Excretion kinetics of ~(13)C-urea breath test: influences of endogenous CO_2 production and dose recovery on the diagnostic accuracy of Helicobacter pylori infection

摘要

We report for the first time the excretion kinetics of the percentage dose of ~(13)C recovered/h (~(13)C-PDR %/h) and cumulative PDR, i.e. c-PDR (%) to accomplish the highest diagnostic accuracy of the ~(13)C-urea breath test (~(13)C-UBT) for the detection of Helicobacter pylori infection without any risk of diagnostic errors using an optical cavity-enhanced integrated cavity output spectroscopy (ICOS) method. An optimal diagnostic cut-off point for the presence of H. pylori infection was determined to be c-PDR (%)=1.47%at 60min, using the receiver operating characteristic curve (ROC) analysis to overcome the “grey zone” containing false-positive and falsenegative results of the ~(13)C-UBT. The present ~(13)C-UBT exhibited 100 % diagnostic sensitivity (true-positive rate) and 100 % specificity (true-negative rate) with an accuracy of 100 % compared with invasive endoscopy and biopsy tests. Our c-PDR (%) methodology also manifested both diagnostic positive and negative predictive values of 100 %, demonstrating excellent diagnostic accuracy. We also observed that the effect of endogenous CO_2 production related to basal metabolic rates in individuals was statistically insignificant (p= 0.78) on the diagnostic accuracy. However, the presence of H. pylori infection was indicated by the profound effect of urea hydrolysis rate (UHR). Our findings suggest that the current c-PDR (%) is a valid and sufficiently robust novel approach for an accurate, specific, fast and noninvasive diagnosis of H. pylori infection, which could routinely be used for large-scale screening purposes and diagnostic assessment, i.e. for early detection and follow-up of patients.