Respuesta inmunológica a varias proteínas del H. pylori en pacientes guatemaltecos / Inmune response to various H. pylori proteins in Guatemalan patients

Se determinó la respuesta inmunológica a proteínas recombinantes de Helicobacter pylori en pacientes dis-pépticos (adultos y niños), pacientes con cáncer gástrico y sus familiares asintomáticos adultos viviendo con ellos. Se utilizó la prueba recomLine® Helicobacter IgG e IgA, y con base en el reconocimiento de los factores de virulencia VacA y CagA se determinó si la cepa de H. pylori era de tipo I o II. El análisis de los datos fue descriptivo y analítico y se estimaron los intervalos de confianza de 95%, con un nivel de error de 0.05 y Odds ratio. El 58.7% (121/206) de los pacientes presentó la bacteria en tinción histológica de biopsia, positividad que disminuyó con la edad y daño histológico. La frecuencia de la respuesta a los anticuerpos IgG fue mayor que IgA, en ambos casos ésta fue menor en los niños. Las proteínas del H. pylori más reconocidas tanto por IgA como IgG fueron VacA y CagA, y la respuesta a las otras proteínas investigadas fue mayor al aumentar el daño histológi-co. La cepa tipo I fue la que predominó en la población en estudio con 66% (136/206). Se deben continuar con los estudios de prevalencia de la cepa tipo I del H. pylori y del reconocimiento de sus antígenos en la población guatemalteca a fin de determinar su utilidad en el diagnóstico y pronóstico de la infección.

The immune response to recombinant Helicobacter pylori proteins was determined in dyspeptic patients (adults and children), patients with gastric cancer and their asymptomatic adults' relatives living with them. The recomLine® Helicobacter IgG and IgA test was used and based on the recognition of the virulence factors VacA and CagA, it was determined whether the H. pylori strain was type I or II. The data analysis was descriptive and analytic, and 95% confidence intervals were estimated, with an error level of 0.05, and Odds ratio. The patients that presented the bacterium in histological biopsy were 58.7% (121/206), positivity that decreased with age and histological damage. The frecuency of response to IgG antibodies was higher than IgA, in both cases it was lower in children. VacA and CagA were the H. pylori proteins most recognized by both IgA and IgG and it was observed that the number of recognized proteins was greater with increasing histological damage. The type I strain was the one that predominated in the study population 66% (136/206). Prevalence studies of the type I strain of H. pylori ant the recognition of its antigens in the Guatemalan population should continue in order to determine its usefulness in the diagnosis and prognosis of infection.

Anti CagA antibody among patients with non-cardia gastric cancer in comparison with non-ulcer dyspepsia in an area with high incidence of gastric cancer

To evaluate the correlation between anti CagA antibody [Ab] and presence of gastric cancer. In a descriptive cross-sectional study during October 2003 to October 2005, in the Gastrointestinal Subspeciality Center in Razi Hospital, Rasht, Iran, we assessed anti-Helicobacter Ab immunoglobulin G [IgG] and anti CagA Ab IgG by the enzyme-linked immunosorbent assay [ELISA] method in 52 patients with gastric adenocarcinoma and 57 patients with nonulceric dyspepsia [NUD]. Among 52 patients with gastric cancer, anti-Helicobacter pylori Ab was negative in 13 [25%] and positive in 39 persons [75%]. Among 57 patients with NUD, anti-Helicobacter pylori Ab was negative in 5 [8.5%] and positive in 52 patients [91.2%] [p=0.043]. This significant difference did not remain after logistic regression for adjustment of confounders [p=0.068]. The CagA Ab was positive in 22 [42.3%] patients with cancer and 32 [56.1%] of the NUD group. There was no difference in this regard before [p=0.212] and after [p=0.131] logistic regression analysis. Anti CagA Ab does not have a significant value as an independent predictive factor in gastric adenocarcinoma