BioProject

Recurrent hepatitis C virus (rHCV) is universal post-liver transplantation (LT), with accelerated fibrosis rates compared to non-transplanted patients. rHCV is associated with increased mortality and morbidity post-transplant and is a leading indication for re-transplantation. We hypothesized that miRNA expression profiles from liver grafts can distinguish severity of HCV recurrence and differentiate this from acute cellular rejection (ACR). Methods Using microarrays, we characterized global microRNA (miRNA) expression from patients with slow HCV fibrosis progression (F<2 Ishak), fast HCV fibrosis progression (F≥2 Ishak), ACR and non-HCV transplanted patients. Selected miRNA were analysed by quantitative PCR (qPCR) using both liver tissue and serum samples. Results We demonstrated changes in miRNA expression in patients with slow HCV fibrosis progression that were anti-fibrogenic, anti-angiogenic and anti-inflammatory in comparison to patients with fast HCV fibrosis progression. miRNA-146a, miRNA-19a, miRNA- 20a and miRNA-let-7e expression were increased in the slow HCV fibrosis progression group. In addition, comparison of patients with fast HCV progression against patients with ACR identified pro-fibrogenic pathways. qPCR analysis on liver tissue and serum confirmed the up-regulation of miRNAs in the slow HCV fibrosis progression group. Conclusion We demonstrate specific miRNA expression signatures that distinguish rate of progression of HCV recurrence and ACR post –liver transplantation. Pathway analysis indicates that specific miRNA may play a regulatory role in these processes. The miRNAs identified may act as potential biomarkers for HCV recurrence post-LT and help distinguish between ACR and recurrent HCV. Overall design: We compared 29 patients in total; 11 patients with slow HCV fibrosis progression, 9 patients with fast HCV fibrosis progression, 5 patients with acute cellular rejection and 4 HCV negative patients with normal liver histology that acted as controls. RNA was extracted from archived histology samples of the RG and NRG and miRNA expression was analysed using the affymetrix Genechip miRNA 2.0 assays.