Acute Helicobacter pylori infection: clinical features, local and systemic immune response, gastric mucosal histology, and gastric juice ascorbic acid concentrations.

Sobala, G. M.; Crabtree, J. E.; Dixon, M. F.; Schorah, C.J.; Taylor, Jennifer; Rathbone, B. J.; Heatley, R. V.; Axon, Anthony

doi:10.1136/gut.32.11.1415

Cited by 316 publications

(194 citation statements)

References 14 publications

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“…ELISA kits for detecting specific immunoglobulin M (IgM) have poor accuracy, and they are not used within clinical routines, despite the recent finding that H. pylori infection elicits a host response involving the expression of specific IgM and IgG in the gastric mucosa. 30 Other noninvasive diagnostic methods include the urea breath test and the H. pylori stool antigen test. These tests are more accurate during childhood.…”

Section: Discussionmentioning

confidence: 99%

Seroprevalence of Helicobacter pylori infection among children of low socioeconomic level in São Paulo

et al. 2010

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CONTEXT AND OBJECTIVE: Helicobacter pylori infection is mainly acquired during childhood, and is associated with significant morbidity in adults. The aim here was to evaluate the seroprevalence and risk factors of H. pylori infection among children of low socioeconomic level attended at a public hospital in São Paulo, Brazil. DESIGN AND SETTING:Cross-sectional study, among patients attended at an outpatient clinic.METHODS: 326 children were evaluated (150 boys and 176 girls; mean age 6.82 ± 4.07 years) in a cross-sectional study. Patients with chronic diseases or previous H. pylori treatment, and those whose participation was not permitted by the adult responsible for the child, were excluded. The adults answered a demographic questionnaire and blood samples were collected. The serological test used was Cobas Core II, a second-generation test. Titers > 5 U/ml were considered positive. RESULTS: H. pylori infection was diagnosed in 116 children (35.6%). Infected children were older than uninfected children (7.77 ± 4.08 years versus 5.59 ± 3.86 years; p < 0.0001). The seroprevalence increased from 20.8% among children aged two to four years, to 58.3% among those older than 12 years. There were no significant relationships between seropositivity and gender, color, breastfeeding, number of people in the home, number of rooms, bed sharing, living in a shantytown, maternal educational level, family income or nutritional status. In multivariate analysis, the only variable significantly associated with H. pylori seropositivity was age.CONCLUSION: Infection had intermediate prevalence in the study population, and age was associated with higher prevalence. RESUMO CONTEXTO E OBJETIVO:A infecção por Helicobacter pylori é adquirida principalmente na infância e é associada a morbidade significativa em adultos.O objetivo foi avaliar a soroprevalência de infecção por H. pylori bem como fatores de risco em crianças de baixo nível socioeconômico atendidas em um hospital público em São Paulo, Brasil. TIPO DE ESTUDO E LOCAL:Estudo transversal, realizado entre pacientes atendidos em ambulatório. MÉTODOS:Foram avaliadas 326 crianças (150 meninos e 176 meninas, idade: média 6,82 ± 4,07 anos) em estudo transversal. Foram excluídas aquelas com doenças crônicas, tratamento prévio de H. pylori e cujo responsável não consentiu participar do estudo. Os responsáveis responderam questionário demográfico e foi coletada uma amostra de sangue. O teste sorológico empregado foi o CobasCore II, exame de segunda geração, sendo considerados positivos títulos > 5 U/ml. RESULTADOS:Infecção por H. pylori foi diagnosticada em 116 (35,6%). A idade dos pacientes infectados foi maior que a dos demais (7,77 ± 4,08 anos versus 5,59 ± 3,86 anos; p < 0,0001). A prevalência aumenta de 20,8% entre dois e quatro anos de idade para 58,3% entre maiores de 12 anos. Não houve relação significativa entre soropositividade e sexo, raça, aleitamento materno, número de pessoas ou de cômodos na casa, compartilhamento de camas, domicílio em favela, escolaridade mat...

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Section: Discussionmentioning

confidence: 99%

Seroprevalence of Helicobacter pylori infection among children of low socioeconomic level in São Paulo

et al. 2010

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“…Previous seroepidemiologic studies indicated that about 50% of adults in the developed countries and nearly 90% of adults in developing countries were seropositive for H. pylori (1). Chronic H. pylori infection may be associated with chronic gastritis (2), peptic ulcer disease (3), mucosal associated lymphoid tissue (MALT) lymphoma (4) and gastric adenocarcinoma (5).…”

Section: Introductionmentioning

confidence: 99%

Serioprevalence of <i>Helicobacter pylori</i> Infection in and its Relationship with ABO Blood Groups

