In order to investigate the relationship between T. cruzi specific antibodies (IgG) levels and the clinical course of chronic chagasic cardiopathy, the authors analyzed sera from 140 non-treated patients with specific drugs from Virgem da Lapa, Minas Gerais, during 10 years. Of these patients, 92 were women and 48 men, varying from 10 to 70 years old (mean = 38 ±13.5 years). Antibody levels were estimated by the mean of titers obtained by an indirect immunofluorescence test, indirect hemagglutination assay and by the mean reactivity indexes (OD/cut-off) obtained by ELISA tests using a conventional antigens and recombinant proteins (CRA+FRA). During the study period, the course of the disease was as follows: 49 did not present cardiac alterations, 29 coursed to cardiopathy, 33 maintained initial cardiopathy, 25 evolved with aggravation of the cardiopathy and 4 with normalization of the electrocardiogram. Statistical analysis showed a significant increase in antibody levels among patients in the group with progressive cardiopathy, as well as in patients with age interval of 20 to 59 years, independent of sex. These findings indicated a direct association between T. cruzi specific antibodies (IgG) levels and the clinical course of chronic chagasic cardiopathy.
Chagas' disease; Chronic chagasic cardiopathy; Serology; Immunoglobulins G; Longitudinal study