[Stool antigen test for diagnosis of Helicobacter pylori infection. Merely a research opportunity, or an effective diagnostic tool?].

Since Helicobacter pylori (H. pylori) infection was recognized as a major cause of peptic ulcer disease and an important risk factor for gastric malignancy, several strategies have been used to diagnose it. These methods are split up along two lines: 1) direct detection of the bacteria, and 2) detection of antigen-antibody assay against H. pylori, or anyhow detection of H. pylori by indirect methods. In this review of literature about the methods to diagnose H. pylori infection, we focused in particular on the non-invasive tests based on H. pylori antigens detection in faeces. Some meta-analyses showed that immunoenzymatic stool tests can be considered reliable in untreated patients, whereas further confirmations are needed before extending their use also in anti-H. pylori treated patients. As it concerns cost-analysis, immunoenzymatic stool test is the most cost-effective among the tests today available. Finally, a newly developed office-based stool test has been evaluated. It does not require laboratory assay, and the results are available within 10 minutes. Preliminary data about its clinical usefulness are promising, but further and wider confirmations are needed, as it has been put on the market quite recently.