ABSTRACT
The clinical manifestations of human Chagas disease are associated with distinct and complex host-parasite interactions that directly involve the host's immune system. In this study, we analysed the relationship between the production of intracytoplasmic cytokines after in vitro stimulation with the recombinant antigens CRA (cytoplasmatic repetitive antigen) or FRA (flagellar repetitive antigen) from Trypanosoma cruzi and the chronic cardiac or indeterminate clinical forms of Chagas disease. The chagasic patient groups consisted of 39 individuals, selected at the Chagas Disease Unit of the Oswaldo Cruz University Hospital, whom presented either a cardiac form without cardiac dilatation (CARD 1), cardiac form with cardiac dilatation (CARD 2) or indeterminate form (IND). Blood samples were obtained from these patients and cultured in the presence of CRA or FRA. The cytokines produced by lymphocytes and monocytes after antigen stimulation were analysed by flow cytometry. Our results showed that the IFN-γ and TNF-α, produced by CD8+ T lymphocytes after in vitro stimulation with CRA, differed among chagasic patients with CARD 1, CARD 2 or IND. We propose that these cytokines could be utilized as immunological markers for clinical cardiac forms of Chagas disease. In a prospective study of patients presenting IND and CARD 1, the assay performed in this paper could serve as a tool to monitor therapeutic interventions, thus improving the patient's quality of life.