Alosco, Michael L.Tripodis, YorghosJarnagin, JohnnyBaugh, ChristineMartin, BrettChaisson, Christine E.Estochen, NateSong, LinanCantu, Robert C.Jeromin, AndreasStern, Robert A.2017-03-282016Alosco, M. L., Y. Tripodis, J. Jarnagin, C. M. Baugh, B. Martin, C. E. Chaisson, N. Estochen, et al. 2016. “Repetitive head impact exposure and later-life plasma total tau in former National Football League players.” Alzheimer's & Dementia : Diagnosis, Assessment & Disease Monitoring 7 (1): 33-40. doi:10.1016/j.dadm.2016.11.003. http://dx.doi.org/10.1016/j.dadm.2016.11.003.http://nrs.harvard.edu/urn-3:HUL.InstRepos:31731825Introduction: Blood protein analysis of total tau (t-tau) may be a practical screening biomarker for chronic traumatic encephalopathy (CTE), a neurodegenerative tauopathy associated with repetitive head impact (RHI) exposure. We examined plasma t-tau in symptomatic former National Football League (NFL) players compared with controls and the relationship between RHI exposure and later-life plasma t-tau. Methods: Ninety-six former NFL players (age 40–69) and 25 same-age controls underwent blood draw to determine plasma t-tau levels. The cumulative head impact index (CHII) quantified RHI exposure. Subjects completed measures of clinical function. Results: A higher CHII predicted greater plasma t-tau in the former NFL players (P = .0137). No group differences in plasma t-tau emerged, but a concentration ≥3.56 pg/mL was 100% specific to former NFL players. Plasma t-tau did not predict clinical function. Discussion Greater RHI exposure predicted higher later-life plasma t-tau concentrations, and further study on plasma t-tau as a candidate screening biomarker for CTE is warranted.en-USAmerican footballChronic traumatic encephalopathyRepetitive head impactsTauTotal tauPlasmaHead traumaJournal Article2017-03-2810.1016/j.dadm.2016.11.003