Autoantibodies and inmunocomplexes in Chagas' disease / Autoanticuerpos e inmunocomplejos en la enfermedad de Chagas

RESUMO

The presence of an autoimmune process mediated by antibodies in Chagas'disease was evaluated by studying EVI antibodies, immune complexes (Clq binding) and anti-DNA antibodies in serum samples from patients with Chagasic infection (Group I), Chagasic infection and Chagasic cardiomyopathy (Group II) and normal Venezuelan blood back donors (Group III). The study was performed on both single serum samples and those obtained longitudinally. With simgle samples the incidence of positivity for EVI antibodies was higher in Group II patients (87.5%) than in Group I (66.6%). However, with the serum samples from a longitudinal study the incidence of patients with persistently positive EVI antibodies was the same in both groups (43%). No relationship coul be established between the incidence of EVI antibodies and eiter the clinical status or the detection of circulating parasites by xenodiagnosis. The immunoglobulin fraction carryng the EVI antibodies was identified as IgG.Higher values of circulating immune comlexes were found in serum samples from patients with Chagasic cardiomyopathy. However no patient from the longitudinal study showed a persistently high Clq binding activity. The levels of anti-DNA antibodies were not different between the groups studied. It was concluded that no evidence was found to link the presence of EVI or other auto-reactive antibodies with heart damage in Chagas'disease