Decreased sensitivity of the ultrarapid urease test for diagnosing Helicobacter pylori in patients with chronic renal failure.

Fifty patients with chronic renal failure and 50 asymptomatic healthy volunteers were studied to determine the prevalence of Helicobacter pylori in the two groups and to compare the results of ultrarapid urease test (URUT) and gastric histology for detecting H. pylori infection. Four gastric antral biopsy specimens were taken. Two specimens were used for the URUT and two were processed routinely. Sections were stained with H&E and Loeffler's methylene blue. Histological examination showed presence of H. pylori in 56% of patients with chronic renal failure (CRF) and in 78% of the controls. The difference was statistically significant (p < 0.05). The URUT was positive in only 16% of patients with CRF compared to 74% in the controls (p < 0.0001). The sensitivity and overall diagnostic accuracy of the URUT to diagnose H. pylori infection were 94.8 and 96%, respectively, in controls but were only 29 and 60%, respectively, in patients with CRF. It is concluded that the prevalence of H. pylori is significantly less in patients with CRF and that the URUT is less sensitive than gastric histology for diagnosing H. pylori infection in these patients.