Modified rapid urease test for detection of Helicobacter pylori infection

Abstract

Background: The rapid urease test is the most widely used standard procedure for the detection of Helicobacter pylori infection. This is because it is a simple, reliable and inexpensive test, which provides results rapidly.

Aim: The aim of the present study was the evaluation of a modified rapid urease test (HUT-test) in comparison with the standard CLO-test. In addition, it was questioned whether the performance of the rapid urease test in two biopsy samples from antrum and gastric body would increase the sensitivity of the test.

Methods: One hundred and fifteen consecutive patients undergoing oesophagogastroduodenoscopy were studied. Diagnosis of H. pylori infection was based on histological examination of biopsy samples from antrum and gastric body. The HUT-test was performed in two biopsy specimens from antrum and body, respectively, and the CLO-test in one antral biopsy sample. The time to positivity and the stability of the HUT-test kit at different storage temperatures were previously optimized by adapting the type and concentration of buffer and indicators.

Results: Sixty patients (52%) were diagnosed as being infected with H. pylori. Sensitivity of the rapid urease tests in biopsy samples from the antrum was 90% for the HUT-test and 88% for the CLO-test, with a specificity of 100% for both tests. Combining biopsies from the antrum and corpus increased the diagnostic sensitivity of the HUT-test to 93%, but the specificity decreased to 98%. In patients with H. pylori infection, the HUT-test gave positive results more rapidly than the CLO-test (104 +/- 21 min compared with 195 +/- 49 min, respectively, P < 0.02).

Conclusion: Application of the HUT-test to a simple biopsy from the antrum can establish the diagnosis of H. pylori infection with high accuracy, similar to that of the standard CLO-test. Compared with the CLO-test, the HUT-test has a significantly faster reaction time, which is an obvious clinical advantage. An additional biopsy from the distal gastric body did not add to the diagnostic efficacy in untreated patients, but may be needed in specific circumstances, such as following treatment.