Blood-based protein biomarkers for stroke differentiation: A systematic review

Computed tomography (CT) scan is the mainstay for diagnosis of stroke; but the facility of CT scan is not easily available. A blood-based biomarker approach is required to distinguish ischemic stroke (IS) from hemorrhagic stroke (HS) in pre-hospital settings. To conduct a systematic review of diagnostic utility of blood biomarkers for differential diagnosis of stroke. A comprehensive literature search was carried out till March 7, 2017 in PubMed, Cochrane, Medline, OVID, and Google Scholar databases. Methodological quality of each study was assessed using the modified Quality Assessment of Diagnostic Accuracy Studies questionnaire. Eighteen studies were identified relevant to our systematic review. Ten single biomarkers and seven panels of different biomarkers were identified which showed potential for differentiating IS and HS. Activated Protein C-Protein C Inhibitor Complex (APC-PCI) (sensitivity-96%), Glial Fibrillary Acidic Protein (GFAP) (specificity-100%) and a panel of APC-PCI & GFAP (sensitivity-71%) and Retinol Binding Protein 4 (RBP4) & GFAP (specificity-100%) were found to have high sensitivity and specificity for differentiating the two stroke types. Our systematic review does not recommend the use of any blood biomarker for clinical purposes yet based on the studies conducted till date.