Alterations in plasma miR-21, miR-590, miR-192 and miR-215 in idiopathic pulmonary fibrosis and their clinical importance

Background Many studies have revealed that microRNA (miRNA) molecules may take part in idiopathic pulmonary fibrosis (IPF). But, the role of miRNAs in the development of IPF is not yet clear. Methods We investigated the plasma levels of miR-21, miR-590, miR-192, and miR-215 in IPF (n = 88) and healthy control (n = 20) groups in this study. We compared the expression levels of target miRNAs in patients with IPF and healthy participants. We grouped the patients with IPF according to age, forced vital capacity, carbon monoxide diffusing capacity (DLCO), gender-Age-pulmonary physiology (GAP) score, the presence of honeycombing and compared the expression levels of target miRNAs in these clinical subgroups. Results 82 (93.18%) of the patients with IPF were male and the mean age was 66.6 ± 8.6 years. There was no significant difference between the gender and age distributions of IPF and the control group. The mean plasma miR-21 and miR-590 levels in IPF group were significantly higher than in the control group (p < 0.0001, p < 0.0001, respectively). There was no significant difference between the miR-192 and miR-215 expression levels of the IPF and control group. Both miR-21 and miR-590 correlated positively with age (p = 0.041, p = 0.007, respectively) while miR-192 and miR-215 displayed a negative correlation with age (p = 0.0002, p < 0.0001, respectively). The levels of miR-192 and miR-215 increased as the GAP score decreased. The levels of miR-192 in patients with honeycombing were significantly lower than in those without honeycombing (p = 0.003). Conclusions Our study showed that both miR-21 and miR-590 were overexpressed in IPF. The miR-21 and miR-590 were associated with DLCO, while miR-192 and miR-215 were associated with the GAP score and honeycombing.