Detecting Cardiac Allograft Rejection in the Era of Personalized Medicine: a Review of Current Genomic Surveillance Techniques

Approximately 25 % of patients will experience an episode of treated cellular rejection in the first year post-transplant. Endomyocardial biopsy has long been considered the gold standard for detecting rejection, despite its invasive nature and limitations in sampling, timing, and interpretation. Numerous prior studies of imaging techniques and biomarkers have failed to provide a reliable non-invasive alternative to biopsy, until the introduction of gene-expression profiling. Gene-expression profiling has been shown to be non-inferior to endomyocardial biopsy in low-risk populations and has now entered routine clinical use. Other novel genomic-based technologies are also beginning to show promise as non-invasive means to determine the risk of rejection but have not yet been validated in large transplant patient populations. This review surveys the clinically relevant genomic-based testing modalities, such as gene expression profiling, microRNA, and cell-free donor DNA for the non-invasive detection of rejection after cardiac transplantation.