The Type of Trypanosoma Cruzi Strain (Native or Non-Native) Used as Substrate for Immunoassays Influences the Ability of Screening Asymptomatic Blood Donors
Ballinas-Verdugo, M.A.; Mejía-Domínguez, A.M.; Sánchez-Guerrero, S.A.; Lerma, C.; Martínez-Cruz, M.; Álvarez-Manilla-Toquero, E.; Jiménez-Díaz, X.; Barrera-Trujillo, F.; Ticante-Cruz, M.D.R.; Estevez-Garcia, I.O.; Amezcua-Guerra, L.M.; Reyes-Lopez, P.A.
Revista de Investigacion Clinica; Organo del Hospital de Enfermedades de la Nutricion 68(6): 286-291
2016
ISSN/ISBN: 0034-8376 PMID: 28134939 Document Number: 688760
The origin (native or non-native) of Trypanosoma cruzi strains used as substrate for immunoassays may influence their performance. 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. 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. 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. 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.