Helicobacter pylori CagA antigen antibodies

BACKGROUND: CagA antigen of Helicobacter pylori is highly immunogenic in humans. There is an increasing evidence that infection with CagA-positive strains is related to the development of peptic ulcer disease, atrophic gastritis, or gastric cancer. The aim of our study was to assess seropositivity to CagA in a group of 95 clinically symptomatic adults who underwent gastroduodenoscopy and to correlate results to their disease characteristics. METHODS AND RESULTS: Serum immunoglobulin G antibodies to CagA detected by ELISA kit (Helicobacter p120, Viva Diagnostika, Germany) were compared to standard IgG specific antibodies against a pool of H. pylori antigens Synelisa Pin plate, ELIAS, Germany). Immunoglobulin G antibodies to CagA were present in 5/31 (16%) serum samples from H. pylori negative persons and 10/28 (36%) serum samples from H. pylori positive patients without peptic ulcer disease compared with 8/11 (73%) H. pylori positive patients with peptic ulcer disease in the past, 11/13 (85%) H. pylori positive patients with duodenal ulcers or duodenitis and 4/5 (80%) H. pylori positive (1/7, 14% H. pylori negative) serum samples from patients with gastric resection for peptic ulcers in the past. Serum levels of antibodies to CagA in the groups of patients with peptic ulcer disease in the past, with present duodenal ulcers of duodenitis and in H. pylori infected patients with gastric resection were significantly higher then those of H. pylori infected patients without peptic ulcer disease (P < 0.05). On the other hand, there was no significant difference in the presence of the specific antibodies against at pool of H. pylori antigens between these four groups. CONCLUSIONS: These data suggest that serologic response to the CagA antigen is more prevalent in H. pylori positive persons with present or past peptic ulceration than among infected persons without peptic ulcer disease. The presence of antibodies to CagA in H. pylori positive persons may be useful for the identification of patients with higher risk or more severe disease.     

Metronidazole- and clarithromycin-resistant Helicobacter pylori in dyspeptic patients in western Sydney as determined by testing multiple isolates from different gastric sites

It is unknown whether antibiotic susceptibility testing of antral isolates alone is representative of Helicobacter pylori susceptibility. We aimed to determine: (i) the prevalence of metronidazole- and clarithromycin-resistant strains in infected dyspeptic patients; and (ii) whether there is consistency in the susceptibility to metronidazole and clarithromycin among isolates cultured from different gastric sites. Antral, body and fundus biopsies were taken from 242 consecutive patients and cultured on blood agar under micro-aerophilic conditions for 5-7 days. Isolates from 66 patients (13 had one, 15 had two and 38 had three isolates) were tested for susceptibility to metronidazole and clarithromycin using previously validated disc diffusion tests. Of the 66 patients, 42 (64%) had strains resistant to metronidazole while four (6.1%) had clarithromycin-resistant strains. The prevalence of metronidazole resistance was not significantly different between men and women (65% vs 60%) or across different age groups. In five (9.4%) of the 53 patients with multiple isolates, discrepant results for metronidazole susceptibility were observed: susceptible antral and body isolates but resistant fundus isolates in two cases and susceptible antral isolates but resistant body and fundus isolates in the others. Clarithromycin susceptibilities were consistent among the isolates cultured from different gastric sites in all patients. It is concluded that metronidazole-resistant strains of H. pylori are common while clarithromycin-resistant strains are rare. Metronidazole susceptibility testing of antral isolates does not appear to be representative of isolates from the body and fundus in a subset of patients.     

Carbohydrate-deficient transferrin: marker of actual alcohol consumption or chronic alcohol misuse?

