Altered Expression of MicroRNAs Following Chronic Allograft Dysfunction with Interstitial Fibrosis and Tubular Atrophy

Chronic allograft dysfunction (CAD) remains the major cause of renal transplant loss and characterized by interstitial fibrosis and tubular atrophy (IFTA). MicroRNAs (miRNAs) are implicated in many biological processes as well as innate and adaptive immune responses. We aimed to investigate whether CAD with IFTA is associated with differential expression of miR-142-5p, miR-142-3p and miR-211 within biopsy and peripheral blood mononuclear cell (PBMC) samples and whether expression of miRNAs are diagnostic for CAD with IFTA and predicts renal allograft function. In this study, biopsy and PBMC samples of 16 CAD with IFTA and 17 normal allografts (NA) were collected. Using Taqman MicroRNA Assays the expression levels of miR-142-5p, miR-142-3p and miR-211 were determined in two groups. Our results showed that miR-142-5p and miR–142-3p were significantly (p<0.0001) up-regulated and miR-211 was significantly (p<0.0001) down-regulated in renal allograft tissues of CAD with IFTA compared with NA recipients. Moreover, miR-142-3p and miR-211 were significantly (p<0.0001) up-regulated and down-regulated respectively in PBMC samples of CAD with IFTA. According to the ROC curve analysis, miR-142-5p in biopsy samples, but miR-142-3p and miR-211 both in biopsy and PBMC samples could be used as a diagnostic biomarker of CAD with IFTA and a prediction factor of allograft function. In this study, miRNAs were differentially expressed in the kidney allograft biopsy and simultaneously in PBMC samples of patients with CAD with IFTA. We suggest that the expression of miRNAs in PBMC might be used for monitoring the post transplantation and also as potential non-invasive biomarkers of kidney graft function and CAD with IFTA.