Performance of TcI/TcVI/TcII Chagas-Flow ATE-IgG2a for universal and genotype-specific serodiagnosis of Trypanosoma cruzi infection

Distinct trypanosoma cruzi genotypes have been considered relevant for patient management and therapeutic response chagas disease. however,typing strategies for genotype-specific serodiagnosis of chagas disease are still unavailable and requires standardization for practical application. in this study,an innovative tci/tcvi/tcii chagas flow ate-igg2a technique was developed with applicability for universal and genotype-specific diagnosis of t. cruzi infection. for this purpose,the reactivity of serum samples (percentage of positive fluorescent parasites-ppfp) obtained from mice chronically infected with tci/colombiana,tcvi/cl or tcii/y strain as well as non-infected controls were determined using amastigote-ama,trypomastigote-trypo and epimastigote-epi in parallel batches of tci,tcvi and tcii target antigens. data demonstrated that “α-tcii-trypo/1:500,cut-off/ppfp = 20%” presented an excellent performance for universal diagnosis of t. cruzi infection (auc = 1.0,se and sp = 100%). the combined set of attributes “α-tci-trypo/1:4,000,cut-off/ppfp = 50%”,“α-tcii-ama/1:1,000,cut-off/ppfp = 40%” and “α-tcvi-epi/1:1,000,cut-off/ppfp = 45%” showed good performance to segregate infections with tci/colombiana,tcvi/cl or tcii/y strain. overall,hosts infected with tci/colombiana and tcii/y strains displayed opposite patterns of reactivity with “α-tci trypo” and “α-tcii ama”. hosts infected with tcvi/cl strain showed a typical interweaved distribution pattern. the method presented a good performance for genotype-specific diagnosis,with global accuracy of 69% when the population/prototype scenario include tci,tcvi and tcii infections and 94% when comprise only tci and tcii infections. this study also proposes a receiver operating reactivity panel,providing a feasible tool to classify serum samples from hosts infected with distinct t. cruzi genotypes,supporting the potential of this method for universal and genotype-specific diagnosis of t. cruzi infection. © 2017 alessio et al.