Gastric juice ammonia vs CLO test for diagnosis of Helicobacter pylori infection.

The aim of the present study was to compare the gastric juice ammonia test to the CLO test for the diagnosis of H. pylori infection in culture-proven cases by receiver operating characteristic (ROC) curve analysis. We studied 75 subjects (44 with chronic gastritis, 10 with gastric ulcer, 6 with duodenal ulcer, 8 with gastric cancer, and 7 normal) by endoscopy with biopsy for tissue diagnosis, culture of H. pylori. CLO test, and by gastric juice ammonia determinations. The culture-positive group had significantly higher intragastric ammonia levels (13.7 +/- 5.8 mg/dl) than the negative group (4.9 +/- 2.4 mg/dl, P < 0.01). In ROC curve analysis, the gastric juice ammonia test showed higher true positive and lower false positive ratios than the CLO test (P < 0.05). In conclusion, the measurement of intragastric juice ammonia levels was considered to be simpler, quicker, and overall a more valuable method for diagnosing H. pylori infection.