Abstract
INTRODUCTION:
Serological cross-reactivity between leishmaniasis and Chagas disease, especially at low titers, leads to difficulties of the seroepidemiological interpretation.
METHODS:
We have studied the ability of urea as a chaotrope to select high-avidity antibodies in IgG ELISA, thus reducing low-avidity IgG cross-reactivity in serologically positive samples in both assays.
RESULTS:
Using 0.5M urea for diluting the sample efficiently defined leishmaniasis or double infections in high-avidity IgG ELISA and eliminated false-positive results.
CONCLUSIONS:
The use of a chaotropic diluting agent is useful for improving the specificity of Chagas disease and leishmaniasis immunoassays.
Keywords:
Serology; Chagas disease; Leishmaniasis; ELISA; IFAT; IgG antibody avidity