Infected malnourished children displayed changes in early activation and lymphocyte subpopulations

Aim Malnutrition and infections cause immunological changes in lymphocyte subpopulations and their functionality. We evaluated the activation capacity of lymphocytes and memory cells in 10 well nourished, seven well nourished infected and eight malnourished infected children before and after treatment. Methods All the children were patients in Mexico City and were less than three years of age. The expression of various cluster of differentiation (CD) cells were assessed by flow cytometry: CD45RA (naive) and CD45RO (memory) antigens on CD4 lymphocytes and CD69 in all lymphocytes. Results Well-nourished infected children showed a higher percentage of activated T lymphocyte (T cells), CD8+ and CD4+ memory cells during the infectious phase, suggesting that the activation mechanisms were triggered by infection. T cells from malnourished infected children showed a lower percentage of activated and memory cells. The T cell population size returned to baseline during the resolution phase of the infection in well-nourished infected children, but their T, B lymphocyte and natural killer (NK) cell counts remained high. In malnourished infected children, activated NK cells counts were low before and after therapy. Conclusion After therapy, malnourished infected children showed poor NK cell responses during the infection's resolution phase, suggesting a persistent malnutrition-mediated immunological deficiency. This article is protected by copyright. All rights reserved.