RESUMEN
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 was assessed by flow cytometry: CD45RA (naïve) 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.
Asunto(s)
Trastornos de la Nutrición del Niño/inmunología , Infecciones/inmunología , Activación de Linfocitos , Trastornos de la Nutrición del Niño/complicaciones , Preescolar , Femenino , Humanos , Lactante , Infecciones/complicaciones , MasculinoRESUMEN
In the adaptive immune response, the types of cytokines produced define whether there is a cellular (T1) or a humoral (T2) response. Specifically, in the T1 response, interleukin 2 (IL-2), interferon γ (IFN-γ) and tumor necrosis factor ß (TNF-ß) are produced, whereas in the T2 response, IL-4, IL-5, IL- 6, IL-10 and IL-13 are primarily produced. Cytokines are primarily involved in the regulation of immune system cells. The aim of the present study was to evaluate the cytokine patterns (Type 1/Type 2) and TNF-α expression levels in children with severe gastrointestinal and respiratory bacterial infections. The enzyme-linked immunosorbent assay (ELISA) technique was used to identify the cytokines and the infectious agents. The results obtained demonstrated that, in general, children with bacterial infections experienced an increase in IL-2, IFN-γ and IL-4 concentrations and a decrease in TNF-α, IL-5 and IL-6 concentrations when compared to healthy children. Specifically, type 1 cytokines and an increased TNF-α concentration were found in children with gastrointestinal infections. However, patients with respiratory infections showed increased concentrations of both T2 (IL-4, IL-6 and IL-10) and T1 (IL-2 and IFN-γ) components. Thus, it was concluded that children with gastrointestinal infections exclusively developed a T1 response, whereas children with respiratory infections developed a T1/T2 response to fight the infection.