Folia Parasitologica 71:004 (2024) | DOI: 10.14411/fp.2024.004

Post-therapeutic cure criterion in chronic Chagas disease using Trypanosoma cruzi chimeric proteins

Tycha Bianca Sabaini Pavan ORCID...¹, Leonardo Maia Leony ORCID...¹, Wayner Vieira de Souza ORCID...², Emily Ferreira Santos ORCID...¹, Ramona Tavares Daltro ORCID...¹, Natália Erdens Maron Freitas ORCID...¹, Larissa Carvalho Medrado Vasconcelos ORCID...¹, Fernanda Lopes Habib ORCID...¹, Ângelo Antônio Oliveira Silva ORCID...¹, Paola Alejandra Fiorani Celedon ORCID...³, Daniel Dias Sampaio ORCID...⁴, Nilson Ivo Tonin Zanchin ORCID...⁵, Silvia Andrea Longhi⁶, Fred Luciano Neves Santos ORCID...^{1, 7}

¹ Advanced Public Health Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz-BA), Salvador, Bahia, Brazil;

² Department of Public Health, Aggeu Magalhães Institute, Oswaldo Cruz Foundation (Fiocruz-PE), Recife, Pernambuco, Brazil;

³ Molecular Biology of Trypanosomatids Laboratory, Carlos Chagas Institute, Oswaldo Cruz Foundation (Fiocruz-PR), Curitiba, Paraná, Brazil;

⁴ Department Brazil's Family Health Strategy, Municipal Health Department, Tremedal, Bahia, Brazil;

⁵ Structural Biology and Protein Engineering Laboratory, Carlos Chagas Institute, Oswaldo Cruz Foundation (Fiocruz-PR), Curitiba, Paraná, Brazil;

⁶ Laboratory of Molecular Biology of Chagas Disease, Institute for Research on Genetic Engineering and Molecular Biology "Dr Héctor Torres", National Scientific and Technological Research Council, Buenos Aires, Argentina;

⁷ Chagas Disease Translational Research Program (Fio-Chagas), Oswaldo Cruz Foundation (Fiocruz-RJ), Rio de Janeiro, Rio de Janeiro, Brazil

Chagas disease (CD) is a neglected disease caused by Trypanosoma cruzi Chagas, 1909. Causative treatment can be achieved with two drugs: benznidazole or Nifurtimox. There are some gaps that hinder progress in eradicating the disease. There is no test that can efficiently assess cure control after treatment. Currently, the decline in anti-T. cruzi antibody titres is assessed with conventional serological tests, which can take years. However, the search for new markers of cure must continue to fill this gap. The present study aimed to evaluate the decline in serological titres using chimeric proteins after treatment with benznidazole in chronic patients diagnosed with CD. It was a prospective cross-sectional cohort study between 2000 and 2004 of T. cruzi-positive participants from the Añatuya region (Argentina) treated with benznidazole. Serum samples from ten patients were collected before treatment (day zero) and after the end of treatment (2, 3, 6, 12, 24 and 36 months). For the detection of anti-T. cruzi antibodies, an indirect ELISA was performed using two chimeric recombinant proteins (IBMP-8.1 and IBMP-8.4) as antigens. The changes in reactivity index within the groups before and after treatment were evaluated using the Friedman test. All participants experienced a decrease in serological titres after treatment with benznidazole, especially IBMP-8.1. However, due to the small number of samples and the short follow-up period, it is premature to conclude that this molecule serves as a criterion for sustained cure. Further studies are needed to validate tests based on these or other biomarkers to demonstrate parasitological cure.

Keywords: Chagas disease, benznidazole, serological test, seroconversion, antibody titre, biomarker

Received: April 24, 2024; Revised: October 14, 2023; Accepted: January 19, 2024; Published online: March 20, 2024  Show citation