Role of Helicobacter pylori infection in the development of pernicious anemia.

It is now accepted that most patients with atrophic gastritis of the stomach have been infected with Helicobacter pylori. Several investigators have also suggested the possibility that H. pylori is involved in the early stages of pernicious anemia, which leads to severe atrophic gastritis of the fundus. In this article, studies investigating the association of this specific form of atrophic gastritis and H. pylori infection are reviewed. Most of the published studies indicate that patients with pernicious anemia are infected with H. pylori less often than are age-matched controls. However, because H. pylori infection may be present before the development of pernicious anemia, prospective studies during the pre-pernicious anemia stage of gastritis are needed.