¹³C Urea Breath Test for Helicobacter pylori: Evaluation of 10-minute Breath Collection

Abstract

AIM: To determine whether a shortened ¹³C urea breath test (¹³C UBT) (breath collection time of 10 min) is as reliable as the standard assay (30 min).METHODS: Two hundred ninety-seven patients (mean ± SD: 53±16 years, 57% female) completed a ¹³C UBT. Breath samples were obtained at baseline and at 5 min intervals up to 30 min. Sixty-seven patients also underwent endoscopic biopsy. Cluster analysis was performed on the ¹³C UBT data to determine the optimal cut-off point at each time interval. Sensitivity and specificity of the ¹³C UBT at all intervals compared with histology and culture and against the standard 30 min interval were determined.RESULTS: The calculated optimal cut-off points for each time interval (T), expressed as delta over baseline (δ‰), were 3.29 δ‰ at T₅, 3.15 δ‰ at T₁₀, 3.42 δ‰ at T₁₅, 3.17 δ‰ at T₂₀, 2.99 δ‰ at T₂₅ and 2.82 δ ‰ at T₃₀. Except at T₅, the risk of false-positive and false-negative test results at each time interval was lower than 2.3% using these cut-off points. When replacing the cut-off points with 3.0 δ‰, the risk of error was still lower than 2.3%. The test at T₁₀ showed 98.6% sensitivity and 98.6% specificity compared with T₃₀. T₁₀ and T₃₀ showed 100% sensitivity and 96% specificity compared with histology and culture.CONCLUSIONS: The ¹³C UBT is an accurate, noninvasive test, even when the breath sample interval is reduced to 10 min. The present study confirms the validity of a cut-off point of 3.0 δ‰ for the 10 min and 30 min ¹³C UBT.