Role of Blood Biomarkers in Differentiating Ischemic Stroke and Intracerebral Hemorrhage

Background and Purpose: Although imaging is the mainstay to differentiate ischemic stroke (IS) from intracerebral hemorrhage (ICH), these facilities are not available everywhere. The present study observed if any blood biomarker(s) could potentially help differentiate between ischemic stroke and intracerebral hemorrhage. Methods: 250 patients with acute stroke within 24 hours of onset (187 IS and 63 patients with ICH) were recruited in the present study. The blood samples were collected closest to the hospital presentation time, but within 24 hours of stroke onset. Blood was analyzed for five biomarkers [S100, glial fibrillary acidic protein (GFAP), N-methyl-D-aspartate receptor subunit antibody (NR2), interleukin 6 (IL6) and brain natriuretic peptide (BNP)] to assess discriminatory ability of each biomarker to differentiate ICH and IS. Results: S100 levels were statistically higher among patients with ICH compared with IS (8 pg/ml versus 4.2 pg/ml respectively, P = 0.003) and IL6 was higher in patients with IS compared with ICH (12.9 pg/ml vs 8.76 pg/ml, P = 0.02). The discriminatory ability to differentiate ICH from IS was better using a combination of the above two biomarkers. The overall discriminatory ability of all biomarkers were low (Area under curve for S100 65%; GFAP 56%; NR2 53%; IL6 59% and BNP 49.8%). Although the positive predictive value of each biomarker was low, the negative predictive value was higher for all biomarkers to diagnose ICH. Conclusions: S100 and IL6 are potential biomarkers for further study and validation. Newer biomarkers with higher discriminatory ability are required in the future for diagnostic use.