Pylori-specific Immunoglobulin Research Articles

Study the Role of Helicobacter Pylori Infection in a Group of Iraqi Patients with Colorectal Cancer

Background Increased developed of colorectal tumor may be linked with Helicobacter pylori. However, theunderlying mechanisms were still uncertain.objective: Helicobacter pylori infection in the world, in particular in developing countries, is one of mostcommon chronic bacterial infections, This bacterium is responsible for many diseases such as gastritis,peptic ulcer, lymphoma and in some patients may lead to gastric cancer, it is in the world has known 2ndmajor cause of death from cancer. H.pylori infection may likely raise the risk of colorectal cancer, accordingto recently published studies. The aimed of this study to detected the role of H. pylori in colorectal cancer.Methods: Serum of 50 colorectal cancer and colorectal normal with positive H. pylori infection patientswere estimated by 14Urea breath test and 25 subjects with no any inflammatory disease as the control group.from each patient were collected Blood samples to investigated of H. pylori specific immunoglobulin G(IgG) and CagA IgG antibodies by using enzyme-linked immunosorbent assay (ELISA).Results: A total of 50 patients in this study 25 had colorectal cancer and 25 had colorectal normal with H.pylori infection (immunoglobulin G (IgG) P ? 0.01 and CagA IgG antibodies P < 0.01) were significantlymore prevalent in the patients with colorectal_ cancer and colorectal normal with Helicobacter pylori_infection compared with the healthy controls (P= 0.00019, P= 0.00022 respectively) The relation wasstatistically non-significant between the antibody seropositivity and gender but Highly significant with age.Conclusion: The findings indicate that Helicobacter pylori_ infection can be regarded as a contributinginfluence for progressive tumor in colorectal.

Effects of Multi-Strain Probiotics on Immune Responses and Metabolic Balance in Helicobacter pylori-Infected Mice.

Chronic inflammation caused by Helicobacter pylori infection increases the risk of developing gastric cancer. Even though the prevalence of H. pylori infection has been decreased in many regions, the development of antibiotic resistance strains has increased the difficulty of eradicating H. pylori. Therefore, exploring alternative approaches to combat H. pylori infection is required. It is well-known that probiotic therapy can improve H. pylori clearance. In this study, H. pylori-infected mice were treated with Lactobacillus fermentum P2 (P2), L. casei L21 (L21), L. rhamnosus JB3 (JB3), or a mixture including the aforementioned three (multi-LAB) for three days. All the lactic acid producing bacteria (LAB) treatments decreased H. pylori loads in the stomach and vacA gene expression, H. pylori specific immunoglobulin (Ig) A, and IgM levels in stomach homogenates, as well as serum levels of interferon-gamma and interleukin-1 beta. The multi-LAB and JB3 treatments further restored the superoxide dismutase and catalase activities suppressed by H. pylori infection. Furthermore, H. pylori infection decreased serum concentrations of 15 kinds of amino acids as well as palmitic acid. The multi-LAB treatment was able to recover the serum levels of alanine, arginine, aspartate, glycine, and tryptophan, which are all important in modulating immune functions. In addition, butyric acid, valeric acid, palmitic acid, palmitoleic acid, stearic acid, and oleic acid levels were increased. In this study, multi-LAB revealed its ability to adjust the composition of metabolites to improve health. To date, the mechanisms underlying how LAB strains crosstalk with the host are not fully understood. Identifying the mechanisms which are regulated by LABs will facilitate the development of effective therapies for infection in the future.

Helicobacter pylori Infection and the Development of Advanced Colorectal Neoplasia.

An association between Helicobacter pylori infection and colorectal neoplasia has been reported in cross-sectional studies. We examined the association between H. pylori infection and the development of advanced colorectal neoplasia (AN) in a screening cohort. 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. 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. 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.

Possible association between Helicobacter pylori infection and vocal fold leukoplakia.

