Antigen stool test for assessment of Helicobacter pylori infection in patients with upper gastrointestinal bleeding

Background: Re-bleeding of Helicobacter pylori-associated peptic ulcer disease is reduced by H. pylori eradication. Aim: To validate a non-invasive test, the Premium Platinum HpSA(TM) stool test, in patients with upper gastrointestinal bleeding. Methods: Stool samples of consecutive patients with relevant bleeding from gastric or duodenal ulcers or erosions were collected at initial endoscopy and during the following week. Samples were assessed using the HpSA(TM) test. H. pylori status was defined by three biopsy-based reference methods: culture, rapid urease test and histology. It was positive if culture was positive or if rapid urease test and histology were positive. Results: One hundred and fourteen patients (mean age, 66 years) were included. In accordance with the definition, 56 (49%) were H. pylori positive. The sensitivity and specificity of the first stool sample were 84% and 90%, respectively. The respective values for two samples from consecutive days were 91% and 86%. In comparison with a serum immunoglobulin G antibody enzyme-linked immunoabsorbent assay, the HpSA(TM) test showed superior specificity. Conclusions: The diagnostic accuracy, in particular the sensitivity, of the HpSA(TM) stool test is reduced by upper gastrointestinal bleeding. The positive predictive value of 89%, however, justifies the initiation of eradication therapy on the basis of a positive stool test. A negative test result should be confirmed by a further diagnostic method.