Screening and Clinical Verification of Extracellular Vesicle Biomarkers

Extracellular vesicles (EVs), lipid bilayer-encapsulated membrane particles carrying proteins, lipids, nucleic acids, and sugars, are shed by most cells into the extracellular milieu and function to mediate intercellular communication. Owing to their stability, ability to carry important cargo, and minimally invasive sampling procedures, EVs have potential to serve as clinical biomarkers for disease diagnosis and monitoring. Approaches for the screening and verification of potential EV biomarkers mainly include five stages, i.e., study design, screening, verification, validation, and clinical application. Potential biomarkers can only be used in clinical diagnosis after rigorous clinical verification to demonstrate sufficiently high sensitivity, specificity, predictive ability, risk/benefit ratio, and clinical feasibility. With the improvement of EV detection technology, many disease-related EV biomarkers have been discovered; however, few have been translated into clinical applications. Although there are still many problems to be overcome in the clinical application of EV biomarkers, we believe that EVs could have applications in the clinical diagnosis and treatment of diseases with further basic research on EVs and improvements in EV detection technology.