Decoding Immune Dysregulation in Sepsis Through Extracellular Vesicles: A Path to Precision Medicine

Sepsis remains a leading cause of mortality worldwide and is increasingly recognized as a syndrome of dynamic immune dysregulation rather than a uniform inflammatory condition. The traditional paradigm of sequential hyperinflammation followed by immunosuppression has been replaced by a more complex view in which these processes coexist and evolve over time, contributing to marked interindividual variability in clinical outcomes. Despite advances in supportive care, current diagnostic and therapeutic approaches are still largely non-specific and fail to account for this biological heterogeneity. Extracellular vesicles (EVs) have emerged as key mediators of intercellular communication and potential integrators of immune activity in sepsis. These nanosized particles carry proteins, nucleic acids, lipids, and metabolites that reflect the functional state of their cells of origin and actively participate in immune regulation. Experimental and clinical evidence indicate that EVs exert context-dependent effects, contributing both to the propagation of inflammatory processes and the establishment of immunosuppressive states through the transfer of regulatory signals. Beyond their mechanistic role, EVs represent a promising platform for immune monitoring. Their cell-specific and dynamic molecular signatures have been associated with disease severity, organ dysfunction, and clinical trajectories, suggesting their role as biomarkers for patient stratification. In parallel, engineered and stem cell-derived EVs are being explored as therapeutic vectors capable of modulating immune responses and restoring immune homeostasis. In this review, we examine current concepts of immune dysregulation in sepsis and discuss how EVs may serve as both mediators and decoders of immune heterogeneity. We propose that EV-based approaches could bridge the gap between high-dimensional immunological profiling and precision immunotherapy, enabling more adaptive and individualized management of septic patients.