Abstract 18175: Predicting Low-grade Rejection After Heart Transplantation In Children Using Whole Genome Sequencing

Introduction: Endomyocardial biopsy (EMB) remains the gold standard for detecting rejection after heart transplantation. EMB is costly, invasive and, particularly, burdensome in children. We aimed to predict low-grade rejection by whole genome sequencing (WGS) in blood sample. Hypothesis: WGS can predict low-grade rejection in children after heart transplantation. Methods: A total of 106 blood samples with corresponding EMB from 18 children who underwent heart transplantation from 2011 to 2014 were analysed. There were 18 baseline preoperative samples and 88 samples taken at the time of each EMB. Grade of rejection corresponding to each blood sample was determined (no rejection, n=34, 1R, n=45, and 2R, n=9). An input of 200 ng of total RNA per sample was prepared and indexed separately for Illumina sequencing using the TruSeq RNA Library Prep Kit v2 (Illumina, San Diego, CA). Next generation WGS was performed. Differential expression (DE) analysis was performed using the limma package. A k-nearest neighbo...