Background: and Purpose Stroke is the second leading cause of death and disability worldwide and its diagnosis, and assessment of prognosis, remains challenging. There is a need for improved diagnostic and prognostic biomarkers. MicroRNAs (miRNAs) play important roles in the post-transcriptional regulation of gene expression and their secretion and remarkable stability in biofluids highlights their potential as sensitive biomarkers in the diagnosis and prognosis of acute stroke. Methods: We carried out a systematic review to assess current evidence supporting the potential of miRNAs to act as unique diagnostic and prognostic biomarkers in blood samples collected from patients suffering acute stroke within 24 hours of symptoms onset. Results: We identified 22 studies eligible for inclusion with 33 dysregulated miRNAs having diagnostic potential in the acute phase of the disease. We identified miR-16, miR-126, and miR-335 as having the highest sensitivity as diagnostic and prognostic biomarkers in acute ischaemic stroke and present original bioinformatic and pathway enrichment analysis of putative miRNA–target interactions. Conclusions miRNAs represent unique biomarkers which have a promising future in stroke diagnosis and prognosis. However, there is a need for more standardized and consistent methodology for the accurate interpretation and translation of miRNAs as novel specific and sensitive biomarkers into clinical practice.

Background: and Purpose Stroke is the second leading cause of death and disability worldwide and its diagnosis, and assessment of prognosis, remains challenging. There is a need for improved diagnostic and prognostic biomarkers. MicroRNAs (miRNAs) play important roles in the post-transcriptional regulation of gene expression and their secretion and remarkable stability in biofluids highlights their potential as sensitive biomarkers in the diagnosis and prognosis of acute stroke. Methods: We carried out a systematic review to assess current evidence supporting the potential of miRNAs to act as unique diagnostic and prognostic biomarkers in blood samples collected from patients suffering acute stroke within 24 hours of symptoms onset. Results: We identified 22 studies eligible for inclusion with 33 dysregulated miRNAs having diagnostic potential in the acute phase of the disease. We identified miR-16, miR-126, and miR-335 as having the highest sensitivity as diagnostic and prognostic biomarkers in acute ischaemic stroke and present original bioinformatic and pathway enrichment analysis of putative miRNA–target interactions. Conclusions miRNAs represent unique biomarkers which have a promising future in stroke diagnosis and prognosis. However, there is a need for more standardized and consistent methodology for the accurate interpretation and translation of miRNAs as novel specific and sensitive biomarkers into clinical practice.