Background: Graft quality is a determinant of graft function after liver transplantation (LT). This study aimed to evaluate graft molecular markers that correlate to peripheral markers associated with graft injury severity.

Patients/Methods: The study prospectively evaluated 74 LT patients (deceased DDLT n=64 and living LDLT n=10 donors). DDLTs were grouped by donor characteristics (standard (SCD) and extended criteria (ECD)), CIT (>12hrs), BMI (>30kg/m2), and graft steatosis. Biopsy samples were collected at pre (L1) and post-reperfusion (L2) times. Total RNA was isolated, labeled, and used for gene expression microarrays. Probeset summaries were obtained by RMA algorithm. Unsupervised cluster analysis compared molecular profiles among grafts. T-test was fit for comparisons (p<0.001; FDR 1%). Pathways were analyzed by IPA. EDTA-anticoagulated blood was drawn at pre-implantation (P1), post-reperfusion (P2), 1-day (POD1) and 2-day (POD2). Cell-free nucleic acids (cf-NAs) were isolated and concentration estimated. cf-DNA was tested by microsatellite markers. Cf-miRNAs were tested by RT-qPCR (spike in: cel-mir-39). Pearson's correlations were fit (p<0.05).

Results: Demographics and clinical characteristics were similar among groups. Transaminases were significantly lower in LDLTs (p<0.001), higher in DDLT and especially increased in steatotic DDLT recipients (p=0.002) at P2. Molecular profiles were similar among grafts at L1 by unsupervised clustering analysis and no deferentially expressed genes were identified among DDLTs adjusting for to CIT. A set of 283 genes involved in metabolism activation were found deferentially expressed between LDLTs and DDLT at L1 time. Post-Reperfusion, we found deferentially expressed genes in DDLT samples associated with inflammation and metabolism. In plasma samples, cf-NAs significantly increased in steatotic livers (p<0.001) at post-reperfusion time (p<0.001) and correlated with AST activity (r=0.744; p<0.001). Furthermore, we identified that 95% of cf-DNA at post-reperfusion time was donor origin and decreased to 5% at POD2. Circulating miR-16, -155, and -146a increased significantly in DDLTs and correlated with AST/ALT in DDLT-ECDs at post-LT (p<0.05). MiR-122 was significantly increased in all groups post LT but decreased faster in LDLTs at POD2.

Conclusions: Peripheral circulating DNA and miRNAs post LT correlates with injury severity and may represent potential biomarkers.

CITATION INFORMATION: Gehrau R, Mas V, Bontha S, Maluf D. Non-Invasive Biomarkers for Graft Quality and Outcome Post-Liver Transplantation. Am J Transplant. 2016;16 (suppl 3).

« Back to 2016 American Transplant Congress