevent and/or cure Helicobacter infection but also to begin to examine how the host immune response prevents and/or exacerbates Helicobacter-induced gastroduodenal disease. Based on these studies a hypothesis is emerging that suggests that protection and/or cure from Helicobacter infection is mediated primarily by an upregulated cellular immune response which may act via an antibody independent mechanism. Paradoxically, following natural infection with H. pylori, a component of the cellular immune response also promotes chronic gastric inflammation without clearance of the organism. The recent development of reliable and reproducible H. pylori/rodent models of disease and the availability of numerous inbred strains, transgenic and knockout animals, will allow investigators to continue to explore the role the host cellular and humoral immune response plays in promoting or preventing this infection.

Diagnosis of Helicobacter pylori infection

A number of diagnostic tests have been developed for the detection of H. pylori. Diagnostic techniques can be divided into invasive and noninvasive methods. The invasive methods require upper gastrointestinal endoscopy and involve culture of gastric biopsy specimens, examination of stained biopsies and detection of urease activity in the biopsies themselves. In addition, we have developed endoscopic diagnosis of H. pylori infection in gastric mucosa using phenol red dye-spraying. The noninvasive methods include urea breath test and serological techniques. Although there has been considerable improvement in the techniques, a combination of at least two different techniques should be used in order to optimize the diagnostic yield. We recommend the use of one rapid test in the combination. The rapid urease test, cytology and the phenol red dye-spraying endoscopy give results available before the patient leaves the endoscopy suite.

Duodenal ulcer treatment: progress from pH to HP

The treatment of duodenal ulcer has evolved from ineffective medical treatments through an era of surgical management, back to increasingly effective medical treatment. The advent of H2-receptor antagonists changed the outlook for ulcer patients. More recently, Helicobacter pylori, an organism which inhabits gastric mucosa exclusively, has been implicated in the pathogenesis of peptic ulcer. This bacterium is found in the stomachs of around 95% of duodenal ulcer patients. Its eradication is shown dramatically to improve the rate at which ulcers relapse. The mechanisms whereby it may cause ulceration are not established--we review current hypotheses. No method of eradication is 100% effective, and many different dual or triple therapy regimens have been tried. Metronidazole resistance is reported but its importance is not yet known. Helicobacter eradication is likely to prove a cost-effective and acceptable treatment for duodenal ulcer, and once its value has gained acceptance widespread uptake of this option is anticipated.

Humoral immune response against Helicobacter pylori as determined by immunoblot

An immunoblot method has been evaluated to diagnose Helicobacter pylori infection serologically by comparing 69 serum specimens from patients with a positive Gram stain and/or culture result and a positive urease test on biopsy material, as well as 51 serum specimens from patients with at least 4 negative urease tests, and negative microscopy and culture results. Sensitivity and specificity was found to be 100%. Recognition of the cross-reacting flagellin (66 kDa), flagellar sheath protein (51 kDa), and a 14 kDa protein are not a criterion for a current H. pylori infection. On the other hand, any combination of at least two of the 180, 120, 90, 75, 67, 29.5 and 19 kDa bands were diagnostic of infection. Three H. pylori strains, which were compared with both gel electrophoretic analyses and immunoblot reactivity, exhibited in part strong qualitative and quantitative differences that particularly affect the 120 kDa pathogenic factor, the large urease subunit and other proteins especially in the molecular mass range from 50 to 67 kDa. IgG immunoblot patterns showed that the choice of H. pylori strain, as well as a reproducible and standardizable antigen preparation, is of great importance for the reliability of serodiagnostic tests. The immunoblot method was found to be a valuable tool for the semi-quantitative confirmation of results achieved with other serological methods as well as optimization and quality control of the antigens used for serodiagnostic purposes.

