Objective To investigate whether sports-related concussion is associated with elevated blood biomarkers reflecting axonal injury (total-tau [T-tau], [tau-A] and [tau-C]) and astroglial injury (S100B), as well as neurons-specific enolase (NSE).

Design and setting A multicenter prospective cohort study involving all 12 teams of the top professional ice hockey league in Sweden.

Participants A total of 288 players consented to participate in the study. Thirty-five players sustained concussions, of whom 28 underwent repeated blood samplings at 1, 12, 36, and 144 hours after the trauma, or when the player returned to play (7->90 days).

Outcome measures Concentrations of T-tau was, tau-A, tau-C, S100B and NSE in blood.

Results Players with sports-related concussion had increased levels of the axonal injury biomarker T-tau compared to preseason values. The highest biomarker concentrations of T-tau were measured immediately after a concussion and decreased during rehabilitation. There was no significant increase in the levels of tau-A in post-concussion samples compared with preseason values. However, serum levels of tau-C were significantly higher in post-concussion samples compared with preseason. The levels of the astroglial injury biomarker S100B were also increased in players with sports-related concussion compared to preseason values. No significant changes were measured in the levels of NSE.

Conclusions Sports-related concussion in professional ice hockey players is associated with acute axonal and injury. Plasma T-tau may be used both in the diagnosis and clinical decision-making when an athlete is declared fit to return to play.

Competing interests None.