The Type of Trypanosoma Cruzi Strain (Native or Non-Native) Used as Substrate for Immunoassays Influences the Ability of Screening Asymptomatic Blood Donors

• Autores: Martha A. Ballinas Verdugo, Ana María Mejía Domínguez, Sergio Arturo Guerrero Sánchez, Claudia Lerma, Mariana Martínez Cruz, Elsa Álvarez Manilla-Toquero, Xochiquetzali Jiménez Díaz, Francelia Barrera Trujillo, Marisela del R. Ticante Cruz, Irving Omar Estévez-García, Luis Manuel Amezcua Guerra, Pedro A. Reyes López
• Localización: Revista de investigación clínica, ISSN 0034-8376, ISSN-e 2564-8896, Vol. 68, Nº. 6, 2016, págs. 286-291
• Idioma: inglés
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• Resumen

  • Background: The origin (native or non-native) of Trypanosoma cruzi strains used as substrate for immunoassays may influence their performance. Objective: To assess the performance of an immunoassay based on a native T. cruzi strain compared to another based on non-native T. cruzi strains, in asymptomatic blood donors from Mexico. Methods: Serum samples from a tertiary referral center were tested by both ELISA-INC9 (native) and Chagatest (non-native) assays. All reactive serum samples were further analyzed by indirect immunofluorescence. Results: Sera from 1,098 asymptomatic blood donors were tested.

    A  4.3  and 0.7% serum reactivity prevalence was observed using ELISA-INC9 and Chagatest, respectively (kappa = 0.13;

    −0.11 to 0.38). Subsequently, indirect immunofluorescence analyses showed higher positivity in serum samples reactive by ELISA-INC9 compared to those reactive by Chagatest (79 vs. 62.5%; p < 0.001). Furthermore, out of the 47 positive samples by both ELISA-INC9 and indirect immunofluorescence, only four (8.5%) were reactive in Chagatest assay. Meanwhile, four (80%) out of the five positive samples by both Chagatest and indirect immunofluorescence were reactive using ELISA-INC9. Conclusion:

    Immunoassays based on a native T. cruzi strain perform better than those based on non-native strains, highlighting the need to develop and validate screening assays in accordance to endemic T. cruzi strains. (REV INVES CLIN. 2016;68:286-91)