United Rapid Urease Test Is Superior than Separate Test in DetectingHelicobacter pyloriat the Gastric Antrum and Body Specimens

Abstract

Background/AimsThe rapid urease test (RUT) is an invasive method to diagnose Helicobacter pylori infection, which relies on the acquisition and examination of gastric antrum and body tissues. We determined and compared the efficacy of RUT when the tissues were examined separately or after being combined.MethodsTwo hundred and fourteen patients were included and underwent esophagogastroduodenoscopy from July 2008 to June 2010. The separate test was defined as evaluating the status of infectivity of H. pylori from the antrum and body separately; whereas the united test was carried out putting both tissues from the antrum and body in the same RUT kit. All RUTs were read by a single observer 1, 3, 6, 12, and up to 24 hours later. We also got two biopsy specimens stained with hematoxylin and eosin and quantified H. pylori density was calculated on a scale of 0 to 3.ResultsOverall positivity for H. pylori was 137 (64%) for the separate test and 148 (69.2%) for the united test (p<0.01). The mean time to a positive test was 3.58 hours for the separate test and 1.69 hours for the united test (p<0.01). The correlation between the time to positive RUT and the severity of histology showed r=+0.556 for the antrum (p<0.01) and r=+0.622 for the body (p<0.01).ConclusionsCombining tissues prior to RUT enhances the detection of H. pylori, as compared with the examination of separate tissues, and shortens the time to develop a positive reaction by approximately 50%. These diagnostic advantages are also accompanied by increased cost-savings.

A combined antral and corpus rapid urease testing protocol can increase diagnostic accuracy despite a low prevalence of Helicobacter pylori infection in patients undergoing routine gastroscopy

“…As previously discussed low background prevalence will negatively impact on test accuracy. In addition only 52% of cases in the Moon et al paper were confirmed on histological analysis without recourse to specific H. pylori stains, 19 unlike our study where a modified Giemsa stain was employed and all positive RUTs were confirmed histologically. Of interest also, a significant percentage of the population were reported to have gastric atrophy (79%), which would affect antral based tests and could represent a source of bias in favour of combined testing.…”

“…In 2012, Moon et al reported an additional yield for a combined RUT approach (69%) compared to both single antral and corpus testing, 59% versus 62%, respectively, in 214 treatment naı¨ve subjects. 19 Although the study designs are similar comparisons are difficult to make as H. pylori infection was very common in their population, 69% versus 35% in ours. As previously discussed low background prevalence will negatively impact on test accuracy.…”

Management ofHelicobacter pyloriinfection—the Maastricht V/Florence Consensus Report

“…Obtaining tissue samples from the antrum and the fundus may increase the sensitivity of the test 111 112. False-negative tests are more frequent than false-positive tests and thus a negative result should not be used to exclude H. pylori .…”

The use of a second biopsy from the gastric body for the detection of Helicobacter pylori using rapid urease test

“…(20) A recent study by Moon et al found that as compared to testing tissues separately for RUT, combining tissues prior to RUT enhanced the detection of H. pylori by a further 8% and shortened the time needed to develop a positive reaction by approximately 50%. (21) However, due to time and cost constraints, some endoscopists may resort to biopsy from the gastric antrum only.…”