Randomized controlled trial: PPI-based triple therapy containing metronidazole versus clarithromycin as first-line treatment for Helicobacter pylori in adolescents and young adults in Japan.

BACKGROUND/AIMS: Treating Helicobacter pylori infection in young people is effective for preventing gastric cancer. This study compares the efficacy of triple therapies in adolescents and young adults in Japan. METHODS: This multicenter, randomized trial was conducted between February 2012 and March 2015. Infected participants were stratified into adolescents (13-19 years) and young adults (20-39 years). They were randomly assigned to a clarithromycin based (PAC) or metronidazole based (PAM) triple therapy for 1 week. RESULTS: Overall, 137 and 169 participants received the PAC and PAM treatments, respectively. In adolescents, the H. pylori eradication rates were 60.5% and 63.4% for PAC, and 98.3% and 100% for PAM in the intention-to-treat (ITT) and per-protocol (PP) analyses, respectively. In young adults, the eradication rates were 67.0% and 66.7% for PAC, and 95.5% and 96.3% for PAM in ITT and PP analyses, respectively. The eradication rate of PAM was significantly higher than that of PAC in both strata. No severe adverse events were observed. CONCLUSION: In Japan, PAM may be selected as a first-line treatment for young people with H. pylori if antibiotic susceptibility tests cannot be performed.

Diagnostic accuracy of urine Helicobacter pylori antibody test in junior and senior high school students in Japan.

BACKGROUND: To prevent gastric cancer, a Helicobacter pylori test-and-treat strategy has been proposed. In Japan, routine urine examinations are performed to screen for kidney diseases; it is therefore convenient to screen for H. pylori infection via urine antibody (u-Ab) testing. AIM: To evaluate the diagnostic accuracy of u-Ab testing in students using 13 C-urea breath testing (UBT) as a standard. METHODS: The study population included 806 junior or senior high school students in Japan who provided urine samples and/or underwent UBT. Students with a positive u-Ab test or discrepant results between the u-Ab test and UBT were asked to provide additional stool and/or blood samples or to repeat the UBT. Urinary protein was detected using a urine test strip. RESULTS: The positive rates for the u-Ab test and UBT were 8.9% (71/795) and 5.5% (44/801), respectively. The u-Ab test showed 88.4% sensitivity and 95.7% specificity using UBT as a standard. In the final diagnoses, the u-Ab test showed 97.6% sensitivity, 96.5% specificity, 61.2% positive predictive value (PPV), and 99.9% negative predictive value (NPV). Of the 508 samples tested using a urine test strip, negative results were obtained for 450 subjects with a sensitivity of 90%, specificity of 97.9%, PPV of 66.7%, and NPV of 99.5%. Proteinuria was detected in 58 samples, with a sensitivity of 100%, specificity of 88.9%, PPV of 40%, and NPV of 100%. CONCLUSIONS: The u-Ab test is highly accurate and suitable for detecting H. pylori infection. However, the occurrence of proteinuria may yield false-positive results.