Changes Of Serum Tumor Necrosis Factor α And Interleukin-18 Contents After Severe Traumatic Brain Injury And The Influence Of Mild Hypothermia Therapy

Objective:To disclose the probably protective mechanism of mild hypothermia protecting brain through investigating the contents changes of TNF-αand IL-18 in serum in patients with severe traumatic brain injury(sTBI)and the influence of mild hypothermia on serum levels of TNF-αand IL-18.Methods:A total of 80 cases with sTBI were treated with normothermia(NT)(NT group,n=40)and mild hypothermia(HT)(HT group,n=40)respectively.ELISA was used to measure serum levels of TNF-αand IL-18 in two groups at 1,3,5,7 and 10 days after injury to observe the contents changes of TNF-αand IL-18 in serum and the influence of mild hypothermia.Contrast clinical prognosis of patients in the two groups to research the protective mechanism of mild hypothermia protecting on patients with sTBI.16 serum specimens of normal persons were used as control group,the collection and conservation of normal specimens were same with that of the sTBI patients.Results:As a result:(1)At each time point,the levels of serum TNF-αand IL-18 in NT group and HT group was higher than that of the control group(P＜0.01).(2)In the NT group,the level of serum TNF-αwas elevated significantly at the beginning of the trauma and peaked on the 3rd day,although dropped obviously on the 10th day,the level of serum TNF-αwas higher than that in the control group(P＜0.01);the level of serum IL-18 elevated gradually after injury and peaked on the 10th day.(3)The level of serum TNF-αin the HT group was lower than that in the NT group at each time point after injury(P＜0.01),and the level of serum IL-18 in the HT group was lower than that in the NT group at 3,7 and 10 days after injury(P＜0.01),but with insignificant difference at 1 day after injury.(4)The treatment of mild hypothermia can improve the clinical prognosis and degrade the mortality through obviously degraded the levels of serum TNF-αand IL-18.Conclusion:(1)The over-expression of TNF-αand IL-18 in patients with sTBI were involved in inflammatory reaction of brain cells after sTBI and play an important role in secondary brain injury(2)The treatment of mild hypothermia can significantly suppress these changes of TNF-αand IL-18,reduce the vascular inflammatory reaction,protect brain tissues and improve the clinical prognosis.(3)Suppressing the inflammatory reaction of brain cells mediated by some cytokines for instance TNF-αand IL-18 may be a new protective mechanism of mild hypothermia protecting brain after sTBI.