Comparison of commercial serological tests for detection of Helicobacter pylori antibodies

Serological testing for Helicobacter pylori infection is one of the diagnostic methods of choice. Various commercial kits that use different antigens have been developed, but data on their diagnostic accuracy and direct comparisons between the tests are lacking. We aimed to evaluate the sensitivity, specificity, and predictive value of three immunoglobulin G enzyme-linked immunosorbent assay kits: Pylori stat, Helico-G, and Premier H. pylori. Serum samples and gastric biopsy findings from 76 patients were evaluated. We found by using a priori cutoff values that the Pylori stat, Helico-G, and Premier kits had overall sensitivities of 96, 96, and 88%, respectively, and specificities of 94, 86, and 96%, respectively, compared with gastric biopsy findings. For 232 serum samples, the Pylori stat test and a previously validated standard serological assay on which the test was based disagreed in 3% of the cases, while for 76 samples that were tested, Helico-G and a previously validated standard assay on which it was based disagreed in 8% of the cases. The intra- and interassay precision of each of the test kits was high. We conclude that serology based on any of these commercial tests represents a reliable and valid method for the diagnosis of H. pylori whether or not highly purified antigens are used.

Elevated risk of Helicobacter pylori infection in submarine crews

In a prospective study designed to elucidate the route of transmission of Helicobacter pylori, the seroprevalence and incidence of Helicobacter pylori infection was determined in the following branches of the armed forces presumed to be at increased risk of acquiring transmissible diseases by the fecal-oral or oral-oral route: German submarine crews (n = 64, mean age 26.2 years) and regular officers of the French infantry (n = 51, mean age 26.5 years) who had served for a minimum of three years. The submarine crews were compared with air force staff (n = 74, mean age 23.7 years), and the French officers with French infantry recruits (n = 135, mean age 20.5 years) who started their service at the beginning of the study. The frequency of IgG and IgA antibody responses to the 120, 88, 86 and 82 kDa proteins was determined by the immunoblot method. The frequency of a positive antibody response was strongly dependent on age (p less than 0.001). When results were controlled for age by the logistic regression analysis, the submarine crews revealed significantly increased frequencies of the IgG and IgA responses compared to air force staff. The antibody responses of French officers and recruits were not significantly different. It is concluded that submarine crews serving during their missions in an overcrowded space with extremely limited sanitary facilities must be considered a high-risk group for Helicobacter pylori infection. These results strongly suggest person-to-person transmission of Helicobacter pylori, by either the oral-oral or the fecal-oral route.

Characterization of risk factors for Helicobacter pylori infection among men attending a sexually transmitted disease clinic: lack of evidence for sexual transmission

The mechanism of transmission of Helicobacter pylori is unknown. To investigate the role of sexual behavior and demographic factors in the acquisition of H. pylori infection, we evaluated the seroprevalence of antibody to H. pylori in 370 men attending an urban sexually transmitted diseases clinic. Sera from the following three groups were analyzed by enzyme-linked immunosorbent assay for H. pylori-specific immunoglobulin G: 78 human immunodeficiency virus (HIV)-seropositive homosexual men, 102 HIV-seronegative homosexual men, and 190 HIV-seronegative heterosexual men. Overall, the seroprevalence of H. pylori was 100 of 370 men (27%), with rates of 18% in HIV-seropositive homosexual men and 20% in HIV-seronegative homosexual men versus 35% in heterosexual men (P less than 0.005, chi 2 test). By ethnic group, 21 (12%) of 181 Caucasian men, 40 (41%) of 97 black men, and 37 (43%) of 87 Hispanic men were seropositive (P less than 0.001, chi 2 test). Multivariate analysis revealed that race was associated with H. pylori seropositivity independent of HIV status, sexual preference, or age. There was no relationship between H. pylori seropositivity and the number of lifetime sexual partners or previous sexually transmitted diseases. Three HIV-seropositive men with H. pylori immunoglobulin G had essentially identical antibody titers over 8 to 16 months of follow-up. In conclusion, black and Hispanic men have significantly higher H. pylori seroprevalence rates than do Caucasian men, but neither sexual behavior nor HIV infection influences the presence or persistence of H. pylori antibody. Further evaluation of the factors associated with these ethnic differences may lead to a better understanding of H. pylori acquisition and transmission.

