MicroRNA profiles in multiple sclerosis: A review of the literature.

Multiple sclerosis (MS) is an inflammatory demyelinating disorder that affects the central nervous system. Although its exact cause remains unknown, it is known that an autoimmune response, triggered by interactions between genetic predisposition and environmental factors, leads to an attack against the myelin sheath. MicroRNAs (miRNAs), small non-coding regulatory RNAs that modulate post-transcriptional gene expression, may play an important role in MS pathophysiology, affecting immunological pathways such as T-cell differentiation, macrophage activation, and apoptosis regulation. Studies have shown altered miRNA profiles in the blood and cerebrospinal fluid of patients with MS, such as miR-142-3p, miR-146a, miR-155, and miR-326, which correlate with disease activity. Other miRNA profiles have the potential to be used as prognostic markers for the conversion from clinically isolated syndrome to relapsing-remitting MS or for progression severity. Therapeutic studies further indicate that miRNA levels dynamically respond to disease-modifying treatments, suggesting utility in monitoring treatment efficacy. EV-associated miRNAs offer enhanced stability, reflect neuroinflammatory processes across the blood-brain barrier, and may serve as accessible biomarkers for personalized disease monitoring. Despite the promising findings, methodological variability, small sample sizes, and limited replication currently limit clinical translation. This review consolidates current knowledge on dysregulated miRNA expression in MS and underscores the need for standardized, longitudinal research to validate their diagnostic and prognostic potential and to clarify mechanistic roles in disease progression.