S100B protein as a biomarker and predictor in traumatic brain injury.

Objectives: To determine the prognostic potential of S100B protein in patients with craniocerebral injury, correlation between S100B protein and time, selected internal diseases, body habitus, polytrauma, and season.

Methods: We examined the levels of S100B protein in 124 patients with traumatic brain injury (TBI).

Results: The S100B protein level 72 h after injury and changes over 72 h afterwards are statistically significant for prediction of a good clinical condition 1 month after injury. The highest sensitivity (81.4%) and specificity (83.3%) for the S100B protein value after 72 h was obtained for a cut-off value of 0.114. For the change after 72 h, that is a decrease in S100B value, the optimal cut-off is 0.730, where the sum of specificity (76.3%) and sensitivity (54.2%) is the highest, or a decrease by 0.526 at the cut-off value, where sensitivity (62.5%) and specificity (62.9%) are more balanced. The S100B values were the highest at baseline; S100B value taken 72 h after trauma negatively correlated with GCS upon discharge or transfer (r=-0.517, P<0.0001). We found no relationship between S100B protein and hypertension, diabetes mellitus, BMI, or season when the trauma occurred. Changes in values and a higher level of S100B protein were demonstrated in polytraumas with a median of 1.070 (0.042; 8.780) μg/L compared to isolated TBI with a median of 0.421 (0.042; 11.230) μg/L.

Conclusion: S100B protein level with specimen collection 72 h after trauma can be used as a complementary marker of patient prognosis.