IFN-GAMMA IN HUMAN CHAGAS-DISEASE - PROTECTION OR PATHOLOGY

An apparently paradoxical role for IFN-gamma in human Chagas' disease was observed when studying the pattern of cytokine production by perip heral blood mononuclear cells (PBMC) obtained from two groups of chaga sic patients after specific stimulation with Trypanosoma cruzi-derived antigens. The groups studied were 1) patients treated with benznidazo le during the acute phase of Trypanosoma cruzi infection and 2) chroni cally infected untreated patients. In the treated group, higher levels of IFN-gamma were produced by PBMC from individuals cured after treat ment when compared to non-cured patients. In contrast, in the chronica lly infected group (not treated) higher levels of IFN-gamma were produ ced by PBMC from cardiac patients in comparison with asymptomatic (ind eterminate) patients, This apparently paradoxical role for IFN-gamma i n human Chagas' disease is discussed in terms of the possibility of a temporal difference in IFN-gamma production during the initial stages of the infection (acute phase) in the presence or absence of chemother apy. The maintenance of an immune response with high levels of IFN-gam ma production during the chronic phase of the infection may favor cure or influence the development of the cardiac form of the disease.