title: Prognostic value of serum s100 protein by elecsys s100 immunoassay in patients with spontaneous subarachnoid and intracerebral hemorrhages.
abstract: OBJECTIVE
  The serum S100 protein has been known to reflect the severity of neuronal damage. The purpose of this study was to assess the prognostic value of the serum S100 protein by Elecsys S100 immunoassay in patients with subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH) and to establish reference value for this new method.
  
  
  METHODS
  Serum S100 protein value was measured at admission, day 3 and 7 after bleeding in 42 consecutive patients (SAH : 20, ICH : 22) and 74 healthy controls, prospectively. Admission Glasgow coma scale (GCS) score, Hunt & Hess grade and Fisher grade for SAH, presence of intraventricular hemorrhage, ICH volume, and outcome at discharge were evaluated. Degrees of serum S100 elevation and their effect on outcomes were compared between two groups.
  
  
  RESULTS
  Median S100 levels in SAH and ICH groups were elevated at admission (0.092 versus 0.283 microg/L) and at day 3 (0.110 versus 0.099 microg/L) compared to healthy controls (0.05 microg/L; p<0001). At day 7, however, these levels were normalized in both groups. Time course of S100 level in SAH patient was relatively steady at least during the first 3 days, whereas in ICH patient it showed abrupt S100 surge on admission and then decreased rapidly during the next 7 days, suggesting severe brain damage at the time of bleeding. In ICH patient, S100 level on admission correlated well with GCS score (r=-0.859; p=0.0001) and ICH volume (r=0.663; p=0.001). A baseline S100 level more than 0.199 microg/L predicted poor outcome with 92% sensitivity and 90% specificity. Logistic regression analyses showed Ln (S100) on admission as the only independent predictor of poor outcome (odd ratio 36.1; 95% CI, 1.98 to 656.3).
  
  
  CONCLUSIONS
  Brain damage in ICH patient seems to develop immediately after bleeding, whereas in SAH patients it seems to be sustained for few days. Degree of brain damage is more severe in ICH compared to SAH group based on the S100 level. S100 level is considered an independent predictor of poor outcome in patient with spontaneous ICH, but not in SAH. Further study with large population is required to confirm this result.
authors.affiliation: Department of Neurosurgery, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
authors.forename: Seok-Mann
authors.initials: SM
authors.lastname: Yoon
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Choi
authors.forename: Hwi-Jun
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jai-Joon
authors.initials: JJ
authors.lastname: Shim
authors.forename: Hack-Gun
authors.initials: HG
authors.lastname: Bae
authors.forename: Il-Gyu
authors.initials: IG
authors.lastname: Yun