Diagnostic and prognostic utility of plasma thrombospondin-1 levels in traumatic brain injury.

Purpose: Thrombospondin-1 (TSP-1), a powerful antiangiogenic agent, is increasingly expressed in mice brain tissues after traumatic brain injury (TBI). However, in the peripheral blood of TBI patients, TSP-1 concentrations have not been identified. This study aimed to determine if TSP-1 measured in the plasma of patients relates to TBI diagnosis and injury severity.

Methods: Plasma TSP-1 levels were assessed in 75 patients with mild to severe TBI and 60 healthy volunteers. Glasgow Coma Scale (GCS) score was recorded to assess traumatic severity. Other relevant clinical characters and laboratory tests were collected to evaluate the diagnostic efficiency of TSP-1. Glasgow outcome scale (GOSE) 3 months after trauma was dichotomized into unfavorable (GOSE_1-4) and favorable (GOSE_5-8) outcomes.

Results: TSP-1 levels were significantly higher in TBI patients than in controls (median 530.4 ng/l, the upper- lower quartiles 373.2-782.1 vs. median 201.5 mg/l, the upper - lower quartiles 83.1-351.4, P < 0.001). Plasma TSP-1 was able to differentiate patients with mild, moderate, and severe TBI from healthy controls with Area Under the Receiver-Operating Characteristic Curve (AUROC) of 0.8089, 0.9312, and 0.9189, respectively. TSP-1 levels were closely and negatively correlated with GCS score (r = -0.41). TSP-1 levels > 624.4 ng/ml independently predicted a 3-month unfavorable outcome with an odds ratio value of 9.666 (95% confidence interval (CI),1.393-69.072). TSP-1 levels significantly discriminated 3-month unfavorable outcome with AUROC of 0.7445 (95%CI, 0.6152-0.8739).

Conclusion: The results of this study indicate that plasma TSP-1 should be further investigated as a diagnostic and prognostic marker for patients with TBI.