Correlations Among Gastric Juice pH and Ammonia, Helicobacter Pylori Infection and Gastric Mucosal Histology

BACKGROUND : To assess the relationships among gastric pH and ammonia level, H. pylori infection, and gastric mucosal histology, we determined the gastric juice pH and ammonia concentration in H. pylori gastritis. METHODS : The pH levels and ammonia concentrations were determined in gastric juice collected from 143 patients with dyspepsia during an endoscopy and compared according to a H. pylori infection. We also looked for correlations between two chemical parameters, between each of these parameters and H. pylori density, and histology. RESULTS : Gastric pH levels and ammonia concentrations were higher in 94 infected patients than in the uninfected (3.16 vs. 1.55, p=0.0001; 5.58 ± 2.69 vs. 2.00 ± 1.49 moL/L, p=0.0001). Among 28 patients who received eradication therapy, 19 (67.9%) were successful, and their gastric pH levels and ammonia concentrations were significantly lower than those in the eradication failure group (1.60 vs. 2.33, p=0.007; 1.77 ± 1.28 vs. 4.02 ± 1.20 μmoL/L, p=0.0001). Gastric pH was significantly associated with intragastric ammonia concentration (p=0.025) and gastritis activity (p=0.018). Gastric pH and the ammonia level were significantly correlated with each other (rs=0.495, p<0.01), and with H. pylori density (rs=0.467; rs=0.735, p<0.01), gastritis severity (rs=0.343; rs=0.478, p<0.01), and gastritis activity (rs=0.418; rs=0.579, p<0.01). CONCLUSION : Gastric juice pH and ammonia concentration reflect well the status of a H. pylori infection, and significantly correlate with each other and with H. pylori density, gastritis severity and activity. These findings suggest that intragastric ammonia produced by H. pylori may have a partial role in an increased gastric juice pH, and has a pathogenic role in H. pylori gastritis.