The Association of microRNA-145 and microRNA-191 with Therapeutic Response in Patients with Inflammatory Bowel Disease.

Background: The discovery of non-invasive biomarkers that can predict the therapeutic response in Inflammatory Bowel Disease (IBD) is of utmost importance in the field of personalized medicine. The present prospective cohort study was designed to investigate the use of circulating levels of plasma microRNA-145 (miR-145) and microRNA-191 (miR-191) in the diagnosis and association with therapeutic response in Crohn's disease (CD) and ulcerative colitis (UC). Methods: The present study was conducted as a retrospective observational cohort study on 183 adult IBD patients, consisting of 96 CD patients and 87 UC patients. Patient data and study parameters were obtained retrospectively from existing clinical records and available laboratory/molecular data collected during routine clinical care. A healthy control group consisting of 92 individuals was included for comparison with the patients with IBD. The circulating levels of miR-145 and miR-191 were assessed in the peripheral blood plasma at baseline using qRT PCR. The clinical response was evaluated at 12 weeks using the CDAI score for CD and the Mayo score for UC. Results: In active IBD, there was significant down-regulation of miR-145 and significant up-regulation of miR-191. Responders at 12 weeks had significantly higher levels of baseline miR-145 (2.0-fold, p < 0.001) and lower levels of miR-191 (1.8-fold, p < 0.001) compared with non-responders. Also, miR-145 negatively correlated with disease activity, and miR-191 positively correlated with acute inflammation markers. ROC curve analysis showed good discriminative values for both miR-145 and miR-191. Conclusions: The level of circulating miR-145 and miR-191 correlates with the activity of IBD. Importantly, the baseline level of miR-145 expression is a non-invasive potential biomarker associated with therapeutic response at 12 weeks.