In this randomized, multicenter trial, we evaluated the effectiveness and side effect profile of a modified omeprazole-based triple therapy to cure Helicobacter pylori infection. The control group consisted of patients treated with standard dual therapy comprising omeprazole and amoxicillin. One hundred and fifty-seven H. pylori infected patients with duodenal ulcers were randomly assigned to receive either a combination of omeprazole 10 mg, clarithromycin 250 mg and metronidazole 400 mg (OCM) given three times daily for 10 days (n = 81), or a combination of omeprazole 20 mg and amoxicillin 1 g (OA) given twice daily for 14 days (n = 76). Prior to treatment and after 2 and 6 weeks, gastric biopsies from the antrum and corpus were obtained for histology and H. pylori culture. H. pylori infection was cured in 97.4% after OCM and in 65.8% after OA in the per-protocol analysis (p < 0.001) (intention-to-treat analysis: 93.4% and 63.2%, respectively). H. pylori was successfully cultured in 122 patients (77%). The overall rate of metronidazole resistance was 19.7% (24/122), no primary resistance to clarithromycin or amoxicillin was found. In the OCM group, all patients infected with metronidazole-sensitive H. pylori strains (n = 51) and those infected with strains of unknown susceptibility to metronidazole (n = 14) were cured (100%), while 77% (10/13) of those harboring metronidazole-resistant strains were cured of the infection (p = 0.36). Side effects leading to premature termination of treatment occurred in 2.5% of the patients in the OCM group and in 1.4% of the OA group. We conclude that combined treatment with omeprazole, clarithromycin and a higher dose of metronidazole is highly effective in curing H. pylori infection, and that this regimen remains very effective in the presence of metronidazole-resistant strains.     

Isolation of a genetic locus associated with metronidazole resistance in Helicobacter pylori

We examined the molecular mechanism of metronidazole resistance by constructing a lambda-Zap II phagemid expression library with genomic DNA from a metronidazole-resistance strain of Helicobacter pylori. Twenty-two clones were found to have elevated MTZ resistances in XLOLR strain of E. coli. Phagemids belonging to the twenty two clones were extracted and then retransformed into the XLOLR strain of E. coli. After MTZ selection, five clones could confer metronidazole resistance consistently. According to Southern hybridization and DNA sequencing, the five clones contained a same locus, recA. In addition, transforming the five clones into BL21 strain of E. coli produced a higher resistance to MTZ. Interestingly, electroporation of one of the five phagemid clones into two MTZ sensitive H. pylori yielded MTZ resistant strains. Comparing amino acid sequence in MTZ resistant with sensitive isolates revealed two point mutations at this locus. Above results suggest that mutation in recA may be associated with metronidazole resistance of H. pylori.     

Human antibody response to Helicobacter pylori lipopolysaccharide: presence of an immunodominant epitope in the polysaccharide chain of lipopolysaccharide

We have examined the antibody response to Helicobacter pylori lipopolysaccharides (LPS) in humans. We used sera from patients with gastroduodenal diseases and healthy adults infected or not infected with H. pylori. Data from the experiments for antibody binding to LPS suggested that the polysaccharide chains from many H. pylori strains showed high immunogenicity in humans. Sera from most (above 70%) H. pylori-infected individuals contained immunoglobulin G (IgG) antibodies against the polysaccharide region highly immunogenic H. pylori LPS. The IgG titers of individual serum samples that reacted strongly with highly immunogenic LPS were quite similar (r2 = 0.84 to 0.98). The results suggest wide distribution among H. pylori strains of a highly antigenic epitope in the polysaccharide moieties of their LPS. Also, the similarity in the titers of individual serum samples against highly immunogenic LPS points to the existence of epitopes sharing a common structural motif. However, some strains showed low antigenicity, even those with polysaccharide-carrying LPS. The dominant subclass of IgG that reacted with the highly immunogenic LPS was IgG2, which was preferentially raised against polysaccharide antigens. Recently, a structure that mimics that of the Lewis antigens was identified in the O-polysaccharide fraction of H. pylori LPS; however, no correlation between antigenicity of the polysaccharide chain in humans and the presence of Lewis antigens was found. The IgA and IgM titers against H. pylori LPS seemed to be mostly nonspecific and directed against lipid A. In a few cases, however, sera from individuals infected with H. pylori gave strong IgA and IgM titers against the highly immunogenic polysaccharide. In conclusion, the LPS of many H. pylori strains possess an antigenic epitope in their polysaccharide regions that is immunogenic in humans. However, our results show that the antigenic epitope is unlikely to be immunologically related to structures mimicking Lewis antigens.     

