Nakata, H et al. (2004) Immunological rapid urease test using monoclonal antibody for Helicobacter pylori. J Gastroenterol Hepatol 19: 970–974

Nakata and colleagues have recently evaluated the immunological rapid urease test (IRUT), a novel method for the diagnosis of Helicobacter pylori infection. Unlike some other methods based on the high urease activity of H. pylori, the IRUT is designed to detect H. pylori urease only, so that the presence of urease from other bacteria does not interfere with results.

Gastric mucus samples were collected from 100 adult patients undergoing upper gastrointestinal endoscopy. The IRUT kit (HLS-2000, Olympus Optical) was then used to measure H. pylori urease in each sample. Briefly, the test involved a 15-minute incubation of the diluted sample with a solid-phase tip, which had been coated with a monoclonal antibody against H. pylori urease. An increase in pH in the urea solution inside the tip then indicated that urease had been adsorbed onto the tip and, therefore, that H. pylori-specific urease was present in the original sample. The efficacy of the test was compared with four established methods: culture, histology, RUT and UBT.

A total of 47 patients had a positive result for at least two of the conventional tests, and so were considered H. pylori-positive. The IRUT showed high sensitivity (91.5%) and specificity (98.1%) and its efficiency was comparable to that of the conventional methods. The authors note that the test can be performed rapidly (within 20 minutes) and is cheaper than the commonly used UBT.