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 high er serum S-100 concentrations compared to patients with ischaemic stro ke, this was not quite statistically significant. Serum S-100 concentr ations were related to infarct size, large (total anterior circulation ) infarcts concentrations having the highest [0.40 (0.22) mu g/L], and small vessel ('lacunar') infarcts concentrations having the lowest [0 .20 (0.06) mu g/L, P < 0.0005] concentrations. S-100 protein concentra tion was also significantly related to clinical outcome at three month s measured using three disability and handicap scales (n = 81): modifi ed Barthel index (r(s) = -0.285, P = 0.01), modified Rankin score (r(s ) = 0.313, P = 0.004) and Lindley score (r(s) = 0.262, P = 0.018) with high values associated with poor clinical outcome. Similarly high val ues of serum S-100 protein were observed in patients who died or were discharged to an institution [median (SQR): 0.63 (0.29) mu g/L and 0.3 7 (0.13) mu g/L, respectively] compared to those who were discharged h ome [0.26 (0.11) mu g/L, P = 0.13]. The present study suggests measure ment of serum S-100 protein could be a useful prognostic marker of cli nical outcome in acute stroke. Whether S-100 concentrations can be alt ered by therapeutic intervention in acute stroke remains to be elucida ted. Indexing terms: acute stroke/serum S-100/Barthel index/Rankin sca le.