Noninvasive stool antigen assay can effectively screen Helicobacter pylori infection and assess success of eradication therapy in hemodialysis patients

Abstract

Helicobacter pylori (H pylori) stool antigen (HpSA), serological antibody against H pylori (immunoglobulin G [IgG]), and urea breath test (UBT) are noninvasive methods used to detect H pylori infection that can allow a patient to avoid the discomfort and risk of invasive endoscopy. However, because the UBT has proven not highly reliable in patients with end-stage renal disease (ESRD), this study attempts to investigate the diagnostic efficacy of HpSA and IgG for H pylori detection in 80 patients with ESRD and 80 dyspeptic patients without renal function impairment as a control group. All patients in both study groups underwent panendoscopy to obtain gastric biopsy specimens for histological examination and H pylori culture. With H pylori infection defined as a positive result on either histological examination or culture, we evaluated the reliability of HpSA and serum IgG in detecting H pylori infection. Forty of the patients with ESRD (50%) and 48 patients in the control group (60%) were proven to be infected with H pylori. To eradicate H pylori infection, these patients were administered a 1-week course of triple therapy. To evaluate the success of H pylori eradication, 38 patients in the ESRD group and 44 patients in the control group underwent a follow-up endoscopy and provided stool samples for HpSA 6 to 8 weeks later. Success of H pylori eradication was found in 86.8% of the patients with ESRD (33 of 38 patents) and 84.1% of the control patients (37 of 44 patients). Before therapy, HpSA for H pylori detection was 97.5% sensitive and 97.5% specific in patients with ESRD, as effective as that in the control group. After therapy, HpSA was 100% sensitive and more than 96% specific to detect the failure of H pylori eradication therapy in both the ESRD and control groups. Conversely, the use of IgG as a screening method for H pylori infection proved to be less effective because it showed a sensitivity of 87.5% and specificity of 80% in this study. Monitoring the success of triple therapy, IgG had a specificity of only 21.9% in the ESRD group and 24.3% in the control group. In summary, HpSA is a noninvasive and reliable tool to screen H pylori infection before therapy and assess the success of eradication therapy in patients with ESRD. © 2001 by the National Kidney Foundation, Inc.