Serodiagnosis of Helicobacter pylori: comparison of enzyme-linked immunosorbent assays

Enzyme-linked immunosorbent assays (ELISAs) have been developed to diagnose Helicobacter pylori infection. However, the methods are not standardized. We therefore prospectively evaluated the sensitivities and specificities of ELISAs developed in the United States and the United Kingdom in a study population comprising 41 consecutive symptomatic outpatients and 35 volunteers. At endoscopy, multiple biopsies were obtained for histology and culture and stained sections were graded for chronic gastritis, active chronic gastritis, and density of H. pylori. Serum samples were analyzed for H. pylori by ELISA. The first set of assays for immunoglobulin G (IgG) and IgA used a pool of sonicated isolates of H. pylori from five patients in the United States (antigen A). The second set of assays, developed in the United Kingdom, used three different antigens: antigen 1, an acid-extractable surface antigen; antigen 2, an acid-extractable antigen from an aflagellate variant; and antigen 3, a urease-containing fraction. Cutoff scores for positive results were determined a priori on the basis of previous serological studies. There was close agreement between histology and culture. In the study population, 36% of the individuals were H. pylori positive. The diagnostic value of the different ELISAs were highly comparable, and the crude antigens performed as well as the more purified antigens. The antigen A IgG had a sensitivity and specificity of 96 and 94%, respectively; the values for antigen 1 were 93 and 96%, respectively. The antigen A IgA and antigen 3 assays were the least sensitive tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum immune response to Helicobacter pylori in children: epidemiologic and clinical applications

Antibody responses to Helicobacter pylori were measured by a solid-phase whole-cell enzyme-linked immunosorbent assay in 150 children and adolescents; in 47 consecutive children undergoing upper gastrointestinal endoscopy, including 17 with H. pylori infection before and after antimicrobial treatment; and in 46 family members of the infected children. Abnormal levels of either IgG or IgA were found in 6% of the 150 children. In the latter group the prevalence of H. pylori seropositivity increased with age. Parents and siblings of the infected children had 94% and 71% seropositivity, respectively, suggesting intrafamilial spread. Abnormal levels of IgG or IgA against H. pylori identified infected children with 95% sensitivity and 84% specificity. Eradication of the infection was accompanied by a significant decrease in IgG and IgA titers, with normalization in 10 cured patients in 12 months or less. We conclude that the method described for evaluation of H. pylori-specific IgG and IgA antibodies gives helpful information on the epidemiology of the infection and represents a useful adjunct to diagnosis and management of chronic gastritis in children.

Characterization of an immunoreactive species-specific 19-kilodalton outer membrane protein from Helicobacter pylori by using a monoclonal antibody

Immunoblotting experiments on hyperimmune rabbit serum and sera from patients with Helicobacter pylori gastritis showed a consistent antibody response to a 19-kDa outer membrane protein antigen. A monoclonal antibody, designated HP 40, which reacted by Western immunoblotting with this protein was produced. It was shared by all H. pylori strains tested (D 273, NCTC 11637, and 24 wild strains) but not by the thermophilic Campylobacter species, Campylobacter fetus, Helicobacter mustellae, or Helicobacter fennelliae. Immunogold staining suggested that the 19-kDa antigen was exposed on the outer surface of the bacteria. Its functional role and effectiveness as a serological diagnostic tool are under study.

Pathogenetic role of Helicobacter pylori in duodenal ulcer disease. Multivariate analysis of factors affecting relapse

