RESUMEN
CONTEXT: Helicobacter pylori (H. pylori) has a worldwide distribution, but the prevalence of infection, virulence factors, and clinical presentation vary widely according to the studied population. In Brazil, a continental country composed of several ethnicities and cultural habits, the behavior of infection also appears to vary, as many other studies have shown. OBJECTIVES: Describe the prevalence of infection with cagA-positive H. pylori strains in a group of children and adolescents who underwent esophagogastroduodenoscopy in Porto Alegre, Rio Grande do Sul. METHODS: Fifty-four gastric biopsy specimens of children and adolescents with H. pylori infection demonstrated by histology, urease test and molecular analysis were tested for the presence of cagA positive H. pylori strains by the polymerase chain reaction method. RESULTS: The prevalence of cagA-positive H. pylori was 29.6% (95% confidence interval, 18 to 43.6%). There were no statistically significant differences in clinical or demographic characteristics or in the endoscopic and histological features of patients infected with cagA-positive strains as compared with those infected by cagA-negative strains. CONCLUSIONS: he study showed a low prevalence of infection with cagA-positive H. pylori strains among children and adolescents who underwent EGD in southern Brazil, in comparison to studies conducted with children from other regions of Brazil. There was no association between the presence of cagA-positive strains and more severe clinical presentations in the studied sample.
Asunto(s)
Antígenos Bacterianos/aislamiento & purificación , Proteínas Bacterianas/aislamiento & purificación , Infecciones por Helicobacter/microbiología , Helicobacter pylori/aislamiento & purificación , Gastropatías/microbiología , Adolescente , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Brasil/epidemiología , Niño , Estudios Transversales , Endoscopía del Sistema Digestivo/métodos , Femenino , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/genética , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Prevalencia , Gastropatías/diagnóstico , Gastropatías/epidemiologíaRESUMEN
Context Helicobacter pylori (H. pylori) has a worldwide distribution, but the prevalence of infection, virulence factors, and clinical presentation vary widely according to the studied population. In Brazil, a continental country composed of several ethnicities and cultural habits, the behavior of infection also appears to vary, as many other studies have shown. Objectives Describe the prevalence of infection with cagA-positive H. pylori strains in a group of children and adolescents who underwent esophagogastroduodenoscopy in Porto Alegre, Rio Grande do Sul. Methods Fifty-four gastric biopsy specimens of children and adolescents with H. pylori infection demonstrated by histology, urease test and molecular analysis were tested for the presence of cagA positive H. pylori strains by the polymerase chain reaction method. Results he prevalence of cagA-positive H. pylori was 29.6% (95% confidence interval, 18 to 43.6%). There were no statistically significant differences in clinical or demographic characteristics or in the endoscopic and histological features of patients infected with cagA-positive strains as compared with those infected by cagA-negative strains. Conclusions he study showed a low prevalence of infection with cagA-positive H. pylori strains among children and adolescents who underwent EGD in southern Brazil, in comparison to studies conducted with children from other regions of Brazil. There was no association between the presence of cagA-positive strains and more severe clinical presentations in the studied sample. .
Contexto Helicobacter pylori (H. pylori) tem distribuição geográfica universal, embora a prevalência da infecção, os fatores de virulência, bem como a apresentação clínica, variem de acordo com a população estudada. No Brasil, um país continental composto por várias etnias e hábitos culturais diversos, o comportamento da infecção também parece variar, como muitos estudos têm demonstrado. Objetivos Descrever a prevalência da infecção por cepas de H. pylori cagA-positivo em um grupo de crianças e adolescentes submetidos a esofagogastroduodenoscopia em Porto Alegre, Rio Grande do Sul. Métodos Cinquenta e quatro (54) fragmentos de biópsia gástrica com presença de H. pylori demonstrada pela análise histológica, teste da urease e análise molecular foram testados para a presença de cepas de H. pylori cagA-positivo pelo método da reação em cadeia da polimerase. Resultados prevalência de cepas de H. pylori cagA-positivo foi de 29,6% (intervalo de confiança de 95%, 18% a 43,6%). Não houve diferenças estatisticamente significativas nas características clínicas e demográficas e nos achados endoscópicos e histológicos entre os pacientes infectados por cepas de H. pylori cagA-positivo em comparação com os cagA-negativo. Conclusões O estudo demonstrou uma baixa prevalência de infecção por cepas de H. pylori cagA-positivo nas crianças e adolescentes submetidas a esofagogastroduodenoscopia no Sul do Brasil em comparação com os estudos realizados com crianças de outras regiões do Brasil. Não houve associação entre a presença de cepas cagA-positivo e desfechos clínicos desfavoráveis na amostra estudada. .
Asunto(s)
Adolescente , Niño , Femenino , Humanos , Masculino , Antígenos Bacterianos/aislamiento & purificación , Proteínas Bacterianas/aislamiento & purificación , Infecciones por Helicobacter/microbiología , Helicobacter pylori/aislamiento & purificación , Gastropatías/microbiología , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Brasil/epidemiología , Estudios Transversales , Endoscopía del Sistema Digestivo/métodos , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/genética , Reacción en Cadena de la Polimerasa , Prevalencia , Gastropatías/diagnóstico , Gastropatías/epidemiologíaRESUMEN
CONTEXT: Gastric cancer is the second most common cause of cancer related death worldwide. Although Helicobacter pylori has been classified as a class I carcinogen, the presence of infection is not a factor that alone is able to lead to gastric cancer, and one of the possible explanations for this is the existence of different strains of H. pylori with different degrees of virulence. OBJECTIVES: To investigate the association between cagA-positive H. pylori and gastric cancer, using polymerase chain reaction (PCR) for the detection of this bacterial strain. METHODS: Twenty-nine patients with gastric cancer were matched by sex and age (± 5 years) with 58 patients without gastric cancer, submitted to upper gastrointestinal endoscopy. All patients were evaluated for the status of infection by H. pylori (through urease test, histological analysis and PCR for the genes ureA and 16SrRNA) and by cagA-positive strain (through PCR for cagA gene). RESULTS: Evaluating the presence of infection by cagA-positive H. pylori, it was verified that the rate of infection was significantly higher in the group with gastric cancer when compared with the matched controls, occurring in 62.1% and 29.3%, respectively (OR = 3.95; CI 95% 1.543-10.096). CONCLUSIONS: There is an association between cagA-positive H. pylori strain and risk of gastric cancer.
