Performance of the 13 C-urea breath test for the diagnosis of H. pylori infection using a substrate synthesized in Brazil: A preliminary study

摘要

OBJECTIVE: The 13 C-urea breath test is the main non-invasive test for the diagnosis of Helicobacter pylori infection. The availability of this test throughout the country is limited, mainly due to the difficulty in obtaining the labeled isotope from abroad. Recently, researchers from the Nuclear Energy Center in Agriculture at the University of S?o Paulo (CENA/USP) succeeded in synthesizing 13 C-enriched urea for Helicobacter pylori diagnosis. The aim of the study was to compare the performance of the 13 C-urea breath test using 13 C-urea acquired abroad with that of a test using 13 C-urea synthesized in Brazil. METHOD: Sixty-four dyspeptic patients participated in the study (24 men and 40 women). Initially, the patients performed the 13 C-urea breath test using the imported substrate (Euriso-Top, France). Seven to fourteen days later, all the patients repeated the test using the Brazilian substrate. The samples from both examinations were processed in an infrared isotope analyzer (IRIS, Wagner Analisen Technik, Germany), and all delta over baseline (DOB) [%] values above four were considered positive results. RESULTS: Twenty-seven patients (42%) exhibited negative results for Helicobacter pylori infection, and thirty-seven patients (58%) exhibited positive results when tested using the foreign substrate (gold standard). There was a 100% concordance regarding the presence or absence of infection when the gold standard results were compared with those obtained using the Brazilian substrate. CONCLUSIONS: Similar performance in the diagnosis of Helicobacter pylori infection was demonstrated when using the 13 C-urea breath test with the Brazilian 13 C-urea substrate and the test with the substrate produced abroad. This validation represents an important step toward increasing the availability of the 13 C-urea breath test throughout the country, which will have a positive influence on the management of Helicobacter pylori infection.