Initiation of noninvasive surveillance for allograft rejection in heart transplant patients>1 year after transplant.

Abstract

Gene expression profiling (GEP) and donor-derived, cell-free DNA (dd-cfDNA) measurement are alternative methods to endomyocardial biopsy (EMB) to monitor for rejection following heart transplantation. We aim to describe our use of GEP and dd-cfDNA in heart transplant recipients>1-year post-transplantation. This is a single-center, retrospective study in post-transplant recipients. For patients who were>1-year post-transplantation and deemed to be at elevated clinical risk for rejection, we collected both GEP and dd-cfDNA every 3 months. Baseline characteristics including GEP, dd-cfDNA levels, rejection episodes, and number of biopsies were obtained. Since July 2019, there were 18 patients being followed with GEP and dd-cfDNA who were>1-year post-transplantation. Nine EMBs had been performed in seven patients due to as follows; three due to elevated GEP ({greater than or equal to} 34), one due to elevated dd-cfDNA ({greater than or equal to} .20%), two due to elevations of both GEP and dd-cfDNA, two due to clinical rejection and one to follow up a post rejection episode. One of the two biopsies due to elevations of both GEP and dd-cfDNA showed acute cellular rejection grade 2R. None of the biopsies due to either an elevation in the GEP or dd-cfDNA revealed any significant rejection. In this study, the use of both GEP and dd-cfDNA led to an increased number of EMB in patients>1-year post-transplantation. Further studies are needed to validate these findings and evaluate long-term consequences of these diagnostic tests in this population.