Research Reports - Predictive value of S-100β protein for prognosis in patients with moderate and severe traumatic brain injury
BMJ. 2013 Apr 4;346
Mercier E, Boutin A, Lauzier F, Fergusson DA, Simard JF, arychanski R, Moore L, McIntyre LA, Archambault P, Lamontagne F, Légaré F, Randell E, Nadeau L, Rousseau F, Turgeon AF
OBJECTIVES: To determine the ability and accuracy of the S-100β protein in
predicting prognosis after a moderate or severe traumatic brain injury.
DESIGN: Systematic review and meta-analysis of randomised controlled trials and
DATA SOURCES: Medline, Embase, Cochrane Central Register of Controlled Trials,
BIOSIS (from their inception to April 2012), conference abstracts, bibliographies
of eligible articles, and relevant narrative reviews.
STUDY SELECTION: Two reviewers independently reviewed citations and selected
eligible studies, defined as cohort studies or randomised control trials
including patients with moderate or severe traumatic brain injury and evaluating
the prognostic value of S-100β protein. Outcomes evaluated were mortality, score
on the Glasgow outcome scale, or brain death.
DATA EXTRACTION: Two independent reviewers extracted data using a standardised
form and evaluated the methodological quality of included studies. Pooled results
were presented with geometric means ratios and analysed with random effect
models. Prespecified sensitivity analyses were performed to explain
RESULTS: The search strategy yielded 9228 citations. Two randomised controlled
trials and 39 cohort studies were considered eligible (1862 patients). Most
studies (n=23) considered Glasgow outcome score ≤3 as an unfavourable outcome.
All studies reported at least one measurement of S-100β within 24 hours after
traumatic brain injury. There was a significant positive association between
S-100β protein concentrations and mortality (12 studies: geometric mean ratio
2.55, 95% confidence interval 2.02 to 3.21, I(2)=56%) and score ≤3 (18 studies:
2.62, 2.01 to 3.42, I(2)=79%). Sensitivity analysis based on sampling time,
sampling type, blinding of outcome assessors, and timing of outcome assessment
yielded similar results. Thresholds for serum S-100β protein values with 100%
specificity ranged from 1.38 to 10.50 µg/L for mortality (six studies) and from
2.16 to 14.00 µg/L for unfavourable neurological prognosis as defined by the
Glasgow outcome score.
CONCLUSIONS: After moderate or severe traumatic brain injury, serum S-100β
protein concentrations are significantly associated with unfavourable prognosis
in the short, mid, or long term. Optimal thresholds for discrimination remain
unclear. Measuring the S-100β protein could be useful in evaluating the severity
of traumatic brain injury and in the determination of long term prognosis in
patients with moderate and severe injury.