Interleukin-27 is abrogated in gastric cancer, but highly expressed in other Helicobacter pylori-associated gastroduodenal diseases.

BACKGROUND: IL-27 has dual roles in the immune response either stimulating Th1 or inhibiting Th17 cells. Because there is a particular link of IL-23/Th17 axis in the development of cancer and IL-27 has been considered a potential treatment for cancer, we evaluated the gastric and serum concentrations of IL-27 in two mutually exclusive Helicobacter pylori-associated diseases, gastric cancer (GC) and duodenal ulcer (DU). MATERIAL AND METHODS: We prospectively studied 110 H pylori-positive patients and 40 healthy blood donors. Serum and gastric concentrations of IL-27 and cytokines of the Th1/Th17 cells were assessed by ELISA. RESULTS: IL-27 was not detected in GC patients, but the cytokine concentration was very high in the patients with DU. IL-27 was also detected in the gastritis patients and in the H pylori-positive blood donors. IL27RA mRNA expression in peripheral blood mononuclear cells, evaluated by rt-PCR, was stimulated by H pylori strains. The cytokine concentration positively correlated with the Th1 and negatively with Th17 cell representative cytokine levels. Gastric IL-27 concentrations were positively correlated with increased degree of mononuclear and polymorphonuclear cells on the antral gastric mucosa of DU patients in consonance with the DU gastritis pattern. IL-12p70 and IFN-γ gastric concentrations were significantly higher in DU than in GC. Conversely, gastric concentrations of Th17 cell-associated cytokines (IL-1ß, IL-6, IL-17A, IL-23, and TGF-ß) were significantly higher in GC than in DU patients. CONCLUSION: Although H pylori infection is able to elicit IL-27 and IL-27Rα secretion, DU and GC have diametrically opposed cytokine patterns.

Virulence factor genotyping of Helicobacter pylori isolated from Costa Rican dyspeptic patients.

BACKGROUND AND AIMS: Costa Rica is one of the countries with the highest incidence and mortality rates for gastric cancer. Helicobacter pylori infection rates are high in the whole country. We have previously shown that H. pylori CagA+ is significantly associated with atrophic gastritis (AG) of the antrum in a dyspeptic population. The aim of this work is to determine if other H. pylori virulence factors (vacA, dupA, oipA, iceA and babA2) are associated with atrophic gastritis (AG) or duodenal ulcer (DU). METHODS: The presence of virulence genes in Costa Rican H. pylori isolates was analyzed by PCR in 151 cultured strains from patients with dyspeptic symptoms. Endoscopic and histopathological diagnoses were available. Odds-ratio and 95% confidence intervals for AG patients vs. non-atrophic gastritis (NAG) or DU patients vs. no duodenal ulcer (NDU) patients were calculated. RESULTS: Amongst the studied isolates, 82% had the cagA+, 76.2% had the vacA s1m1, 97.0% had the oipA+, 21.0% had the icea1, 79.0% had the iceA2, 44.0% had the babA2+ and 76.0% the dupA+ genotypes. Infection with H pylori cagA+, dupA+, oipA+, iceA, babA2+, and vacA s1m1 genotypes was not associated with AG risk. The frequency of the dupA gene was 78.7 and 60.9% in isolates from patients with NDU and DU, respectively, and its presence was significantly associated with decreased risk of duodenal ulcer [odds-ratio: 0.33, p = 0.024, confidence interval 95% (0.11-0.85)]. CONCLUSION: H. pylori dupA genotype is inversely associated with DU risk in this population.

HELICOBACTER PYLORI INFECTION AND IMMUNE PROFILE OF PATIENTS WITH DIFFERENT GASTRODUODENAL DISEASES.

