Peripheral inflammatory markers in patients with prolonged disorder of consciousness after severe traumatic brain injury.

Background Inflammatory processes are known to be the key secondary effects of severe traumatic brain injury (sTBI). The aim of the present study was to assess the value of peripheral inflammatory markers in the chronic unconscious phase after sTBI. Methods This was a prospective cohort study. A total of 101 patients with prolonged disorder of consciousness (DoC) and 22 healthy controls (HC) were enrolled in the study. Serum levels of interleukin (IL)-1β, -4, -6, -10, -13, and tumor necrosis factor-α (TNF-α) were investigated in patients with prolonged DoC after sTBI. In addition, the Coma Recovery Scale-revised (CRS-R) was used to quantify the consciousness level, and clinical outcomes at 12 months were determined using the Glasgow Outcome Scale (GOS). Predictive logistic model was built based on the demographic characteristics and cytokine levels. Results At baseline, IL-6, -10, -13, and TNF-α levels were significantly higher in patients with prolonged DoC compared with controls, while no differences in cytokine levels were observed between patients in a vegetative state (VS) and those in a minimally conscious state (MCS). IL-13 and TNF-α were found to be correlated with behavioral scores in patients with prolonged DoC, and were associated with recovery 12 months later. Conclusions The results of the study provide information about long-term inflammatory responses in the chronic unconscious phase after brain trauma. Further larger studies are required to validate the value of these inflammatory markers.