Tadege¹,

Mengistu²,

Desta³

et al. 2005

Ethiopian Journal of Health Development

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Background: Helicobacter pylori infection occurs worldwide, but the prevalence varies greatly among countries and among population groups studied. People with blood group O have been noted to be more susceptible to H. pylori infection. Objectives: To determine the magnitude of H. pylori infection in adult patients with and without dyspeptic symptoms attending Felege Hiwot Hospital, Bahir Dar, North West Ethiopia. We also prospectively examined the relationship between H. pylori infection and ABO blood groups in those subjects to clarify the possible association. Methods: A case-control study was conducted between dyspeptic (n=100) and non-dyspeptic patients (n=100) for the presence of H. pylori infection between mid November 2002 and March 2003 by using serology. Results: Of the total 200 subjects, 128 (64%) were males and 72 (36%) females with mean age of 32.7, range 15-75, years. Of these, 112 (56%) and 66 (33%) were found positive and negative for H. pylori infection, respectively, by EIA. Borderline values were measured in 22/200 (11%). H. pylori infection was detected in 124/200 (62%) of study subjects by immunoblot. The most prevalent blood group was type O (43%), followed by A (23.5%), B (22.5%) and AB (11%). In comparison of the subjects with blood group O and the other blood groups, no statistical significance could be identified in the seroprevalence of H. pylori ( p>0.05). Conclusion:The overall seroprevalence of H. pylori infection in Bahir Dar in this study was between 63% and 70% in dyspeptic patents and 49% and 54% in non-dyspeptic patients by EIA and IB, respectively. There were no statistically significant differences in the frequency of H. pylori seroprevalence between dyspeptic and non-dyspeptic patients. There was no statistically significant association between H. pylori infection and sex, age and ABO blood groups. Thus, further investigations along this line are recommended. [Ethiop.J.Health Dev. 2005;19(1):55-59]

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“…It causes type B gastritis and contributes to the development of peptic ulcers and probably gastric carcinoma (4,32) and lymphoma (19,51). H. pylori gastritis usually begins with an acute inflammatory response, predominantly the formation of polymorphonuclear granulocytes (PMNs), which is followed by infiltration with mononuclear cells (44). The bacteria persist in the gastric mucosa despite vigorous specific cellular and humoral responses.…”

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confidence: 99%

Cloning and genetic characterization of Helicobacter pylori catalase and construction of a catalase-deficient mutant strain

1996

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The N-terminal sequence of a protein, originally described as an adhesin of Helicobacter pylori, was used in an oligonucleotide-based screening procedure of an H. pylori plasmid library in Escherichia coli. Five independent plasmid clones were isolated, all mapping to the same chromosomal region and encoding the H. pylori catalase. The gene, designated katA, comprises 1,518 nucleotides and encodes a putative protein of 505 amino acids with a predicted M r of 58,599. A second open reading frame, orf2, encoding a putative 32,715-Da protein of unknown function, follows katA. The transcriptional start site of katA mRNA was determined, but no typical consensus promoter sequence was present. A potential binding site for the Fur protein is located upstream of katA. When introduced into the catalase-deficient E. coli double-mutant UM255, the cloned gene readily complemented E. coli for catalase activity. H. pylori KatA is highly homologous to catalases in both prokaryotes and eukaryotes, with the highest homology being shown to Bordetella pertussis (64.9%), Bacteroides fragilis (59.8%), and Haemophilus influenzae (57.9%) catalases. Transposon insertion mutants were generated in three independent H. pylori strains by TnMax5-mediated transposon shuttle mutagenesis. In contrast to the wild-type strains, no significant catalase-specific enzymatic activity could be detected in the mutant strains, consistent with the fact that no additional katA-homologous gene copies were found in the H. pylori chromosome. No significant difference between wild-type and mutant strains for binding to epithelial cells was apparent, suggesting that KatA is not involved in H. pylori adhesion. The cloning and genetic characterization of katA are essential steps for further investigation of the role of catalase in the defense of H. pylori against oxygendependent killing mechanisms by polymorphonuclear granulocytes, a process not well understood for this chronically persisting pathogen.

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Acute Helicobacter pylori infection: clinical features, local and systemic immune response, gastric mucosal histology, and gastric juice ascorbic acid concentrations.

Cited by 316 publications

References 14 publications

Seroprevalence of Helicobacter pylori infection among children of low socioeconomic level in São Paulo

Seroprevalence of Helicobacter pylori infection among children of low socioeconomic level in São Paulo

Serioprevalence of <i>Helicobacter pylori</i> Infection in and its Relationship with ABO Blood Groups

Cloning and genetic characterization of Helicobacter pylori catalase and construction of a catalase-deficient mutant strain

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