Co- and/or post-translational modifications are critical for TCH4 XET activity

OBJECTIVES: We sought to examine the extent to which physicians recognize H. pylori as a causal agent in peptic ulcer disease or as a potential cofactor in other gastrointestinal diseases, and to observe how this knowledge has influenced diagnostic and therapeutic practices. METHODS: We used a national mail survey in the U.S. between February and May of 1996, querying 5994 U.S. physicians (family/general practitioners [FPs], internists [IMs], and gastroenterologists) selected at random from three different membership databases of professional associations. RESULTS: The response rate was 52%. More than 95% of physicians who treat symptoms empirically would prescribe acid suppressant therapy rather than anti-H. pylori therapy. Between 43% and 66% of physicians, varying in frequency by medical specialty, would treat the infection in H. pylori-positive patients with nonulcer dyspepsia. In confirmed peptic ulcer disease, between 88% and 100% of physicians would treat the H. pylori infection, depending on the physician group and whether or not the presentation of an ulcer was recurrent. Although 103 distinct anti-H. pylori regimens were reported, 89% of the gastroenterologists and 70% of the primary care physicians (PCPs) used combinations of antimicrobials with reported cure rates of at least 80%. CONCLUSIONS: General knowledge regarding H. pylori-associated diseases was widespread among primary care physicians and gastroenterologists. However, anti-H. pylori therapies judged ineffective were reported as the first choice regimen by 5% of gastroenterologists and 18% of primary care physicians. Gastroenterologists appear to implement the latest scientific developments in the field rapidly whereas PCPs manifest a delayed response, due to either insufficient knowledge or to other factors influencing their approach to treatment.     

Eradication of Helicobacter pylori in developing countries]

A NIH Consensus Conference recommended Helicobacter pylori eradication to all ulcer patients, based mainly on information coming from countries with a low prevalence of infection in general population. The epidemiological situation is different in developing countries, where a pandemic of H. pylori goes unchecked, and most people become infected at young age. It is possible that response to eradication therapies and reinfection rate were to be included among the differences between developed and developing countries, raising doubts about the worldwide applicability of NIH recommendations. Limited published evidence and our experience suggest that eradication therapies have a lower efficacy and reinfection rate is significantly higher in developing compared to developed countries. In spite of this, the risk of ulcer recurrence after H. pylori eradication is substantially reduced compared to antisecretory therapy. Model analysis to evaluate the cost-effectiveness of H. pylori eradication, using figures that probably include the clinical and costs situation of developing countries, suggests that also from an economic perspective H. pylori eradication should be the standard treatment for peptic ulcer disease in developing countries. Local studies must determine the best eradication therapy for a particular geographical location, and longer follow-up of eradicated patients is needed to determine the true reinfection rate.     

Unsuccessful deflation of a bifoil balloon during percutaneous mitral valvuloplasty

Triple therapy (bismuth and two antibiotics) will eradicate Helicobacter pylori infection in 70-90% of subjects. Treatment failure has been attributed to patient compliance and antimicrobial drug resistance. The aim of this study was to examine factors influencing the eradication of H. pylori following triple therapy. Thirty seven subjects with H. pylori cultured from antral biopsies were treated with colloidal bismuth subcitrate (120 mg qid for 2 weeks), metronidazole (400 mg tid for 1 week) and amoxycillin (500 mg tid for 1 week). Pretreatment isolates of H. pylori were tested for metronidazole susceptibility by agar dilution according to the National Committee for Clinical Laboratory Standards guidelines. Factors including age, sex, clinical diagnosis and metronidazole resistance were evaluated in relation to H. pylori. The overall metronidazole resistance was 32%. Metronidazole resistant strains were more frequent in females, with a resistance rate of 54%. Helicobacter pylori eradication occurred in 68% of patients with a metronidazole susceptible stain and only 17% of patients with a metronidazole resistant strain (P < 0.03). Helicobacter pylori eradication is dependent upon susceptibility to metronidazole. This data would support the role for routine metronidazole susceptibility testing using appropriate standardized methods when triple therapy is to be considered.     

