Role of the systemic cellular immune response in the pathogenesis of Helicobacter pylori-associated duodenal ulcer.

20 patients colonized by H. pylori (9 with duodenal ulcer, 11 with antral gastritis) were examined for the presence of a systemic cellular immune response to H. pylori using an in vitro lymphocyte transformation assay. Infiltration of the antral mucosa by myelomonocytic cells was assessed by immunohistology as a parameter of local cellular immune response. A systemic H. pylori-induced cellular reaction could be demonstrated in 11 patients all of whom showed an intense myelomonocytic infiltration of the antral mucosa. In this group 7 of 9 duodenal ulcers occurred. The findings support the hypothesis, that a specific cellular immune response might be involved in the pathogenesis of H. pylori-associated gastritis and duodenal ulcer. A protective role of systemic cellular immunity to H. pylori seems rather unlikely.