Several studies have indicated the larynx as possible Helicobacter pylori (H. pylori) reservoirs. This study explored the association between H. pylori and vocal fold leukoplakia. The case-control study involved 51 patients with vocal fold leukoplakia and 35 control patients with vocal polyps. Helicobacter pylori was detected in tissues by the rapid urease test, nested polymerase chain reaction (PCR), and single-step PCR. The H. pylori-specific immunoglobulin antibodies were detected in plasma by enzyme-linked immunosorbent assay (ELISA). Helicobacter pylori-positive rate of vocal fold leukoplakia and vocal polyps was 23.5% versus 11.4% (P = .157), 37.2% versus 14.3% (P = .020), 27.5% versus 8.6% (P = .031), and 70.6% versus 68.6% (P = .841) detected by rapid urease test, nested PCR, single-step PCR, and ELISA, respectively. Regression analysis indicated that H. pylori infection (P = .044) was the independent risk factor for vocal fold leukoplakia. Helicobacter pylori infection exists in the larynx and may be associated with vocal fold leukoplakia.

A cohort study on Helicobacter pylori infection associated with nonalcoholic fatty liver disease.

Previous studies have suggested a link between Helicobacter pylori (H. pylori) infection and nonalcoholic fatty liver disease (NAFLD), yet large-scale longitudinal studies are lacking to elucidate this association. A cohort study of 17,028 adults without NAFLD at baseline, who participated in a repeated health screening examination including an H. pylori-specific immunoglobulin G antibody test, was conducted to evaluate the association between H. pylori and NAFLD development. Fatty liver was diagnosed by ultrasonography. During the 83,130 person-years follow-up, participants with H. pylori infection had a higher rate of incident NAFLD than those who were uninfected. In a multivariable model adjusted for age, sex, body mass index, smoking status, alcohol intake, regular exercise, year of screening exam, and education level, the hazard ratio (HR) for NAFLD development in participants with H. pylori infection compared to those without infection was 1.21 [95% confidence interval (CI), 1.10-1.34]. The association persisted after further adjustment for metabolic variables, inflammatory marker, and liver enzymes. The association between H. pylori and NAFLD was still evident in an analysis using fatty liver index as a surrogate marker of NAFLD. In addition, the association between H. pylori infection and incident NAFLD did not differ across clinically relevant subgroups evaluated. H. pylori infection was significantly associated with the development of NAFLD, independent of metabolic and inflammatory risk factors. H. pylori infection may play a pathophysiologic role in NAFLD development, indicating that H. pylori eradication might play a role in reducing the risk of NAFLD.

Helicobacter pylori infection is an independent risk factor of early and advanced colorectal neoplasm.

The role of Helicobacter pylori (H. pylori) in the development of colorectal neoplasm remains controversial. We examined the association between H. pylori infection and colorectal neoplasm in a large sample of healthy participants who underwent screening colonoscopy. A cross-sectional study of 8916 men, who participated in a regular health-screening examination that included an H. pylori-specific immunoglobulin G antibody test and colonoscopy, was conducted to evaluate the association between H. pylori and colorectal neoplasm. Multivariable analyses adjusted for age, body mass index, smoking status, alcohol intake, regular exercise, regular aspirin use, and family history of colorectal cancer showed that the odds ratio (OR) (95% confidence interval [CI]) for any adenoma and advanced neoplasm was 1.32 (1.07-1.61) and 1.90 (1.05-3.56) in participants with H. pylori infection and without H. pylori infection, respectively. The association persisted after further adjustment for inflammatory markers or metabolic variables including fasting blood glucose, triglycerides, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol. Regarding the location, a positive association was confined to cases with proximal adenomas and was observed similarly in all the evaluated subgroups. In a large-scale study, carefully controlled for confounding factors, involving asymptomatic participants without a history of colonoscopy, H. pylori infection was significantly associated with the risk of any colorectal adenoma and advanced colorectal neoplasm. Prospective studies are necessary to determine whether H. pylori eradication can reduce this risk.

Association between Helicobacter pylori seropositivity and mild to moderate COPD: clinical implications in an Asian country with a high prevalence of H. pylori.

