PERFORMANCE OF HELICOBACTER-PYLORI ACID EXTRACT AND UREASE ENZYME-LINKED IMMUNOSORBENT ASSAYS IN RELATION TO C-14 UREA BREATH TEST

The C-14-urea breath test has been shown to be a reliable non-invasive method to detect the presence or absence of H. pylori infection. Alte rnatively, a number of techniques have been devised to detect circulat ing antibodies against H. pylori in serum, the most commonly used bein g 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 C-14-urea breath test. Seventy-five gastroenterology outpatients were screened for the presence of H. pylori infection using the urea b reath test. At the same time serum specimens were obtained. Thirty-sev en patients had a positive breath test, i.e. they expired more than 2% of the oral C-14 test dose within 60 min. Using the breath test as re ference, sensitivity and specificity for the acid extract were 89.2% a nd 84.2% respectively, and for the urease ELISA 81.1% and 89.5%. Agree ment between the two ELISAs was found in 82.7%, overall agreement betw een all three tests was observed in 77.3%. All three tests were found to be useful for monitoring therapy directed against H. pylori.