Biomarkers of traumatic brain injury in vitreous humor: A pilot study

Background: Traumatic brain injury (TBI) is one of the major causes of morbidity and mortality worldwide. The patients' and injuries' heterogeneity associated with TBI, alongside with its variable clinical manifestations, make it challenging to make diagnosis and predict prognosis. Therefore, the identification of reliable prognostic markers would be relevant both to support clinical decision-making and forensic evaluation of polytraumatic deaths and cases of medical malpractice. This pilot study aimed to evaluate some of the main biomarkers specific for brain damage in sTBI and mmTBI deaths in samples of vitreous humor (VH) in order to verify whether predictors of prognosis in TBI can be found in this matrix. Methods: VH were obtained from both eyes (right and left) of 30 cadavers (20 sTBI and 10 mmTBI) and analysed. These factors were evaluated: NSE (neuron-specific enolase), S100 calcium-binding protein (S100), glial fibrillary acidic protein (GFAP), Brain-derived neurotrophic factor (BDNF), Copeptin, Interleukin 6 (IL-6), Ferritin, Lactate dehydrogenase (LDH), C-Reactive Protein (CRP), Procalcitonin (PCT), Glucose and Neutrophil gelatinaseassociated lipocalin (N-Gal). Results: Four of the analysed proteins (LDH, ferritin, S100 and NSE) proved to be particularly promising. In particular, logistic regression analysis found a good discriminatory power. Conclusions: Given the peculiarity of the matrix and the poor standardization of the sampling, such promising results need to be furtherly investigated in serum before being implemented in the forensic practice.