P037 MicroRNA-31 and microRNA-200 family reflect disease activity in Crohn’s disease: results from the BIOMIR study

Abstract Background Accurate assessment of disease activity in inflammatory bowel disease (IBD) is of paramount importance in decisions regarding treatment strategies. To apply a treat-to-target strategy, a tight assessment of activity is mandatory. MicroRNAs (miRNAs) are small, non-coding short (ribonucleic acid) RNAs that have a role in the regulation of genes and protein expression. MiRNAs have altered expression in multiple autoimmune disorders including IBD. The aim of the study was to assess the tissue and circulating miR-31, miR-200b, and miR-200c expression levels as potential biomarkers for intestinal disease activity in patients with Crohn’s disease (CD). Methods The study included 45 patients with histopathologically confirmed CD and active disease (defined as fecal calprotectin (fCal) > 50 ug/g and Short Endoscopic Score of Crohn’s Disease (SES-CD) > 3), and 21 subjects as controls for the validation cohort. Demographic and clinical data, biomarkers (fCal), endoscopy data, the expression levels of miR-31, miR-200b, and miR-200c in tissue and serum were assessed (by RT-PCR). Receiver operating characteristic (ROC) analysis was performed to assess the miR-31, miR-200b, and miR-200c expression levels as potential biomarkers for active CD. Results Mean fCal was 1540 +/- 890 ug/g. Mean SES-CD was 8.9 +/- 4.2. Tissue and circulating miR-31 was significantly correlated with fCal (r = 0.81, r = 0.83, p < 0.01) and with SES-CD (r = 0.82, r = 0.79, p < 0.01). The expression level of miR-31 was significantly upregulated in CD tissue cases compared to the control tissue samples (6.24 ± 1.57 vs. 3.70 ± 1.44; p < 0.01). Similarly, serum miR-31 expression levels in CD patients were significantly upregulated than in control serum samples (-2.07 ± 1.00 vs. 0.78 ± 0.42; p < 0.01). The expression levels of tissue miR-200b and miR-200c were significantly upregulated in CD tissue cases compared to the control tissue samples (-5.25 ± 0.93 vs. -4.69 ± 0.80, p = 0.03 for miR-200b, and -0.86 ± 0.96 vs. 0.39 ± 0.66, p < 0.01 for miR-200c). Similarly, serum miR-200b and miR-200c expression levels in CD patients were significantly upregulated than in the control serum samples (p < 0.05). ROC analysis revealed that the expression levels of the selected miRNAs could help to discriminate active CD patients from healthy controls with very good specificity and sensitivity. Conclusion Tissue and circulating miR-31, miR-200b, and miR-200c reflect disease activity in CD patients and can be used as biomarkers for active CD. Furthermore, circulating miR-31, miR-200b, and miR-200c may be used as non-invasive biomarkers for active CD patients.