Trypanosoma cruzi: A 6 x histidine-fused Tc24 protein useful for the serological diagnosis of Chagas' disease

A Trypanosoma cruzi protein containing six histidine residues at its N-terminal sequence (6 x his-Tc24) was used as antigen in an enzyme-linked immunosorbent assay (ELISA) to screen a large number of Chagasic patients' sera from different endemic areas. The protein has been recognised by all the chagasic sera so far tested. The desirability of using 6 x his-Tc24 as a tool for Chagas' disease diagnosis was evaluated by comparing the performance of the ELISA test using 6 x his Tc24 and the Tc24 fused with Schistosoma japonicum glutathione S-transferase (Tc24-Sj26). The results indicate that Tc24 peptide devoid of the Sj26 portion increased the sensitivity of antibody detection. Thus the proposed 6 x his-Tc24 protein would be suitable for serodiagnosis of Chagas' disease and to monitor patients submitted to drug treatment.