Gastric juice urease test and brushing urease test for Helicobacter pylori detection.

ABSTRACT

The aim of the study was to demonstrate the sensitivity, specificity and accuracy of gastric juice urease test and brushing-urease test compared to the biopsy-urease test for Helicobacter pylori (H. pylori) detection. For each patient, two milliliters of gastric juice was collected and one milliliter in the supernatant was tested for rapid urease reactions. One gastric mucus brushing and two biopsies were taken from the body and the antrum. The brushing specimens were tested for rapid urease reaction by shaking the brush into the urea broth. The gold standards for diagnosing of H. pylori are positive H. pylori upon specimen culture or positive identification of H. pylori from polymerase chain reaction (PCR) assay using primer for vac A gene. Forty patients were enrolled in the study including ten patients with gastric ulcer, six patients with duodenal ulcer and twenty four patients with non-ulcer dyspepsia. Brushing-urease test and biopsy-urease test were not different sensitivity (87.50% vs 93.20%), specificity (100% vs 100%) and accuracy (90.25% vs 95.50%). The gastric juice urease test had a sensitivity of 65.25 per cent, specificity of 100 per cent and accuracy of 75 per cent for detecting of H. pylori infection. In conclusion, gastric juice urease test had low sensitivity in the diagnosis of H. pylori infection. Brushing-urease test is as accurate as biopsy-urease test in detecting H. pylori infection. However, the brushing method had lower gastric tissue injury than the biopsy and so should be used for detecting H. pylori infection in patients with coagulopathy.