Stool antigen for the diagnosis of <i>Helicobacter pylori</i> infection in cirrhosis: comparative usefulness of three different methods

Abstract

BACKGROUND: Helicobacter pylori infection may lead to peptic ulcer disease, and causes significant morbidity in patients with cirrhosis. The measurement of H. pylori antigens in human stools has been proposed as a valuable, non-invasive, diagnostic tool. A number of tests have recently been commercialized. However, very few data are available on their reliability in patients with cirrhosis. AIM: To evaluate the usefulness of three new tests--HpSA (Meridian Diagnostics Inc., Cincinnati, OH, USA), Simple H. pyl (OPERON S.A., Zaragoza, Spain) and FemtoLab H. pylori (Connex, Martinsried, Germany)--in the diagnosis of H. pylori infection in cirrhotic patients. METHODS: H. pylori infection was determined in 79 cirrhotic patients (48 men, 31 women; age range, 29-82 years; mean, 62 +/- 11 years) by concordance of histology and urea breath test. The sensitivity, specificity and positive and negative predictive values of each stool test were calculated. RESULTS: According to the reference method, the sensitivities of HpSA, Simple H. pyl and FemtoLab H. pylori immunoassays were 76%, 87% and 78%, respectively, and their specificities were 93%, 62% and 79%, respectively. CONCLUSIONS: Faecal tests are non-invasive and easy-to-perform tools for the diagnosis of H. pylori infection. However, their sensitivity and specificity seem to be non-optimal in patients with cirrhosis.