[Diagnosis of Helicobacter pylori infection].

A number of direct (histology, specific culture) and indirect (serology, urease test, breath test) diagnostic tests for Helicobacter pylori (H. pylori) are available. The gold standard for H. pylori presence or absence is still histology (tissue stained by Giemsa) without or in combination with specific culture. For routine practice a combination of histology (two antral and two body biopsies) and the urease test (one antral and one body biopsy specimen) is recommended in patients undergoing upper GI endoscopy. The reaction velocity of the urease test can be semi-quantitatively graded and, thus, allows a rough estimate of the grade and the activity of gastritis. The simplest and least expensive non-invasive method is serologic testing for IgG and/or IgA antibodies. Latex-agglutination methods are "quick tests", useful for screening purposes. ELISA based tests accurately quantitate the amount of antibody (titer) present and are a promising tool for assessing the efficacy of H. pylori eradication treatment. 13 C/14 C-urea breath tests are reliable non-invasive methods for the diagnosis of ongoing H. pylori infection.