Serum miR-21 and miR-155 expression in idiopathic pulmonary fibrosis

To investigate the expression of serum miRNA-21(miR-21) and miRNA-155 (miR-155) in idiopathic pulmonary fibrosis (IPF).A study including 65 patients with IPF and 65 similar age and gender healthy controls was performed. Serum specimens were collected from all subjects. Total RNA was extracted and the quantitative reverse transcription-polymerase chain reaction was used to measure serum miR-21 and miR-155 in both groups. Clinicopathologic features were assessed to determine associations with serum miR-21 and miR-155 concentrations.Serum miR-21 expression was significantly higher in IPF samples than in healthy controls (p < 0.01), while serum miR-155 expression did not show a statistically significant difference (p > 0.05). Forced vital capacity (FVC) and radiologic features were associated with miR-21 and miR-155 expression in serum (p < 0.05). Neither miR-21 nor miR-155 expression was statistically significantly associated with clinicopathologic parameters, such as gender (p > 0.05) and age (p > 0.05).These findings suggest that serum miR-21 is associated with IPF and the degree of damage indicated by FVC and radiologic examinations could correlate with miR-21 and miR-155 expression in serum. From another perspective, our study confirmed serum miRNA can be stable and detectable in serum of patients with IPF, which could prove useful as it could be considered as a new biomarker in serum for diagnosis and assessment of prognosis of IPF in the future.