Serum CXCL12 concentration in patients with severe traumatic brain injury are associated with mortality

Background: CXC chemokine ligand-12 (CXCL12) is released during brain injury. The objective of this study was to investigate relationship between serum CXCL12 concentration, mortality and trauma severity in patients with traumatic brain injury (TBI).

Methods: We determined serum CXCL12 concentration of 132 controls and 132 patients with severe TBI. Trauma severity was assessed using Glasgow Coma Scale (GCS) score. The end-point of the study was 30-day mortality.

Results: Serum CXCL12 concentration were significantly higher in the patients than in the controls (13.3±6.8 vs. 1.5±0.5 ng/ml, P<0.001). There was a negative correlation between CXCL12 concentration and GCS scores (r=-0.588, P<0.001). The optimal cutoff value of CXCL12 as a mortality indicator was estimated to be 15.4 ng/ml, which yielded a sensitivity of 71.0% and a specificity of 72.2%, with the area under curve at 0.808 [95% confidence (CI), 0.730-0.871]. Serum CXCL12 concentration>19.5 ng/ml were associated independently with 30-day mortality (odds ratio, 6.951; 95% CI, 2.027-18.477; P<0.001) and 30-day overall survival (hazard ratio, 4.398; 95% CI, 2.088-15.286; P<0.001).

Conclusions: Increased serum CXCL12 concentration is associated highly with trauma severity and mortality following TBI.