Effects of azadirachtin on mortality, growth, and immunological function in the wolf spider, Schizocosa episina (Araneae: Lycosidae)

Broth culture supernatants from 14 (34%) out of the 41 H. pylori strains tested, induced vacuolization in Intestine 407 cells in titers ranging from 1:2 to 1:64. 20% of H. pylori strains isolated from children and 42% of strains isolated from adults expressed vacuolating activity. Serum antibody to cytotoxin produced by H. pylori was detected with a neutralization assay. Anticytotoxic antibodies were present in all sera from patients infected with cytotoxic H. pylori strains. The toxin-neutralizing activity of sera from individuals infected with H. pylori suggests that the cytotoxin is produced in vivo.     

Functional dyspepsia, gastric emptying of solids, and Helicobacter pylori infection

The origin of functional dyspepsia (FD) is unknown, however, abnormal gastric emptying and infection by H. pylori have been suggested as possible causes. OBJECTIVE: The aim of this study was to test the hypothesis that infection by H. pylori could be related to alterations in gastric emptying of solids and play a role in the pathophysiology of dyspepsia. METHODS: Studies were performed on 12 controls: 6 males, 6 females, age 40 +/- 13, and on 45 FD patients: 15 males and 30 females, age 43.5 +/- 12. Clinical criteria for FD diagnosis were post-prandial epigastric pain, nausea, vomiting or epigastric bloating, with normal blood test, upper endoscopy and abdominal ultrasound. Diagnosis of H. pylori infection was either by growth positive on culture of antral biopsy or by all of the following: on Gram stain, urease test positive and visualization of microorganisms in the antral biopsy. Gastric emptying of solids was studied with a radio-nuclide technique. Patients were prospectively classified in 4 groups according to the main symptom: reflux-like, ulcer-like, dysmotility, and non-specific. RESULTS: H. pylori infection was observed in 21/32 (66%) FD patients. No significant differences in the gastric emptying of solids between the control group and patients with FD (tl/2 80 +/- 17 minutes vs 75 +/- 16 min). The presence of H. pylori infection did not influence gastric emptying rates (78 +/- 16 minutes in infected patients vs 73 +/- 15 min in non infected patients). Gastric emptying times were similar among the four subgroups of FD patients. CONCLUSIONS: No significant differences in gastric emptying of solids were found in H. pylori infected persons as compared with the controls. These findings suggest that H. pylori infection and/or changes in gastric emptying of solids do not play a role in the pathophysiology of FD.     

Glucose- and phorbol ester-induced insulin secretion in human insulinoma cells--association with protein kinase C activation

To investigate the incidence and demographics of gastric hypoacidity among persons infected with human immunodeficiency virus (HIV), 146 asymptomatic subjects were evaluated with use of a radiotelemetry device (Heidelberg capsule). Gastric hypoacidity (minimum gastric pH of > or = 3) occurred in 24 subjects (17%). Demographic characteristics, CD4 cell counts, and Helicobacter pylori serological status were evaluated for an association with gastric pH. Subjects with hypoacidity were more likely to have positive H. pylori serology than were subjects without hypoacidity (15 of 24 vs. 23 of 74, respectively; P = .004). Multivariate analysis indicated that a positive H. pylori serology was the most significant predictor of hypoacidity, accounting for an increase in gastric pH of 39%. A history of injection drug use, heterosexual transmission of HIV, and male gender were also associated with an elevated gastric pH. CD4 cell counts did not contribute to predictions of gastric pH. A history of H. pylori infection is relatively common in HIV-positive black and Hispanic populations and is a predictor of gastric pH.     

