Role of Fas [CD95] in T lymphocytes Apoptosis in malnourished children

ABSTRACT

Apoptosis is programmed cell death. Lymphocyte apoptosis was described in peripheral blood and lymphatic organs in malnutrition. Little has been done to explore Fas [CD95] function in apoptosis of lymphocyte populations in malnourished children. To address this issue, we studied the apoptosis in T lymphocytes in different types of malnutrition. We also aimed to assess the role of Fas in this apoptosis in relation to clinical and laboratory parameters in the studied patients. Sixty three malnourished infants and children were compared to 27 healthy controls. Beside thorough history and clinical examination, laboratory investigation and evaluation of flow cytometry assessment of T lymphocytes was done to all cases and controls. The viability of T lymphocytes was determined by anti CD3 combined with anti CD95 and fluorescence dye 7-amino actinomycin D [7AAD]. There was a decrease in the percentage and absolute lymphocyte count [CD3[+]], with increased apoptosis in these cells compared with the controls. There was up-regulation of Fas expression in CD3[+] cells. Furthermore CD3[+]/CD95[+] cells were highly less viable, more apoptotic than CD3[+]/CD95[-] in the patients with malnutrition and than CD3[+]/CD95[+] cells in donors. The differences were highly significant. All the clinical and laboratory parameters of the studied patients showed no significant correlation with any of the apoptotic indices. We concluded that the increased apoptosis of T lymphocytes in malnourished children may be the cause of the decreased lymphocyte count in peripheral blood in these cases. This intern may be related to the decreased cell mediated immunity and the more common occurrence of infection in such cases. Furthermore the up-regulation of Fas may be the molecular basis for apoptosis in T lymphocytes in these malnourished children