Abstract
Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a group of chronic inflammatory disorders characterized by alternating episodes of flares and clinical remission, often leading to intestinal fibrosis. MicroRNAs (miRNAs) are small non-coding RNAs that regulate, among other processes, cell proliferation, inflammation, and fibrosis, all of which are crucial in IBD pathogenesis and healing. Given their role in these mechanisms, miR-103a, miR-145, and miR-191 were selected as promising candidates for IBD diagnostic biomarkers. Serum expressions of miR-103a, miR-145, and miR-191 were analyzed in 47 IBD patients and 30 healthy controls. Expressions were quantified using qPCR and normalized to miR-375-3p. All analyzed miRNAs were significantly upregulated in both UC and CD compared to healthy controls. ROC curve analysis revealed miR-103a as the most promising biomarker, with AUC = 0.893 in UC and AUC = 0.905 in CD. Moreover, miR-103a demonstrated excellent sensitivity and specificity, 89.3% and 80% in UC, and 84.2% and 83.3% in CD, respectively. miR-191 also effectively differentiated UC patients from healthy individuals (AUC = 0.848; sensitivity 89.3%; specificity 80%). Comparable results of diagnostic indicators were obtained in the CD group, however, with lower sensitivity (73.7%). miR-145 showed good ability in differentiating both UC and CD patients with high sensitivity (85.7%; 84.2%) and satisfactory specificity (66.7%; 63.3%). The obtained results indicate the promising diagnostic potential of circulating miR-103a, miR-145, and miR-191 for both UC and CD.