BACKGROUND: The association between infection with Helicobacter pylori and different gastroduodenal diseases is related to bacterial, host and environmental factors. Studies have demonstrated an association between the genetic diversity of H. pylori, especially in the vacA and cagA genes, and the development of digestive diseases such as peptic ulcer and gastric cancer. In addition, the nature of the host inflammatory response may explain these different manifestations of infection caused by this microorganism. In this respect, host factors that regulate the immune and inflammatory responses involving the functional interaction of H. pylori infection with different components of the immune system, particularly T cells, in gastroduodenal diseases still need further investigation. OBJECTIVE: To characterize the immune response, including immunity induced by infection with H. pylori, especially virulent strains (vacA alleles and cagA gene), by analyzing the cytokine profile and T-cell population present in gastroduodenal diseases in a Brazilian population. METHODS: In a prospective study, gastric biopsies were collected from 554 patients with different gastroduodenal diseases for histological analysis and for the determination of bacterial genotype and cytokine production (IL-4, IL-10, IFN-γ and IL-12) by ELISA. RESULTS: The predominant genotype of the H. pylori strains isolated from the patients studied was s1m1cagA+, which was more common among patients with gastric ulcer, duodenal ulcer and gastric cancer. A significant association was observed between the s1m1cagA+ genotype and a higher degree of inflammation, higher neutrophil activity and the development of intestinal metaplasia. The gastric concentrations of IFN-γ and IL-12 were significantly higher in patients infected with H. pylori than in uninfected individuals. Higher levels of these cytokines were detected in patients with gastric ulcer and cancer, while the levels of IL-4 and IL-10 in the gastric mucosa were lower in these patients. In addition, IFN-γ and IL-12 concentrations in gastric biopsies were higher in patients infected with the virulent s1m1cagA+ genotype. In contrast, IL-4 and IL-10 levels were higher in tissue infected with s2m2cagA in gastric biopsies. CONCLUSION: Our study shows that the interaction between the type of infectious strain and the Th1 immune response can influence and perpetuate gastric inflammation, and thus contributes to the development of the different clinical manifestations of H. pylori infection.

Infecção pelo Helicobacter pylori e perfil imunológico em pacientes com diferentes doenças gastroduodenais / Helicobacter pylori infection and immune profile of patients with different gastroduodenal diseases

ABSTRACT BACKGROUND: The association between infection with Helicobacter pylori and different gastroduodenal diseases is related to bacterial, host and environmental factors. Studies have demonstrated an association between the genetic diversity of H. pylori, especially in the vacA and cagA genes, and the development of digestive diseases such as peptic ulcer and gastric cancer. In addition, the nature of the host inflammatory response may explain these different manifestations of infection caused by this microorganism. In this respect, host factors that regulate the immune and inflammatory responses involving the functional interaction of H. pylori infection with different components of the immune system, particularly T cells, in gastroduodenal diseases still need further investigation. OBJECTIVE: To characterize the immune response, including immunity induced by infection with H. pylori, especially virulent strains (vacA alleles and cagA gene), by analyzing the cytokine profile and T-cell population present in gastroduodenal diseases in a Brazilian population. METHODS: In a prospective study, gastric biopsies were collected from 554 patients with different gastroduodenal diseases for histological analysis and for the determination of bacterial genotype and cytokine production (IL-4, IL-10, IFN-γ and IL-12) by ELISA. RESULTS: The predominant genotype of the H. pylori strains isolated from the patients studied was s1m1cagA+, which was more common among patients with gastric ulcer, duodenal ulcer and gastric cancer. A significant association was observed between the s1m1cagA+ genotype and a higher degree of inflammation, higher neutrophil activity and the development of intestinal metaplasia. The gastric concentrations of IFN-γ and IL-12 were significantly higher in patients infected with H. pylori than in uninfected individuals. Higher levels of these cytokines were detected in patients with gastric ulcer and cancer, while the levels of IL-4 and IL-10 in the gastric mucosa were lower in these patients. In addition, IFN-γ and IL-12 concentrations in gastric biopsies were higher in patients infected with the virulent s1m1cagA+ genotype. In contrast, IL-4 and IL-10 levels were higher in tissue infected with s2m2cagA in gastric biopsies. CONCLUSION: Our study shows that the interaction between the type of infectious strain and the Th1 immune response can influence and perpetuate gastric inflammation, and thus contributes to the development of the different clinical manifestations of H. pylori infection.