The pathogenesis of duodenal ulcer disease is multifactorial and the contribution of Helicobacter pylori in relation to the other factors to the release of duodenal ulcer is unknown. To investigate this, we studied 147 patients with endoscopically proven healed ulcers. These patients were randomized to receive either placebo, misoprostol 200 micrograms or misoprostol 300 micrograms four times daily, and clinical, personal, physiological and endoscopic characteristics were obtained prospectively. Endoscopy was performed at the active phase of the ulcer and when the ulcer healed. Biopsies were taken from the antrum to assess histologically for: (1) the activity of gastritis as assessed by the degree of polymorph infiltration, (2) the degree of chronic inflammation by the degree of chronic inflammatory cells infiltration and degree of mucosal degeneration, and (3) bacteriologically for the presence of H. pylori. The severity of the gastritis and the bacterial density were graded independently by two pathologists. The patients were assessed at two-month intervals for 12 months or until the ulcer relapsed. The results demonstrated that the relapse rates of duodenal ulcer were similar in the three treatment groups. The relapse rate was higher in the group with higher density of the bacteria (P less than 0.05). The degree of gastritis did not affect the relapse rate of duodenal ulcer in either the placebo or misoprostol group or in all patients combined. Stepwise logistic regression analysis identified that increased duodenal inflammation, male sex, early-onset disease, and H. pylori adversely affected relapse of the ulcer. We conclude that multiple factors affect the relapse of duodenal ulcer and H. pylori is one of them.

Seroepidemiology of Helicobacter pylori infection in Greece

Helicobacter pylori infection is strongly associated with chronic gastritis and peptic ulceration. As the prevalence of H. pylori infection in southern European populations is not known, a serological survey of 1069 samples from three different age groups in the Greek population was carried out with an enzyme-linked immunosorbent assay (ELISA) for antibodies to these bacteria. The antigen was an ultracentrifuged supernate of whole cell sonicates of 5 isolates of H. pylori assessed by electrophoresis and by immunoblotting with negative and positive sera. The sensitivity of the test was 97.43% and the specificity 100% for IgG antibodies; IgA and IgM antibodies to the antigen preparation were not found. Antibodies to H. pylori were detected among 39.4% of children aged 1-10 years, 67.1% of recruits (20-27 years) and 70% of blood donors (20-50 years). The prevalence of antibodies did not differ with sex in each of the age groups. The proportion of individuals with antibodies to H. pylori was higher in the younger age groups than those reported for similar age groups in western Europe.

Campylobacter pylori infection: experience in a multiracial population

Over a 15-month period, 399 patients with dyspepsia were investigated for the presence of Campylobacter pylori infection. Half of the patients (50.6%) had Campylobacter organisms in the antrum of the stomach. C. pylori was found in 96.1% of patients with histological changes of chronic active gastritis in the antrum. Of patients with duodenal and gastric ulcers, 87.8% and 87.5%, respectively, had Campylobacter organisms, as did 39.3% of patients with non-ulcer dyspepsia. C. pylori infection was most commonly found in Chinese and Indians. Although the prevalence of infection appeared to increase with age, there was an equal distribution amongst the sexes.

Comparison of anti-Helicobacter (Campylobacter) pylori IgG antibodies between different areas of Belgium

We have collected sera from 4053 patients of different parts of Belgium. Sera were randomly selected whatever the kind of pathology. Anti-Helicobacter (Campylobacter) pylori IgG were determined with an ELISA technique using whole formalized bacteria. The results suggest that the mean antibody titres differ between various areas, with an overall higher prevalence in the north-western part of the country.

Cellular and humoral immune responses in Campylobacter pylori-associated chronic gastritis

Gastric cellular and humoral immune response investigated by immunoperoxidase staining of 53 antral biopsies showed significant differences in Campylobacter pylori-associated gastritis as compared with non-bacterial chronic gastritis and normal controls. IgA, secretory component, and complement C3 coated bacilli were seen in all cases of active chronic gastritis. C3 was always associated with coating by IgA, IgM, or both, which were rarely seen in gastritis without polymorphonuclear neutrophil infiltration. Intraepithelial mononuclear cellular infiltration was seen in 18 of 26 cases of C. pylori-associated chronic gastritis. The intraepithelial mononuclear cells stained positively for T cells and histiocytes.

