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IMMUNOPATHOLOGY OF CHAGAS DISEASE
Cardiomiopatia Chagásica/patologia
Doença Aguda
Animais
Doença Crônica
Cães
Imunidade Celular
Microscopia Eletrônica
Andrade, Zilton de Araújo | Date Issued:
1999
Author
Affilliation
Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil
Abstract
The main clinical forms of Chagas disease (acute, indeterminate and chronic cardiac) present strong evidences for the participation of the immune system on pathogenesis. Although parasite multiplication is evident during acute infection, the intense acute myocarditis of this phase exhibits clear ultrastructural signs of cell-mediated immune damage, inflicted to parasitized and non-parasitized myocardiocytes and to the endothelium of myocardial capillaries (microangiopathy). Inflammation subsides almost completely when immunity decreases parasite load and suppressor factors modulate host reaction, but inflammation does not disappear when the disease enters the indeterminate phase. Inflammation becomes mild and focal and undergoes cyclic changes leading to complete resolution. However, the process is maintained because the disappearance of old focal lesions is balanced by the upsurge of new ones. This equilibrium allows for prolonged host survival in the absence of symptoms or signs of disease. The chronic cardiac form is represented by a delayed-type, cell-mediated diffuse myocarditis, that probably ensues when the suppressive mechanisms, operative during the indeterminate phase, become defaulted. The mechanism responsible for the transition from the indeterminate to the cardiac form, is poorly understood.
DeCS
Cardiomiopatia Chagásica/imunologiaCardiomiopatia Chagásica/patologia
Doença Aguda
Animais
Doença Crônica
Cães
Imunidade Celular
Microscopia Eletrônica
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