Profiling of miRNAs Contained in Circulating Extracellular Vesicles and Associated with Sepsis Development in Burn...

Sepsis is the leading cause of mortality in patients with burn injuries and it may represent, in these patients, a real diagnostic challenge. Here we studied the profile of miRNAs contained in extracellular vesicles (EVs) (EV-miRNAs) isolated from plasma from burn patients complicated by sepsis at admission and 7 days later. We enrolled 28 burn patients, 18 with (Burn Septic Patients-BSPs) and 10 without (Burn non-Septic Patients-BnSPs) sepsis. Ten healthy subjects (HSs) were used as additional controls. After EV isolation by charge precipitation and miRNA extraction, we proceeded with a two-phase approach. Through a first screening phase, we identified 178 miRNAs differentially expressed in BSPs compared to HSs. Among these, by a validation phase based on qRT-PCR, we found that miR-483-5p, miR-193a-5p, and miR-188-3p were increased in the BSPs compared to the BnSPs and HSs. Upon ROC analysis, all three miRNAs showed a good accuracy in differentiating BSPs from BnSPs, especially miR-483-5p (AUC = 0.955, p-value = 0.001). Moreover, we found 173 miRNAs differentially expressed in BSPs after 7 days from enrollment compared to T0, among whose miR-1-3p, miR-34a-3p, and miR-193a-5p decreased in BSPs after 7 days, in parallel with a decrease in SOFA scores. Finally, the other two miRNAs, miR-34a-3p and miR-193a-5p, positively correlated with the SOFA score. In conclusion, we identified several miRNAs-namely miR-483-5p, miR-193a-5p, and miR-188-3p-with potential clinical utility as diagnostic biomarkers in a heterogeneous population of burn patients at high risk of developing sepsis. Moreover, we found some miRNAs (miR-1-3p, miR-34a-3p, and miR-193a-5p) that vary according to the course of sepsis and others (miR-34a-3p and miR-193a-5p) that are associated with its clinical severity.