Sustained Release of Neuron-specific Enolase to Serum in Amateur Boxers

Primary Objective: We assess the potential of a panel of serum biomarkers to identify chronic neuronal injury in amateur boxers as compared to healthy controls without any history of head trauma.

Research Design: Observational case-control study.

Methods And Procedures: A panel of serum biomarkers was measured by a novel biochip array technique on the Evidence Investigator. Serum samples were taken after a 2-month period of nonparticipation in boxing.

Main Outcomes And Results: Boxers had higher serum levels of neuron-specific enolase (NSE, median [range] 11 [2.3-41] ng/mL) than controls (4.8 [0.78-27] ng/mL, p = 0.014) but unchanged levels of the other brain damage biomarker candidates, S-100B, brain-derived neurotrophic factor and heart-type fatty acid binding protein.

Conclusions: The more than doubled median serum level of NSE in boxers after an extended resting period suggests that repetitive head trauma results in sustained release of this brain-specific protein to the peripheral circulation.