Blood biomarkers for brain injury in concussed professional ice hockey players

Pashtun Shahim1,*, Gisela Malmgård2, David H Wilson3, Jeffrey Randall3, Birgitta Kallberg4, Yelverton Tegner5, Kaj Blennow6, Henrik Zetterberg6

1Neurochemistry, 2Clinical Chemistry Laboratory, Sahlgrenska University Hospital/ Mölndal, Mölndal, Sweden, 3Quanterix Corporation, Lexington, MA, United States, 4Clinical Chemistry Laboratory, Mölndal, 5Department of Health Sciences, Luleå University of Technology, Luleå, 6Neuroscience and Physiology, Mölndal, Sweden

Introduction: Lack of objective measures hamper acute diagnosis and clinical decision-making about return to play after sports-related concussion.

Objectives: To determine whether sports-related concussion is associated with elevated levels of blood biochemical markers of injury to the central nervous system, and to assess whether plasma levels of these biomarkers predict return to play in professional ice hockey players suffering from sports-related concussion.

Methods: A multi-centre study involving all 12 teams of the top professional ice hockey league in Sweden, the Swedish Hockey League (SHL). Two hundred eighty-eight professional ice hockey players from 12 teams contesting during the season of 2012/2013 consented to participate. All players underwent clinical pre-season baseline testing regarding concussion assessment measures. Forty-seven players from two of the 12 ice hockey teams underwent blood sampling prior to the start of the season. Thirty-five players suffered concussion from September 2012 to January 2013 and of these 28 underwent repeated blood samplings at 1, 12, 36, 144 h, and when the players returned to play.

Results: Players with sports-related concussion had increased levels of the axonal injury biomarker T-tau (median, range, 10.0 pg/mL [2.0-102]) compared to preseason values (4.5 pg/mL [0.06-22.7]; P < 0.0006). The levels of the astroglial injury biomarker S-100B were also increased in players with sports-related concussion (median, range, 0.075 pg/mL [0.037-0.24]) compared to preseason values (0.045 pg/mL [0.005-0.45]; P < 0.0001). The highest biomarker concentrations of T-tau and S-100B were measured immediately after a concussion and decreased during rehabilitation. No significant changes were measured in the levels of NSE.

Conclusion: Sports-related concussion in professional ice hockey players is associated with acute axonal and astroglial injury. Plasma T-tau, which is a highly CNS-specific protein, is a promising biomarker to be used both in diagnosis and prognosis of concussion

Keywords: Biomarker, Brain