Background: As has been shown previously, S-100beta levels in serum can be a useful predictor of brain damage after head trauma. This pilot study was designed to investigate whether urine samples, which are much easier to obtain, could be used for the same purpose instead of serum samples.
Methods: Ninety-six consecutive patients admitted with head trauma were recruited in the study. After exclusion of 54 patients, mostly because of significant additional trauma, S-100beta levels were analyzed in serum and urine of 42 patients using a luminometric assay. A range for normal values was established based on samples from ten healthy volunteers.
Results: S-100beta serum levels increased proportional to the severity of the head trauma, as had been previously shown by several other groups. In many patients, initial increases in urine S-100beta levels were seen later than in serum, after which the kinetics of S-100beta levels in urine seemed to follow that established for serum levels. S-100beta values in urine were on average about 54% lower in urine than in serum.
Conclusions: S-100beta levels in urine obtained on admission to the hospital are not a good indicator for the extent of brain damage. However, urine S-100beta levels obtained at later time points might be a useful indicator for the development of secondary brain injury.