Rapid recurrence of Helicobacter pylori infection in Peruvian patients after successful eradication. Gastrointestinal Physiology Working Group of the Universidad Peruana Cayetano Heredia and The Johns Hopkins University

Helicobacter pylori is associated with gastritis, peptic ulcer disease, and gastric cancer. Since gastric cancer is common in Peru, eradication of H. pylori may help to reduce the occurrence of gastric cancer. This study involved three randomized trials to determine the efficacy of four different triple-drug therapy regimens. The most successful regimen was furazolidone combined with bismuth subsalicylate and amoxicillin, which eradicated infection in 82% of patients. Patients successfully treated were followed every 2-3 months to determine the recurrence rate of H. pylori infection. Of 105 patients with H. pylori eradication documented by pathology and culture, 52% (55) returned for follow-up endoscopy, and in 73% (40) of these 55 the infection recurred during the 8-month follow-up period. Thirty-five patients from whom H. pylori was eradicated and who were tested for antibodies to H. pylori remained consistently seropositive. Rapid recurrence of H. pylori infection after successful eradication suggests that measures other than antimicrobial therapy are needed to fight H. pylori in developing countries.     

Helicobacter pylori in 1997

In this review Helicobacter pylori (H. pylori) infection and its relation to different diseases is presented. H. pylori doesn't cause inconvenience to most infected people, though all infected persons have chronic active gastritis. The 10 year risk of peptic ulcer for people infected with H. pylori is about 10%. Randomized double-blinded trials have shown that eradication of H. pylori can cure most patients with peptic ulcer disease. Some people infected with H. pylori develop atrophic gastritis which is a risk factor for development of gastric cancer. It is not known if H. pylori screening and eradication would have a prophylactic effect against gastric cancer. It is also unknown if persons with non-organic dyspepsia and persons in long-term treatment with proton-pump-inhibitors would benefit from H. pylori eradication.     

Peptic ulcer in Greenland Inuit: evidence for a low prevalence of duodenal ulcer

In an eight years period new peptic ulcer was diagnosed in 127 Inuit patients at the Central Hospital, Dronning Ingrids Hospital, Nuuk/Godth?b. The ratios: duodenal ulcers (DU): prepyloric ulcers (PPU): gastric ulcers (GU) were 17:22:88. The male:female ratio was 2:1. 46 of the patients were living permanently in Nuuk, 81 in The Districts. There were no significant differences in the type of ulcers among the two groups. The incidence of GU among the Nuuk population was comparable to the incidence in the Danish population (0.63/1000 inhabitants per year), whereas the mean age at the time of diagnosis was only 45 years, thus the patients were approximately 15 years younger than the Danish counterparts. The incidence of DU among the Inuits was 0.15/1000 inhabitants per year, significantly less than in the Danish population. The frequency of Helicobacter (H.) pylori infection among 56 Inuits with dyspeptic symptoms was: 0.61. Only 6/12 patients suffering from DU had a positive test for H. pylori infection. Conclusions: The incidence of duodenal ulcers in the Inuit population was only 10% of the incidence in a Danish population, whereas the incidence of gastric ulcers among the Inuits was comparable to the incidence among Danes. Only 50% of Inuit patients with proven DU had a positive test for H. pylori infection, whereas the frequency of H.pylori infection in a population with dyspeptic symptoms corresponded very well to the frequency reported from other populations.     

No evidence exists for methylation inactivation of the p16 tumor suppressor gene in ovarian carcinogenesis

Mongolian gerbils are a laboratory host for gastric colonization with Helicobacter pylori, showing gastritis followed by typical gastric ulcer after infection with H. pylori. In such gerbils, we evaluated combined therapies of amoxicillin (AMPC) and clarithromycin (CAM) as antibiotics, and omeprazole (OPZ) as a H+/K+ adenosine triphosphatase (ATPase) inhibitor. The gerbils were orally inoculated with 2 x 10(8) bacilli of H. pylori ATCC 43504. Four weeks after inoculation, the infected gerbils were orally treated singly with OPZ, AMPC, and CAM, and their insufficient efficacy on bacterial clearance was confirmed by a polymerase chain reaction technique, and by a culture method. In contrast, combined therapy of OPZ plus either AMPC or CAM showed significant bacterial clearance, demonstrating the efficacy of this combined therapy in the gerbil model. Mongolian gerbils are suggested to be useful for the pharmacological evaluation of anti-H. pylori compounds.     

