UREA BREATH TESTS FOR THE DETECTION OF HELICOBACTER-PYLORI INFECTION

Mechanism of urea breath tests: The [C-13]- and [C-14]-urea breath tests exploit the powerful urease enzyme of Helicobacter pylori; hydrolysis of label led urea releases labelled CO2, which is excreted in the exhaled breath. Distribution of urea throughout the stomach prevents sampling error and allows semiquantitative assessments of the extent of H. pylori infection. Both tests are easy to perform with minimum opportunity for observer variation or methodological error, and thus are very sensitive and specific tests for H. pylori. Advantages of the [C-13]-urea breath test: The major advantage of the [C-13]-urea breath test is its stable non-radioactive natural isotope; it can be used repeatedly on anyone (including pregnant women and children), samples can be sent by post and a user's licence is not needed. The [C-13]-urea breath test has been modified and a standard European protocol developed, which is simpler and cheaper than previous methods. No special equipment is needed for the test, and patients can be tested in groups. This test can be used to assess suppression, clearance, recurrence and eradication of H. pylori and is widely used for phase 2 clinical trials of new anti-H. pylori drugs. Conclusion: Both breath tests provide a clinical standard against which the sensitivity and specificity of other methods can be validated and either can be used as the sole method for assessing eradication of H. pylori.