Low sensitivity of invasive tests for the detection of Helicobacter pyloriinfection in patients with bleeding ulcer

Background - A high false negative rate for antral infection with Helicobac ter pylori when assessed by rapid urease test has recently been reported in patients with bleeding ulcer. This result could partly explain the differi ng prevalence of H. pylori infection in bleeding and non-bleeding ulcers. Aims - To evaluate the accuracy of a rapid urease test (UT) histology and c ulture for detection of H. pylori in antral biopsies from acute bleeding pe ptic ulcer patients using a serological test as reference. Patients and Methods - All consecutive patients with active bleeding gastri c or duodenal ulcer at endoscopic examination admitted in six university ho spitals in France were considered For inclusion. Five antral biopsies were token during the diagnostic endoscopy for UT, culture and histology. A bloo d sample was taken for H. pylori serology. Results - One hundred and eighty one patients were included and 129 (71%) h ad a positive serology, The sensitivity of UT, histology and culture for de fection of H. pylori infection were 41%, 33% and 34%, respectively. The sen sitivity and specificity of the combination of the three invasive tests wer e 48.8% (95% CI: 40.2-57.4) and 90.6% (95% CI: 82.6-99) respectively. In th e 52 serologically negative patients, only 5 had at least one invasive posi tive test. The sensitivity of the invasive tests decreased significantly wi th age but was not influenced by NSAIDs intake. OF 80 patients with positiv e serological test and negative histological evaluation for H. pylori, chro nic antral inflammation was found in 70 patients (87%). In 46 patients with both negative serological test and H. pylori negative test according to hi stology, only 13 (28%) had chronic antral inflammation. Conclusions - The sensitivity of invasive tests for detection of H, pylori is low during acute ulcer bleeding, and they should be used with caution in this condition. A serological test is recommended to identify patients wit h H. pylori infection in spite of negative invasive tests.