RESUMO CONTEXTO: A associação da infecção por Helicobacter pylori com diferentes doenças gastroduodenais pode estar associada a fatores bacterianos, do hospedeiro e do ambiente. Nesse contexto, estudos têm demonstrado que a diversidade genética do H. pylori, sobretudo nos genes vacA e cagA, está associada ao desenvolvimento de doenças gastroduodenais como a úlcera péptica e o câncer gástrico. Além disso, a natureza da resposta inflamatória do hospedeiro pode explicar essas diferentes manifestações da infecção por esse microrganismo. Portanto, fatores do hospedeiro que regulam as respostas imunológica e inflamatória, envolvendo a interação funcional da infecção por H. pylori com diferentes membros do compartimento imunológico, especialmente respostas imunes de células T nas doenças gastroduodenais, ainda precisam ser melhor estudados. OBJETIVO: Caracterizar a resposta imune, incluindo imunidade induzida por infecção pelo H. pylori, especialmente com cepas virulentas de H. pylori (alelos vacA e gene cagA), através da análise do perfil de citocinas e da caracterização da população de células T presentes em doenças gastroduodenais em nossa população. MÉTODOS: Em um estudo prospectivo, foram coletadas biópsias gástricas de 554 pacientes portadores das diferentes doenças gastroduodenais. Nas amostras biológicas destes pacientes foi realizada a determinação do genótipo bacteriano e a detecção das citocinas IL-4, IL-10, INF-γ e IL-12 através do método Elisa. Foram obtidas biópsias gástricas para avaliação histológica. RESULTADOS: Observamos que o genótipo predominante nas cepas de H. pylori isoladas dos pacientes estudados foi s1m1cagA positivo, sendo mais frequentes entre os pacientes com úlcera gástrica, úlcera duodenal e câncer gástrico. Houve associação significativa das cepas com o genótipo s1m1cagA positivo com maior grau de inflamação, atividade neutrofílica e desenvolvimento de metaplasia intestinal. As concentrações gástricas de INF-γ e IL-12 foram significativamente mais elevadas em pacientes infectados pelo H. pylori do que nos não infectados. Foram detectados níveis mais elevados dessas citocinas nos portadores de úlcera e câncer gástrico, sendo que nesses pacientes foram observados níveis mais baixos de IL-4 e IL-10 na mucosa gástrica. Além disso, as concentrações de INF-γ e IL-12 em biópsias gástricas, foram mais elevadas nos pacientes portadores das cepas bacterianas virulentas s1m1cagA+. Contrariamente, os níveis de IL-4 e IL-10 foram maiores em tecido infectado por cepas s2m2cagA. Pacientes com maior grau de inflamação, de atividade neutrofílica e presença de metaplasia intestinal, apresentaram níveis mais elevados de INF-γ e IL-12 e uma concentração mais baixa de IL-4 e IL-10 nas biópsias gástricas. CONCLUSÃO: Nosso estudo demonstra que a interação entre o tipo de cepa infectante e resposta imunológica com perfil Th1, podem influenciar e perpetuar a inflamação gástrica contribuindo para o desenvolvimento de diferentes manifestações clínicas na infecção pelo H. pylori.

Risk factors of Helicobacter pylori infection in an urban community in Northeast Brazil and the relationship between the infection and gastric diseases.

INTRODUCTION: Helicobacter pylori, a water contaminant, is the primary pathogenic agent associated with gastric diseases in humans. Exposure to H. pylori is more likely higher in developing countries. This study aimed to evaluate the risk factors associated with H. pylori infection in patients undergoing endoscopy to validate the cause of dyspeptic symptoms in an urban population in northeast Brazil and to compare the urease test and polymerase chain reaction assay results with the histopathological findings. METHODS: We evaluated 200 of 759 individuals with dyspeptic complaints from Campina Grande, State of Paraiba, northeast Brazil. Patients underwent endoscopy, followed by gastric biopsies. Logistic regression analysis was performed to adjust for confounders and to determine significant risk factors of dyspeptic disorders. RESULTS: Women accounted for 72.5% (145/200) of the participants. Approximately 59.8% (120/200) of the samples tested positive for H. pylori based on histological examinations. The specificity of polymerase chain reaction assay was higher than that of the urease test (77% vs. 64%, p=0.034). City drinking water [odds ratio (OR): 2.6; 95% confidence interval (CI): 1.3-5.21; p=0.004] and smoking (OR: 4.0; 95% CI: 1.13-14.5; p=0.031) were the risk factors of H. pylori infection. Belching was the most common symptom associated with H. pylori infection (p=0.05). CONCLUSIONS: The increased risk of H. pylori infection associated with non-treated water consumption indicates the need for improvements in public water treatment and better sanitary conditions because these can be a source of not only H. pylori infections but also other water-borne pathogen infections.

