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

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.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.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.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.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.