Effect of benznidazole treatment in antigen recognition. The reactivity of sera from 25 patients with Chagas disease (A), 15 patients in the indeterminate (IND) stage (B), 10 in the chronic and cardiac phase (CCC) (C), 8 patients in the early chronic cardiac stage of the disease (G1 and G2) (D) and 10 digestive chagasic patients (E) were assayed by ELISA against KMP11, HSP70, PFR2, Tgp63 and STcA before benznidazole treatment (T0), and 3 (T1), 6 (T2), and 9 (T3) months post-treatment for A, B, C and D and 9 (T3) months post-treatment for E. Data are expressed as optical density (O.D.) values. The data are the result of a statistical analysis of the median of the differences in antigen-specific recognition that were separately analyzed in each treated patient at the different post-treatment times relative to T0. The p values were obtained by the Wilcoxon matched pair test and significant differences (p < 0.05) are indicated.