Campylobacter pylori in Japan: bacteriological feature and prevalence in healthy subjects and patients with gastroduodenal disorders

The presence of Campylobacter pylori was investigated in biopsy specimens obtained during gastrofiberscopy from 103 consecutive patients prospectively. Patients included 25 with gastric ulcer, 4 with duodenal ulcer, 5 with coexisting gastroduodenal ulcer, 31 with gastroduodenal ulcer with gastritis, 27 with gastritis, 3 with gastric polyps and 8 with gastric cancer. Results were compared with 20 healthy control subjects who were endoscopically normal. Two specimens each were taken from 3 sites in the stomach. One part was used for a histological study to examine the presence of the organisms. The other part was cultured using Skirrow's agar microaerophilically. Conventional microflora and C. pylori were examined in gastric contents of some cases. Bacteriological features of isolated strains of C. pylori were identical to the NCTC strain. C. pylori was the most dominant organism in gastric contents at any pH level. Detection rates of C. pylori by bacteriological culture were 96% in gastric ulcer, 100% in duodenal ulcer, 80% in coexisting gastroduodenal ulcer, 84% in gastroduodenal ulcer with gastritis, 70% in gastritis, 100% in gastric polyps and 100% in gastric cancer, and the percentages recognized by histological studies were 81, 100, 100, 84, 71, 67, and 57%, respectively. The values in healthy controls were 55% by histological and bacteriological methods (P less than 0.001 compared with overall ulcer patients). These results supported the close association between C. pylori and gastroduodenal diseases.

Improved growth of Campylobacter pylori in a biphasic system

The recovery of Campylobacter pylori from clinical specimens is difficult, even when done with an optimal medium, atmosphere, and temperature. The growth of this organism was investigated by comparing a biphasic system with broth culture. The effects of gyration, inoculum, and pH were studied. Brucella agar and broth supplemented with 2.5% fetal bovine serum were used. Growth in the biphasic system was an average of 2 log units (7 X 10(8) versus 5 X 10(6) CFU/ml) greater than that in the broth system (P less than 0.01), and this occurred 12 to 24 h sooner in the biphasic system. When gyration was added, an average of 1 log unit of growth improvement was seen in comparable systems. Improved growth was also seen with low inoculum levels, in which stationary-phase cells in the broth system reached 10(5) CFU/ml compared with 10(7) CFU/ml in the biphasic system. At the three pH ranges studied, growth was best at pH 8 to 9 (6 X 10(9) CFU/ml), averaging 2 log units greater growth than that at pH 6 to 7 and 4 log units greater growth than that at pH 4.5 to 5.5 (P less than 0.01). The improved recovery of the organism for low inoculum levels in a biphasic system may be important for long-term storage and clinical isolation.

Seroepidemiological study of the immune response to Campylobacter pylori in potential risk groups

To gain more understanding of the epidemiology of Campylobacter pylori infection, the immune response to the organism was studied in the following selected potential risk groups: endoscopy staff (n = 45), dental staff (n = 58), orphanage children (n = 24), psychiatric patients (n = 58), and family contacts of Campylobacter pylori-infected patients (n = 55). The frequency of an IgG and IgA antibody response in the different groups was determined by the immunoblot method and compared with that in an appropriate control group (n = 189). The frequency of a positive antibody response was dependent on age (p less than 0.0001) but not on sex. When results were corrected for age by logistic regression analysis, all groups, with the exception of dental staff and orphanage children, revealed a significantly raised frequency of an IgA and combined IgG/IgA immune response compared to controls. There was not a significant difference for the IgG response, except in orphanage children. It is concluded that endoscopy staff, family contacts of Campylobacter pylori-infected patients and people living in closed communities such as psychiatric patients and orphanage children must be considered as risk groups for Campylobacter pylori infection. The findings support the notion that person-to-person spread and a common source are the predominant modes of transmission of Campylobacter pylori in addition to endoscopes.

Diagnostic value of an immunoassay to detect anti Campylobacter pylori antibodies in non-ulcer dyspepsia

An enzyme-linked immunosorbent assay (ELISA) for detection of IgG antibodies against Campylobacter pylori was used to examine sera from 70 patients with non-ulcer dyspepsia. 48 patients had C pylori associated gastritis according to culture or histology; mean optical density (OD) of the ELISA was significantly higher than that for the 22 patients with normal antral mucosa and absence of C pylori. Positive and negative predictive values for campylobacter-associated gastritis were 100% above OD 2.10 and below OD 1.00, respectively. Serology might replace endoscopy in the diagnosis of campylobacter-associated gastritis.