Risk factors of helicobacter pylori infection in an urban community in northeast Brazil and the relationship between the infection and gastric diseases

Abstract INTRODUCTION: Helicobacter pylori, a water contaminant, is the primary pathogenic agent associated with gastric diseases in humans. Exposure to H. pylori is more likely higher in developing countries. This study aimed to evaluate the risk factors associated with H. pylori infection in patients undergoing endoscopy to validate the cause of dyspeptic symptoms in an urban population in northeast Brazil and to compare the urease test and polymerase chain reaction assay results with the histopathological findings. METHODS: We evaluated 200 of 759 individuals with dyspeptic complaints from Campina Grande, State of Paraiba, northeast Brazil. Patients underwent endoscopy, followed by gastric biopsies. Logistic regression analysis was performed to adjust for confounders and to determine significant risk factors of dyspeptic disorders. RESULTS: Women accounted for 72.5% (145/200) of the participants. Approximately 59.8% (120/200) of the samples tested positive for H. pylori based on histological examinations. The specificity of polymerase chain reaction assay was higher than that of the urease test (77% vs. 64%, p=0.034). City drinking water [odds ratio (OR): 2.6; 95% confidence interval (CI): 1.3-5.21; p=0.004] and smoking (OR: 4.0; 95% CI: 1.13-14.5; p=0.031) were the risk factors of H. pylori infection. Belching was the most common symptom associated with H. pylori infection (p=0.05). CONCLUSIONS: The increased risk of H. pylori infection associated with non-treated water consumption indicates the need for improvements in public water treatment and better sanitary conditions because these can be a source of not only H. pylori infections but also other water-borne pathogen infections.

Epstein-Barr virus association with peptic ulcer disease.

Background. Helicobacter pylori (HP) infection and nonsteroidal anti-inflammatory drugs (NSAID) use are considered the main risk to develop peptic ulcer disease (PUD). However, PUD also occurs in the absence of HP infection and/or NSAID use. Recently, we have found evidence that Epstein-Barr virus (EBV) reactivation increases the risk to develop premalignant and malignant gastric lesions. Objective. To study a possible association between EBV and PUD. Methods. Antibodies against an EBV reactivation antigen, HP, and the HP virulence factor CagA were measured in sera from 207 Mexican subjects, controls (healthy individuals, n = 129), and PUD patients (n = 78, 58 duodenal and 20 gastric ulcers). Statistical associations were estimated. Results. Duodenal PUD was significantly associated with high anti-EBV IgG titers (p = 0.022, OR = 2.5), while anti-EBV IgA was positively associated with gastric PUD (p = 0.002, OR = 10.1). Conclusions. Our study suggests that EBV reactivation in gastric and duodenal epithelium increases the risk to develop PUD.

Plasticity Region Genes jhp0940, jhp0945, jhp0947, and jhp0949 of Helicobacter pylori in Isolates from Mexican Children.

BACKGROUND: The genes jhp0940, jhp0945, jhp0947, and jhp0949 belong to the plasticity region of the Helicobacter pylori genome. Due to their prevalence in isolates from patients with gastritis, duodenal ulcer, and gastric cancer, they have been proposed as markers of gastroduodenal diseases. These genes are associated with pro-inflammatory cytokine induction through the NF-κB activation pathway. Nevertheless, the status of these genes is unknown in H. pylori isolates from children. The aim of the present work was to determine the frequency of the jhp0940-jhp0945-jhp0947-jhp0949 genes in H. pylori isolates from children. MATERIALS AND METHODS: We identified the jhp0940, jhp0945, jhp0947, and jhp0949 genes and the relationship of each with the virulence factors cagA, cagPAI, and dupA by PCR in 49 isolates of H. pylori from children. The results were corroborated using dot blots. In addition, we compared the prevalence of these genes with the prevalence in adults. RESULTS: The prevalence of jhp0940 (53.1%), jhp0945 (44.9%), jhp0947 (77.6%), and jhp0949 (83.7%) was determined in the isolates from children, as was the prevalence of the virulence genes cagA (63.3%), cagPAI (71.4%), and dupA (37.5%). No association was found between the four genes of the plasticity region and the virulence genes. The presence of the intact locus integrated by jhp0940-jhp0945-jhp0947-jhp0949 was very common among the isolates from children. CONCLUSION: The genes jhp0940, jhp0947, and jhp0949 were present in more than 50% of the H. pylori isolates, and the joint presence of jhp0940-jhp0945-jhp0947-jhp0949 was very frequent. The frequency of these genes in isolates from children could contribute to the virulence of H. pylori and the evolution of the infection.

