Liquid Biopsy in Organ Damage: small extracellular vesicle chip-based assessment of polytrauma

BACKGROUND: Despite major advances in medicine, blood-borne biomarkers are urgently needed to support decision-making, including polytrauma. Here, we assessed serum-derived extracellular vesicles (EVs) as potential markers of decision-making in polytrauma. OBJECTIVE: Our Liquid Biopsy in Organ Damage (LiBOD) study aimed to differentiate polytrauma with organ injury from polytrauma without organ injury. We analysed of blood-borne small EVs at the individual level using a combination of immunocapture and high-resolution imaging. METHODS: To this end, we isolated, purified, and characterized small EVs according to the latest Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines from human blood collected within 24 h post-trauma and validated our results using a porcine polytrauma model. RESULTS: We found that small EVs derived from monocytes CD14(+) and CD14(+)CD61(+) were significantly elevated in polytrauma with organ damage. To be precise, our findings revealed that CD9(+)CD14(+) and CD14(+)CD61(+) small EVs exhibited superior performance compared to CD9(+)CD61(+) small EVs in accurately indicating polytrauma with organ damage, reaching a sensitivity and a specificity of 0.81% and 0.97%, respectively. The results in humans were confirmed in an independent porcine model of polytrauma. CONCLUSION: These findings suggest that these specific types of small EVs may serve as valuable, non-invasive, and objective biomarkers for assessing and monitoring the severity of polytrauma and associated organ damage.