Molecular cloning and expression of Campylobacter pylori species-specific antigens in Escherichia coli K-12

A gene bank of Campylobacter pylori DNA in Escherichia coli was constructed by cloning Sau3A-cleaved DNA fragments into the bacteriophage vector lambda EMBL3. The expression of C. pylori antigens was determined by screening the gene library with adsorbed C. pylori whole-cell rabbit antisera. One recombinant clone which reacted positively (lambda CP2) was studied further. Immunoblot analysis with lambda CP2 showed a polypeptide band of 66 kilodaltons (kDa) reacting antigenically with the adsorbed antiserum. Extraction of DNA from lambda CP2 and digestion with SalI revealed a DNA insert of 17 kilobases (kb). Subcloning with SalI and the E. coli vector pUC18 showed that the DNA also encoded a 31-kDa antigen. The cloned antigens were shown by immunoblotting to have the same molecular weight in E. coli as in C. pylori and to be present in all C. pylori strains. Antiserum was raised against the cloned polypeptides and found to react only with C. pylori when analyzed by dot blotting and indirect immunofluorescence. The cloned antigens were determined to be expressed from the pUC18 lac promoter. The DNA encoding these antigens was radiolabeled with 32P and found to hybridize only to C. pylori strains. Immunoblotting with affinity-purified polyclonal antibody to the urease enzyme of C. pylori revealed that the cloned antigens may be part of the urease enzyme.

The reliability of urease tests, histology and culture in the diagnosis of Campylobacter pylori infection

The accuracy of various staining techniques for immersion microscopy, of five media for culture and five urease test modalities for the detection of Campylobacter pylori infection is reported. It was found that 2% urea unbuffered gel preparation is the most accurate urease test (sensitivity: 89%, specificity: 98%) but a minimal amount of 10,000 CFU/ml is necessary to observe positivity and the sensitivity of urease tests drops to 52% in patients under antimicrobial treatment. For histological diagnosis, modified Giemsa staining was shown to be slightly superior to H&E. The most valuable diagnosis technique is culture when the biopsy specimen is transported and processed under appropriate conditions. A 94% sensitivity rate was observed with 'BCC agar', a new medium containing brain heart infusion, activated charcoal and horse serum.

The role of serology in the diagnosis of Campylobacter pylori infection

Circulating antibodies to Campylobacter pylori in patients with campylobacter-associated gastritis are sufficiently specific to allow serodiagnosis of this condition. This is possible by various techniques, the most convenient being enzyme-linked immunosorbent assay. Applications of serodiagnosis are in two areas--in clinical practice, where proper evaluation is still required, and in epidemiology. Here serodiagnosis shows the prevalence of C. pylori in the general population and in specific population groups. A study of C. pylori and dyspeptic symptoms in a group of healthy blood donors showed a significant association between C. pylori and history of peptic ulceration. However in most donors the gastritis was clinically silent.

Campylobacter pylori: clinical, histological, and serological studies

The presence of Campylobacter pylori, histologically diagnosed gastritis, and antibodies to C pylori were determined in a series of 113 patients undergoing endoscopy. Paired biopsy specimens from the fundus, body, and antrum were collected from 59 patients and from the antrum of 54 patients. The presence of C pylori was confirmed by either culture or silver stain in 30 of 59, 31 of 59, and 54 of 103 biopsy specimens from the fundus, body, and antrum, respectively. Of the specimens which contained C pylori 20 of 30 (66%) from the fundus, 25 of 31 (80%) from the body, and 54 (100%) from the antrum showed gastritis. C pylori and gastritis were shown in seven of nine (78.1%) of patients with gastric ulcers and in nine of 11 (82%) of patients with duodenal ulcers. Using an enzyme linked immunosorbent assay (ELISA) technique to detect IgG antibody to C pylori, all patients with histologically diagnosed gastritis and organisms present had titres of greater than or equal to 640; eight of 39 (21%) of patients without gastritis and without organisms gave similar titres. Hence the presence of C pylori was associated with gastritis and with raised titres of IgG antibody.

