Objective: To observe the immunological function changes in T lymphocyte in severe burn patients with sepsis, and to explore its relationship with sepsis.
Methods: Fifty-nine burn patients with burn surface exceeding 30% TBSA were enrolled in the study, and they were divided into sepsis group (S, n =43) and non-sepsis group (NS, n = 16). The peripheral venous blood samples of the patients in both groups were collected on 1, 3, 5, 7, 14, 21 and 28 post-burn days (PBD). The T lymphocyte proliferation ability and the interleukin-2 (IL-2) level in both groups were observed and the correlation between them were analyzed. The percentage of CD3+/CD4+ T lymphocytes and its apoptosis rate were determined by flow cytometry and the correlation between them was analyzed.
Results: Compared with that in NS group, the proliferation ability of T lymphocyte and the level of IL-2 were significantly decreased in patients in S group on 1, 14, 21, and 28 PBD (P < 0.05 or P < 0.01). The inhibition of T lymphocyte proliferation was positively correlated to the low level of IL-2 production in burn patients (r = 0.82, P < 0.01). The percentage of CD3+/CD4+ T lymphocytes in S group were obviously lower than that in NS group on 1, 5, 14, 21, 28 PBD, whereas on opposite tendency in the apoptosis rate of CD3+ CD4+ T lymphocytes were found at the same time (P < 0.05 or P < 0.01). The percentage of CD3+/CD4+ T lymphocytes was negatively correlated to apoptosis rate of T lymphocytes (r = -0.66, P < 0.05).
Conclusion: The immunological function of T lymphocyte in severely burn patients with sepsis is depressed persistently. Apoptosis of T lymphocyte may participate in the pathological process of cell immunological disorder induced by sepsis.