title: Repetitive head impact exposure and later-life plasma total tau in former National Football League players.
abstract: BACKGROUND
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Alosco
authors.affiliation: Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.
authors.forename: Yorghos
authors.initials: Y
authors.lastname: Tripodis
authors.affiliation: Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Johnny
authors.initials: J
authors.lastname: Jarnagin
authors.affiliation: Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Interfaculty Initiative in Health Policy, Harvard University Boston, MA, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Baugh
authors.affiliation: Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA; Data Coordinating Center, Boston University School of Public Health, Boston, MA, USA.
authors.forename: Brett
authors.initials: B
authors.lastname: Martin
authors.affiliation: Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA; Data Coordinating Center, Boston University School of Public Health, Boston, MA, USA.
authors.forename: Christine E
authors.initials: CE
authors.lastname: Chaisson
authors.affiliation: Quanterix Corporation, Lexington, MA, USA.
authors.forename: Nate
authors.initials: N
authors.lastname: Estochen
authors.affiliation: Quanterix Corporation, Lexington, MA, USA.
authors.forename: Linan
authors.initials: L
authors.lastname: Song
authors.affiliation: Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Department of Neurosurgery, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Cantu
authors.affiliation: Quanterix Corporation, Lexington, MA, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jeromin
authors.affiliation: Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Department of Neurosurgery, Boston University School of Medicine, Boston, MA, USA; Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Stern
keywords: American football; Chronic traumatic encephalopathy; Head trauma; Plasma; Repetitive head impacts; Tau; Total tau