SERUM S-100 PROTEIN, RELATIONSHIP TO CLINICAL OUTCOME IN ACUTE STROKE

The clinical significance of serum S-100 protein, a protein released b y damaged brain tissue, was assessed in patients with acute ischaemic or haemorrhagic stroke and matched controls. Serum S-100 protein conce ntration was significantly elevated in patients with ischaemic stroke [median (SQR): 0.27 (0.09) mu g/L, n=68] and haemorrhagic stroke [0.43 (0.23) mu g/L, n=13] compared to controls [0.11 (0.03) mu g/L, n=51, P<0.0001]. Although patients with haemorrhagic stroke had higher serum S-100 concentrations compared to patients with ischaemic stroke, this was not quite statistically significant. Serum S-100 concentrations w ere related to infarct size, large (total anterior circulation) infarc ts concentrations having the highest [0.40 (0.22) mu g/L], and small v essel ('lacunar') infarcts concentrations having the lowest [0.20 (0.0 6) mu g/L, P < 0.0005] concentrations. S-100 protein concentration was also significantly related to clinical outcome at three months measur ed using three disability and handicap scales (n=81): modified Barthel index (r(s)=-0.285, P=0.01), modified Rankin score (r(s)=0.313, P=0.0 04) and Lindley score (r(s)=0.262, P=0.018) with high values associate d with poor clinical outcome. Similarly high values of serum S-100 pro tein were observed in patients who died or were discharged to an insti tution [median (SQR): 0.63 (0.29) mu g/L and 0.37 (0.13) mu g/L, respe ctively] compared to those who were discharged home [0.26 (0.11) mu g/ L, P=0.13]. The present study suggests measurement of serum S-100 prot ein could be a useful prognostic marker of clinical outcome in acute s troke. Whether S-100 concentrations can be altered by therapeutic inte rvention in acute stroke remains to be elucidated. Indexing terms: acu te stroke!serum S-100/Barthel index/Rankin seal.