medwireNews: Serum S-100β protein concentrations are significantly associated with unfavorable prognosis after moderate or severe traumatic brain injury, a study finds.
The finding shows the potential for measurements of S-100β protein (a subunit of a calcium binding protein) to gauge the severity of traumatic brain injury and determine long-term prognosis, say the researchers in BMJ.
"This meta-analysis identified a significant association between S-100β protein serum concentrations and short (less than three months), mid (three to six months) or long term (six months and above) prognosis in patients with moderate to severe traumatic brain injury," explain Alexis Turgeon (Laval University, Quebec City, Canada) and colleagues.
Turgeon and team conducted a systematic review and meta-analysis of randomized control trials (RCTs) and observational studies of patients with moderate to severe traumatic brain injury.
The literature search yielded 9228 citations that consisted of two RCTs and 39 cohort studies, which together involved 1862 patients with at least one measurement of S-100β protein within 24 hours after traumatic brain injury.
A higher serum S-100β protein concentration than controls was significantly associated with an increased likelihood of mortality, a Glasgow outcome score less than or equal to 3 (indicating unfavorable outcome), as well as brain stem death.
Serum S-100β protein values of 1.38 to 10.50 µg/L predicted mortality with 100% specificity, and a sensitivity of 14 to 60%.
With regard to unfavorable neurologic prognosis based on a Glasgow outcome score, the threshold values for 100% specificity raged from a serum S-100β protein concentration of 2.16 to 14.0 µg/L.
"The measure of S-100β protein concentrations could potentially play a role as part of a decision aid in the prognostic evaluation of patients with traumatic brain injury as well as to potentially rule out important traumatic brain injury," write the authors.
"As part of a decision aid, the S-100β protein concentration could serve to… avoid exposing patients to unnecessary radiation from imaging, allow better triage and use of resources, and thus be a potentially cost effective measure."
Turgeon et al note that the optimal parameters for S-100β protein concentration as a prognostic evaluation tool are yet to be determined, such as optimal biochemical methods, timing of sampling, and prognostic threshold.
"Further research is needed to explore combination of variables known to be associated with clinical outcomes of traumatic brain injuries to develop a prognostic model with a high discriminative capacity," they conclude.
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