Perfil fenotípico de células mononucleares do sangue periférico de pacientes portadores de febre do dengue em diferentes fases da doença

• Autor(a) principal: Merlo, Bianca Bortolini
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/5900
• topic: Dengue; Imunopatologia; Células; Leucócitos; Doenças Infecciosas e Parasitárias; 61

The objective of the present study was to examine the PBMC immunological status of patients with Dengue Fever during different stages of disease. Blood samples from 22 patients with Dengue Fever, were collected at three different stages of the disease: at acute phase, Day 0 (1-2 days after disease onset), convalescent phase, Day 7 (7 days after the first sample) and post-cure phase, Day 60 (60 days after the first sample). Peripheral blood mononuclear cells were stained using fluoresceinlabeled monoclonal antibodies to both PBMC subset markers and the activation markers, such as CD69, CD25 and HLA-DR, and analyzed using flow cytometry. The results have showed lower platelets count compared to control group, on the different stages of Dengue Fever. In acute phase, the white blood cells counts in patients with Dengue Fever were lower, with decreased numbers of monocytes, neutrophils and lymphocytes. The same was observed for absolute numbers of B cells, CD4+ and CD8+ T cells. The results show a lower number of NK cells on acute phase of Dengue Fever, but an increase was observed on percentage of NK cells in total lymphocytes. Concerning the activation status of the peripheral blood cells, our results have demonstrated that the percentage of CD8+ T and CD4+T cells expressing CD69 was significantly higher, and this increased was more evidenced on CD8+ T cells. Moreover was demonstrated a higher percentage of T CD4+HLA-DR+ and CD4+CD25+, on acute phase of the disease and a higher percentage of T CD8+HLA-DR+ on convalescent phase. The association analysis between the hematological parameters and the immunological status of the peripheral blood mononuclear cells with the presence of clinical manifestations of the disease has revealed that severe Dengue Fever patients presented a lower percentage of CD8+HLA-DR+ T lymphocytes, compared with the mild Dengue Fever patients. Therefore, data presented here suggest that host immune response is important to clearance viral. However, additional studies were needed to evaluate the role of immune response in the immunopathological mechanism during Dengue virus infection.