Role of ammonia in the pathogenesis of the gastritis, hypergastrinaemia, and hyperpepsinogenaemia I caused by Helicobacter pylori infection.

Abstract

Studies were performed in patients with and without renal failure to investigate the role of bacterial ammonia production in the pathogenesis of the mucosal abnormalities caused by Helicobacter pylori. The high rate of H pylon ammonia production in uraemic patients should accentuate any ammonia induced effects. The median (range) gastric juice ammonium concentration in the H pylori positive patients with renal failure was 19 mmol/l (1I-43) compared with 5 mmoIl (1-11) in the H pylon positive patients without renal failure (p<0005). In the H pylori negative patients the values were 3 mmol/l (0.5-11) and 0.7 mmol/l (0.1-1.4) respectively in the patients with and without renal failure (p<O.Ol). Despite the much higher ammonia production in the H pylon positive uraemic patients, the nature and severity of their gastritis was the same as that in the H pylori positive non-uraemic patients. The median (range) fasting serum gastrin concentration was raised in the uraemic patients compared with the non-uraemic patients but was similar in the uraemic patients with (95 pmoIl (52-333)) or without (114 pmoIIl (47-533)) H pylori infection. The median (range) serum pepsinogen I concentration was also high in the uraemic compared with the non-uraemic patients and was significantly higher in uraemic patients with H pylon (352 ng/ml, range 280-653) than in those without H pylori infection (165 ng/ml, range 86-337) (p<0.01).These findings indicate that the gastritis and hypergastrinaemia associated with H pylori infection are not the result of mucosal damage induced by the organism's ammonia production.

<i>Mt 21-42</i>: Development and Validation of an Automatic Device Proposed for the Endoscopic Diagnosis of <i>Helicobacter pylori</i> Infection and Atrophic Gastritis

“…In this study, the authors reported a strong correlation between the presence of the bacterium and the levels of ammonium. Subsequently, several other reports have been published on this topic [9,10,11,12,13,14,15,16,17,18]. Most of them confirmed the relation between ammonium and infection but they significantly differed about the concentrations detected (table 2); moreover, an evident overlap between infected and uninfected patients occurred in all studies.…”

“…Moreover, the peculiar characteristic of gastric juice makes this determination much more problematic than in other mediums. This may account for the discrepancies reported in the literature about this parameter and its possible role in diagnosing H. pylori infection [8,9,10,11,12,13,14,15,16,17,18]. …”

“…Although individual evaluations have not been performed, the cumulative effect of long persistence at room temperature, freezing and centrifugation has proven to modify the measurement of pH and ammonium. This aspect may be account for the differences reported in the literature about gastric juice pH and, in particular, ammonium determination [10, 11, 13, 14,16,17,18]. …”

Helicobacter pylori

“…Gastric juice ammonia concentrations correlate with the severity of gastritis in man [56], but findings in patients with uraemia argue against ammonia as an important cause of gastritis. Uninfected patients with renal failure had much less gastritis than infected controls, even though both groups have similar intragastric ammonia levels [57]. However, it may be oversimplistic to consider ammonia and gastritis separately as ammonia released by H .…”

Eradication of Helicobacter pylori Restores Elevation of Serum Gastrin Concentrations in Patients with End-Stage Renal Disease.

“…However, studies on the influence of H. pylori infection on the serum gastrin concentration in patients with end-stage renal disease have been limited and the results are conflicting. Luzza et al reported thatpatients on dialysis with H. pylori infection exhibit a higher serum gastrin concentration than those without H. pylori infection (5), while other studies have not found such differences (6)(7)(8).…”