Jornal de Pediatria
Print version ISSN 0021-7557
ALFONZO, Miguel Antonio et al. Functional state of CD4+ and CD8+ T lymphocytes and their role in the slow progression of HIV infection in pediatric patients. J. Pediatr. (Rio J.) [online]. 2012, vol.88, n.2, pp. 161-168. ISSN 0021-7557. http://dx.doi.org/10.2223/JPED.2183.
OBJECTIVE: To evaluate simultaneously the functional state of CD4+ and CD8+ T lymphocytes from Venezuelan HIV-1-infected pediatric patients. METHODS: Children were assigned to subgroups of rapid progressors (RPs) and slow progressors (SPs), based on clinical features. To determine the degree of CD4+ and CD8+ T-lymphocyte functionality, flow cytometry techniques were used, and diverse parameters of the functionality of these cells were characterized by ex vivo tests, such as expression of CD95/Fas and CD127, and frequency of apoptosis. In addition, we determined, in cultured peripheral blood mononuclear cells, HIV-specific proliferation and the production of interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ), besides measuring intracellular IFN-γ in CD4+ T cells. RESULTS: Our results indicate that several molecular and cellular mechanisms of CD4+ and CD8+ T lymphocytes are deteriorated in RPs in comparison with SPs and controls. Indeed, both types of T lymphocytes from RPs exhibited an increased expression of CD95/Fas (p < 0.01), a significantly reduced expression of CD127 (p < 0.01), and an augmented frequency of apoptosis (p < 0.01). Furthermore, T cells from these patients displayed a diminished capacity of mitogen proliferation (p < 0.05), a reduced percentage of IFN-γ producing CD4+ T lymphocytes (p < 0.05) and a smaller capacity of IL-10, TNF-α and IFN-γ production (p < 0.01) in comparison with SP and control patients. CONCLUSION: Our findings indicate that the decline of the normal T lymphocyte molecular and cellular responses is related to a rapid progression and a decreased resistance to HIV-1 infection in children.
Keywords : HIV; progression; pediatric patients; immune function.