MicroRNA cargo of extracellular vesicles as mediators of immune dysregulation in pediatric immune thrombocytopenia: from pathogenetic drivers to biomarkers

Pediatric immune thrombocytopenia (ITP) is an acquired autoimmune disorder, caused by the production of autoantibodies against platelets which leads to thrombocytopenia. It is characterized by profound alterations in both inflammatory and immune profiles. In this context, the role of microRNAs (miRNAs) as post-transcriptional regulators of immunity and the function of extracellular vesicles (EVs) as key mediators of intercellular communication are two fundamental aspects for understanding ITP pathophysiology. In ITP, altered miRNA expression disrupts immune tolerance, lymphocyte subtype differentiation and platelet production. miRNAs are incorporated into EVs and transferred to recipient cells, which confers greater stability to the miRNAs. To date, the interaction between miRNAs and EVs in pediatric ITP has been relatively understudied. In this review, we examine the landscape of dysregulated miRNAs in ITP, focusing in particular on their role in immune dysregulation and on the contribution of EVs as carriers of pathogenic miRNAs. The relationship between EVs and miRNAs could facilitate the development of non-invasive diagnostic tools and EV-based therapeutic strategies designed to reestablish immune homeostasis in pediatric ITP.