PREVALENCE OF ANTI-R-13 ANTIBODIES IN HUMAN TRYPANOSOMA-CRUZI INFECTION

Infection with Trypanosoma cruzi develops in three phases: acute, inde terminate or asymptomatic, and chronic phase (with cardiac or digestiv e manifestations). Moreover, transmission may occur from infected moth ers to newborn, the so-called congenital form. In the present study, h umoral responses against T. cruzi total extract and against the 13 ami no acid peptide named R-13 derived from the parasite ribosomal P prote in, previously described as a possible marker of chronic Chagas heart disease, were determined in chagasic patients and in blood bank donors from endemic areas. While in sera from acute phase, only IgM anti-T. cruzi response was observed, both IgM and IgG anti-T. cruzi antibodies were detected in sera from congenitally infected newborns. The percen tage of positive response in sera from blood bank donors was relativel y high in endemic regions, Antibodies against the R-13 peptide were pr esent in a large proportion of cardiac chagasic patients but were tota lly lacking in patients with digestive form of Chagas' disease. Furthe rmore, anti-R-13 positive responses were detected in congenitally infe cted newborns.