RESUMO
Natural Killer (NK) cells play an important role in immune surveillance against tumors. The present work aimed to study the cytotoxic activity of NK cells and T cell subsets in peripheral blood of 13 patients with primary in central nervous system (CNS). As controls 29 healthy subjects with the age range equivalent to the patients were studied. The methods employed were: a) determination of cytotoxic activity of NK cells towards K562 target cells, evaluated by single cell-assay; b) enumeration of CD3+ lymphocytes and their CD4+ and CD8+ subsets defined by monoclonal antibodies; c) the identification of tumors were done by histologic and immunochemistry studies. The results indicated that adults and children with tumor in CNS display reduced percentage of total T cells, helper/inducer subset and low helper/suppressor ratio. The cutotoxic activity of NK cells was decreased in patients with CNS tumors due mainly to a decrease in the proportion of target-binding lymphocytes. These results suggest that cytotoxic activity of NK cells may be affected by the immunoregulatory disturbances observed in patients with primary tumors in CNS.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Criança , Pré-Escolar , Adulto , Adolescente , Neoplasias do Sistema Nervoso Central/imunologia , Células Matadoras Naturais/imunologia , Subpopulações de Linfócitos T/imunologia , Neoplasias do Sistema Nervoso Central/sangue , Citotoxicidade Imunológica , Imunidade Celular , Subpopulações de Linfócitos T/químicaRESUMO
The aim of the present investigation was to study the distribution of T-cell subsets in peripheral blood defined monoclonal antibodies and by the lymphocyte proliferative response to phytohemagglutinin (PHA) in 30 children febrile seizures and in 14 age-matched control subjects. Frequent respiratory, urinary and dermatologic infections were observed in 22 patients. The immunologic parameters showed that 64 percent of the patients presented an increases number of CD8+ cells and a low helper/suppressor ratio was observed in 60 percent of the patients. In addition, the proliferative response of lymphocytes to PHA was impared in the patients. It was observed the presence of inhibitory activity on lymphocyte function in the plasma of 33 percent of children with febrile seizures. These results suggest that patients with febrile seizures have an impairment of cellular immunity that may be connected with this epileptic syndrome and explain the infections observed.