A novel tablet-based C-13 urea breath test for Helicobacter pylori with enhanced performance during acid suppression therapy

Background: The urea breath test (UBT) can still be improved in terms of us er-friendliness and accuracy during acid-suppression therapy. This study wa s designed to evaluate a novel, rapidly disintegrating C-13 UBT tablet, whi ch was supplemented with citric acid to facilitate diagnosis of Helicobacte r pylori in the hypochlorhydric stomach. Methods: The efficacy of a fasting C-13 tablet-based UBT (TUBT) was compared with that of a standard C-13 UBT (SUBT) during 40 min after dosing, and optimal sampling points were determ ined. The single-point TUBT was validated against a 'gold standard' (GS) in cluding a TUBT, culture, histology, and a CLO test in 134 dyspeptic patient s, and its optimal cut-off point was determined by means of a biometric met hod. In addition, 20 SUBT-positive patients were randomized to perform eith er the TUBT or the SUBT after 7 days of omeprazole therapy (20 mg twice dai ly). Results: Compared with a SUBT, the TUBT gave a quicker and wider separ ation between positive and negative results and an earlier optimal sampling point (10 versus 40 min). At 10 min the TUBT correctly classified 40 of 42 GS-positive subjects (sensitivity, 95%) and all of 92 GS-negative patients (specificity, 100%), and the optimal cut-off point was 1.8 delta per mil. Furthermore, when optimal sampling points were used, the TUBT (t = 10 min) proved to be more accurate than the SUBT (t = 40 min) during omeprazole tre atment, correctly identifying all of 10 and 3 of 9 H. pylori-infected patie nts, respectively. Conclusions: By supplying C-13 urea and citric acid as a rapid-release tablet, it is possible to shorten the duration of the C-13 U BT to 10 min, omit the test meal, and still maintain excellent accuracy, ev en during acid suppression therapy.