EFFECT OF HELICOBACTER-PYLORI INFECTION ON INTRAGASTRIC UREA AND AMMONIUM CONCENTRATIONS IN PATIENTS WITH CHRONIC-RENAL-FAILURE

Aim-To assess the value of measuring the gastric juice urea : ammonium ratio in detecting Helicobacter pylori infection in patients with chr onic renal failure. Methods-Twenty three (12 men) patients with establ ished chronic renal failure and dyspepsia were studied. Gastric juice (2 nil) was aspirated during endoscopy to measure urea and ammonium. T he upper gastrointestinal tract was routinely inspected and two antral biopsy specimens obtained. The C-14-urea breath test was conducted wi thin 14 days of endoscopic examination to determine H pylori antibody response. Results-The median (range) serum urea concentration in 11 pa tients with renal failure and H pylori infection was similar to that i n 12 without H pylori infection. The median gastric juice urea concent ration in subjects with infection was lower than that in the subjects without infection (p < 0.01). The median gastric juice ammonium concen tration in subjects with the infection was higher compared with subjec ts without infection (p < 0.01). There was an overlap of the urea and ammonium concentrations in gastric juice from both H pylori positive a nd negative subjects. The urea : ammonium ratio was 0.16 (0.01-1.11) f or subjects with H pylori compared with 1.63 (1.0-18.9) in subjects wi thout infection (p < 0.001). Conclusion-The urea : ammonium ratio diff erentiated both groups, with the exception of one false negative resul t. The urea: ammonium ratio proved almost as effective in identifying the presence of H pylori infection in subjects with chronic renal fail ure as it had in subjects with normal renal function.