Plasma microvesicles in patients admitted to the emergency department for mild traumatic brain injury: first clues to understand their role

BACKGROUND: Mild traumatic brain injury (mTBI) represents one of the main causes of emergency department (ED) admission. Microvesicles (MVs) have been shown to play an important role in cell-to-cell communication. However, their role in mTBI needs to be clarified. METHODS: Patients admitted to the ED for mTBI, with or without minor trauma of the limbs, were enrolled. Patients with isolated minor trauma of the limbs served as control group. Five healthy volunteers were also enrolled. Blood sample was collected within 8 hours from admission and plasmatic MVs were subsequently isolated and quantified. Through flow cytometry MVs were further characterized on a subgroup of patients and controls. A 30-day follow-up phone call evaluated the presence of post-traumatic sequelae. RESULTS: One hundred and fifteen mTBI and 40 control patients were enrolled between July 2014 and March 2015. Plasma MVs size and concentration were significantly higher (P=0.0011 and P<0.0001, respectively) in mTBI patients compared to both controls and healthy volunteers. No difference was observed in terms of MVs concentration and size neither according to age, sex, anticoagulant therapy nor presence of post-traumatic sequelae. At MVs characterization, (FAS-Ligand expression was significantly higher in mTBI patients compared to controls (P=0.035). CONCLUSIONS: Both plasmatic MVs size and concentration are significantly higher in patients admitted to the ED for mTBI, compared to controls and healthy subjects.