Abstract: Objective To observe the differential expression of exosomal miRNAs in patients with traumatic blood loss induced by allogeneic blood transfusion, screen out the differentially expressed exosomal miRNAs, and lay the foundation for the subsequent study of target genes and pathways. Methods Peripheral blood samples were collected from 3 trauma patients before and after transfusion, respectively. Through high-throughput sequencing of exosome miRNA extracted and harvested from plasma samples, the differential expression of exosome miRNA was analyzed and compared between the two groups. Meanwhile, fluorescence quantitative PCR was used to further verify the differential gene expression. Results High-throughput sequencing analysis found that a total of 1 570 miRNA were differentially expressed. Compared with the control group, 1 189 miRNA were up-regulated and 381 miRNA were down-regulated in the experimental group. When fold change≥2.0, P-value ≤0.05 were used as the threshold for differential miRNA screening, there were 14 differentially expressed miRNA with significant changes. 5 miRNA were significantly up-regulated, including miR-499a-5p, miR-200a-3p, miR-372-3p, miR-novel-chr12_5583 and miR-novel-chr22_24253. 9 miRNA were significantly down-regulated, including miR-6852-5p, miR-452-5p, miR-1287-5p, miR-204-3p, miR-375-3p, miR-502-3p, miR-345-5p, miR-novel-chr7_38986 and miR-451a. Conclusions Allogeneic blood transfusion triggers differential expression of exosomal miRNA in patients with traumatic blood loss. Its mechanism may affect the regulation of the patient's immune system through different signaling pathways. However, the degree of immune regulation in patients and the correlation with tumors need to be further studied with larger sample size.

Key words: Blood transfusion, Exosome, miRNA, High-throughput sequencing