Diagnostic efficacy of 13 C-urea breath test for Helicobacter pylori infection in hemodialysis patients

The noninvasive urea breath test (UBT) avoids the discomforts and risks of invasive endoscopic methods of Helicobacter pylori detection. This study investigated the diagnostic efficacy of carbon 13 (13C)-labeled UBT for H pylori detection in 70 patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) and 70 dyspeptic controls without renal impairment. With H pylori infection defined as a positive result on either histological examination or culture of gastric biopsy specimen, we evaluated the reliability of the 13C-UBT in detecting H pylori infection in both groups. To ascertain whether HD therapy affects the diagnostic efficacy of the UBT, the test was performed twice in patients with ESRD (before and after HD) at least 72 hours apart. In each UBT session, the baseline, 10-minute, and 15-minute (Δ15) gas samples were obtained to analyze excess 13CO2 /12CO2 ratio (ECR). Histological stain and/or culture studies found that 33 of the patients with ESRD (47.1%) and 42 of the control patients (60%) had H pylori infection. 13C-UBT for H pylori detection in patients with ESRD was found to be only 93.8% sensitive and 85.3% specific. These results were achieved by gas sampling (Δ15) after HD therapy with a cutoff ECR value greater than 5. Conversely, the UBT in the control group achieved the greatest diagnostic efficacy (sensitivity, 97.6%; specificity, 96.4%) with a comparatively lower ECR cutoff value of 4. We conclude that the diagnostic accuracy for H pylori detection in patients with ESRD could be improved by performing 13C-UBT (Δ15) after HD therapy and assessing the UBT with a cutoff ECR value greater than 5. However, the diagnostic efficacy of the UBT for patients with ESRD remained less accurate than that for dyspeptic patients without renal impairment.