Clinical significance of miR-6515-5p in predicting diagnosis and prognosis for acute respiratory distress syndrome suffering from pulmonary fibrosis.

Background: The high mortality rate of ARDS is closely related to pulmonary fibrosis (PLF), and the degree of pulmonary fibrosis affects the prognosis of ARDS. Numerous studies indicated the abnormal expression of miRNAs in the pathogenesis of various lung diseases, such as ARDS and PLF. This study aimed to explore the expression of serum miR-6515-5p and its clinical performance in ARDS complicated with PLF.

Methods: RT-qPCR analysis was employed to measure miR-6515-5p levels within the serum specimens from ARDS patients who either had PLF or did not. Receiver Operating Characteristics (ROC) curve was conducted to evaluate the diagnostic value of miR-6515-5p. To analyze the risk factors linked with the development of PLF in ARDS patients, logistic regression analysis was conducted. Kaplan-Meier curve was conducted to assess the prognostic value of miR-6515-5p in predicting the outcome of ARDS patients with PLF. Multivariate COX regression analysis was performed to identify the PLF-related risk factors associated with outcomes.

Results: Serum miR-6515-5p was downregulated in ARDS patients, especially in patients suffering from PLF. miR-6515-5p expression can distinguish ARDS patients from healthy individuals and related to the occurrence of PLF. Most patients with low miR-6515-5p expression had low FVC and DLCO, as well as high Murray score and APACHE II score. Moreover, miR-6515-5p expression has a certain high value in differentiating ARDS patients with PLF from those without PLF. In addition, miR-6515-5p may be a prognostic marker in ARDS patients suffering from PLF.

Conclusions: These data identified the abnormal expression of miR-6515-5p in ARDS and PLF, and implied a potential clinical early diagnostic and prognostic marker in ARDS suffering from PLF.