Diagnostic And Monitoring Values Of Peripheral Blood Mononuclear Cell MiRNAs In Inflammatory Bowel Disease

Background and ObjectiveInflammatory bowel disease(IBD)is a chronic,relapsing inflammatory condition of the gastrointestinal tract related to immune disorder.Prevalence of IBD reaches 0.3% in developed countries while it is relatively lower in developing countries.However,with the ongoing industrialization,prevalence of IBD in Asia,South America and Africa has been rising in decades.The etiology of IBD remains largely unknown while dominant view believes that it is due to immune dysregulation triggered by microbes in gut.IBD patients often present with unspecific symptoms and due to the lack of gold standard,doctors need to exclude infective colitis and other non-infective colitis before diagnosing.These often lead to diagnose delay.Meanwhile,there is currently no cure for the disease,but only surgery or medication to relieve symptoms and minimize relapse.Thus,it is crucial to monitor disease activity.Nowadays,fecal calprotectin,C-reactive protein(CRP)and erythrocyte sedimentation rate(ESR)are main indexes used in clinic to monitor disease activity.Unfortunately,all of them lack specificity and are with limited sensitivity in different conditions.To solve this,we use miRNA sequencing to find new biomarkers that can diagnose and monitor IBD in peripheral blood monomolecular cell(PBMC).MethodsWe isolate PBMC with density gradient centrifugation and then extracted RNA to do further miRNA sequencing or q RT-PCR.After analyzing differential expression of miRNA in three groups(Crohn’s disease(CD)group,ulcerative colitis(UC)group and healthy control(HC)group),we did further cluster analysis of the miRNAs and enrichment analysis of targets of the miRNAs to find specific pathways or molecular functions of CD and UC.Afterwards,7 candidate miRNAs were validated.Expression of the 7 miRNAs were determined by q RT-PCR in 164 participants(CD 87,UC 38,HC 38).Their performance in diagnosing and monitoring were evaluated and compared to high sensitivity CRP(hs CRP),ESR and fecal calprotectin.ResultsWe found 34 potential CD-specific miRNAs,51 potential UC-specific miRNAs and 38 miRNAs related to both by miRNA-seq.We chose miR-92b-3p,miR-96-5p,miR-320 b,miR-542-5p,miR-582-5p,miR-941 and miR-3065-5p to do further validation.We found miR-542-5p and miR-582-5p have potential value in diagnosing IBD.When used to diagnose UC,AUROC of miR-542-5p is 0.775(95% CI 0.665-0.885,p < 0.001)with 76.32% sensitivity and 82.05% specificity when cutoff is 1.15.Meanwhile,AUROC of miR-582-5p is 0.715(95% CI 0.594-0.836,p = 0.001)with 64.86% sensitivity and 78.95% specificity when cutoff is 1.01.When used to diagnose CD,AUROC of miR-542-5p is 0.771(95% CI 0.687-0.855,p <0.001)with 72.41% sensitivity and 82.05% specificity when cutoff is 1.13.Meanwhile,AUROC of miR-582-5p is 0.705(95% CI 0.611-0.798,p < 0.001)with 60.92% sensitivity and 78.95% specificity when cutoff is 1.03.miR-96-5p was found to have good performance in monitoring disease activity of both CD and UC.AUROC of miR-96-5p to identify CD clinical activity is 0.737(95%CI 0.623-0.852,p < 0.001)with 64% sensitivity and 77.42% specificity when cutoff is 0.75.It has better performance than hs CRP,ESR and fecal calprotectin.And miR-96-5p also positively correlated with CD clinical activity(ρ= 0.402,p < 0.001).Besides,AUROC of miR-96-5p to identify CD endoscopic activity is 0.855(95%CI 0.695-1.000,p = 0.029)with 73.68% sensitivity and 100% specificity when cutoff is 0.35.And miR-96-5p also positively correlated with CD endoscopic activity(ρ = 0.446,p = 0.033).As for UC,AUROC of miR-96-5p to identify moderate and severe activity is 0.766(95%CI 0.580-0.952,p = 0.009)with 83.3% sensitivity and 73.1% specificity when cutoff is 0.87.It has similar performance with hs CRP and better than ESR and fecal calprotectin.Besides,miR-96-5p positively correlated with Partial Mayo Score(ρ = 0.371,p = 0.022)as well as Mayo Score(ρ = 0.507,p = 0.032).ConclusionsIn conclusion,PBMC miRNAs have diagnostic and monitoring values in IBD and can avoid unnecessary invasive examination.Among them,miR-542-5p and miR-582-5p have potential to diagnose IBD while miR-96-5p can monitor disease activity of IBD.