Evaluation of S100B blood level as a biomarker to avoid computed tomography in patients with mild head trauma under antithrombotic medication

Abstract Purpose The goal of this prospective study was to analyze the potential of S100B protein as a negative predictive marker for intracranial hemorrhage (ICH) after mild head trauma (MHT) in patient under antithrombotic medication. Methods Patients under antithrombotic medication who had MHT were consecutively included in this study. S100B blood levels were determined from samples drawn within 6 hours after injury and were analyzed with the results of head CT performed within the 24 hours after injury. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of S100B levels for the detection of ICH, with a cut-off set at 0.105 μg/L, were calculated. Results A total of 308 patients (151 men and 157 women) with a mean age of 79.1 ± 10.5 years (SD) were included in the analysis. CT was positive for the presence of ICH in 33 patients (10.7%; 95% CI: 7.5–14.7%). In the study population, S100B showed a sensitivity of 84.8% (95%CI: 68.1–94.9%), a specificity of 30.2% (95% CI: 24.8–36.0%), a NPV of 94.3% (95% CI: 87.2–98.1%), and a PPV of 12.7% (95% CI: 8.6–17.9%) for the diagnosis of ICH. Conclusion The results of this study suggest that a S100B serum level