Infliximab therapy decreases the expression of serum and faecal miR‐126 and miR‐20a in paediatric Crohn's disease: A pilot study.

Aim: We aimed to evaluate the serum and faecal expression of miR‐126 and miR‐20a in children with Crohn's disease (CD) during infliximab (IFX) therapy. Methods: In this prospective observational study, serum and faeces from CD patients were collected before IFX therapy (T0), after induction (T1) and after 6 months from IFX (T2). IFX levels were determined by Enzyme‐linked immunosorbent assay at T1 and T2. miRNAs were profiled through Real‐Time RT‐PCR. The activity of disease was evaluated through the Paediatric Crohn's disease activity index (PCDAI), serum C‐reactive protein (CRP) and faecal calprotectin. Results: Nine CD children were enrolled. Serum and faecal miR‐126 and miR‐20a levels were higher at T0 and showed a time‐dependent decrease, being significantly down‐regulated after IFX treatment at T2. Specifically, IFX levels recorded at T1 and T2 negatively correlated with the serum and faecal expression of miR‐126 and miR‐20a. Serum and faecal changes of miR‐126 and miR20‐a were positively associated with the decrease of the inflammatory marker CRP and PDCAI at all time points. Conclusion: In children with CD, IFX therapy decreases the expression of serum and faecal miR‐126 and miR‐20a, suggesting an involvement of these two miRNAs in the action of the drug. [ABSTRACT FROM AUTHOR]