Blood biomarkers of ischemic stroke

Abstract

This review provides a summary of the protein and RNA biomarkers that have been studied for the diagnosis and assessment of ischemic stroke. Many of the biomarkers identified relate to the pathophysiology of ischemic stroke, including ischemia of CNS tissue, acute thrombosis and inflammatory response. These biomarkers are summarized by their intended clinical application in ischemic stroke including diagnosis, prediction of stroke severity and outcome, and stratification of patients for stroke therapy. Among the biomarkers discussed are recent whole genome studies using RNA expression profiles to diagnose ischemic stroke and stroke etiology. Though many candidate blood based biomarkers for ischemic stroke have been identified, none are currently used in clinical practice. With further well designed study and careful validation, the development of blood biomarkers to improve the care of patients with ischemic stroke may be achieved.

Fig. 1

Gene expression profiles to distinguish ischemic stroke from controls at <3, 5 and 24 hours after stroke onset. Hierarchical cluster plot of the 1355 genes found to be differentially expressed between ischemic stroke and controls (FDR0.05, fold change >  |1.2|). Genes are shown on the Y-axis, and patients are shown on the X-axis. Genes that have a high level of expression are shown in red, and genes with a low level of expression are shown in green. From the larger list of 1355 genes, a list of 18 genes (29 probesets) were identified that optimally discriminate between ischemic stroke and controls. This 18 gene panel could distinguish ischemic stroke from control with 89% sensitivity and 100% specificity. This 18 gene profile has subsequently been studied in a larger set of stroke patients and demonstrated similar sensitivity and specificity (Table 2). This figure is adapted from Tang Y et al. Annals of Neurology, 2006, pages 1089–1102 [27]