positive PPFP result has little chance of coming from a
TC, confirming therapeutic failure. We considered that
despite the good performance of FC-AFEA-IgG at
serum dilution 1/16,384, the lower specificity to identify
therapeutic failure should rule out this serum dilution for
clinical purposes.
We conclude that this flow cytometric approach is a
major advance in serological assessments for clinical
investigations on Chagas disease. We intend to continue
this field of research by focusing our attention on the
influence of the degree of heart and mega damage on
FC-ALTA-IgG1 and FC-AFEA-IgG reactivity, with
appropriate caution regarding the choice o f anti-human
IgG antibodies.
Acknowledgements
This work was supported by CPqRR/FIOCRUZ,
Conselho Nacional de Desenvolvimento Científico e
Tecnológico (CNPq — Grant 475805/2003-8) and
UNICEF/UNDP/World Bank/WHO Special Program
for Research and Training in Tropical Disease (TDR)
and the Project Development Grant Committee (Grant
A30451). We thank Teresa C. Abreu Ferrari from
Faculdade de Medicina, Universidade Federal de Minas
Gerais/UFMG for statistical support. We also thank
John and Jane VandeBerg, from the Southwest Foun-
dation for Biomedical Research for critical ly reading the
manuscript and making editorial suggestions and
changes.
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