First case of Helicobacter pylori infection resistant to seven antibiotics in Iran.

Treatment of Helicobacter pylori infection with common antibiotics is typically recommended for several digestive conditions, including peptic ulcers. However, reports of resistant H. pylori isolates are increasing, and unfortunately, these do not respond to currently available therapeutic regimens. We report the case of a 31-year-old woman with two peptic ulcers in the duodenal antrum. An H. pylori strain was isolated, and tested for antibiotic resistance using agar dilution and disk diffusion. The isolated strain was found to be resistant to all seven antibiotics that were tested. Therefore, constant monitoring for antibiotic resistance should be performed prior to initiating antibiotic therapy.

First case of Helicobacter pylori infection resistant to seven antibiotics in Iran

Treatment of Helicobacter pylori infection with common antibiotics is typically recommended for several digestive conditions, including peptic ulcers. However, reports of resistant H. pylori isolates are increasing, and unfortunately, these do not respond to currently available therapeutic regimens. We report the case of a 31-year-old woman with two peptic ulcers in the duodenal antrum. An H. pylori strain was isolated, and tested for antibiotic resistance using agar dilution and disk diffusion. The isolated strain was found to be resistant to all seven antibiotics that were tested. Therefore, constant monitoring for antibiotic resistance should be performed prior to initiating antibiotic therapy.

Peptic ulcer disease in Helicobacter pylori-infected children: clinical findings and mucosal immune response.

OBJECTIVES: Peptic ulcer disease (PUD) is highly prevalent among adults but less common in children. Helicobacter pylori infection, the main cause of PUD, is, however, acquired extremely early in life. The aim of the study was to analyze clinical characteristics of children with PUD in a country with a high prevalence of the disease and to evaluate which host factors could determine this clinical outcome. METHODS: Children referred for upper gastrointestinal (GI) endoscopy with suspicion of peptic diseases were included prospectively during an 8-year period. Antral biopsies were performed to determine H pylori presence and mucosal cytokines profile. RESULTS: A total of 307 children between 3 and 18 years old were enrolled. Of the total, 237 children (46% boys) with complete data were included. H pylori infection was confirmed in 133 (56.1%) participants. Duodenal ulcer (DU) was diagnosed in 32 patients (13.5%); among them 29 were infected with H pylori (90.6%). Infected children had a nodular appearance of the gastric mucosa more often than noninfected children. Noninfected children had fewer lymphoid follicles and less inflammatory infiltrate than infected children. Only mucosal polymorphonuclear cell infiltration was more intense in DU-infected children as compared with non-DU-infected children. DU-infected children had higher levels of mucosal interferon-γ than noninfected and non-DU-infected patients. Non-DU-infected children had also higher levels of mucosal interleukin-10 than noninfected patients (P < 0.05). CONCLUSIONS: PUD in children, especially DU, is strongly associated with H pylori infection in developing countries. There is no distinctive clinical presentation of children with PUD. T-helper cytokine balance may influence clinical outcomes in children.

Single nucleotide polymorphisms of Helicobacter pylori dupA that lead to premature stop codons.

BACKGROUND: The detection of the putative disease-specific Helicobacter pylori marker duodenal ulcer promoting gene A (dupA) is currently based on PCR detection of jhp0917 and jhp0918 that form the gene. However, mutations that lead to premature stop codons that split off the dupA leading to truncated products cannot be evaluated by PCR. METHODS: We directly sequence the complete dupA of 75 dupA-positive strains of H. pylori isolated from patients with gastritis (n = 26), duodenal ulcer (n = 29), and gastric carcinoma (n = 20), to search for frame-shifting mutations that lead to stop codon. RESULTS: Thirty-four strains had single nucleotide mutations in dupA that lead to premature stop codon creating smaller products than the predicted 1839 bp product and, for this reason, were considered as dupA-negative. Intact dupA was more frequently observed in strains isolated from duodenal ulcer patients (65.5%) than in patients with gastritis only (46.2%) or with gastric carcinoma (50%). In logistic analysis, the presence of the intact dupA independently associated with duodenal ulcer (OR = 5.06; 95% CI = 1.22-20.96, p = .02). CONCLUSION: We propose the primer walking methodology as a simple technique to sequence the gene. When we considered as dupA-positive only those strains that carry dupA gene without premature stop codons, the gene was associated with duodenal ulcer and, therefore, can be used as a marker for this disease in our population.

