ABSTRACT
Background & objectives Certain genotype(s) of Helicobacter pylori strains may play important role in the development of gastric cancer (GC) and peptic ulcer disease (PUD). This study was undertaken to investigate the association of cagA, cagA3/ region subtypes, babA2 and vacA genotypes of H. pylori with GC, PUD and non-ulcer dyspepsia (NUD) as there are no such studies from India. Methods A total of 348 consecutive adult patients (NUD 241, PUD 45, GC 62) undergoing upper gastrointestinal endoscopy between September 2002 and May 2007 in a tertiary referral centre at Lucknow, north India, were enrolled. H. pylori infection was diagnosed by rapid urease test, culture, histopathology and PCR. Genotyping for cagA, cagA3/ subtypes, babA2 and vacA was performed by PCR using sequence specific primers. Results H. pylori infection was higher in patients with PUD than with GC (80 vs. 56.5%, P < 0.01) and NUD (80 vs. 55.2%, P= 0.002). cagA positive H. pylori isolates were detected in 80 per cent in GC, 83.3 per cent in PUD and 76.7 per cent in NUD with no significant difference among them. Only A subtype of cagA3/ was detected and its distribution in GC, PUD and NUD was 68.8, 69.4 and 52.6 per cent respectively. Presence of babA2 genotype was 31.4 per cent and it had significant association with PUD when compared with NUD (52.8 vs. 26.3%, P<0.003). On univariate regression analysis, s1a allele was associated with GC (P<0.050) and s1a/m2 vacA genotype with both GC (P=0.014) and PUD (P=0.016). Interpretation & conclusions H. pylori infection was strongly associated with PUD with a very high proportion of patients with GC have s1a allele and s1a/m2 vacA genotype. Both s1a/m2 vacA genotype and babA2 are associated with PUD. The study shows that different virulence attributes of H. pylori are involved in different gastroduodenal disorders.
Subject(s)
Adult , DNA Primers , Dyspepsia/epidemiology , Dyspepsia/microbiology , Female , Genome-Wide Association Study , Genotype , Helicobacter Infections/diagnosis , Helicobacter Infections/epidemiology , Helicobacter Infections/genetics , Helicobacter pylori/genetics , Helicobacter pylori/pathogenicity , Humans , India/epidemiology , Logistic Models , Male , Middle Aged , Peptic Ulcer/epidemiology , Peptic Ulcer/microbiology , Polymerase Chain Reaction , Stomach Neoplasms/epidemiology , Stomach Neoplasms/microbiology , Urease/diagnosis , VirulenceABSTRACT
La dispepsia afecta la calidad de vida de muchos pacientes y en muchos casos está asociada a la infección por Helicobacter pylori. Esta bacteria es reconocida como el agente causal de la gastritis crónica, se asocia al desarrollo de úlceras gástrica y duodenal y está relacionada con el desarrollo de cáncer gástrico. Como objetivo primario se planteó establecer los hallazgos clínicos, endoscópicos e histológicos asociados a la infección por Helicobacter pylori considerando los genotipos cag A y vac A en pacientes con dispepsia que acudieron al Servicio de Gastroenterología del Hospital Central Universitario Antonio María Pineda. Se trata de un estudio epidemiológico descriptivo de corte transversal. La población estuvo conformada por los pacientes con dispepsia que acudieron al servicio y el muestreo fue de tipo no probabilístico intencional, puesto que se tomó a la población que consultó con síntomas dispépticos y que cumplieron con los criterios de inclusión y exclusión establecidos. Dichos pacientes se interrogaron sobre síntomas dispépticos, se les realizó endoscopia digestiva superior, se describieron los hallazgos endoscópicos y se les tomó muestra para estudio histológico y de genotipificación. Se encontró una incidencia de infección por H. pylori de 98,5%, la infección predominó en el sexo femenino, los genotipos cag A positivos y las formas alélicas m1/s1 son los más frecuentes en la población estudiada y, los mismos se asocian con gastritis crónica, úlceras gástricas y metaplasia intestinal incompleta...
Dyspepsia affects quality of life for many patients and often is associated with Helicobacter pylori infection. This bacterium is recognized as the causative agent of chronic gastritis, is associated with development of gastric and duodenal ulcers and, with the development of gastric cancer. Primary objective was raised to establish the clinical, endoscopic and histological findings associated with Helicobacter pylori infection considering genotypes cag A and vac A in patients with dyspepsia who attended the Gastroenterology Service of Hospital Central Universitario Antonio María Pineda. This is a cross-sectional descriptive epidemiological study. The population consisted of patients with dyspepsia who attended the gastroenterology service. The sampling was intentionally non-probabilistic, since we only took the people who consulted with dyspeptic symptoms and met the established criteria of inclusion and exclusion. These patients were questioned about dyspeptic symptoms, underwent upper gastrointestinal endoscopy, endoscopic findings were described and samples were taken for histology and genotyping. We found an incidence of H. pylori of 98.5%, infection prevailed in females, the genotypes cag A positive and m1/s1 allelic forms are most frequent in the population studied and, the same is associated with chronic gastritis, gastric ulcers and intestinal metaplasia incomplete...