title: Glial Fibrillary Acidic Protein and Ubiquitin C-Terminal Hydrolase-L1 Are Not Specific Biomarkers for Mild CT-Negative Traumatic Brain Injury.
abstract: Glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1) have been studied as potential biomarkers of mild traumatic brain injury (mTBI). We report the levels of GFAP and UCH-L1 in patients with acute orthopedic injuries without central nervous system involvement, and relate them to the type of extracranial injury, head magnetic resonance imaging (MRI) findings, and levels of GFAP and UCH-L1 in patients with CT-negative mTBI. Serum UCH-L1 and GFAP were longitudinally measured from 73 patients with acute orthopedic injury on arrival and on days 1, 2, 3, 7 after admission, and on the follow-up visit 3-10 months after the injury. The injury types were recorded, and 71% patients underwent also head MRI. The results were compared with those found in patients with CT-negative mTBI (n= 93). The levels of GFAP were higher in patients with acute orthopedic trauma than in patients with CT-negative mTBI (p= 0.026) on arrival; however, no differences were found on the following days. The levels of UCH-L1 were not significantly different between these two groups at any measured point of time. Levels of GFAP and UCH-L1 were not able to distinguish patients with CT-negative mTBI from patients with orthopedic trauma. Patients with orthopedic trauma and high levels of UCH-L1 or GFAP values may be falsely diagnosed as having a concomitant mTBI, predisposing them to unwarranted diagnostics and unnecessary brain imaging. This casts a significant doubt on the diagnostic value of GFAP and UCH-L1 in cases with mTBI.
authors.affiliation: Division of Clinical Neurosciences, Department of Neurosurgery, Turku University Hospital, Turku, Finland.|Division of Clinical Neurosciences, Department of Rehabilitation and Brain Trauma, Turku University Hospital, Turku, Finland.|Department of Neurology, University of Turku, Turku, Finland.
authors.forename: Jussi P
authors.initials: JP
authors.lastname: Posti
authors.affiliation: Department of Neurology, University of Turku, Turku, Finland.
authors.forename: Iftakher
authors.initials: I
authors.lastname: Hossain
authors.affiliation: Perioperative Services, Intensive Care Medicine and Pain Management, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Riikka S K
authors.initials: RSK
authors.lastname: Takala
authors.affiliation: Systems Medicine, VTT Technical Research Centre of Finland Ltd, Tampere, Finland.
authors.forename: Hilkka
authors.initials: H
authors.lastname: Liedes
authors.affiliation: Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors.forename: Virginia
authors.initials: V
authors.lastname: Newcombe
authors.affiliation: Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors.forename: Joanne
authors.initials: J
authors.lastname: Outtrim
authors.affiliation: Perioperative Services, Intensive Care Medicine and Pain Management, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Ari J
authors.initials: AJ
authors.lastname: Katila
authors.affiliation: Division of Clinical Neurosciences, Department of Neurosurgery, Turku University Hospital, Turku, Finland.|Division of Clinical Neurosciences, Department of Rehabilitation and Brain Trauma, Turku University Hospital, Turku, Finland.
authors.forename: Janek
authors.initials: J
authors.lastname: Frantzén
authors.affiliation: Department of Neurology, University of Turku, Turku, Finland.
authors.forename: Henna
authors.initials: H
authors.lastname: Ala-Seppälä
authors.affiliation: Department of Clinical Neurosciences, Neurosurgery Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Coles
authors.affiliation: Department of Neurology, University of Turku, Turku, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Kyllönen
authors.affiliation: Department of Neurology, University of Turku, Turku, Finland.
authors.forename: Henna-Riikka
authors.initials: HR
authors.lastname: Maanpää
authors.affiliation: Department of Neurology, University of Turku, Turku, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Tallus
authors.affiliation: Department of Clinical Neurosciences, Neurosurgery Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hutchinson
authors.affiliation: Systems Medicine, VTT Technical Research Centre of Finland Ltd, Tampere, Finland.
authors.forename: Mark
authors.initials: M
authors.lastname: van Gils
authors.affiliation: Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors.forename: David K
authors.initials: DK
authors.lastname: Menon
authors.affiliation: Division of Clinical Neurosciences, Department of Rehabilitation and Brain Trauma, Turku University Hospital, Turku, Finland.|Department of Neurology, University of Turku, Turku, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Tenovuo
keywords: GFAP; TBI; UCH-L1; biomarker; orthopedic injury