Urease test of the gastric content deposits for diagnosis of Helicobacter pylori infection in the gastric mucosa

A rapid urease test was applied to the examination of the deposit of gastric juice for diagnosing H. pylori in the gastric mucosa. Two hundred and twenty patients blindly randomized were examined in a case control study. The standard rapid urease test kit Jatrox-H.p.-Test (Rohm Pharma, Germany) was used to determine urease activity in the deposit of gastric juice and duodenal [n = 110 (Group 1)] and gastroduodenal [n = 110 (Group 2)] mucosae. Giemsa staining was employed as a comparison method to examine H. pylori infection in the gastric and duodenal mucosae. The availability of regions of duodenal metaplasia was confirmed by periodic acid-Schiff and alcian blue (Serva) staining tests (pH 1.0 and 2.5, respectively). The results of evaluation of the efficiency of the rapid urease test of gastric juice deposit and gastric and duodenal mucosae in Groups 1 and 2 were as follows: sensitivity (SE) (0.97, 0.99, 0,96), specificity (SP) (0.97, 0.97, 0.99), prevalence (0.64, 0.67, 0.24), test accuracy (TA) (0.96, 0.98, 0.98), negative (0.95, 0.97, 0.99) and positive (0.98, 0.99, 0.96) predictive values; positive (38.8, 33.0, 96.0) and negative (0.03, 0.01, 0.04) likelihood ratios. It is expedient to employ the rapid urease test for the diagnosis of H. pylori infection in the stomach (Se 96-99%, Sp 97%, TA 97-98%). When the test of gastric juice deposit and gastric biopsy is positive, the probability of gastric H. pylori availability is 98-99%. When the test is negative (the probability of H. pylori absence is 95-97%), duodenal biopsy is made. When the test of duodenal biopsy is positive, the probability of H. pylori availability is 96%. When it is negative, the probability of H. pylori absence is 99%. An algorithm of use of the rapid urease test to diagnose H. pylori in different intestinal parts (stomach, duodenum) has been developed.