Serum S-100 Protein, Relationship to Clinical Outcome in Acute Stroke

Abstract
The clinical significance of serum S-100 protein, a protein released by damaged brain tissue, was assessed in patients with acute ischaemic or haemorrhagic stroke and matched controls. Serum S-100 protein concentration was significantly elevated in patients with ischaemic stroke [median (SQR): 0·27 (0·09) μg/L, n = 68] and haemorrhagic stroke [0·43 (0·23) μg/L, n = 13] compared to controls [0·11 (0·03) μg/L, n = 51, Ps=–0·285, P = 0·01), modified Rankin score ( rs = 0·313, P = 0·004) and Lindley score ( rs = 0·262, P = 0·018) with high values associated with poor clinical outcome. Similarly high values of serum S-100 protein were observed in patients who died or were discharged to an institution [median (SQR): 0·63 (0·29) μg/L and 0·37 (0·13) μg/L, respectively] compared to those who were discharged home [0·26 (0·11) μg/L, P = 0·13]. The present study suggests measurement of serum S-100 protein could be a useful prognostic marker of clinical outcome in acute stroke. Whether S-100 concentrations can be altered by therapeutic intervention in acute stroke remains to be elucidated. Indexing terms: acute stroke/serum S-100/Barthel index/Rankin scale.