In vivo expression of Helicobacter pylori virulence genes in patients with gastritis, ulcer, and gastric cancer.

The best-studied Helicobacter pylori virulence factor associated with development of peptic ulcer disease or gastric cancer (GC) rather than asymptomatic nonatrophic gastritis (NAG) is the cag pathogenicity island (cagPAI), which encodes a type IV secretion system (T4SS) that injects the CagA oncoprotein into host epithelial cells. Here we used real-time reverse transcription-PCR (RT-PCR) to measure the in vivo expression of genes on the cagPAI and of other virulence genes in patients with NAG, duodenal ulcer (DU), or GC. In vivo expression of H. pylori virulence genes was greater overall in gastric biopsy specimens of patients with GC than in those of patients with NAG or DU. However, since in vitro expression of cagA was not greater in H. pylori strains from patients with GC than in those from patients with NAG or DU, increased expression in GC in vivo is likely a result of environmental conditions in the gastric mucosa, though it may in turn cause more severe pathology. Increased expression of virulence genes in GC may represent a stress response to elevated pH or other environmental conditions in the stomach of patients with GC, which may be less hospitable to H. pylori colonization than the acidic environment in patients with NAG or DU.

High prevalence of duodenal ulcer in a tertiary care hospital in the city of São Paulo, SP, Brazil.

CONTEXT: In spite of Helicobacter pylori infection being the etiological cause of peptic ulcer and its high prevalence in Brazil, the prevalence of peptic ulcer disease has been poorly studied. OBJECTIVES: To verify the peptic ulcer disease prevalence in patients of a tertiary care hospital. METHODS: Diagnostic findings from 1,478 consecutive endoscopies were correlated with the urease test results for H. pylori infection diagnosis and demographic data in a total of 3,779 endoscopies performed in 2005. The mean age of the patients was 51.14 ± 16.46, being 613 (41.5%) men. RESULTS: Peptic ulcer was diagnosed in 494 (33.4%) patients with a mean age of 54.86 ± 14.53, 205 (52%) were men, being 391 (26.5%) duodenal ulcer and 103 (7%) gastric ulcer. Normal endoscopy was found in 272 (18.4%) patients with a mean age of 38.4 ± 15.22, being 49 (18%) men. The comparison of peptic ulcer group with the patients that had normal endoscopy revealed that H. pylori infection [P = 0.005; OR = 1.70; 95% CI = 1.17-2.47], male gender [P<0.0001; OR = 5.53; 95%CI = 3.67-8.34] and older age [P<0.0001; OR = 1.08; 95%CI = 1.06-1.09] increased the risk of peptic ulcers. The overall H. pylori prevalence was 53% (786). CONCLUSIONS: Prevalence of duodenal ulcer is high in a Brazilian population that had H. pylori infection associated with older age and male gender as important determinants to gastrointestinal diseases outcome. Future prospective studies should confirm these findings.

High prevalence of duodenal ulcer in a tertiary care hospital in the city of São Paulo, SP, Brazil / Alta prevalência de úlcera duodenal num hospital terciário na cidade de São Paulo

CONTEXT: In spite of Helicobacter pylori infection being the etiological cause of peptic ulcer and its high prevalence in Brazil, the prevalence of peptic ulcer disease has been poorly studied. OBJECTIVES: To verify the peptic ulcer disease prevalence in patients of a tertiary care hospital. METHODS: Diagnostic findings from 1,478 consecutive endoscopies were correlated with the urease test results for H. pylori infection diagnosis and demographic data in a total of 3,779 endoscopies performed in 2005. The mean age of the patients was 51.14 ± 16.46, being 613 (41.5 percent) men. RESULTS: Peptic ulcer was diagnosed in 494 (33.4 percent) patients with a mean age of 54.86 ± 14.53, 205 (52 percent) were men, being 391 (26.5 percent) duodenal ulcer and 103 (7 percent) gastric ulcer. Normal endoscopy was found in 272 (18.4 percent) patients with a mean age of 38.4 ± 15.22, being 49 (18 percent) men. The comparison of peptic ulcer group with the patients that had normal endoscopy revealed that H. pylori infection [P = 0.005; OR = 1.70; 95 percent CI = 1.17-2.47][ign], male gender [P<0.0001; OR = 5.53; 95 percentCI = 3.67-8.34][ign] and older age [P<0.0001; OR = 1.08; 95 percentCI = 1.06-1.09] increased the risk of peptic ulcers. The overall H. pylori prevalence was 53 percent (786). CONCLUSIONS: Prevalence of duodenal ulcer is high in a Brazilian population that had H. pylori infection associated with older age and male gender as important determinants to gastrointestinal diseases outcome. Future prospective studies should confirm these findings.

