Prospective blinded trial of a fecal antigen test for the detection of Helicobacter pylori infection

OBJECTIVE: We prospectively studied an FDA-approved stool test for the diag nosis of Helicobacter pylori infection based on the detection of antigens s hed in stool. METHODS: We studied 108 patients undergoing endoscopy. Stool samples were c ollected on the day of the endoscopy and read in a blinded manner by a tech nician who was unaware of the findings of the endoscopy. The results of sto ol testing were compared to those of the rapid urease test (Pyloritek). RESULTS: There were 51 patients infected with H. pylori by rapid urease tes ting and 57 who were not. The sensitivity of the stool test was 86% (95% co nfidence interval: 77-96%), the specificity was 91% (81-97%), with a positi ve predictive value of 89% (77-96%) and a negative predictive value of 88% (81-97%). The likelihood ratio for a positive test was 10.18 and the likeli hood ratio for a negative test was 0.11. CONCLUSIONS: The stool test was se nsitive and specific for the detection of H. pylori in a U.S. population. ( C) 2000 by Am. Cell. of Gastroenterology.