Salivary-specific immunoglobulin G in the diagnosis of Helicobacter pylori infection in dyspeptic patients

OBJECTIVES: Helicobacter pylori infection is arguably the most common chronic bacterial infection in humans. The high prevalence and the association with peptic ulceration and gastric cancer indicate that simple, noninvasive methods for diagnosis of the infection are needed. In this study, the accuracy of salivary diagnosis for H. pylori infection was assessed. METHODS: Saliva and serum samples of 152 dyspeptic patients were tested for H. pylori IgG and IgA by an in-house ELISA. All patients underwent gastroscopy with biopsy. RESULTS: One hundred thirty-one patients (86%) were found to be H. pylori positive on histology. Duodenal ulcer was found in 67 patients; 85 had no macroscopic lesion. Salivary and serum H. pylori IgG as well as serum H. pylori IgA titers were significantly higher in H. pylori-positive than in H. pylori-negative patients. The sensitivity and specificity of salivary H. pylori IgG were 82% and 71%, respectively; the positive and negative predictive values were 95% and 40%, respectively; and the accuracy 81%. The corresponding figures for serum H. pylori IgG were 97% and 91%; 98% and 83%; and 96%. Those for serum H. pylori IgA were 80% and 52%; 91% and 30%; and 76%. The sensitivity of salivary H. pylori IgG in detecting duodenal ulcer was 83% (56/67) that of serum H. pylori IgG was 97% (65/67) (odds ratio = 0.15; confidence interval = 0.02-0.8; p = 0.02). CONCLUSIONS: Salivary H. pylori IgG was a fairly sensitive and accurate indicator of gastric H. pylori colonization, with a high positive predictive value in our population. Data, however, suggest that salivary H. pylori IgG measurements do not compare favorably with serology.     

Utilization of proteinase K-treated cells as lipopolysaccharide antigens for the serodiagnosis of Helicobacter pylori infections

We have evaluated the use of proteinase K (PK)-treated cells isolated from Helicobacter pylori as lipopolysaccharide (LPS) antigens in an immunoblot assay and an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of H. pylori infection. The sera from patients with chronic gastritis, gastric ulcer, duodenal ulcer or gastric cancer, and from healthy adults with or without H. pylori infection were assayed with three commercial serodiagnostic kits (HM-CAP, Helico-G, and G.A.P. II) and novel methods relying on the use of PK-treated cells. The PK-treated cells used in these assays were selected on the basis of their possibility to possess a common epitope in the O-polysaccharides of H. pylori, which is known to be highly immunogenic in humans. Of the sera from these patients, 71-94% were positive with the commercial kits, 97% with immunoblot assay, and 90% with ELISA. On the other hand, of the healthy adults infected with H. pylori, 72-97% were positive with the commercial kits, 86% with immunoblot assay, and 72% with ELISA. PK-treated cells that did not contain the common epitope were unsuitable as an antigen for immunoblot assay or ELISA. Furthermore, the reactivity of these sera reacted specifically with H. pylori PK-treated cells but not with LPSs from other gram-negative bacteria, such as Campylobacter, Proteus, Bordetella, and Salmonella. These results demonstrate that the serological assays relying on the use of H. pylori PK-treated cells possessing a highly antigenic epitope are potentially useful as a serodiagnostic test for H. pylori infection.     

The lipid peroxidation inhibitor indenoindole H290/51 protects myocardium at risk of injury induced by ischemia-reperfusion

