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Double-antigen sandwich ELISA based on chimeric antigens for detection of antibodies to Trypanosoma cruzi in human sera.
Freitas, Natália Erdens Maron; Santos, Emily Ferreira; Leony, Leonardo Maia; Silva, Ângelo Antônio Oliveira; Daltro, Ramona Tavares; Vasconcelos, Larissa de Carvalho Medrado; Duarte, Gabriela Agra; Oliveira da Mota, Cristiane; Silva, Edimilson Domingos; Celedon, Paola Alejandra Fiorani; Zanchin, Nilson Ivo Tonin; Santos, Fred Luciano Neves.
Afiliação
  • Freitas NEM; Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Bahia, Brazil.
  • Santos EF; Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Bahia, Brazil.
  • Leony LM; Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Bahia, Brazil.
  • Silva ÂAO; Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Bahia, Brazil.
  • Daltro RT; Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Bahia, Brazil.
  • Vasconcelos LCM; Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Bahia, Brazil.
  • Duarte GA; Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Bahia, Brazil.
  • Oliveira da Mota C; Gonçalo Moniz Public Health Central Laboratory (LACEN-BA), Salvador, Bahia, Brazil.
  • Silva ED; Bio-Manguinhos, Oswaldo Cruz Foundation (FIOCRUZ-RJ), Rio de Janeiro, Rio de Janeiro, Brazil.
  • Celedon PAF; Molecular Biology Institute of Paraná (IBMP), Curitiba, Paraná, Brazil.
  • Zanchin NIT; Carlos Chagas Institute, Oswaldo Cruz Foundation (FIOCRUZ-PR), Curitiba, Paraná, Brazil.
  • Santos FLN; Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Bahia, Brazil.
PLoS Negl Trop Dis ; 16(3): e0010290, 2022 03.
Article em En | MEDLINE | ID: mdl-35275913
BACKGROUND: Enzyme-linked immunosorbent assays (ELISA) are generally the chosen test for Chagas disease (CD) diagnosis; however, its performance depends on the antigen preparation adsorbed to the solid phase, which may lead to false-positive results and cross-reactions. The use of chimeric recombinant antigens can overcome this limitation. Four chimeric antigens from Trypanosoma cruzi (IBMP-8.1, IBMP-8.2, IBMP-8.3 and IBMP-8.4) were developed and evaluated in phase I, II and III studies using indirect ELISA as diagnostic platform. However, peroxidase-labeled secondary anti-human IgG antibody, which is employed in indirect ELISAs, limits its use for the detection of species-specific and class-specific antibodies. To overcome this limitation, peroxidase-labeled antigens can be utilized, diagnosing both acute or chronic infection, in a species and immunoglobulin class-independent manner, through the use of a double-antigen sandwich ELISA (DAgS-ELISA). We aimed to evaluate and validate the diagnostic performance of the chimeric antigens IBMP-8.1, IBMP-8.2, IBMP-8.3 and IBMP-8.4 in the DAgS-ELISA platform. METHODOLOGY/PRINCIPAL FINDINGS: DAgS-ELISA was optimized by checkerboard titration. In phase I study, 207 positive and 205 negative samples were evaluated. Cross-reactivity to other infections was also assessed using 68 samples. The selected conditions for the tests utilized 25 ng of antigen per well and the conjugate diluted at 1:2,000 for all molecules. In the phase I study, the areas under the curve of IBMP-8.1, IBMP-8.2, IBMP-8.3 and IBMP-8.4 were 98.7%, 99.5%, 98.6% and 98.8%, respectively. Among the positive samples, IBMP-8.1 antigen classified 53 (25.6%) as false negative, IBMP-8.2, 27 (13%), IBMP-8.3, 24 (11.6%) and IBMP-8.4, 43 (20.8%), giving sensitivities of 74.4%, 87%, 88.4% and 79.2%, respectively. The only antigen that did not reach 100% specificity was IBMP-8.3, with 96.6%. IBMP-8.3 was also the only molecule to show cross-reactivity with HTLV. CONCLUSIONS/SIGNIFICANCE: DAgS-ELISA is a promising tool for immunodiagnosis, and despite the high AUC values, the performance of this assay was different from the values obtained by our group when using these antigens in the indirect ELISA, for this reason, improvements are being considered to increase the sensitivity of the DAgS-ELISA.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Trypanosoma cruzi / Doença de Chagas Tipo de estudo: Diagnostic_studies Limite: Humans Idioma: En Revista: PLoS Negl Trop Dis Assunto da revista: MEDICINA TROPICAL Ano de publicação: 2022 Tipo de documento: Article País de afiliação: Brasil País de publicação: Estados Unidos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Trypanosoma cruzi / Doença de Chagas Tipo de estudo: Diagnostic_studies Limite: Humans Idioma: En Revista: PLoS Negl Trop Dis Assunto da revista: MEDICINA TROPICAL Ano de publicação: 2022 Tipo de documento: Article País de afiliação: Brasil País de publicação: Estados Unidos