Serum cytokines and activation ex vivo of CD4+ and CD8+ T cells in chagasic chronic Mexican patients

The clinical manifestations of human Chagas disease are associated with several factors, including immunological alterations, in this regard, many studies propose that tissue damage might be more severe in the absence of immune regulatory mechanisms, other factors are the genetic background of host and parasite. Trypanosoma cruzi population is genetically, biochemistry and pathogenic diverse along the Latin-America continent and phylogenetic ally are divided into six intra-species lineages TcI-VI. The TcI lineage has a wide distribution with heterogeneous virulence and pathogenesis within strains. In Mexico, the main circulating lineage is TcI in human infections. We analyzed intracytoplasmic cytokines of unstimulated peripheral T lymphocytes, and the level of cytokines (IL-2, IL-4, IL-12, IL-10, IFN-γ and sIL-2R) in the serum of Mexican chagasic subjects. The population studied consisted of 15 asymptomatic individuals, 17 patients with chronic chagasic cardiopathy (CCC), 20 patients with cardiopathy but negative serology for T. cruzi, and 10 healthy subjects. The analysis of CD4+ cells revealed that CCC and asymptomatic patients have higher CD25+ and CD69 activation markers than controls. The Th1 subset (CD4+/IFN- γ +) was higher in CCC than in asymptomatic and control subjects, whereas Th2 subset was markedly high in asymptomatic subjects. Circulating cytokines were below level detection with the exception of IL-2 and sIL-2R. Infection with Mexican Trypanosoma cruzi strains in asymptomatic chagasic subjects have a tendency for a Th2 response with higher CD8+/IFN-γ T cells. In contrast, CCC patients have low levels of intracellular IFN- γ and IL-2 cytokines. In both groups circulating serum cytokines are below the detectable level.