OBJECTIVE: Elevated blood ammonia is an important pathogenic factor of hepatic encephalopathy. Although colonic bacteria are considered the main source of ammonia, the stomach in subjects with urease-producing Helicobacter pylori (H. pylori) is an alternative site. The objective of this study was to determine whether H. pylori is associated with this complication. METHODS: After assessing liver function and portal hypertension, 55 cirrhotics were evaluated for encephalopathy and H. pylori infection. Response to 2 weeks of amoxicillin (2 g/day) and omeprazole (40 mg/day) was then assessed in 17 (13 H. pylori-positive, four H. pylori-negative) encephalopathic subjects. RESULTS: H. pylori infection was more common (67 % vs 33%, p = 0.004) among encephalopathic patients. Additional factors associated with encephalopathy included older age (60.1 +/- 1.5 vs 49.8 +/- 2.4 yr, p = 0.001), lower albumin (3.17 +/- 0.08 vs 3.69 +/- 0.12 g/dl, p = 0.001), higher total bilirubin (2.24 +/- 0.20 vs 1.53 +/- 0.23 mg/dl, p = 0.034), greater ascites score (0.8 +/- 0.1 vs 0.3 +/- 0.1, p = 0.01), greater diuretic score (1.1 +/- 0.1 vs 0.3 +/- 0.1, p = 0.002), and greater modified Child score (6.7 +/- 0.3 vs 5.1 +/- 0.3, p = 0.001). When adjusted for severity of cirrhosis and age, H. pylori continued to demonstrate a statistical association (p = 0.039). After anti-H. pylori therapy, symptomatology in infected encephalopathic patients appeared to improve, whereas noninfected subjects were unaffected. CONCLUSION: In cirrhotic patients, H. pylori infection is associated with hepatic encephalopathy, especially in younger patients with decompensated liver disease.     

Helicobacter pylori among preschool children and their parents: evidence of parent-child transmission

This study assessed the role of parental infection status in the transmission of Helicobacter pylori infection in a large population-based sample of preschool-aged children. The subjects, who lived in Ulm, Germany, and in two nearby communities, were screened for school fitness between January and July 1997. Their H. pylori infection status was determined by 13C-urea breath test. Of 1522 eligible children, 1221 (80.2%) participated in the study. Crude prevalence of H. pylori infection in children was 11.3% (95% confidence interval [CI], 9.5-13.3) and 36.4% in their parents (95% CI, 33.5-39.4). The crude odds ratio (OR) for H. pylori infection of children whose mothers were infected was 16.5 (95% CI, 8.9-30.8) and 7.9 after adjustment for potential confounders (95% CI, 4.0-15.7). The crude OR if the child's father was infected was 7.8 (95% CI, 2. 5-24.2) and 3.8 after adjustment for potential confounders (except maternal infection) (95% CI, 0.8-19.1). The results suggest that infected parents, especially infected mothers, may have a key role in transmission of H. pylori within families.     

Differential stimulation of interleukin-12 (IL-12) and IL-10 by live and killed Helicobacter pylori in vitro and association of IL-12 production with gamma interferon-producing T cells in the human gastric mucosa

The objective of these experiments was to examine the ability of Helicobacter pylori to stimulate interleukin-10 (IL-10) or IL-12 and select for either Th1 or Th2 cells. Gastric biopsy specimens were collected from patients who were categorized with respect to the presence of H. pylori and gastric disease as well as their age, gender, medications, and other factors. As Th1 and Th2 cells are selected by IL-12 and IL-10, respectively, biopsy specimens were screened for mRNA and protein for these cytokines. Although mRNA for IL-12 and IL-10 was detected in biopsy specimens obtained from both infected and uninfected patients, IL-12 protein predominated. Levels of IL-10 and IL-12 in gastric tissue did not change in response to infection. Moreover, gamma interferon (IFN-gamma)-producing T cells were found in both the infected and the uninfected gastric mucosa. Stimulation of peripheral blood leukocytes from either infected or uninfected donors with various concentrations of live or killed H. pylori induced immunoreactive IL-12 and IL-10. After stimulation with live H. pylori, IL-12 levels increased more than 30-fold, whereas IL-10 levels increased only 2- to 5-fold, compared to cells stimulated with medium alone. Interestingly, killed H. pylori induced significantly more IL-10 (P < 0.05) than live H. pylori, while recombinant urease only induced IL-10. These results demonstrate that live H. pylori selectively stimulates the induction of IL-12 and Th1 cells that produce IFN-gamma, whereas preparations used in oral vaccines induce more IL-10 and may favor Th2 cell responses.