Avaliação de monócitos supressores CD14+/HLA-DRlow/-, das subpopulações Linfocitárias T CD4/CD8 e de citocinas TNF-α e IL-10 em pacientes com Doença de Chagas crônica, em suas diferentes formas clínicas, após o uso de Benzonidazol

Abstract

Chagas' disease (CD) has as etiological agent the protozoan Trypanosoma cruzi (T. cruzi). A large number of patients remain asymptomatic for several years, with no signs of cardiac or digestive abnormalities characterizing the indeterminate form of CD. It is not completely clear how some infected individuals develop severe forms of the disease and the fact that the clini-cal manifestations are heterogeneous. Myeloid derived suppressor cells (MDSCs) may exhibit the CD14+ HLA-DR- / low phenotype and have been shown to suppress the immune response against tumors or microbes and, as a result, play important roles in the critical balance between parasite elimination and damage caused to host tissues due to exacerbated inflammation. Thus, the present study evaluated the expression of these cells, as well as the profile of lymphocyte and cytokine subpopulations (IL-10, TNF-α), in the different clinical forms of CD. This is a cross-sectional study with adult patients of both sexes, diagnosed with chronic CD, who underwent previous etiologic treatment and were followed up at the pharmaceutical care service of the Chagas Disease Research Laboratory. Fifty-seven patients were analyzed, of these 23 with indeterminate form (asymptomatic form), 26 with cardiac form (symptomatic form), 08 with mixed form (symptomatic form). For the determination of CD14+ HLA-DR-/low suppressor monocytes and CD4 and CD8 T lymphocyte subpopulations, whole blood was used with EDTA anticoagulant and flow cytometry analysis was performed using serum EL-SA for cytokine analysis. The study of the T lymphocyte CD4/CD8 subpopulations showed no statistical difference between the clinical forms. Regarding the analysis of the CD14+/HLA-DR- population, it is observed that the group of asymptomatic (undetermined) individuals expresses a greater number of these cells than the symptomatic ones. Similar be-havior was observed in the analysis of the suppressor population that poorly expresses HLA-DR, showing by means of the medium fluorescence intensity (MFI) that the group of asymp-tomatic ones has an MFI lower than the symptomatic ones. Finally, in the evaluation of cyto-kines, it is observed that the concentration of TNF-α is similar in the different clinical forms and that of IL-10 is higher in the symptomatic group. Thus, these findings suggest that this population of suppressor cells may be involved in the process of balancing the immune re-sponse characteristic of the indeterminate form of CD, and that symptomatic individuals are still able to maintain some regulatory mechanisms, such as the production of anti-inflammatory cytokine IL-10.