[Diagnosis of Helicobacter pylori colonization of the gastric mucosa. A prospective comparative study of direct test methods and validation of a new urease test].

A prospective study including 119 patients submitted for routine endoscopy of the upper gastrointestinal tract was initiated to compare three commercial biopsy urease tests with regard to sensitivity and specificity in detecting Helicobacter pylori colonization of the gastric mucosa and their reaction velocity. Specific culture, microscopy after staining with methylene-blue, histologic search after modified Giemsa staining and the combined results of culture and histology ("true standard") served as reference methods. The sensitivity and specificity of all three tests were high: Angass urease test 92.0%/97.7%, Telen-Quick test 94.7%/100%, CLO-test 94.7%/100% (analysis of one antrum and one body biopsy in a single test kit). Telen-Quick and CLO-tests reacted faster than the Angass urease test, but a period of 24 hours was necessary for all three tests to detect "true negatives". Histology and microscopy were reliable reference methods concerning sensitivity and specificity, while culture was characterized by inferior sensitivity (78.6%) and high specificity (100%).