Circulating microRNAs as biomarkers for acute ischemic stroke: a systematic review

Acute ischemic stroke is a leading cause of death and disability worldwide. Unlike myocardial infarction there is no current blood test to diagnose acute ischemic stroke. MicroRNAs are very stable in the blood and have been suggested as potential diagnostic markers. This review aimed to systematically assess case-control studies investigating the association of circulating microRNAs with acute ischemic stroke. Medline, CINAHL, Cochrane Library, Web of Science Scopus, and PubMed were searched for studies that examined the association of circulating microRNAs in acute ischemic stroke patients. Studies meeting specific inclusion and exclusion criteria (such as blood sample were obtained within 24 hours of an acute ischemic stroke) were selected for data extraction. Two authors extracted data from the included studies relevant to study design, patient characteristics, and relative microRNA expression. Eight studies were included involving 572 cases and 431 healthy controls. Twenty-two microRNAs (12 up-regulated and 10 downregulated) were reported as differentially expressed. Only one microRNA, miR-106b, was reported as differentially expressed in at least 2 studies. Significant heterogeneity in the design and methods of the included studies was noted. Differential expression of a large number of microRNAs has been reported early following acute ischemic stroke. More research is required in larger patient populations to further evaluate the diagnostic potential of the reported microRNAs