BackgroundHelicobacter pylori infection is a major cause of gastric diseases. The clinical implications of H. pylori infection in various diseases outside the gastrointestinal system have also been reported, including in some respiratory disorders. In this study, we investigated the seroprevalence of H. pylori in patients with mild to moderate COPD in an Asian country with a high prevalence of H. pylori infection. Also, we aimed to elucidate the association between the seroprevalence of H. pylori and the decline of lung function in patients with COPD.MethodsParticipants who underwent a medical checkup for H. pylori at a referral hospital in Korea were recruited for this study. All participants were tested for H. pylori infection using an immunoassay of the H. pylori-specific immunoglobulin G (IgG) concentration and a rapid urease test at the time of endoscopy with a gastric mucosal specimen. We assessed the decline in lung function using the spirometric data of those who underwent spirometry more than three times.ResultsIn total, 603 participants (201 patients with COPD and 402 controls) were analyzed. The seroprevalence of H. pylori IgG in the patients and controls was 45.8% and 52.2%, respectively (P=0.134). The H. pylori IgG level in patients with COPD was not significantly different from that of the controls (114.8 and 109.6 units/mL, respectively; P=0.549). In addition, there were no significant differences in the annual forced expiratory volume in 1 second or forced vital capacity between the participants with H. pylori seropositivity and seronegativity.ConclusionThis study showed no relationship between H. pylori infection and COPD in a country with a high burden of H. pylori infection. Furthermore, H. pylori infection did not affect the rate of lung function decline in this study population.

Association of H. pylori Infection with Insulin Resistance and Metabolic Syndrome Among Lebanese Adults

Several epidemiological studies proposed an association between Helicobacter pylori ( H. pylori) infection with insulin resistance (IR) and metabolic syndrome (MetS). However, up to date there is no conclusive evidence regarding this association. To investigate the prevalence and correlates of H. pylori infection among Lebanese adults and to evaluate its association with IR and MetS. Stored blood samples of adults participating in the national Nutrition and Non-Communicable Diseases Risk factors survey conducted in Lebanon were used for this study (n = 308). H. pylori-specific immunoglobulin G antibody titers were measured by ELISA. Data available included, in addition to anthropometric measurements, sociodemographic and lifestyle characteristics, blood pressure, and biochemical indices (serum insulin, HDL, LDL, TAG, glucose). A HOMA -IR level was used to assess insulin resistance. The International Diabetes Federation criteria were used to classify study participants with MetS. The prevalence of H. pylori infection in the study sample was 52% (95% CI, 46.43-57.57). A higher crowding index was associated with a 50% increase in the odds of infection (OR, 1.41; CI, 1.08-2.27). Blood pressure, waist circumference, serum HDL, LDL, TAG, and glucose levels were comparable between H. pylori positive and negative subjects. The odds of IR and MetS were not significantly different between the two groups. Prevalence of H. pylori infection in Lebanon is comparable to other developing countries. Furthermore, our findings suggested no association of H. pylori infection with IR or MetS. Eradication of H. pylori infection to prevent IR or MetS is not warranted.

Salivary IgG assay to detect Helicobacter pylori infection in an Indian adult population

Helicobacter pylori infection, the commonest chronic bacterial infection in humans, causes chronic gastritis, peptic ulcer, and possibly gastric carcinoma and lymphoma. Recently, investigators have focused on its role in the development of extra-gastrointestinal diseases with oral manifestations. H. pylori infection can be diagnosed by various methods. Of late, H. pylori IgG antibodies have been detected in saliva using enzyme-linked immunosorbent assay (ELISA). However, local validation of serological test is needed before implementing a test in different populations. To detect anti H. pylori specific immunoglobulin G (IgG) antibodies in saliva of adult patients with gastrointestinal symptoms by ELISA, to diagnose H. pylori infection in such patients by histopathology, and to evaluate the diagnostic accuracy of the immunoassay as compared to histopathologic diagnosis. The study included 40 adult patients with gastrointestinal symptoms suggestive of peptic ulcer disease. Saliva samples were analyzed for anti H. pylori IgG using EIAgen H. pylori IgG kit. Histopathologic diagnosis using gastric biopsy samples was the gold standard. The sensitivity and specificity of the test were 79.31% and 63.64%, respectively. The positive and negative predictive values were 85.19% and 53.85%, respectively. The accuracy of EIAgen H. pylori IgG kit for salivary detection of anti H. pylori IgG antibodies was found to be 75%. EIAgen H. pylori IgG assay is a noninvasive, moderately accurate, and sensitive method for the detection of H. pylori infection in saliva. Salivary anti H. pylori IgG test prior to endoscopy is a useful screening test for seroepidemiological studies.

