休克期切痂对烫伤大鼠Th1/Th2型细胞因子的影响

目的：探讨烫伤大鼠伤后不同时间切痂对辅助性T淋巴细胞亚群Th1／Th2细胞功能性极化的影响。方法：160只健康雄性Wistar大鼠制备背部30％总体表面积Ⅲ度烫伤模型，随机分为单纯烫伤对照组以及伤后8、24和96h切痂组。在伤后4、12、24、48、96、120和168h活杀动物采集血液和脾脏标本；酶联免疫吸附法(ELISA)检测血浆、脾脏匀浆中的γ-干扰素(IFN-γ)和白介素-4(IL-4)含量。结果：烫伤4h大鼠上述细胞因子均迅速上升，Th1型细胞因子IFN-γ在伤后24h达峰值，其后逐渐下降；Th2型细胞因子IL-4进行性升高；伤后7d出现明显偏向Th2型反应的现象。切痂组两型Th细胞因子的变化幅度小于单纯烫伤对照组，其中8h切痂组变化最小，24h和96h切痂组次之。结论：休克期切痂有利于抑制严重烧伤后Th2的漂移。

Escharectomy during burn shock stage on Th1/Th2 polarization of helper T lymphocytes in rats after thermal injury

OBJECTIVE: To determine the type-1/type-2 cytokine response of helper T lymphocytes after thermal injury, and to investigate the effects of escharectomy during burn shock stage on the polarization of Th cells. METHODS: One hundred and sixty male Wistar rats were randomized into four groups. In group A, animals were subjected to a 30 percent full-thickness thermal injury without escharectomy. In groups B, C and D, escharectomy and skin allograft were done at 8, 24, and 96 hours postburn, respectively. At 4, 12, 24, 48, 96, 120 and 168 hours postburn, animals were killed and bloods samples as well as spleens were harvested. Enzyme linked immunoadsorbent assay (ELISA) was applied to determine interferon-gamma(IFN-gamma) and interleukin-4(IL-4) levels in blood and spleen tissues. RESULTS: Levels of IFN-gamma and IL-4 rapidly and significantly were increased after scald injury. IFN-gamma levels began to rise within 4 hours postburn, peaking at 24 hours later. IL-4 showed a persistent elevation up to 168 hours postburn, thereby leading to a dominant tendency of Th2 cytokine response on postburn day 7. In group A, all above parameters revealed most obvious changes compared with controls, then ranked in group D, B and C. CONCLUSION: Escharectomy during burn shock stage is helpful to prevent the shift to Th2 cell response after severe thermal injury.