ABO blood groups and Helicobacter pylori cagA infection: evidence of an association

Diseases resulting from Helicobacter pylori infection appear to be dependent on a host of genetic traits and virulence factors possessed by this microorganism. This paper aimed to investigate the association between the ABO histo-blood groups and H. pylori cagA infections. Genomic DNA samples (n = 110) of gastric biopsies obtained from patients with endoscopic diagnosis of peptic ulcers (n = 25) and chronic active gastritis (n = 85) were analyzed by PCR using specific primers for the cagA gene. Of the samples, 66.4 percent (n = 73) tested positive and 33.6 percent (n = 37) negative for the gene. The cagA strain was predominant in peptic ulcers (n = 21; 84.0 percent) compared with chronic active gastritis (n = 52; 61.2 percent) (p = 0.05; OR 3.332; 95 percent CI: 1.050-10.576). Additionally, the cagA strain was prevalent in the type O blood (48/63; 76.2 percent) compared with other ABO phenotypes (25/47; 53.2 percent) (p = 0.01; OR 2.816; 95 percent CI: 1.246-6.364). These results suggest that H. pylori cagA infection is associated with the O blood group in Brazilian patients suffering from chronic active gastritis and peptic ulcers.

Correlación Endoscópica-Histopatológica del Cag-A del Helicobacter Pylori / Endoscopic-Hystopathological Correlation of Helicobacter Pylory Cag-A

Resumen En la actualidad más de la mitad de la población mundial esta infectada con Helicobacter Pylori pero solo del 10 al 20 % desarrollan la enfermedad. La variación en el resultado clínico de la patología inducida por el H. Pylori es multifactorial, entre estos están los factores de la virulencia habiéndose identificado los genotipos cagA, vacA e ice A. que contribuyen en su patogenia. El genotipo cagA ha sido asociado con la enfermedad ulcero péptica, atrofia de la mucosa gástrica y cáncer gástrico, identificado entonces como un factor de virulencia del H. Pylori y responsable de éstas complicaciones en muchas series mundiales. El objetivo de nuestro trabajo fue deternimar el genotipo cagA de H. Pylori en nuestro medio, mediante ELISA y ver su correlación con los hallazgos endoscópicos e histopatológicos de la mucosa gástrica en pacientes del Instituto de Gastroenterología Boliviano Japonés de Cochabamba. Se incluyeron en el estudio a 171 pacientes positivos para H. Pylori, diagnosticados por cualquiera de los tres métodos utilizados: Test rápido de Ureasa, Serología e Histología. En los pacientes diagnosticados mediante serología con ELISA se detectó positividad para cagA en 101 (59.1 %) de los pacientes, con un 66.3% del sexo femenino y 33.7% varones y una edad promedio de 39.5 años, con un rango de 29 a 59 años. La gastritis verrucosa, gastritis nodular, gastritis erosiva y la ulcera duodenal fueron los hallazgos endoscópicos mas frecuentes en los pacientes con H. Pylori cag A (+). En los pacientes con diagnóstico histopatológico de metaplasia intestinal y atrofia gástrica, no se encontró diferencia estadísticamente significativa entre los pacientes cag A positivos Vs los negativos, pero sí en aquellos con gastritis crónica activa (67. 7%) H .Pylori cagA positivo.

Abstract Currently more of half people of the world is infected with Helicobacter Pilory but only from 10 to 20 % develops the di-sease, the variation in the clinical result of the pathology induced by the Helicobacter Pilory is multifactorial, one of these factors is the virulence factor, having been identified the genotypes, cagA, vacA and ice A. that contribuys in the pa-thogeny. The genotype cagA has been associated with peptic ulcer, atrophy of the mucous gastric and gastric cáncer, identified as a factor of virulence of H. pylori and the causer for these complications in many world series. The aim of our work was to determinet the genotype cagA of helicobacter in our enviroment, by means of ELISA and to see his correlation with the finds endoscopios and histopatologics of the gastric mucous in patients of the Bolivian Japa-nese Institute of Gastroenterology of cochabamba. They were included in the study 171 positive patients to H. pylori, diagnosed by any ofthree used methods: rapid Test of Ureasa, Serology and Histology, in these patients by means serology with ELISA there were detected positivity To cagA in 101 (59.1 % ) ofthe patients with 66.3 % ofthe females and 33.7 % males of 39.5 % years, with a range from 29 to 59years. The wart gastritis, nodular gastritis, erosive gastritis and the sore duodenal were the finds endoscopios more frequent in the patients with H.pylori cagA (+). In the patients with diagnosis histopatologic of metaplasia intestinal and gastric atrophy, not find statistically significant difference between the patients cagA positives vs the negatives, but ¡fin those with chronic active gastritis (67.7 % ) h. Pylori cagA positive.

H. pylori infection and the correlation to chronic active gastritis detected by the histological criteria of the sydney system.

In Thailand, chronic active gastritis and chronic atrophic gastritis have not been given frequent mention. Our aim is to present the relationships of the many variables in histological classification of chronic bacterial gastritis by the Sydney System. This paper presents the prevalence of chronic active gastritis by studying the degree of H. pylori infection detected by the Modified Toluidine Blue staining (MTBs) and histological grading, using the Sydney System. A total of 355 dyspeptic patients who underwent endoscopy in Kawila hospital, Chiang Mai, northern Thailand from January 1996 to January 1998, were included in the study. Overall, 284 patients (80.3 %) had an H. pylori infection. Diagnosis varied from normal, chronic gastritis, and acute gastritis to chronic active gastritis in 11 (3.1 %), 95 (26.8 %), 0 (0 %), 249 (70.1 %) patients respectively. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of neutrophils presented with lymphocytes are 85.2, 90.1, 97.2, and 60.4 %, respectively. We conclude from the study that chronic active gastritis is a very common condition in Thailand. If chronic active gastritis is present, H. pylori is usually detected, and the degree of infection is well correlated to the degree of inflammation.