The measure of 2 plasma biomarkers — total tau protein and glial fibrillary acidic protein (GFAP) — may be a useful guide in determining whether college athletes can return to play after sustaining a concussion, according to the results of study published in JAMA Network Open.

Athletes who sustain a sports-related concussion (SRC) need to be monitored carefully before return to sports (RTS) in order to prevent a second concussion and long-term neurologic consequences. Monitoring the 2 biomarkers can help to determine which players will require more time before return to sports, noted the study authors.

The study, which was conducted by the National Collegiate Athletics Association (NCAA)–Department of Defense Concussion Assessment, Research, and Education Consortium, identified 308 participants who had sustained a SRC at some point between February 2015 and May 2018. A total of 127 participants with a confirmed SRC with both RTS information and a blood sample provided at postinjury were included in the study. All athletes completed clinical testing and blood collection at preseason (baseline), 0 to 21 hours postinjury, 24 to 48 hours postinjury, time of symptom resolution, and 7 days following unrestricted RTS.

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Participants in the study were aged 17 to 23 years; most were men (76.4%) and White individuals (64.6%). A total of 65 participants (51.1%) had RTS less than 14 days and 62 (48.8%) had RTS of 14 days or more. Approximately half of the athletes had no prior concussions (55.9%).

A total of 3 plasma biomarkers — total tau protein, GFAP, and neurofilament light chain protein (Nf-L) — were measured and included in the final analysis. These biomarkers were compared in athletes who were able to RTS in less than 14 days with those who took more than 14 days to RTS. Linear mixed models identified significant associations for both mean plasma total tau (24-48 hours postinjury, <14 days RTS vs ≥14 days RTS: -0.65 pg/mL vs -0.14 pg/mL) and GFAP postinjury (postinjury, 14 days RTS vs ≥14 days RTS: 4.72 pg/mL vs 4.39 pg/mL).

The researchers also examined how well a combined biomarker panel (Nf-L, GFAP, and total tau) differed between athletes with 14 days or more before RTS vs those with less than 14 days before RTS. At postinjury, no single biomarker significantly discriminated between the groups when examined individually. When biomarkers were combined, they reached significance, but were poor at distinguishing the groups.

Limitations of the study include the relatively small number of athletes who sustained an SRC with complete information on RTS date and blood biomarkers; therefore, the findings may not be generalized to the wider collegiate community.

“Although preliminary, the current results highlight the potential role of biomarkers in tracking neuronal recovery, which may be associated with duration of RTS,” concluded the authors. “Continued longitudinal tracking of this cohort is underway.”

Disclosure: This article was made possible with support from the Grand Alliance Concussion Assessment, Research, and Education (CARE) Consortium, funded, in part by the NCAA and the Department of Defense. A full list of the authors’ financial disclosures can be found in the article.


Pattinson CL, Meier TB, Guedes VA, et al. Plasma biomarker concentrations associated with return to sport following sports-related concussion in collegiate athletes — a Concussion Assessment, Research, and Education (CARE) Consortium study. JAMA Netw Open. 2020;3(8):e2013191.