Diagnostic values of proenkephalin and S100B protein in traumatic brain injury

Background: The primary aim of this study was to investigate the diagnostic values of serum S100 calcium-binding protein B (S100B) and proenkephalin (P-ENK) levels in brain damage caused by traumatic brain injury (TBI). Methods: We prospectively collected serum blood samples of 58 adult patients admitted to our emergency department due to TBI. Serum S100B and P-ENK levels were measured and compared according to clinical findings and outcomes of the patients. Results: When patients with brain injury were compared to controls, statistical significance was determined in both S100B and P-ENK levels. According to the receiver operating characteristic (ROC) analysis, cut-off values for serum S100B and P-ENK levels for the differential diagnosis of patients with and without brain damage were found to be 785.944 ng/mL and 2.445 ng/mL, respectively. There was a statistical significance in both S100B and P-ENK levels when patients who were discharged and those who died were compared. Conclusions: Serum S100B and P-ENK levels are found to be elevated in patients with TBI when compared to controls. Additionally, serum levels of both markers are found to be elevated in patients with multiple lesions when compared to patients with a single lesion. Serum S100B and P-ENK levels may also be used as predictors of mortality in patients with TBI.