Nitrofurans in the treatment of gastritis associated with Campylobacter pylori. The Gastrointestinal Physiology Working Group of Cayetano Heredia and The Johns Hopkins Universities

We conducted a double-blind, placebo-controlled, randomized treatment study in Peruvian adults with antral gastritis associated with Campylobacter pylori. Patients received either 400 mg of furazolidone (n = 14), 400 mg of nitrofurantoin (n = 24), or a placebo (n = 31) for 14 days. Endoscopy was carried out at baseline, 1 day after ceasing therapy, and 6 wk after the end of treatment to verify colonization by C. pylori and determine the extent of gastric inflammation. Treatment with nitrofurantoin or furazolidone markedly reduced or, in some cases, cleared C. pylori from the antrum (p less than 0.0005 compared with placebo). Resolution of acute gastric inflammation, as evidenced by decreased polymorphonuclear leukocyte infiltration and regeneration of the mucus layer, paralleled the reduction in bacterial colonization (p less than 0.005 compared with placebo). A high percentage of patients experienced relapse (recolonization by C. pylori and return to pretreatment levels of gastritis) within 6 wk after cessation of treatment. Significant relief of dyspeptic symptoms was not evident during the study.

Campylobacter-like organisms and Candida in peptic ulcers and similar lesions of the upper gastrointestinal tract: a study of 247 cases

Campylobacter-like organisms were detected by light microscopy in association with 57 of 102 (56%) of gastric ulcers, all the gastric erosions associated with gastritis, three of five (60%) of gastric erosions without gastritis, five of 13 (39%) of mild superficial gastritis and two of 36 (6%) of normal gastric mucosa. They were also seen in four of 20 (20%) of duodenal ulcers, but not in duodenal erosions with duodenitis or normal duodenal biopsy specimens. They were seen in association with 12 of 64 (19%) of cases of Barrett's oesophagus. Moniliasis was seen in nine of 78 (12%) of the gastric ulcers in which campylobacter-like organisms were found, and the incidence of moniliasis was three of 15 (20%) in association with duodenal ulcers when ulcer debris was present in biopsy material, and in association with six of 25 (24%) of cases of Barrett's oesophagus. These findings do not support the hypothesis that campylobacter-like organisms cause inflammatory and ulcerative lesions of the upper gastrointestinal tract.

Bacteria in ulcer pathogenesis

A great deal of information about the spiral bacteria of the stomach has accumulated in the past 5 years. These bacteria, currently named Campylobacter pylori but likely to be renamed as a new genus, have adapted to living beneath the mucus layer and above the gastric surface mucous cells. When metaplastic gastric mucous cells are also present in the duodenal bulb, C. pylori may also get a foothold in this latter location. Observations of the high prevalence of C. pylori in patients with gastritis and with duodenal ulcers, and the slightly lower prevalence in patients with gastric ulcer, have led to the hypothesis that the bacteria play an aetiological role in these three conditions. There is now fairly convincing evidence that the organisms can cause active chronic gastritis. The most persuasive of this comes from reports of the rapid development of gastritis and symptoms in two volunteers who swallowed the organism, plus two other series of accidental challenges. Other evidence is provided by the waning and waxing of gastritis, which has been correlated in several studies with clearance followed by recrudescence of the organisms. The role of the bacterium in peptic ulcer is less certain. The present data do not provide strong evidence for a causal role in gastric ulcer, although we cannot rule out that it may be important in some. The very high prevalence in patients with duodenal ulcer, including one series in children (who rarely harbour the organism), raises the distinct possibility that the bacteria play an aetiological role in this form of ulcer. Reports of ulcer healing with antibiotics and of lower recurrence rates in those cleared of the organism, increase the possibility, However, methodological flaws in some studies, plus the usual need for confirmation of key studies, indicate that we should await more definitive evidence before accepting that duodenal ulcer can be an infectious disease.

