Comparative Assessment of the Prognostic Value of Biomarkers in Traumatic Brain Injury Reveals an Independent Role for Serum Levels of Neurofilament Light

PLoS One. 2015 Jul 2;10(7):e0132177. doi: 10.1371/journal.pone.0132177. eCollection 2015.

Abstract

Traumatic brain injury (TBI) is a common cause of death and disability, worldwide. Early determination of injury severity is essential to improve care. Neurofilament light (NF-L) has been introduced as a marker of neuroaxonal injury in neuroinflammatory/-degenerative diseases. In this study we determined the predictive power of serum (s-) and cerebrospinal fluid (CSF-) NF-L levels towards outcome, and explored their potential correlation to diffuse axonal injury (DAI). A total of 182 patients suffering from TBI admitted to the neurointensive care unit at a level 1 trauma center were included. S-NF-L levels were acquired, together with S100B and neuron-specific enolase (NSE). CSF-NF-L was measured in a subcohort (n = 84) with ventriculostomies. Clinical and neuro-radiological parameters, including computerized tomography (CT) and magnetic resonance imaging, were included in the analyses. Outcome was assessed 6 to 12 months after injury using the Glasgow Outcome Score (1-5). In univariate proportional odds analyses mean s-NF-L, -S100B and -NSE levels presented a pseudo-R2 Nagelkerke of 0.062, 0.214 and 0.074 in correlation to outcome, respectively. In a multivariate analysis, in addition to a model including core parameters (pseudo-R2 0.33 towards outcome; Age, Glasgow Coma Scale, pupil response, Stockholm CT score, abbreviated injury severity score, S100B), S-NF-L yielded an extra 0.023 pseudo-R2 and a significantly better model (p = 0.006) No correlation between DAI or CT assessed-intracranial damage and NF-L was found. Our study thus demonstrates that S-NF-L correlates to TBI outcome, even if used in models with S100B, indicating an independent contribution to the prediction, perhaps by reflecting different pathophysiological processes, not possible to monitor using conventional neuroradiology. Although we did not find a predictive value of NF-L for DAI, this cannot be completely excluded. We suggest further studies, with volume quantification of axonal injury, and a prolonged sampling time, in order to better determine the connection between NF-L and DAI.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Axons / pathology
  • Brain Damage, Chronic / epidemiology
  • Brain Damage, Chronic / etiology
  • Brain Injuries / blood*
  • Brain Injuries / cerebrospinal fluid*
  • Brain Injuries / complications
  • Brain Injuries / diagnostic imaging
  • Brain Injuries / mortality
  • Cerebrospinal Fluid Proteins / analysis*
  • Female
  • Follow-Up Studies
  • Glasgow Coma Scale
  • Glasgow Outcome Scale
  • Humans
  • Male
  • Middle Aged
  • Neurofilament Proteins / blood*
  • Neurofilament Proteins / cerebrospinal fluid*
  • Phosphopyruvate Hydratase / blood
  • Prognosis
  • Reflex, Pupillary
  • Retrospective Studies
  • S100 Calcium Binding Protein beta Subunit / blood
  • Tomography, X-Ray Computed
  • Trauma Severity Indices

Substances

  • Cerebrospinal Fluid Proteins
  • Neurofilament Proteins
  • S100 Calcium Binding Protein beta Subunit
  • S100B protein, human
  • neurofilament protein L
  • Phosphopyruvate Hydratase

Grant support

The authors have no support or funding to report.