Use of an enzyme-linked immunosorbent assay that utilizes the Tc13Tul antigen of Trypanosoma cruzi to monitor patients after treatment with benznidazole.

Tc13Tul antigen is expressed in the mammalian stages of Trypanosoma cruzi, the etiological agent of Chagas' disease. Here, we designed and validated an enzyme-linked immunosorbent assay using the recombinant Tc13Tul (Tc13Tul-ELISA) and found that it had 82.5% sensitivity and 97.05% of specificity. To evaluate whether the decrease in antibodies against Tc13Tul may be used as an early marker of the effect of chemotherapy with benznidazole, sera from 30 T. cruzi-infected children were evaluated by Tc13Tul-ELISA before and after benznidazole treatment. While in Group A (6 months-4 years old, n = 16) the decrease of more than 30% of Tc13Tul-ELISA values showed a sensitivity similar to that of conventional serology (CS); in Group B, (5-12 years old, n = 14) the decrease of Tc13Tul-ELISA values was a better parameter than negativization of CS to monitor the impact of treatment. Therefore, the dosage of anti-Tc13Tul antibodies may be useful as a methodology complementary to CS to evaluate chagasic patients undergoing chemotherapy with benznidazole.