title: Glial neuronal ratio: a novel index for differentiating injury type in patients with severe traumatic brain injury.
abstract: Neurobiochemical marker levels in blood after traumatic brain injury (TBI) may reflect structural changes detected by neuroimaging. This study evaluates whether correlations between neuronal (ubiquitin carboxy-terminal hydrolase-L1 [UCH-L1]) and glial (glial fibrillary acidic protein [GFAP]) biomarkers may be used as an indicator for differing intracranial pathologies after brain trauma. In 59 patients with severe TBI (Glasgow Coma Scale [GCS] score≤8) serum samples were obtained at the time of hospital admission and analyzed for UCH-L1 and GFAP. Glial neuronal ratio (GNR) was evaluated as the ratio between GFAP and UCH-L1 concentrations. A logistic regression analysis was used to identify variables associated with type of injury. GNR had a median of 0.85 and was positively correlated with age (R=0.45, p=0.003). Twenty-nine patients presented with diffuse injury and 30 with focal mass lesions as assessed by CT scan at admission and classified according to the Marshall Classification. GNR was significantly higher in the focal mass lesion group compared with the diffuse injury group (1.77 versus 0.48, respectively; p=0.003). Receiver operating characteristic curve analysis showed that GNR discriminated between types of injury (area under the curve [AUC]=0.72; p=0.003). GNR was more accurate earlier (≤12 h after injury) than later (AUC=0.80; p=0.002). Increased GNR was independently associated with type of injury, but not age, gender, GCS score, or mechanism of injury. GNR was significantly higher in patients who died, but was not an independent predictor of death. The data from the present study indicate that GNR provides valuable information about different injury pathways, which may be of diagnostic significance. In addition, GNR may help to identify different pathophysiological mechanisms following different types of brain trauma, with implications for therapeutic interventions.
authors.affiliation: Department of Anesthesiology, University of Florida, Gainesville, Florida 32615, USA. smondello@banyanbio.com
authors.forename: Stefania
authors.initials: S
authors.lastname: Mondello
authors.forename: Andreas
authors.initials: A
authors.lastname: Jeromin
authors.forename: Andras
authors.initials: A
authors.lastname: Buki
authors.forename: Ross
authors.initials: R
authors.lastname: Bullock
authors.forename: Endre
authors.initials: E
authors.lastname: Czeiter
authors.forename: Noemi
authors.initials: N
authors.lastname: Kovacs
authors.forename: Pal
authors.initials: P
authors.lastname: Barzo
authors.forename: Kara
authors.initials: K
authors.lastname: Schmid
authors.forename: Frank
authors.initials: F
authors.lastname: Tortella
authors.forename: Kevin K
authors.initials: KK
authors.lastname: Wang
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Hayes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood*; D001930:Brain Injuries / Q000097:blood* / Q000473:pathology* / Q000503:physiopathology; D002452:Cell Count; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009457:Neuroglia / Q000473:pathology; D009474:Neurons / Q000473:pathology; D012372:ROC Curve; D012680:Sensitivity and Specificity; D043222:Ubiquitin Thiolesterase / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein; C482860:UCHL1 protein, human; D043222:Ubiquitin Thiolesterase