Discordant temporal patterns of S100β and cleaved tau protein elevation after head injury:: a pilot study

There is considerable interest in S100(beta) protein as a potential marker that can be used to quantify central nervous system injury.(1,2) However, increasing appreciation that S100(beta) may be produced by non-neural tissue (specifically adipocytes), has led to a search for more specific markers of brain injury. Recent interests have focused on a cleaved form of tau protein (c(tau)P) which is elevated in CSF from patients suffering traumatic brain injury.(3) We have investigated whether levels in peripheral blood are a satisfactory alternative to provide an accessible marker of CNS injury severity. We measured levels of S100(beta) and c(tau)P in arterial blood from 20 patients with severe head injury. When compared with normal values S100(beta) was elevated 10-fold in the first 24 hours and c(tau)P was elevated at all time points, but showed a reversal of the temporal trend observed with S100(beta). Patients with a poor outcome (GOS 1-3) had significantly higher S100(beta) levels on day one. Plasma c(tau)P levels did not correlate with outcome following head injury.