Outcome of patients with inconsistent results from ¹³C-urea breath test and bacterial culture at the time of assessment of Helicobacter pylori eradication therapy in Japan

Background/Aims: At the assessment of eradication therapy of Helicobacter pylori, the results of ¹³C-urea breath test and other methods such as bacterial culture are occasionally inconsistent. In this study, we examined the outcomes of inconsistent results. Methodology: Four hundred and four patients with peptic ulcer who were H. pylori-positive and who had completed eradication therapy were studied. Bacterial culture, rapid urease tests and ¹³C-urea breath test were performed between one and three months after the end of the therapy. The cut-off value for the ¹³C-urea breath test used originally in this study was 2.5 per mil. We investigated the outcome of inconsistent results by following up the patients every 6 to 12 months. Results: At the initial assessment of eradication therapy, we observed inconsistent results with bacterial culture and ¹³C-urea breath test in 43 of 404 patients. Most of them (40 of 43) were culture-negative but urea breath test-positive, and the majority became negative for both tests. Based on the follow-up results, the optimum value for ¹³C-urea breath test at the assessment of eradication therapy was found to be 3.5 per mil. Conclusions: We found that outcomes of inconsistent results were variable, indicating the importance of the follow-up of patients after eradication therapy of H. pylori.