Evaluation of three recombinant proteins for the development of ELISA and immunochromatographic tests for visceral leishmaniasis serodiagnosis

Anna Raquel Ribeiro dos Santos Ângela Vieira Serufo Maria Marta Figueiredo Lara Carvalho Godoi Jéssica Gardone Vitório Andreza Pain Marcelino Daniel Moreira de Avelar Fernandes Tenório Gomes Rodrigues George Luiz Lins Machado-Coelho Fernanda Alvarenga Cardoso Medeiros Selma Maria Bezerra Jerônimo Edward José de Oliveira Frederico Crepaldi Nascimento Santuza Maria Ribeiro Teixeira Ricardo Tostes Gazzinelli Ronaldo Alves Pinto Nagem Ana Paula Fernandes About the authors

BACKGROUND

Visceral Leishmaniasis (VL) is an infectious disease that is a significant cause of death among infants aged under 1 year and the elderly in Brazil. Serodiagnosis is a mainstay of VL elimination programs; however, it has significant limitations due to low accuracy.

OBJECTIVE

This study aimed to evaluate three recombinant Leishmania infantum proteins (rFc, rC9, and rA2) selected from previous proteomics and genomics analyses to develop enzyme-linked immunosorbent assay (ELISA) and immunochromatographic tests (ICT) for the serodiagnosis of human VL (HVL) and canine VL (CVL).

METHODS

A total of 186 human (70 L. infantum-infected symptomatic, 20 other disease-infected, and 96 healthy) and 185 canine (82 L. infantum-infected symptomatic, 27 L. infantum-infected asymptomatic, and 76 healthy) sera samples were used for antibody detection.

FINDINGS

Of the three proteins, rA2 (91.5% sensitivity and 87% specificity) and rC9 (95.7% sensitivity and 87.5% specificity) displayed the best performance in ELISA-HVL and ELISA-CVL, respectively. ICT-rA2 also displayed the best performance for HVL diagnosis (92.3% sensitivity and 88.0% specificity) and had high concordance with immunofluorescence antibody tests (IFAT), ELISA-rK39, IT-LEISH®, and ELISAEXT. ICT-rFc, ICT-rC9, and ICT-rA2 had sensitivities of 88.6%, 86.5%, and 87.0%, respectively, with specificity values of 84.0%, 92.0%, and 100%, respectively for CVL diagnosis.

MAIN CONCLUSIONS

The three antigens selected by us are promising candidates for VL diagnosis regardless of the test format, although the antigen combinations and test parameters may warrant further optimisation.

Key words:
visceral leishmaniasis; recombinant proteins; diagnosis; ELISA; immunochromatographic test


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