Helicobacter pylori Seropositivity in Institutionalized Children With Down Syndrome

To the Editors: Helicobacter pylori is usually acquired in early infancy and probably persists throughout the life.1 Host genetic background, environment, and bacterial determinants contribute to the development of H. pylori-associated diseases.2 Poor living and socioeconomic conditions as well as overcrowding are among the main risk factors for infection during childhood.3 Children with Down syndrome (DS) have multiple immunologic defects.4 It remains controversial whether abnormality of immune responses in such children increases the propensity to infections. We undertook a study to find H. pylori seropositivity among children with DS compared with age- and gender-matched children having other intellectual disabilities with similar nutritional regimen and living and hygienic environment. Peripheral blood samples were collected from 24 children with DS and 24 children with other intellectual disabilities who were residents of 3 institutes for intellectually disabled children in Tehran. The paired match of each DS case was selected from other intellectual disabilities cases of the same institute, so the matched cases had similar living conditions. Serum H. pylori-specific immunoglobulin G (IgG) antibody was measured using ELISA (enzyme-linked immunosorbent assay) method, according to manufacturer's instructions (IMMUNOLAB GmbH, Germany). The results were considered positive if H. pylori IgG titer were >0.1 U/mL. For statistical analysis, χ2 test and nonparametric tests (Mann-Whitney and Kruskal–Wallis tests) were used. A P value of ≤0.05 was considered statistically significant. The DS and other intellectual disabilities groups each consisted of 13 females and 11 males, ranging in age from 1 to 15 years, and the mean age ± SD was 5.75 ± 4.35. H. pylori-specific IgG was detected in 17 of 24 (70.8%) DS children with a median titer of 30.09 U/mL. Among other intellectual disabilities children, 15 of 24 (62.5%) were seropositive with a median IgG of 34.34 U/mL. The seroprevalence of H. pylori infection in children with DS did not significantly differ from that in children suffering from other intellectual disabilities (odds ratio: 1.45; 95% confidence interval: 0.43–4.87). In the current small groups, seropositivity rates were similar in DS and other intellectual disabilities children in relation to age. More than half of seropositive children in DS (52.9%) and other intellectual disabilities (60%) groups were younger than 6 years, and this difference was not statistically significant. The median duration of institutionalization was 30 months (range, 6–96 months) for DS group and 24 months (range, 7–96 months) for other intellectual disabilities group. The antibody response against H. pylori was not associated with gender and duration of institutionalization. The current study demonstrated high seropositivity for H. pylori in DS children. The high seropositivity may be attributed to the fact that overcrowding, sanitary conditions, and dietary regimen in childhood affect the route of H. pylori transmission and infection.3 No significant difference was found in the risk of H. pylori seropositivity between children with DS and those with other intellectual disabilities. Two studies have reported H. pylori seropositivity in children with DS with lower rates. Jaber5 assessed 24 children with DS in Saudi Arabia and found a 29.2% seropositivity rate. A study of 46 children with DS by Failla et al6 showed that 19.5% of cases were seropositive. Both studies were of noninstitutionalized children with DS, whereas we examined children reside permanently in the institutes. Hence, the higher seropositivity of H. pylori infection might be explained by institutionalization and sanitary conditions as major risk factors. On the other hand, children with DS did not show a significantly higher susceptibility to H. pylori infection than children with other intellectual disabilities. It seems that host response against H. pylori infection is similarly influenced by environmental conditions in DS versus other intellectually disabled cases. Masoumeh Douraghi, PhD Department of Microbiology Shahid Beheshti University of Medical Sciences Division of Microbiology Department of Pathobiology School of Public Health Tehran University of Medical Sciences Tehran, Iran Hossein Goudarzi, MD, PhD Department of Microbiology Shahid Beheshti University of Medical Sciences [email protected] Mahmoud Nateghi Rostami, PhD Department of Public Health Qom University of Medical Sciences Qom, Iran Elnaz Sadat Mirsamadi, MSc Department of Microbiology Shahid Beheshti University of Medical Sciences Tehran, Iran

