OP34 Whole blood profiling of T-cell-derived miRNA allows the development of prognostic models in inflammatory bowel disease

Abstract

Abstract Background There is an unmet need for blood-based biomarkers that help predict disease and its course at inception to allow tailoring of treatments, achieve early mucosal healing and improve clinical outcomes. In our study, we explore the clinical utility of miRNAs in Inflammatory bowel disease (IBD). Methods A 2-stage prospective multi-centre case–control study was performed. Small RNA sequencing was performed on a discovery cohort of immunomagnetically separated leucocytes (90 CD4+ and CD8+ T-lymphocytes and CD14+ monocytes) from 32 patients (9 CD, 14 UC, 8 healthy controls) to identify differentially expressed cell-specific miRNAs.Top miRNAs were then validated in whole blood in 294 treatment naïve newly diagnosed IBD and non-IBD patients (97 UC, 98 CD, 98 non-IBD) using RT-qPCR, recruited across 5 centres in UK and Europe. Phenotype and outcome data were collected and Cox proportional hazards were derived to assess the contribution of each miRNA to outcomes; defined as the need for 2 or more immunosuppressants and/or surgery after initial disease remission. RT-qPCR target miRNA relative quantification was calculated using 2−ΔΔCq method. Results Each leucocyte subset (30 CD4+ T cells, 28 CD8+ T cells and 32 CD14+ monocytes) was analysed between disease and controls, adjusting for age, gender and batch effects. A total of three miRNAs differentiated IBD from controls in CD4+ T cells including miR-1307-3p (FDR p = 0.01), miR-3615 (p = 0.02) and miR-4792 (p = 0.01); these signals being UC specific. In CD8 T cells, miR-200b-3p was the only differentially expressed miRNA and no CD14+ signals were seen.Three miRNAs were validated in whole blood in an independent multi-centre cohort of 294 patients using RT-qPCR. miR-1307-3p predicted IBD (1.55 fold change (fc),IQR: 1.00–1.87; p = 2.77 × 10–5),in particular UC (1.69 fc, IQR: 1.01–2.00; p = 1.56 × 10–6). Similarly, miR-3615 and miR-4792 were up-regulated in UC compared with controls (1.21fc, IQR:0.91–1.48; p = 8.26 × 10−4and 1.91 fc, IQR: 0.81–2.56; p = 9.21 × 10–3, respectively).There was no correlation with conventional inflammatory markers. Follow-up data were available on 195 IBD patients of which 80 patients required treatment escalation over a median time of 371 days (IQR: 140–711). miR-1307-3p was able to predict disease course in IBD (HR 1.98, IQR: 1.20–3.27; log-rank p = 1.80 × 10−3), in particular CD (HR 2.81; IQR: 1.11–3.53, p = 6.50 × 10–4). In UC, both miR-3615 (HR 3.34, CI: 1.43–7.78, p = 0.01) and miR-4792 (HR 3.96, CI: 1.65–9.52; p = 2.11 × 10–3) predicted treatment escalation. Conclusion We have identified unique CD4+ T-cell miRNAs that are differentially regulated in IBD. These blood-based miRNAs are able to predict treatment escalation at disease inception and have the potential for clinical translation.