Release of glial fibrillary acidic protein and protein S100B are related to the neurovascular status in acute ischaemic stroke

Aims: This study aimed at an analysis of Glial Fibrillary Acidic Protein (GFAP) and Protein S100B in acute ischemic stroke, their association with the neurovascular status and potential value as monitoring parameters.

Methods: In 69 consecutive patients, serial venous blood samples were taken on admission, 6, 12, 18, 24, 48, 72, 96, and 120 hours after stroke onset. The neurovascular status was assessed by repetitive extracranial and transcranial duplex sonography. Neurological deficits were quantified by the NIH stroke scale, and functional outcome was assessed with the modified Rankin Scale.

Results: Mean GFAP values were elevated from admission on with highest levels 48 hours whereas Protein S100B started to increase not until 6 hours after stroke onset. GFAP and Protein S100B release were highly correlated with severity of neurological deficits and infarct volume. In patients with persistent middle cerebral artery occlusion, GFAP increased significantly compared to patients with normal sonographic findings (P=0.019) and recanalisation after thrombolysis resulted in a significant reduced increase (P=0.038). GFAP and Protein S100B concentrations were associated with the functional outcome after 3 months.

Conclusion: Release kinetics of GFAP are associated with patients clinical deficits and infarct volume, depend on the neurovascular status on admission and on early recanalisation after thrombolysis, and may be used as an additional predictor of the early course and functional outcome. In contrast to Protein S100B, GFAP serum concentrations above the cut-off-value within 6 hours in 67% our patients suggest that GFAP could show a better performance as a diagnostic and monitoring parameter at the time of intervention.