Diagnostic efficacy of C-13-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 in vestigated the diagnostic efficacy of carbon 13 (C-13)-labeled UBT for H py lori detection in 70 patients with end-stage renal disease (ESRD) undergoin g hemodialysis (HD) and 70 dyspeptic controls without renal impairment. Wit h H pylori infection defined as a positive result on either histological ex amination or culture of gastric biopsy specimen, we evaluated the reliabili ty of the C-13-UBT in detecting H pylori infection in both groups. To ascer tain whether HD therapy affects the diagnostic efficacy of the UBT, the tes t 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 (Delta 15) gas samples were obtained to analyze excess (CO2)-C-13/(CO2)-C- 12 ratio (ECR). Histological stain and/or culture studies found that 33 of the patients with ESRD (47.1%) end 42 of the control patients (60%) had H p ylori infection,C-13-UBT for H pylori detection in patients with ESRD was f ound to be only 93.8% sensitive and 85.3% specific, These results were achi eved by gas sampling (Delta 15) after HD therapy with a cutoff ECR value gr eater than 5, Conversely, the UBT in the control group achieved the greates t diagnostic efficacy (sensitivity, 97.6%; specificity, 96.4%) with a compa ratively lower ECR cutoff value of 4, We conclude that the diagnostic accur acy for H pylori detection in patients with ESRD could be improved by perfo rming C-13-UBT (Delta 15) after HD therapy and assessing the UBT with a cut off ECR value greater than 5, However, the diagnostic efficacy of the UBT f or patients with ESRD remained less accurate than that for dyspeptic patien ts without renal impairment. (C) 2000 by the National Kidney Foundation, In c.