The potential utility of blood-derived biochemical markers as indicators of early clinical trends following severe traumatic brain injury

Objective: Severe traumatic brain injury (TBI) is a dynamic neuropathologic process in which a substantial proportion of patients die within the first 48-hours. The assessment of injury severity and prognosis are of primary concern in the initial management of severe TBI. Supplemental testing that aids in the stratification of patients at high risk for deterioration may significantly improve posttraumatic management in the acute setting. Methods: This retrospective study assessed the utility of both single-marker and multimarker models as predictive indicators of acute clinical status after severe TBI. Forty-four patients who sustained severe TBI (admission Glasgow Coma Scale [GCS] score ≤8) were divided into two cohorts according to a dichotomized clinical outcome at 72 hours after admission: Poor status (death or GCS score ≤8) and improved status (GCS score improved to >8). Threshold values for clinical status prediction were calculated for serum S-100B, matrix metalloproteinase-9, and plasma D-dimer, upon admission and at 24 hours after TBI by the use of receiver operating characteristic analysis. Performance characteristics of these single-marker predictors were compared with those derived from a multimarker logistic regression analysis. Results: Biomarkers with the greatest predictive value for poor status at 72 hours included serum S-100B on admission, as well as plasma D-dimer and serum S-100B at 24 hours, for which, associations were strongly significant. Multimarker analysis indicated no substantial improvement in prediction accuracy over the best single predictors during this time frame. Conclusion: In conjunction with other clinical, physical, and radiologic evidence, blood-derived biochemical markers may serve to enhance prediction of early clinical trends after severe TBI.