TRYPANOSOMA-CRUZI - A 6 X HISTIDINE-FUSED TC24 PROTEIN USEFUL FOR THESEROLOGICAL 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-lin ked immunosorbent assay (ELISA) to screen a large number of Chagasic p atients' sera from different endemic areas. The protein has been recog nised by all the chagasic sera so far tested. The desirability of usin g 6 x his-Tc24 as a tool for Chagas' disease diagnosis was evaluated b y comparing the performance of the ELISA test using 6 x his Tc24 and t he Tc24 fused with Schistosoma japonicum glutathione S-transferase (Tc 24-Sj26). The results indicate that Tc24 peptide devoid of the Sj26 po rtion increased the sensitivity of antibody detection. Thus the propos ed 6 x his-Tc24 protein would be suitable for serodiagnosis of Chagas' disease and to monitor patients submitted to drug treatment.