Diagnosis of Helicobacter pylori infection with a new non-invasive antigen-based assay

Background. Helicobacter pylori is a common human pathogen implicated in certain gastrointestinal diseases. In the search for new non-invasive techniques to diagnose H pylori infection, we evaluated an EIA for H pylori antigen in stool (HpSA). Methods. In a prospective multicentre study, stool specimens from 501 patients (276 men, 225 women; age range 17-88 years, mean 52) undergoing gastroscopy in 11 centres throughout Europe were tested with HpSA and the carbon-13-urea breath test. At endoscopy, four biopsy samples were taken for histology (haematoxylin and eosin) and H pylori detection (giemsa in both antrum and corpus, culture and rapid urease test). Patients were defined as positive for H pylori if histology (antrum, corpus, or both) and urease test were positive, or if culture was positive. Patients classified as having H pylori infection received an eradication regimen; 107 were reassessed 4 weeks after therapy. Findings. Of 272 patients with H pylori infection by the predefined criteria, 256 were positive by HpSA (sensitivity 94.1% [95% CI 90.6-96.6]). Of 219 patients without infection, 201 were negative by HpSA (specificity 91.8% [87.3-95.1]). Interpretation. The stool assay was a reliable and easy-to-use tool for diagnosis of H pylori infection. The test was accurate even shortly after treatment.