OBJECTIVETo determine the serum level and mRNA expression of type-1/type-2 cytokines of T lymphocytes in spleens of rats after thermal injury and to investigate the effects of escharectomy during burn shock stage on IFN-gamma and IL-4.

METHODSOne hundred and sixty male Wistar rats were randomized into four groups. In group A, animals were not subjected to escharectomy. In groups B, C and D, escharectomy and skin allograft were performed at 8, 24, 96 hours postburn (PB) respectively. At 4, 12, 24, 48, 96, 120 and 168 hours PB, animals were killed and blood and spleens samples were harvested. ELISA was applied to determine the concentration of IFN-gamma and IL-4 in serum. The expression pattern of IFN-gamma and IL-4 were observed at mRNA level in T lymphocytes isolated from spleen by RT-PCR.

RESULTSThe serum level of IFN-gamma and IL-4 rose rapidly and significantly after scald injury, expression of IFN-gamma and IL-4 mRNA in rats' T lymphocyte were also up-regulated spontaneously. The serum level of IFN-gamma and its mRNA expression began to rise within 4 hours PB, peaking at 24 hours PB. Whereas IL-4 and its mRNA expression showed a persistent elevation. Thereby leading to a dominant tendency of Th2 cytokine response on 7 d PB. In group A all above parameters revealed most obvious changes compared with controls, then ranked in group D, B and C.

CONCLUSIONEscharectomy during burn shock stage is helpful to decrease the harmful over expression of Th2-type lymphocyte after severe thermal injury.