Helicobacter pylori, gastric juice, and arterial ammonia levels in patients with cirrhosis

Helicobacter pylori urease activity is a potential source of ammonia in the stomach of patients with cirrhosis. However, the possible role of H. pylori in the pathogenesis of hepatic encephalopathy deserves further investigations. The current study evaluates the relationship among H. pylori infection, gastric juice ammonia concentrations, and arterial ammonia levels in patients with cirrhosis. Overall, 14 patients with cirrhosis with overt hepatic encephalopathy, 19 with subclinical hepatic encephalopathy, and 13 without encephalopathy were enrolled. All patients underwent upper endoscopy, and gastric biopsy specimens were taken for H. pylori assessment (rapid urease test, histology, and culture). A gastric juice sample and an arterial blood sample were obtained for ammonia level assessment. Patients with overt encephalopathy had both higher arterial ammonia levels and a more severe hepatic impairment than the remaining patients, whereas gastric juice ammonia concentrations did not differ among the three groups. H. pylori prevalence was similar among groups. Patients with H. pylori infection had significantly higher gastric juice ammonia concentrations than those without infection (2.3 +/- 1.3 vs. 0.9 +/- 0.6 mmol/L, respectively; p = 0.003); however, no difference in arterial ammonia levels emerged between the two groups (37.7 +/- 18.6 vs. 37.6 +/- 18.8 micromol/L, respectively). No significant correlation was found between gastric juice ammonia concentrations and arterial ammonia levels. The data suggest that liver impairment remains crucial in ammonia disposal in patients with cirrhosis, whereas H. pylori infection does not seem to play a major role in the pathogenesis of hyperammonemia in these patients.