Investigation of the Association betweenHelicobacter pyloriInfection and Normal Tension Glaucoma

To investigate whether Helicobacter pylori infection is associated with normal tension glaucoma (NTG). One hundred consecutive NTG patients (group 1) from an outpatient glaucoma clinic were enrolled. Medical records of the 88 control participants (control 1) of the outpatient clinic, and 104 NTG patients (group 2) and 1116 healthy controls (control 2) (1220 subjects in total) from a primary health care center were reviewed retrospectively to compare the results. Serum samples from all subjects were analyzed for the presence of H. pylori-specific immunoglobulin G antibodies using ELISA. The distributions of serologic H. pylori test results of the NTG patients and control subjects were compared, and possible associations between clinical phenotypes and positive serologic results were assessed. Bilaterality of NTG patients was also analyzed. NTG patients had significantly more positive serologic results than did the healthy controls. There were significant differences between group 1 and control 1 patients (P = 0.020; odds ratio [OR], 2.05), group 1 and control 2 patients (P = 0.016; OR, 1.73), and group 2 and control 2 patients (P = 0.008; OR, 1.83). However, no significant association was found between clinical characteristics and a positive serologic result for H. pylori in NTG patients. This study suggests that H. pylori infection may be associated with an increased risk for NTG. H. pylori may play a role in the development or progression of NTG as a secondary aggravating factor because of the coexistence of other main causes or it may be the primary cause.

Online immunoaffinity assay‐CE using magnetic nanobeads for the determination of anti‐Helicobacter pylori IgG in human serum

About two-thirds of the world's population is infected with Helicobacter pylori (H. pylori). This Gram-negative bacterium is the most important etiological agent of chronic active type B gastritis and peptic ulcer diseases. Conventional methods such as gastric biopsy, ELISA and culture, require a long time for the determination of H. pylori infections. Moreover, the antibodies in human serum sample are capable to react immunologically with the purified H. pylori antigens immobilized on different kinds of support like magnetic nanobeads. In this study, we have developed an online immunoaffinity assay-CE to determine the concentration of anti-H. pylori IgG using magnetic nanobeads as a support of the immunological affinity ligands and an LIF as a detector. The separation was performed in 0.1 M glycine-HCl, pH 2, as the background electrolyte. The linear calibration curve to predict the concentration of H. pylori-specific immunoglobulin G antibodies in serum was produced within the range of 0.12-100 U/mL. The linear regression equation was i = 492.86+96.03 × C(anti-H. pylori), with the linear regression coefficient r(2) = 0.999. The LOD calculated by fluorescence detection procedure was of 0.06 U/mL. The whole assay was done in no more than 35 min and it was entirely automatized. The development of immunoaffinity assay-CE in this study demonstrates that there is a large possibility to introduce nanotechnology in several fields with significant advantages over the classic methodologies. Our proposition comprises the diagnosis and screening field.

Experimental Helicobacter pylori Infection Induces Antral‐Predominant, Chronic Active Gastritis in Hispid Cotton Rats (Sigmodon hispidus)

