Comparison of cell culture with epimastigote antigens of Trypanosoma cruzi.

Various epimastigote antigens of Trypanosoma cruzi were compared with an amastigote-trypomastigote antigen from infected cell cultures by complement fixation (CF) and gel diffusion (Ouchterlony). CF results with human Chagasic sera showed that the amastigote-trypomastigote antigen was usually more sensitive than epimastigote antigens tested. In addition, cross-reactions with normal and other sera were no greater and perhaps less frequent than with crude epimastigote antigens. Specificity of the amastigote-trypomastigote antigen, however, was less than with a protein extract of epimastigotes. Gel diffusion results with human Chagasic and hyper-immunized rabbit sera indicated differences between epimastigote and amastigote-trypomastigote antigens whereas differences by CF with the same sera were equivocal.