Expression Levels of MicroRNA-125b in Serum Exosomes of Patients with Asthma of Different Severity and its Diagnostic Significance

Background: This study aimed to investigate the expression levels of microRNA (miRNA)-125b in serum exosomes and its diagnostic efficacy for asthma severity. Methods: The study included 80 patients with untreated asthma and 80 healthy volunteers. The patients were divided into 4 groups according to disease severity: 20 with the intermittent state, 20 with the mildly persistent state, 20 with the moderately persistent state, and 20 with the severely persistent state. The expression levels of miRNA-125b in serum exosomes of each group were detected using a quantitative polymerase chain reaction and compared. The Spearman correlation analysis was used to study the correlation between the expression levels of miRNA-125b in serum exosomes and asthma severity. The diagnostic efficacy of the expression levels of miRNA-125b in exosomes for asthma severity was evaluated using the Receiver Operating Characteristic (ROC) curve. Results: The expression levels of miRNA-125b in serum exosomes of patients with intermittent, mildly persistent, moderately persistent, and severely persistent asthma were all higher than those in the healthy control group, with statistically significant differences. The expression levels of miRNA-125b were also statistically significantly different among patients in each group. The Spearman correlation analysis showed a positive correlation of the relative expression of miRNA-125b in serum exosomes with asthma severity. The area under the ROC curve of the diagnostic efficacy of miRNA-125b in serum exosomes for patients with intermittent, mildly, moderately, and severely persistent asthma was 0.7770, 0.8573, 0.9111, and 0.9995, respectively. Conclusion: The expression levels of miRNA-125b in serum exosomes had a high diagnostic efficacy and might serve as a noninvasive diagnostic marker for asthma severity.