Can the C-14 urea breath test replace follow-up endoscopic biopsies in patients treated for Helicobacter pylori infection?

BACKGROUND: The C-14 urea breath test (UBT) is the most specific noninvasive test to detect Helicobacter pylori, with reported sensitivity and specificity rates of 90% and 95%, respectively. This test has not been evaluated for eradication after a therapeutic trial. The goal of this study was to assess the accuracy of C-14 UBT in the diagnosis and eradication of H. pylori infection in patients with duodenal ulcer who were treated with a triple drug regimen. METHODS: Sixty patients with active duodenal ulcers who tested positive for the rapid urease test had a C-14 UBT at 0 weeks (at enrollment) and at 6 and 12 weeks using 5 microCi (185 KBq) of C-14 urea. A single breath sample was collected at 15 minutes for UBT. H. pylori was eradicated using lansoprazole and two antibiotics. RESULTS: Receiver operator characteristic curves showed that, using a value of 400 counts per minute (cpm), UBT had a sensitivity rate of 91%, specificity rate of 93%, positive predictive value of 77%, and a negative predictive value of 97% in the prediction of H. pylori eradication. The mean + 3 SD of H. pylori-negative patients was 380.1 cpm; at this cutoff value, the sensitivity and specificity rates were 91.3% and 92.8%, respectively. CONCLUSION: The C-14 UBT was an accurate, rapid, and easily administered test to diagnose initial H. pylori infection and to monitor its eradication, thereby obviating the need for repeated endoscopic biopsies.