Serum lipocalin-2 concentrations and mortality of severe traumatic brain injury

Lipocalin-2 is related to acute brain injury. We assessed the prognostic value of serum lipocalin-2 in head trauma.

Blood samples were collected from 115 controls and 115 patients with severe traumatic brain injury. Trauma severity was assessed by Glasgow Coma Scale (GCS) scores at baseline. Thirty-day mortality and overall survival time were recorded.

Compared with the controls, serum lipocalin-2 concentrations were significantly increased in the patients. Lipocalin-2 concentrations were independently associated with GCS scores (t=-7.271, P<0.001) and serum C-reactive protein concentrations (t=4.325, P<0.001). Under receiver operating characteristic curve for 30-day mortality, sensitivity and specificity were 85.7% and 63.2% respectively for lipocalin-2 concentrations at a cutoff value of 591ng/ml. Additionally, area under curve (AUC) of lipocalin-2 concentrations [AUC, 0.825; 95% confidence interval (95% CI), 0.743-0.889] was equivalent to that of GCS scores (AUC, 0.869; 95% CI, 0.793-0.925; P=0.413). Moreover, serum lipocalin-2 concentrations >591ng/ml emerged as an independent predictor for 30-day mortality (odds ratio, 4.360; 95% CI, 1.908-12.430) and overall survival (hazard ratio, 3.820; 95% CI, 1.935-10.500).

Enhanced serum concentration of lipocalin-2 at admission is associated with trauma severity and neuroinflammation as well as is a predictor of mortality after head trauma.