The hispid cotton rat has proven to be an excellent animal model for a variety of human infectious disease agents. This study was performed to evaluate the use of the cotton rat as a model of Helicobacter pylori infection. Thirty-eight inbred cotton rats were orogastrically inoculated with a human strain of H. pylori. Twenty-eight control cotton rats were dosed with vehicle only. Animals were sacrificed at 2, 4, 12, 26, or 38 weeks after inoculation for bacterial and histologic and immunologic examinations. Helicobacter pylori was cultured from the glandular stomach of 89% of the infected cotton rats. The level of colonization was consistently high (approximately 10(4-6) colony-forming units/g tissue). Histologically, the spiral bacteria were demonstrated on the epithelial surface and in the foveolae of the gastric mucosa with highest numbers in the antrum. H. pylori infection was associated with antral-predominant, chronic active gastritis which progressively increased in severity over time. By week 26 of infection, moderate antral gastritis had developed with frequent involvement of the submucosa and formation of lymphocytic aggregates. Splenic T cells from infected cotton rats expressed mRNAs for interferon-gamma, interleukin-4, interleukin-6, and interleukin-10 following in vitro stimulation with H. pylori. Serum levels of H. pylori-specific immunoglobulin G were significantly elevated after 12 weeks of infection. The H. pylori-infected cotton rat represents a novel animal model that should prove useful for studies of H. pylori-induced chronic active gastritis and factors affecting gastric colonization by this pathogen.

B-Cell and T-Cell Immune Responses to ExperimentalHelicobacter pyloriInfection in Humans

The acute antibody and T-cell immune response to Helicobacter pylori infection in humans has not been studied systematically. Serum from H. pylori-naive volunteers challenged with H. pylori and cured after 4 or 12 weeks was tested by enzyme-linked immunosorbent assays for anti-H. pylori-specific immunoglobulin M (IgM) and IgA established using bacterial lysates from homologous (the infecting strain) and heterologous H. pylori. Proteins recognized by IgM antibody were identified by mass spectrometry of immunoreactive bands separated by two-dimensional gel electrophoresis. Mucosal T-cell subsets (CD4, CD8, CD3, and CD30 cells) were assessed by immunohistochemistry. All 18 infected volunteers developed H. pylori-specific IgM responses to both homologous or heterologous H. pylori antigens. H. pylori antigens reacted with IgM antibody at 4 weeks postinfection. IgM Western blotting showed immunoreactivity of postinfection serum samples to multiple H. pylori proteins with molecular weights ranging between 9,000 (9K) to 150K with homologous strains but only a 70K band using heterologous antigens. Two-dimensional electrophoresis demonstrated that production of H. pylori-specific IgM antibodies was elicited by H. pylori flagellins A and B, urease B, ABC transporter binding protein, heat shock protein 70 (DnaK), and alkyl hydroperoxide reductase. Mucosal CD3, CD4, and CD8 T-cell numbers increased following infection. IgM antibody responses were detected to a range of homologous H. pylori antigens 2 to 4 weeks postchallenge. The majority of H. pylori proteins were those involved in motility and colonization and may represent targets for vaccine development.

Prevalence of Helicobacter pylori in Patients with Nasal Polyps: A Preliminary Report

The aim of the study is to determine the presence of H. pylori in nasal polyps by both immunohistochemical staining with H. pylori antibody of biopsy specimens and enzyme-linked immunoadsorbent assay (ELISA) of sera. A prospective, controlled, clinical trial. We enrolled 30 patients with nasal polyps and 20 controls with middle concha bullosa undergoing endoscopic sinus surgery (ESS). Blood samples of both the study and control groups were evaluated for anti-H. pylori specific immunoglobulin (Ig)G antibodies by ELISA. In addition, biopsy specimens of the removed polyps and the mucosal part of middle conchas were examined by the immunohistochemical analysis with H. pylori antibody. In the blood samples, specific IgG antibodies to H. pylori were found in 26 (86.7%) of 30 polyp patients and 17 (85%) of 20 controls. In 6 (20%) of the 30 patients, H. pylori was identified in the nasal polyp tissue, but it was not detected in the mucosal part of the middle concha specimens. No significant statistical difference was observed for H. pylori antibodies by ELISA among the patients with nasal polyps and the control group (Fisher's exact test, P = .59). However, there was a statistical difference between the polyp biopsy specimens and the control biopsy specimens by immunohistochemical staining (Fisher's exact test, P = .037). This study indicates that H. pylori was found in increased prevalence in the nasal polyps. However, further controlled epidemiologic studies would be necessary to confirm our results and clarify the potential underlying pathogenetic mechanisms.

