Identification of anti-acetylcholinesterase and anti-idiotype antibodies in human and experimental Chagas' disease: pathological implications.

This report presents evidence that human acetylcholinesterase (AChE; acetylcholine hydrolase, EC3.1.1.7) exhibits immunological cross-reactivity with the protozoan parasite Trypanosoma cruzi. The immunological probes used indicate that the cross-reactive determinant is an oligosaccharidic epitope. Antibodies to AChE were detected in a high proportion of T. cruzi-infected patients sera and during the experimental infection of BALB/c mice. Moreover, anti-idiotypic antibodies against an anti-AChE rabbit antibody or a monoclonal antibody to a parasite surface antigen of 80-85 kDa were detected in sera of patients presenting the chronic cardiac form of the disease. The antibodies were less frequently found in sera from individuals with asymptomatic chronic infection. Our data may provide a biochemical basis for denervation hypersensitivity in Chagas' disease. In addition, it may support the notion of an idiotype-anti-idiotype regulation of conducting tissue damage during the course of T. cruzi infection.