CONTEXTO: Apesar da infecção pelo Helicobacter pylori ser causa de úlcera péptica e de sua alta prevalência no Brasil, a prevalência da úlcera péptica tem sido pouco estudada. OBJETIVOS: Verificar a prevalência da doença ulcerosa péptica em pacientes de um hospital terciário. MÉTODOS: Achados diagnósticos de 1.478 endoscopias consecutivas foram correlacionados com os resultados de testes de urease para diagnóstico de infecção pelo H. pylori e dados demográficos num total de 3.779 endoscopias realizadas em 2005. A média de idade dos pacientes foi 51,14 ± 16,46, sendo 613 (41,5 por cento) homens. RESULTADOS: A úlcera péptica foi diagnosticada em 494 (33,4 por cento) pacientes com média de idade de 54,86 ± 14,53, 205 (52 por cento) eram homens, sendo 391 (26,5 por cento) úlceras duodenais e 103 (7 por cento) úlceras gástricas. Endoscopia normal foi achada em 272 (18,4 por cento) pacientes com média de idade de 38,4 ± 15,22, sendo 49 (18 por cento) homens. A comparação do grupo de úlcera péptica com os pacientes que tinham endoscopia normal revelou que a infecção pelo H. pylori [P = 0,005; OR = 1,70; 95 por cento CI = 1,17-2,47][ign], gênero masculino [P<0,0001; OR = 5,53; 95 por cento CI = 3,67-8,34][ign] e idade mais avançada [P<0,0001; OR = 1,08; 95 por cento CI = 1,06-1,09] aumentaram o risco de úlceras pépticas. A prevalência de infecção pelo H. pylori no total foi de 53 por cento (786). CONCLUSÕES: A prevalência da úlcera duodenal é alta numa população brasileira de um hospital terciário que teve a infecção pelo H. pylori, idade avançada e gênero masculino como determinantes importantes de evolução para doença gastrointestinal. Estudos futuros prospectivos devem confirmar esses achados.

Association of circulating VacA-neutralizing antibodies with gastric cancer and duodenal ulcer.

OBJECTIVE: To study the association between anti-VacA antibodies and pre-neoplastic lesions (IM), gastric cancer (GC), and duodenal ulcer (DU). METHODS: A case-control study that included 347 patients, 90 with IM, 60 with GC, 52 with DU, and 145 with non-atrophic gastritis was conducted. For the analysis, a polytomous logistic regression models were used. Anti-VacA antibodies were identified in sera from these patients, either by Western blot assay (WB), using antigens produced by H. pylori s1m1 strain, or by neutralization assay challenging HeLa cells with H. pylori VacA s1m1 cytotoxin. RESULTS: Results of the WB assay showed no association between WB-anti-VacA antibodies and gastroduodenal diseases. In contrast, when antibodies that neutralize VacA cytotoxic activity were studied, a significant association was found with IM (OR 2.7, 95% CI 1.4-5.1) and DU (OR 2.3, 95% CI 1.1-4.9) and an even stronger association with GC (OR 3.9, 95% CI 1.8-8.5). A significant association with histological subtypes of GC (diffuse and intestinal) and of IM (complete and incomplete) was also found. In addition, the association showed a significant dose-response effect in the case of GC, but not of DU or IM. These associations did not change substantially after adjustment for confounding factors. MAIN CONCLUSION: This study showed that VacA-neutralizing antibodies are significantly associated with gastroduodenal diseases, especially GC, and that they might be used as risk markers of GC and DU.

Higher number of Helicobacter pylori CagA EPIYA C phosphorylation sites increases the risk of gastric cancer, but not duodenal ulcer.

