Serum miRNA 146b-5p a pharmacodynamic biomarker in adult inflammatory bowel disease

Inflammatory bowel disease (IBD) impacts the gastrointestinal tract, resulting in multiple hospitalizations, complications, and diminished quality of life. IBD has two subtypes: Crohn's Disease (CD) and Ulcerative Colitis (UC). Evidence suggested that immune response dysregulation and genetic susceptibility are the main disease pathogenesis. IBD diagnosis is established by clinical, laboratory, radiological, endoscopic and histological criteria. MiRNA-146 suppresses proinflammatory cytokines and activates T regulatory lymphocytes (Tregs). Serum miRNA-146b-5p targets genes and cytokines responsible for inhibiting autophagy and maintaining cell homeostasis. This study aimed to evaluate the role of miRNA -146b-5p in diagnosis of IBD and response to treatment. The study consisted of sixty 60 participants separated into 3 groups. Blood samples were withdrawn from 20 acute IBD cases before treatment (Group I), 20 Chronic IBD patients on treatment (Group II) and 20 apparently healthy controls (Group III) for assay of miRNA-146b-5p using the Real-Time polymerase chain reaction (PCR), fecal calprotectin and C reactive protein (CRP). The study revealed statistically significant variation between the 3 studied groups according to stool fecal calprotectin, CRP and microRNA-146b-5p (p < 0.001). There was a statistically significant difference in microRNA-146b-5p expression among Ulcerative Colitis cases and the control Group and among Crohn's Disease cases and the control Group III (p < 0.001). There was no difference in microRNA-146b-5p among the CD and UC patients (p>0.05). Multi-Regression analysis showed that smoking was a significant variable for CD but not for UC. In conclusion, MiRNA-146b-5p was proved with a superior performance as a biomarker for early diagnosis of IBD and for follow up response to treatment.