Clinical significance of serum high mobility group box 1 protein in patients with severe traumatic brain injury

Abstract

Objective To detect the levels of high mobility group box 1 protein HMGB1),tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6),C-reactive protein (CRP) in order to explore the clinical significance of HMGB1 in patients with severely traumatic brain injury.Methods A total of 75 patients composed of 40 male and 35 female with severely traumatic brain injury were hospitalized from March 2011 through March 2012.The scores of Glasgow Coma Scale (GCS) were 5-8 within 12 hours after brain injury.Casualties with history of hypertension,diabetes,severe diseases of heart,liver and kidney,and with concurrent trauma of other parts of body were excluded.Another 50 healthy subjects were enrolled as controls.Serum samples were taken from both patients and controls at admission.The levels of HMGB1,TNF-α and IL-6 were measured by using enzyme-linked immunosorbent assay (ELISA).The level of CRP was measured by using automatic biochemistry analyzer.Comparisons of the levels of HMGB1,TNF-α,IL-6and CRP between casuahies and healthy controls were carried out.The correlations of HMGB1 with TNF-α,IL-6,CRP in patients with severe traumatic brain injury were analyzed.Thereafter,75 patients were divided into two groups post hoc:the death group and the survival group.On the 1st day,the 3rd day and the 7th day after trauma,serum HMGB1 was detected.The comparison of HMGB1 was made between death group and survival group by using t-test.Results Serum HMGB1 level in the traumatic patients was higher than that of healthy controls (P ＜ 0.01).Correlative analysis showed that there was a positive correlation between HMGB1 and TNF-α (r =0.365,P＜0.05),IL-6 (r=0.530,P＜0.05),CRP (r=0.661,P＜0.05) in patients with severe traumatic brain injury.Serum HMGB1 level in the death group was higher than the survival group (P ＜ 0.01).Conclusions Increased serum HMGB1 level was found after severe traumatic brain injury.There were positive correlations between HMGB1 and three inflammatory factors,TNF-α,IL-6and CRP.Serum HMGB1 should be used as reliable hiomarker to judge the prognosis of patients with severe traumatic brain injury. Key words: High mobility group box 1 protein; Tumor necrosis factor-α; Interleukin-6; C-reactive protein ; Inflammatory factor ; Inflammatory reaction ; Severe traumatic brain injury ; Prognosis