Two decades of Helicobacter pylori: a review of the Fourth Western Pacific Helicobacter Congress

Helicobacter pylori and extragastric diseases

Since the discovery of Helicobacter pylori, several studies have investigated the hypothetical role of this bacterium in various extragastric diseases, e.g. ischemic heart disease, idiopathic thrombocytopenic purpura, iron-deficiency anaemia, and other disorders. The majority of these studies are epidemiological or eradication trials, but there are also case reports and in-vitro studies. Idiopathic thromobocytopenic purpura is the disease that shows the strongest link with H. pylori infection. There is also evidence of a role of CagA-positive H. pylori infection in iron-deficiency anaemia and ischemic heart disease. The association between H. pylori infection and other extragastric diseases remains controversial, being mostly supported by 'case reports', small pilot studies, or just in-vitro data. Further studies are needed to identify whether there is any pathological implication for H. pylori infection in these diseases.

Helicobacter pylori and extragastric diseases -- other helicobacters

The role of Helicobacter pylori infection is explored in more and more extragastric diseases without definite proof in most of the studies, except possibly some hematologic diseases. In cardiovascular diseases, including stroke, the presence of CagA positive strains may be involved. The possible role of helicobacters in hepatobiliary diseases goes beyond that of H. pylori to involve enterohepatic helicobacters. New Helicobacter species are regularly described and molecular methods are developed to improve their detection. Helicobacter felis remains the major species to be used in animal models of Helicobacter infection.