title: Performance Assessment of Four Chimeric Trypanosoma cruzi Antigens Based on Antigen-Antibody Detection for Diagnosis of Chronic Chagas Disease.
abstract: The performance of serologic tests in chronic Chagas disease diagnosis largely depends on the type and quality of the antigen preparations that are used for detection of anti-Trypanosoma cruzi antibodies. Whole-cell T. cruzi extracts or recombinant proteins have shown variation in the performance and cross-reactivity. Synthetic chimeric proteins comprising fragments of repetitive amino acids of several different proteins have been shown to improve assay performances to detect Chagasic infections. Here, we describe the production of four chimeric T. cruzi proteins and the assessment of their performance for diagnostic purposes. Circular Dichroism spectra indicated the absence of well-defined secondary structures, while polydispersity evaluated by Dynamic Light Scattering revealed only minor aggregates in 50 mM carbonate-bicarbonate (pH 9.6), demonstrating that it is an appropriate buffering system for sensitizing microplates. Serum samples from T. cruzi-infected and non-infected individuals were used to assess the performance of these antigens for detecting antibodies against T. cruzi, using both enzyme-linked immunosorbent assay and a liquid bead array platform. Performance parameters (AUC, sensitivity, specificity, accuracy and J index) showed high diagnostic accuracy for all chimeric proteins for detection of specific anti-T. cruzi antibodies and differentiated seropositive individuals from those who were seronegative. Our data suggest that these four chimeric proteins are eligible for phase II studies.
authors: Aggeu Magalhães Research Center, FIOCRUZ-PE, Recife, PE, Brazil.
authors: Fred Luciano Neves
authors: http://orcid.org/0000-0002-3944-0818
authors: FL
authors: Santos
authors: Molecular Biology Institute of Paraná, Curitiba, PR, Brazil.
authors: Paola Alejandra Fiorani
authors: PA
authors: Celedon
authors: Molecular Biology Institute of Paraná, Curitiba, PR, Brazil.|Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil.
authors: Nilson Ivo Tonin
authors: NI
authors: Zanchin
authors: Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil.
authors: Tatiana de Arruda Campos
authors: Tde A
authors: Brasil
authors: Molecular Biology Institute of Paraná, Curitiba, PR, Brazil.|Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil.
authors: Leonardo
authors: L
authors: Foti
authors: Aggeu Magalhães Research Center, FIOCRUZ-PE, Recife, PE, Brazil.
authors: Wayner Vieira de
authors: WV
authors: Souza
authors: Biomanguinhos, FIOCRUZ-RJ, Rio de Janeiro, RJ, Brazil.
authors: Edmilson Domingos
authors: ED
authors: Silva
authors: Aggeu Magalhães Research Center, FIOCRUZ-PE, Recife, PE, Brazil.
authors: Yara de Miranda
authors: Yde M
authors: Gomes
authors: Molecular Biology Institute of Paraná, Curitiba, PR, Brazil.|Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil.
authors: Marco Aurélio
authors: MA
authors: Krieger
mesh_terms: D000913:Antibodies, Protozoan / Q000276:immunology*; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D014355:Chagas Disease / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D012698:Serologic Tests / Q000379:methods; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C060967:cytoplasmic antigen, Trypanosoma