Performance of Helicobacter pylori acid extract and urease enzyme-linked immunosorbent assays in relation to 14C-urea breath test.

The 14C-urea breath test has been shown to be a reliable non-invasive method to detect the presence or absence of H. pylori infection. Alternatively, a number of techniques have been devised to detect circulating antibodies against H. pylori in serum, the most commonly used being enzyme-linked immunosorbent assays (ELISA). In the present study we compared the value of two ELISA antigen preparations, an acid glycine extract and a urease preparation, in relation to the results achieved in a 14C-urea breath test. Seventy-five gastroenterology outpatients were screened for the presence of H. pylori infection using the urea breath test. At the same time serum specimens were obtained. Thirty-seven patients had a positive breath test, i.e. they expired more than 2% of the oral 14C test dose within 60 min. Using the breath test as reference, sensitivity and specificity for the acid extract were 89.2% and 84.2% respectively, and for the urease ELISA 81.1% and 89.5%. Agreement between the two ELISAs was found in 82.7%, overall agreement between all three tests was observed in 77.3%. All three tests were found to be useful for monitoring therapy directed against H. pylori.