BACKGROUND: Helicobacter pylori infection is one of the most common infections worldwide and is associated with gastric cancer and peptic ulcer. Bacterial virulence factors such as CagA have been shown to increase the risk of both diseases. Studies have suggested a causal role for CagA EPIYA polymorphisms in gastric carcinogenesis, and it has been shown to be geographically diverse. We studied associations between H. pylori CagA EPIYA patterns and gastric cancer and duodenal ulcer, in an ethnically admixed Western population from Brazil. CagA EPIYA was determined by PCR and confirmed by sequencing. A total of 436 patients were included, being 188 with gastric cancer, 112 with duodenal ulcer and 136 with gastritis. RESULTS: The number of EPIYA C segments was significantly associated with the increased risk of gastric carcinoma (OR=3.08, 95% CI=1.74 to 5.45, p<10-3) even after adjustment for age and gender. Higher number of EPIYA C segments was also associated with gastric atrophy (p=0.04) and intestinal metaplasia (p=0.007). Furthermore, patients infected by cagA strains possessing more than one EPIYA C segment showed decreased serum levels of pepsinogen I in comparison with those infected by strains containing one or less EPIYA C repeat. Otherwise, the number of EPIYA C segments did not associate with duodenal ulcer. CONCLUSIONS: Our results demonstrate that infection with H. pylori strains harbouring more than one CagA EPIYA C motif was clearly associated with gastric cancer, but not with duodenal ulcer.Higher number of EPIYA C segments was also associated with gastric precancerous lesions as demonstrated by histological gastric atrophic and metaplastic changes and decreased serum levels of pepsinogen I.

dupA polymorphisms and risk of Helicobacter pylori-associated diseases.

The dupA of Helicobacter pylori has been suggested as a virulence marker associated with the development of duodenal ulcer disease. However, the studies performed in different geographical areas have shown that there are variations in the prevalence of dupA and its association with H. pylori clinical outcomes. Our group did not observe associations between the presence of dupA and H. pylori clinical outcomes in Brazil. On the other hand, we observed 2 mutations in the sequence of dupA that lead to stop codons: a deletion of an adenine at position 1311 and an insertion of an adenine at position 1426 of the gene. Our aim was to evaluate associations of the presence of dupA with duodenal ulcer and gastric cancer, considering dupA-positive only those H. pylori strains that do not have the mutations in the gene sequence. We also evaluated the effect of infection with a strain carrying an intact dupA on the gastric mucosa histology and IL-8 gastric levels. Colonization with strains that had the intact dupA was negatively associated with gastric carcinoma (p=0.001, OR=0.32, 95% CI=0.16-0.66). The presence of dupA was also associated with an increased degree of antral mucosa inflammation (p=0.01) and with decreased corpus atrophy (p<0.01) as well as with increased gastric mucosa IL-8 levels (p=0.04). In conclusion, the infection with a H. pylori strain containing the dupA without the stop codon polymorphisms is associated with a lower risk of development of gastric carcinoma in Brazilian subjects.

Helicobacter pylori CagA protein polymorphisms and their lack of association with pathogenesis.

AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strains with a single amplicon were sequenced and results were used to characterize the 3' variable region of the cagA gene. To establish the number and type of tyrosine phosphorylation motifs Glutamine acid-Proline-Isoleucine-Tyrosine-Alanine (EPIYA) bioinformatic analysis using Amino Acid Sequence Analyzer-Amino Acid Sequence Analyzer software was conducted. Analysis of the association between the number of EPIYA motifs and the gastric pathology was performed using chi(2) test and analysis of the presence of EPIYA-C motifs in relation to the pathology was made by logistic regression odds ratios. Comparisons among EPIYA types found and those reported in GenBank were performed using a proportion test in Statistix Analytical Software version 8.0. RESULTS: After amplification of the 3' of the cagA gene, 106 from 122 isolates presented a single amplicon and 16 showed multiple amplicons. As expected, diversity in the size of the cagA unique fragments among isolates was observed. The 106 strains that presented a single amplicon after 3' cagA amplification came from patients with gastritis (19 patients), atrophic gastritis (21), intestinal metaplasia (26), duodenal ulcer (22) and gastric cancer. DNA sequence analysis showed that the differences in size of 3' cagA unique fragments was attributable to the number of EPIYA motifs: 1.9% had two EPIYA motifs, 62.3% had three, 33.0% had four and 2.8% had five motifs. The majority of tested clinical strains (62.3%) were found to harbor the ABC combination of EPIYA motifs and a significant statistical difference was observed between the frequencies of ABCC tyrosine phosphorylation motifs and Western strains sequences deposited in GenBank. CONCLUSION: The present report describes a lack of association between H. pylori CagA-protein polymorphisms and pathogenesis. ABCC high frequency variations compared with Western-strains sequences deposited in GenBank require more investigation.