Production of anti-Helicobacter pylori urease-specific immunoglobulin in egg yolk using an antigenic epitope of H. pylori urease.

The potential therapeutic effects of Helicobacter pylori-specific immunoglobulin (IgY-Hp) derived from egg yolk and identification of the immunodominant H. pylori proteins have previously been reported. In this study, the urease epitope that is recognized by IgY-Hp was identified and used as an immunogen to produce urease-specific IgY (IgY-HpU). Epitope regions were mapped and peptides of selected epitope regions were synthesized. The IgY-Hp titre against synthetic peptides was evaluated using ELISA analysis. Hens were immunized with synthetic peptides conjugated with BSA. Urease activity was quantified by measuring the optical density of an indicator dye. Of the five synthetic peptides assayed, a peptide representing 15 amino acid residues of UreB (UB-3; aa 396-410, DNDNFRIKRYLSKYT) was specifically recognized by the IgY-Hp. Immunization of hens with BSA-conjugated UB-3 resulted in the generation of IgY-HpU. IgY-HpU markedly reduced H. pylori urease activity by 80 % as compared to control IgY (IgY-BSA). The availability of the synthetic UreB-derived peptide enabled the production of highly specific anti-urease IgY, which had a significant inhibitory effect on H. pylori urease activity. Therefore, specific IgY-HpU produced using the synthetic peptide may be an effective tool against infection by H. pylori.

Helicobacter pylori infection and the risk for open-angle glaucoma

Purpose To determine the frequency of exposure to Helicobacter pylori infection in glaucoma patients. Design Prospective case-control study. Participants Ninety-seven consecutive patients attending a glaucoma clinic. These included 38 patients with primary open-angle glaucoma (POAG), 19 with normal pressure glaucoma (NPG), 16 with pseudoexfoliation glaucoma (PXE), and 24 with ocular hypertension (OHT). Ninety-four age-matched participants without glaucoma served as a control population. Methods Serum was analyzed for the presence of H. pylori–specific immunoglobulin G antibodies by enzyme-linked immunosorbent assay. Main outcome measures Serologic analysis for H. pylori. Results Seropositivity for H. pylori was higher in patients with glaucoma (26.0%) than in controls (20.2%), but this did not achieve statistical significance ( P = 0.46). A total of 26.3% of POAG patients, 26.3% of NPG patients, 25.0% of PXE patients, and 25.0% of OHT patients were seropositive. Conclusions This study suggests that exposure to H. pylori infection is not associated with open-angle glaucoma.

Common presence of Helicobacter DNA in the gallbladder of patients with gallstone diseases and controls.

Several species of Helicobacter colonise the biliary tract of animals and cause hepatobiliary diseases. Helicobacter species have also been identified in the gallbladder of a high proportion of Chilean patients with gallbladder cancer. To determine the presence of Helicobacter species, particularly Helicobacter pylori and Helicobacter bilis, in the gallbladder of patients with non-malignant gallbladder diseases and control patients. DNA was extracted from gallbladder samples from 122 consecutive patients undergoing cholecystectomy. The presence of Helicobacter genus-specific or Helicobacter pylori and Helicobacter bilis species-specific DNA was determined by polymerase chain reaction and sequence analysis. The presence of Helicobacter pylori-specific immunoglobulin G in the serum (n=84) and bile (n=104) samples was determined by enzyme linked immunosorbent assay. Helicobacter DNA was detected in 61 (50.0%) gallbladder samples: 29 of 60 (48.3%) patients with symptomatic gallstone, six of 10 (60.0%) patients with asymptomatic gallstones, 11 of 15 (73.3%) patients with other biliary diseases, and 15 of 37 (40.5%) control patients, respectively. Among them, 39 samples were positive for Helicobacter pylori but none were positive for Helicobacter bilis. Sequence analysis of Helicobacter genus-positive samples showed that 56 samples were Helicobacter pylori and five were Helicobacter species 'Liver 3' strain. Overall, there was no significant difference in the detection rate of Helicobacter DNA or the levels of serum and bile Helicobacter pylori-specific immunoglobulin G in the various biliary disease groups compared with control patients. Neither was there any significant difference in the blood biochemistry and liver function tests between patients with positive and negative Helicobacter DNA detection. Helicobacter species' DNA are commonly present in the gallbladder of patients with gallstone diseases and in controls, implying that Helicobacter infection alone may not play a significant role in the formation of gallstones. However, our results do not exclude the possibility of Helicobacter infection as a cofactor in the development of gallstones.

