Notfalldiagnostik bei leichtem Schädel-Hirn-Trauma

Evaluation of Acute Glial Fibrillary Acidic Protein and Ubiquitin C-Terminal Hydrolase-L1 Plasma Levels in Traumatic Brain Injury Patients with and without Intracranial Lesions

This pilot study aimed to evaluate the association of plasma ubiquitin C-terminal hydrolase-L1 (UCH-L1), glial fibrillary acidic protein (GFAP), and S100 calcium-binding protein B (S100B) with intracranial abnormalities visible on a computed tomography (CT) scan (CT positive) and injury severity in acute traumatic brain injury (TBI). For these purposes, a cohort of 109 adult TBI patients was recruited within 6 h from the injury event. A hyperacute subcohort of 20 patients who had their blood collected within 2 h from injury was analyzed separately for early acute biomarker levels. Levels of GFAP and UCH-L1 were analyzed using the prototype Abbott i-STAT™ TBI Plasma Test (Abbott Laboratories, Abbot Park, IL), alongside S100B measurement (Elecsys; Roche Diagnostics, Penzberg, Germany). In the hyperacute subcohort, GFAP and UCH-L1, but not S100B, levels were significantly higher in the CT-positive group compared to CT-negative patients. AUC values for differentiation between CT-positive and CT-negative patients were 0.97 for GFAP, 0.87 for UCH-L1, and 0.60 for S100B. Severity discrimination, defined by Glasgow Coma Scale (GCS) score, was then analyzed in the total patient cohort. Levels of all three biomarkers were significantly different between mild (GCS, 13-15) and moderate/severe (GCS, 3-12) injury groups. UCH-L1 showed the highest area under the curve value for severity discrimination (0.94), followed by GFAP (0.91) and S100B (0.83). These results support the clinical utility of GFAP and UCH-L1 as TBI biomarkers able to rule out CT-positive injury in acute TBI. Moreover, excellent differentiation of GFAP and UCH-L1 between mild and moderate/severe TBI groups affirms their close association with the underlying pathology.

Increased S-100 B levels are associated with fractures and soft tissue injury in multiple trauma patients

BACKGROUND

S-100 B protein was identified as a biomarker for traumatic brain injury, but studies suggest that extracranial injuries may also lead to increased S-100 B serum levels. In this study, we aim to quantify the impact of injury patterns on S-100 B levels in patients with suspected multiple trauma.

METHODS

Patients with suspected multiple trauma treated at a Level 1 Trauma centre in Switzerland were included in this retrospective patient chart review. Extent of injuries and severity was assessed and S-100 B levels on admission measured. Potential predictors of increased S-100 B levels (>0.2 µg/L) were identified through uni- and multivariable analyses.

RESULTS

In total, 1,338 patients with suspected multiple trauma were included. Multivariable logistic regression showed a significant association with increased S-100 B levels in long bone fracture (OR 2.3, 95% CI: 1.3-4.1, p = 0.004), non-long bone fracture (OR 3.0, 95% CI: 2.2-4.3, p<0.001), thoracic injury (OR 2.6, 95% CI: 1.6-4.2, p<0.001), and deep tissue injury/wounds (OR 1.9, 95% CI: 1.4-2.6, p<0.001). Head trauma with intracerebral bleeding was only weakly associated (OR 2.0, 95% CI 1.2-3.5, p = 0.01) and head trauma without intracranial bleeding was not associated with an increased S-100 B protein level (p = 0.71). Trauma severity was also related to increased S-100 B levels (OR per ISS: 1.1, 95% CI 1.0-1.1, p<0.001). S-100 B levels <0.57 µg/L had a high diagnostic value to rule out in-hospital mortality (negative predictive value: 1.0, 95% CI: 0.98-1.00).

CONCLUSION

Fractures and thoracic injuries appeared as main factors associated with increased S-100 B levels. Head injury may only play a minor role in S-100 B protein elevation in multiple trauma patients. A normal S-100 B has a good negative predictive value for in-hospital mortality. S100-B levels were associated with trauma severity and might thus be of use as a prognostic marker in trauma patients.