S100B as a surrogate marker for successful clot lysis in hyperacute middle cerebral artery occlusion

Objectives: The astroglial protein S100B is a marker of cerebral tissue damage. This study investigated whether the serum kinetic of S100B may serve as a surrogate marker of successful clot lysis and early recanalisation (<6 hours) in hyperacute proximal middle cerebral artery (MCA/M1) occlusion. Methods: The authors prospectively included 23 patients (mean (SD) age, 70.2 (11.0) years) presenting with MCA/M1 occlusion on magnetic resonance angiography (n=18), intra-arterial angiography (IA; n=2), or transcranial Doppler sonography (TCD, n=3) within five hours after symptom onset. Rates of recanalisation and their point of time were determined using TCD or IA. Individual S 10013 values were determined at hospital admission, every eight hours within the first three days, and at 12 hour intervals from day 4 to day 6. Additionally, the S100B area under the curve (AUC) and the S 10013 peak value were obtained. Results: Early recanalisation (<6 hours after symptom onset, n=7) was associated with a significantly lower mean S100B AUC compared with no recanalisation (22.2 (40.1) versus 406.8 (284.4) mug/l per hour; p<0.001). Using receiver operating calculations, a single S100B value obtained 48-96 hours after stroke onset of less than 0.4 mug/l (cut off point) provided a 86% sensitivity and 100% specificty for sufficient MCA/M1 clot lysis <6 hours. The overall accuracy for a single S100B value obtained in the 48-96 hours time window was as high as for the AUC (95.7%). Conclusion: A single S 10013 value <0.4 mug/l obtained 48-96 hours after stroke onset indicates succesful clot lysis <6 hours in MCA/M1 occlusion with a high degree of accuracy. Thus, determination of a single S100B value may serve as a surrogate marker of early and sufficient MCA/M1 recanalisation in large scale thrombolytic studies.