Peripheral blood T lymphocytes in burn injury in young children

In our study 31 patients were observed and treated at the burn center of Tyumen city, including 19 boys and 12 girls, aged 1 year to 3 years, with the area of burn wounds of II-IIIAB degree from 7% to 70% of the body surface. Flow cytometry method with monoclonal antibodies CD3, CD4, CD8, CD25 and HLA-DR was used for immunophenotyping of blood lymphocytes. β2-microglobulin (β2-MG) was determined in blood serum using ELISA technique. The venous blood samples conserved with EDTA were taken and analyzed at 24 hours, 7 and 20 days after the injury, thus corresponding to toxic and septic/toxic phase of the disease. Results: There was a statistically significant decrease in the absolute numbers of CD3-positive cells (p < 0.001) and the ratio of CD4/CD8 (p < 0.05) within 24 hours after burn against reference values. The absolute number of CD3⁺ cells was increased by day 20 of the disease (p < 0.05), yet being under control counts. The number of CD25-expressing T cells did not significantly increase after a burn. Meanwhile, The absolute counts of HLA- DR significantly increase after 20 days (p < 0.001). In addition, there was a significant correlation between the mean values of β2-MG and the levels of CD25 expressing cells (r = 0.58) in the first 24 hours after the injury. Significant negative correlations were found between the average values of β2-MG and the absolute numbers of CD3⁺ and CD4⁺ cells after 24 hours and 7 days of illness. The average values of β2-m throughout the duration of the study were significantly higher in patients with burns than in control group, but without significant differences between measurements at 24 hours, 7 or 20 days. The data obtained indicate a constant activation of T cells twenty days after severe burns. Early release of β2-MG is associated with activation of lymphocytes increasing their susceptibility to apoptosis, thus suggesting an altered immune response and a need to support the immune system of patients during first hours after severe burns.