Effect of biopsies on sensitivity and specificity of ultra-rapid urease test for detection of Helicobacter pylori infection:A prospective evaluation

摘要

AIM: To prospectively assess the sensitivity, specificity and time to positivity of theUItra-rapid urease test (URUT) for Helicobacter pylori ( H pylori ), and compare the results of one with those of two biopsies.METHODS: Five antral biopsies were taken in consecutive patients undergoing upper endoscopy: one and two biopsies for URUT, and one each for H pylori culture and histology.URUT was read at 1, 5, 10, 20 and 30 rain, 1, 2, 3 and 24 h after biopsy insertion into the reagent. A positive histology and/or culture was used as positive reference “gold standards”:RESULTS: URUT was more sensitive for detecting Hpy/ori with two biopsies rather than one, at all time points up to 120 rain. The sensitivity improved from 3.6% to 82.1% for one biopsy and 10.7% to 85.7% for two biopsies from 1 to 120 rain. The sensitivity reached 96.4% at 24 h for both,but the specificity reduced from 100% to 96% and 92% for one and two biopsies, respectively.CONCLUSION: Development of a positive URUT result is hastened by doubling the number of gastric biopsies. We recommend taking two instead of one biopsy to achieve an earlier positive URUT result so that H pylorieradication therapy can be initiated before patient is discharged from the endoscopy suite.