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

Abstract

OBJECTIVE:The 13C-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 São Paulo (CENA/USP) succeeded in synthesizing 13C-enriched urea for Helicobacter pylori diagnosis. The aim of the study was to compare the performance of the 13C-urea breath test using 13C-urea acquired abroad with that of a test using 13C-urea synthesized in Brazil.METHOD:Sixty-four dyspeptic patients participated in the study (24 men and 40 women). Initially, the patients performed the 13C-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 13C-urea breath test with the Brazilian 13C-urea substrate and the test with the substrate produced abroad. This validation represents an important step toward increasing the availability of the 13C-urea breath test throughout the country, which will have a positive influence on the management of Helicobacter pylori infection.

Review: Diagnosis of Helicobacter pylori infection

“…This fact was highlighted in two studies from Israel. 44 Finally, Best et al performed a diagnostic test accuracy review on non-invasive diagnostic tests (UBT, serology, and stool antigen tests, SAT) for H. pylori infection. 43 A preliminary study from Brazil demonstrated that a 13 C-urea substrate synthesized by a local company could achieve the same performance in the UBT for the diagnosis of H. pylori infection as the substrate produced by foreign biotechnology companies.…”

“…The authors therefore hope that this may contribute to a wider dissemination of this test in the country; its availability is currently restricted to large cities and university centers. 44 Finally, Best et al performed a diagnostic test accuracy review on non-invasive diagnostic tests (UBT, serology, and stool antigen tests, SAT) for H. pylori infection. Studies that evaluated at least one of these tests against the reference standard (i.e., histopathologic examination using different stains) in patients suspected of having an H. pylori infection were included.…”

Pathogenesis and clinical management of Helicobacter pylori gastric infection

“…This test is based on the mechanism of bacterium degradation of 13C or 14C-labeled urea into CO 2 , which can be measured in the exhaled air using a mass or infrared spectrometer[85]. A Brazilian study[86] evaluated the use of a locally manufactured isotope in UBT, trying to reduce the importation costs of this substance, which is considered a limitation for the performance of this method in many countries. The assay concluded that the substrate manufactured in Brazil with reduced costs had similar performance when compared to the one imported from foreign countries.…”

Separação de 13C por cromatografia de troca iônica em sistema cascata e produção de 13CO

“…Diversas metodologias vêm sendo propostas para aplicação do 13 C na área médica, como o diagnóstico de doenças gástricas e avaliação de metabolismo de diferentes substratos. O aumento na aplicação dessa ferramenta deve-se a sua simplicidade, segurança, eficácia e principalmente por não ser invasivo e não emitir radiação (MODAK, 2007;COELHO et al, 2018).…”

“…A princípio tinha-se o domínio das técnicas de aplicação e métodos analíticos para detecção de radioisótopos, o melhoramento das análises de espectrometria e tecnologias de produção de compostos enriquecidos proporcionou o maior emprego de isótopos estáveis, resultando em uma redução na aplicação de radioisótopos. O aprimoramento da tecnologia isotópica possibilitou o crescimento da aplicação do 13 C, sendo amplamente utilizado em diferentes áreas da ciência, com destaque para a área animal como, por exemplo, na avaliação do metabolismo de aminoácidos (STRADIOTTI et al, 2016) ou mesmo no diagnóstico de Helicobacter pylori (H. pylori) em gatos e cachorros (NEIGER; SIMPSON, 2000), já na área biomédica também se aplica no diagnóstico de H. pylori (COELHO et al, 2018), testes de função hepática (AFOLABI et al, 2012) A substituição do emprego dos radioisótopos de C ( 14 C) é realizada, com sucesso, com o uso de moléculas enriquecidas (marcadas) no isótopo estável 13 C.…”