Concussion Biomarkers Are Still Unreliable

Healthy college athletes express concussion-related serum biomarkers in variable concentrations, a recent study found. In turn, the researchers deemed the measured serum biomarkers as unreliable.

To reach this conclusion, the researchers measured 7 serum concentrations in 415 participants. The participants were college athletes who had not had a concussion and who had not had recent impacts to the head.

The researchers also analyzed the results in relation to the participants’ sex and race, which they say was essential.


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In all, 61% of the participants were male and 40% were white.

Men were found to have exhibited higher levels of ubiquitin carboxy-terminal hydrolyzing enzyme L1 (UCH-L1) and S100 calcium binding protein B (S100B) than women, while women had higher levels of 2′,3′-cyclic-nucleotide 3′-phosphodiesterase (CNPase).

At baseline, participants who were black had higher levels of UCH-L1 and S100B than white participants, while white participants had higher levels of β-amyloid peptide 42 (42) and CNPase.

The researchers also evaluated test-retest reliability and reliable change indices among 31 of the women participants, reporting for Aβ42, total τ, S100B, and UCH-L1 over a 6- to 12-month interval.

Test-retest reliability was generally poor, ranging from −0.02 to 0.40. Aβ42 significantly increased from time 1 to time 2.

“Evidence suggested poor reliability for serum biomarkers,” the researchers concluded. “However, understanding how other factors influence biomarker expression, as well as knowledge of reliable change metrics, may improve clinical interpretation and future study designs.”

—Colleen Murphy



Asken BM, Bauer RM, DeKosky ST, et al. Concussion biomarkers assessed in collegiate student-athletes (BASICS) I: normative study. Neurology. 2018;91(23):2109-2122.