A re-testing range is recommended for 13C- and 14C-urea breath tests for Helicobacter pylori infection in China

Abstract

Background The urea breath test (UBT) is widely used for diagnosing Helicobacter pylori infection. In the Shenzhen Kuichong People’s Hospital, some UBT findings were contradictory to the histology outcomes, therefore this study aimed to assess and compare the diagnostic performance of both 13C- and 14C-UBT assays. Methods We recruited 484 H. pylori-treatment naïve patients, among which 217 and 267 were tested by the 13C-UBT or 14C-UBT, respectively. The cutoff value for H. pylori positivity based on manufacturer’s instruction was 4% delta over baseline (DOB) for the 13C-UBT, and 100 disintegrations per minute (DPM) for the 14C-UBT. Gastric biopsies of the antrum and corpus were obtained during endoscopy for histopathology. Results In patients who were tested using the 13C-UBT kit, histopathology was positive in 136 out of 164 UBT-positive patients (82.9% concordance), and negative in 46 out of 53 UBT-negative cases (86.8% concordance). For the 14C-UBT-tested patients, histopathology was positive for H. pylori in 186 out of 220 UBT-positive patients (84.5% concordance), and negative in 41 out of 47 UBT-negative cases (87.2% concordance). While the 13C-UBT and 14C-UBT each had a high sensitivity level of 95.1% and 96.9%, respectively, their specificity was low, at 62.2% and 54.7%, respectively. By using new optimal cutoff values and including an indeterminate range (3–10.3% DOB for 13C-UBT and 87–237 DPM for 14C-UBT), the specificity values can be improved to 76.7% and 76.9% for the 13C- and 14C-UBT, respectively. Conclusions The establishment of an indeterminate range is recommended to allow for repeated testing to confirm H. pylori infection, and thereby avoiding unnecessary antibiotic treatment. Trial registration: Chinese Clinical Trial Registry, ChiCTR2000041570. Registered 29 December 2020- Retrospectively registered, http://www.chictr.org.cn/edit.aspx?pid=66416&htm=4

Performance evaluation of a novel 14C-urea breath test (solid scintillation) for the diagnosis of helicobacter pylori infection

“…[22] A recent study revealed a sensitivity of 96.9% for 14 C-UBT but a specificity of only 54.7% or 76.9% after adjusting the cutoff values. [23] In the present study, the cutoff values were those recommended by the manufacturer, and the observed sensitivity and specificity were close to that of the 2 meta-analyses. [21,22] In terms of safety, during the trial, 1 participant experienced 1 AE (incidence rate of 0.4%).…”

Evaluation of urea breath test as a diagnostic tool for Helicobacter pylori infection in adult dyspeptic patients

“…The trade-off between sensitivity and specificity must be put in mind in clinical setting, when selecting the assessment technique[ 31 ]. For instance, liquid scintillation counting is the recommended method when high sensitivity is essential to bypass missing true results, while solid scintillation counting could be a better selection, when high specificity is crucial to minimize false positives.…”