Helicobacter pylori infection and blood groups

Bacterial attachment is a prerequisite for colonization of the gastric epithelial surface. Recently, it was demonstrated that the receptor for Helicobacter pylori is the blood group antigen Lewis b, which is exposed only in blood group O. We prospectively examined the prevalence of blood groups in H. pylori-positive and -negative patients. To avoid a genetic bias, we compared blood group prevalence of our patients with the general population of Israel.

In the 187 consecutive patients we studied, in addition to regular upper endoscopy, H. pylori status and blood group. Exposure to H. pylori was diagnosed when the results of two or more of three methods were found to be positive.

Exposure was found in 123 patients and 64 negative. The groups were similar in average age and origin, and no significant difference was demonstrated for blood group. Blood group distribution between any given origin was not significantly different in our patients and in a sample of 182,701 blood donors.

Positivity for H. pylori was not associated with blood group O. Our observation does not support the conclusion that the receptor for H. pylori in the gastric mucosa is the blood group antigen Lewis b.