Role of microRNA-9-5p as a diagnostic biomarker of acute stroke

Stroke is the second leading cause of death worldwide. MicroRNA-9-5p has been reported to be upregulated in ischemic stroke; however, no previous study has explored its expression in hemorrhagic stroke. The objective of this study was to investigate microRNA-9-5p as a biomarker to differentiate between ischemic and hemorrhagic stroke. This was a case–control study. It was found that microRNA-9-5p was upregulated in both ischemic stroke (IS) and hemorrhagic stroke (HS) compared to controls ( p < 0.0001). However, no significant difference was observed between the IS and HS groups ( p > 0.9999). Moreover, microRNA-9-5p could distinguish IS and HS from controls with AUC = 0.9225 and AUC = 0.9245, respectively. However, it could not differentiate IS from HS (AUC = 0.592). There was also no significant correlation between microRNA-9-5p expression fold and either IL-6 or CRP. In conclusion, microRNA-9-5p was upregulated in both IS and HS and may serve as a biomarker to distinguish stroke patients from controls, but it cannot differentiate between stroke types.