Soluble ST2 predicts outcome and hemorrhagic transformation after acute stroke

OBJECTIVE ST2 is a member of the toll-like receptor superfamily that can alter inflammatory signaling of helper T-cells. We investigated whether soluble ST2 (sST2) could independently predict outcome and hemorrhagic transformation (HT) in the setting of stroke. METHODS We measured sST2 in patients enrolled in the Specialized Program of Translational Research in Acute Stroke (SPOTRIAS) network biomarker study. 646 patients had plasma samples collected at the time of hospital admission and 210 patients had a second sample collected 48 h after stroke onset. Functional outcome was assessed using the modified Rankin Scale (mRS), with good and poor outcomes defined as mRS 0-2 and 3-6, respectively. HT was classified using ECASS criteria. The relationships between sST2, outcome, and HT were evaluated using multivariable logistic regression, Kaplan-Meier survival analysis and receiver operating characteristic curves. RESULTS 646 patients were included in the analysis (mean age 69 years; 44% women), with a median NIHSS of 5 [IQR: 2-12]. The median sST2 level on hospital admission was 35.0 ng/mL [IQR: 25.7-49.8 ng/mL] and at 48 h it was 37.4 ng/mL [IQR 27.9-55.6 ng/mL]. sST2 was independently associated with poor outcome (OR: 2.77, 95% CI: 1.54-5.06; P = 0.003) and mortality (OR: 3.56, 95% CI: 1.58-8.38, P = 0.001) after multivariable adjustment. Plasma sST2 was also associated with hemorrhagic transformation after adjustment for traditional risk factors (OR: 5.58, 95% CI: 1.40-37.44, P = 0.039). INTERPRETATION Soluble ST2 may serve as a prognostic biomarker for outcome and hemorrhagic transformation in patients with acute stroke. ST2 may link neuroinflammation and secondary injury after stroke.