Helicobacter pylori and extragastric diseases.

While Helicobacter pylori infection was initially revealed to be associated only with some gastroduodenal diseases, further studies have shown its possible role in several extragastric diseases. For idiopathic thrombocytopenic purpura, sideropenic anemia, and vitamin B12 deficiency, the diagnosis of H. pylori infection is recommended, and there are many other conditions such as cardiovascular, neurological, dermatological, and respiratory diseases in which H. pylori may possibly play a role. Interestingly, a potential role has also been described for GI neoplastic diseases, including colorectal and pancreatic cancer. Different mechanisms of action have been proposed, ranging from the induction of a low grade inflammatory state to the occurrence of molecular mimicry mechanisms. This review summarizes the results of the most relevant studies published on this topic over the last year.