Asunto(s)
Adenocarcinoma/microbiología , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Neoplasias Gástricas/microbiología , Adolescente , Estudios de Casos y Controles , Femenino , Genotipo , Infecciones por Helicobacter/complicaciones , Helicobacter pylori/patogenicidad , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Factores de RiesgoRESUMEN
CONTEXT: Gastric cancer is the second most common cause of cancer related death worldwide. Although Helicobacter pylori has been classified as a class I carcinogen, the presence of infection is not a factor that alone is able to lead to gastric cancer, and one of the possible explanations for this is the existence of different strains of H. pylori with different degrees of virulence. OBJECTIVES: To investigate the association between cagA-positive H. pylori and gastric cancer, using polymerase chain reaction (PCR) for the detection of this bacterial strain. METHODS: Twenty-nine patients with gastric cancer were matched by sex and age (± 5 years) with 58 patients without gastric cancer, submitted to upper gastrointestinal endoscopy. All patients were evaluated for the status of infection by H. pylori (through urease test, histological analysis and PCR for the genes ureA and 16SrRNA) and by cagA-positive strain (through PCR for cagA gene). RESULTS: Evaluating the presence of infection by cagA-positive H. pylori, it was verified that the rate of infection was significantly higher in the group with gastric cancer when compared with the matched controls, occurring in 62.1 percent and 29.3 percent, respectively (OR = 3.95; CI 95 percent 1.543-10.096). CONCLUSIONS: There is an association between cagA-positive H. pylori strain and risk of gastric cancer.
CONTEXTO: O câncer gástrico é a segunda causa mais comum de mortes relacionadas à neoplasia em todo o mundo. Embora o Helicobacter pylori seja classificado como um carcinógeno classe I, a presença da infecção não é um fator que isoladamente possa conduzir ao câncer gástrico e, uma das possíveis justificativas, é a existência de diferentes linhagens de H. pylori com diferentes graus de virulência. OBJETIVO: Investigar a associação entre H. pylori cagA-positivo e câncer gástrico, utilizando a reação em cadeia de polimerase (PCR) para a detecção desta linhagem bacteriana. MÉTODOS: Vinte e nove pacientes com câncer gástrico foram pareados por sexo e por idade (± 5 anos) com 58 pacientes sem câncer gástrico, submetidos a endoscopia digestiva alta. Todos os pacientes foram avaliados quanto à presença de infecção pelo H. pylori (com teste da urease, análise histológica e PCR para os genes ureA e 16SrRNA) e pela linhagem cagA desta bactéria (com PCR para o gene cagA). RESULTADOS: Avaliando a presença de infecção por H. pylori cagA-positivo, verificou-se que a taxa da infecção era significativamente mais alta no grupo de pacientes com câncer gástrico, quando comparado com o grupo controle, ocorrendo em 62,1 por cento e em 29,3 por cento, respectivamente (OR = 3,95; CI 95 por cento 1,543-10,096). CONCLUSÕES: Há associação entre H. pylori cagA-positivo e risco de câncer gástrico.
Asunto(s)
Adolescente , Femenino , Humanos , Masculino , Adenocarcinoma/microbiología , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Neoplasias Gástricas/microbiología , Estudios de Casos y Controles , Genotipo , Infecciones por Helicobacter/complicaciones , Helicobacter pylori/patogenicidad , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND AND AIMS: The role of Helicobacter pylori infection in gastro-oesophageal reflux disease is controversial. The aim of this study was to evaluate the prevalence of colonization by cagA-positive and cagA-negative H. pylori strains in the spectrum of gastro-oesophageal reflux disease. METHODS: A total of 108 patients (50 male/58 female; mean age, 50.3 years) with dyspepsia and peptic ulcer or erosive gastritis/duodenitis were categorized into patients without reflux and patients with reflux oesophagitis graded from I to IV. All patients underwent upper endoscopy with biopsies of the antrum. H. pylori was detected by histology, urease test and polymerase chain reaction. The cagA status was diagnosed in the gastric biopsy by polymerase chain reaction. RESULTS: The overall prevalence of H. pylori colonization in patients with reflux was 68.6% and was 70.2% in those without oesophageal disease (P = 0.862). Colonization by cagA-positive strains was also not statistically different between the two groups (31.4% versus 40.4%, P = 0.332). However, patients with grades II-IV reflux oesophagitis were less colonized by the bacterium (36.4%) than patients with grade I oesophagitis (77.5%) (P = 0.009). H. pylori cagA-positive strains were also less likely to colonize the stomach of patients with grades II-IV oesophagitis (0%), than grade I reflux oesophagitis (40%) patients and controls (40.4%). CONCLUSIONS: Infection of the stomach by H. pylori and especially by H. pylori cagA strains may play a protective role against the development of the most severe forms of gastro-oesophageal reflux disease.