Helicobacter pylori-specific immunoglobulin synthesis in gnotobiotic piglets: evidence for the induction of mucosal immunity in the stomach

Short term tissue biopsy cultures and paired, sera, bile and gastric and intestinal contents from Helicobacter pylori-infected gnotobiotic piglets were tested for the synthesis of H. pylori-specific immunoglobulin (Ig) isotype production by antigen-specific ELISA from post-infection days (PIDs) 2–28. Serum antibody levels in all three Ig isotypes were elevated from baseline values by PID 14, serum IgM levels reached peak levels on PID 14 and by PID 28 bile was strongly positive for IgA and IgG. Intestinal, but not gastric contents from infected piglets, contained IgA-specific antibody from PID 14 onward. Gastric mucosal epithelia adjacent to areas of inflammation in infected but not uninfected control piglets produced readily detectable amounts of porcine secretory component (SC); IgA-positive plasma cells were identified in gastric submucosa and lamina propria in these areas. Culture fluid supernatants, collected from explanted gastric cardia and antra and intestinal ilea of H. pylori-infected piglets had trace amounts of IgA as early as PID 2 in some animals, and strong IgA reactivity in all by PID 28. Supernatants also contained H. pylori-specific IgG by PID 14. A strong gastric lymph node IgA response contrasted with moderate IgA production in mesenteric lymph nodes and spleen. Mucosal biopsy production of H. pylori-specific IgG was more evenly distributed throughout the lymphoid system. These data support the contention that the Ig response to H. pylori is initiated within the gastric compartment and matures over time to a generalized IgA-dominated mucosal and IgG-dominated nonmucosal humoral immune response.

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

Serology and (13)C-urea breath test have been widely used as noninvasive tests to detect Helicobacter pylori infection. However, easier collection of samples and lower costs are desirable for diagnosis of the individual patient or for use in epidemiologic studies. Our aim was to study the diagnostic accuracy of a recently developed urine-based enzyme-linked immunosorbent assay (ELISA) kit for the detection of H pylori-specific immunoglobulin G (IgG) antibodies in children. Specimens of serum and randomly voided urine were collected from 816 children (0-15 years old) and were analyzed using 2 serum-based ELISA kits and a urine-based ELISA kit, respectively. Based on results of serology, the sensitivity, specificity, and accuracy of the urine-based ELISA kit were evaluated. With regard to false-positive and false-negative results, urinary IgG concentrations and IgG/creatinine levels were studied. Both serum-based ELISAs were positive in 41 children and were negative in 666, who were enrolled in this study. The remaining 109 children were excluded because of disagreement between the results of the 2 serum-based ELISAs, including indeterminate values. Overall sensitivity, specificity, and accuracy of urine-based ELISA test compared with serology were 85.4%, 95.5%, and 94.9%, respectively. On positivity rates, the urine-based ELISA was closely coincident with the serum-based ELISA in each age group. There was no correlation between antibody levels detected by urine-based ELISA and each serum-based ELISA. Urinary IgG concentrations and IgG/creatinine levels were significantly higher in false-positives and were lower in false-negatives than in true-positives plus true-negatives for serology. Most of those with false-positive results had trace to moderate proteinuria. The urine-based ELISA is an alternative to serum-based ELISA for diagnosis of H pylori infection in children and should be suitable for large-scale epidemiologic studies concerning the organism. In children with proteinuria, results of the test should be interpreted with caution. It is possible that the urine-based ELISA method would be applicable to diagnosis of other infectious diseases.