Immunoblot analysis of immune response to Campylobacter pylori and its clinical associations

Systemic immune response to Campylobacter pylori was detected by the immunoblot technique in serum samples from 200 patients, 129 blood donors, and 96 children. The results of the IgG immunoblot test showed excellent correlation with the detection of C pylori by culture and also with histopathological examination of the antrum, as well as with peptic ulcer disease. An IgA response also occurred and gave results comparable with those of the IgG immunoblot test, although on a quantitatively lower scale. The IgM immunoblots were of no help in the serodiagnosis of C pylori infection. The protein bands that seemed to be the most specific for C pylori and which were consistently observed in patients positive for C pylori were a 110 kilodalton and a 63 kilodalton band on the IgG immunoblot and an 89 kilodalton band on the IgA immunoblot. A 94 kilodalton and a 28 kilodalton band were also included in the evaluation. While immunoblot analysis may be used effectively for the serodiagnosis of C pylori infection and can distinguish between patients with normal antrum mucosa and those with gastritis, the test does not help to distinguish between those patients with antrum gastritis who subsequently develop peptic ulcers and those who do not.

Antibody response to Campylobacter pylori in an ethnic group lacking peptic ulceration

The association between duodenal ulcer, gastritis and gastroduodenal colonization with Campylobacter pylori suggests a causal role for this newly described bacterium. In an attempt to challenge the verity of this association we studied a group of people in whom duodenal ulcer is apparently absent. Serological evidence of infection was sought with a sensitive, specific ELISA assay for C. pylori specific IgG and was compared with results from control sera from teenagers referred for respiratory viral serology, volunteer blood bank donors, patients with duodenal ulcers and patients in whom the presence or absence of C. pylori had been determined by histological and microbiological examination of gastric tissue. A relatively isolated group of Australian Aborigines in whom peptic ulceration is virtually unknown, was observed to possess age-specific mean C. pylori antibody levels comparable those found in a group of white Australian dyspeptic patients without microbiological evidence of infection with this organism. The antibody levels of Aborigines were lower than those found in an aged-matched group of 'healthy' white Australians, both of these groups having levels which were significantly lower than the levels found in culture positive white Australian dyspeptic patients. It was found that 21/144 'healthy' white Australians (14.6%) had antibody levels greater than or equal to the lower 99% confidence interval of the mean level found in culture positive patients, while only 2/274 Aborigines (0.7%) had such elevated levels. By contrast, 89/142 (62.7%) patients with endoscopically proven duodenal ulcer had similarly elevated specific antibody levels. These differences were highly significant. We consider these findings to be consistent with the hypothesis that C. pylori is important in the pathogenesis of duodenal ulcer.

Persistence of Campylobacter pyloridis despite healing of duodenal ulcer and improvement of accompanying duodenitis and gastritis

Campylobacter pyloridis has been associated with antral gastritis and duodenal ulcer. To study the pathogenetic role of these organisms in duodenal ulcer, endoscopic biopsies, two from the first part of duodenum, four from antrum, and four from body and fundus, were taken before and after four weeks of cimetidine treatment (1.2 g/day) from 67 patients with active duodenal ulcer. The biopsies were examined for the presence and severity of any inflammation by two independent pathologists in the absence of any clinical information and for the occurrence and density of Campylobacter pyloridis by culture and Warthin-Starry stain. Before treatment, inflammation was present in 71.1, 100, and 25.8%, while the organisms were present in 34.3, 91.0, and 79.1% of the duodenal, antral, and fundal biopsies, respectively. With complete healing of duodenal ulcer, inflammation was present in 48.9, 98.2, and 30.2%, while the organisms were present in 25, 76.7, and 63.3% of the respective mucosae. With ulcer healing, duodenitis became significantly milder (P less than 0.05). With improvement of gastritis and duodenitis, there was no significant change in the occurrence and density of Campylobacter pyloridis. These findings indicate that healing of duodenal ulcer is not influenced by the presence of Campylobacter pyloridis, which is frequently found in the gastroduodenal mucosa of patients with duodenal ulcer, but does not appear to be associated with mucosal inflammation except in the antrum.