Early Activation of T, B and NK Lymphocytes in Infected Malnourished and Infected Well-Nourished Children

In vitro response of T (CD3+, CD4+ and CD8+), B (CD19+) and NK (CD56+) peripheral blood lymphocytes to the mitogens PHA, PWM and IL-2, respectively, were compared in three groups of children: non-infected well-nourished, well-nourished infected and malnourished infected children. This response was measured by analysing the expression of the early activation antigen CD69 by three-color flow cytometry. All T lymphocyte subsets of malnourished infected children showed impaired activation capability, as the percentages of CD3+CD69+, CD4+CD69+ and CD8+CD69+ lymphocyte were lower than those observed in well-nourished infected children. The percentage of B lymphocytes (CD19+) was also significantly decreased in malnourished as compared to well-nourished infected children. These results indicate that malnutrition influences the function and proportion of peripheral lymphocytes suggesting that malnourished children have a defect which alters their activation process and might explain some of the T immuno-regulatory abnormalities observed in these children.