Genome Transplant Dynamics: Non-invasive Sequencing-based Diagnosis of Rejection

Previous attempts to develop a non-invasive marker of graft rejection have focused on recipient-specific immune responses, and thus have inherent limitations in both sensitivity and selectivity, especially in distinguishing rejection from infection. The investigators' goal is to use a novel DNA sequencing technology to develop a rapid, inexpensive, and non-invasive method for monitoring organ transplant recipients for graft rejection. The investigators' research is driven by the fact that acute and chronic rejection of thoracic organ transplants remain major causes of patient morbidity and mortality, and require intense resource utilization. The investigators' novel approach is the first to focus on a donor-specific marker of acute rejection. The investigators will use high throughput next generation sequencing to monitor the proportion of cell-free donor DNA to recipient DNA in the recipient's blood stream as a marker of rejection. This approach is enabled by the fact that an organ transplant is also effectively a genome transplant, and by monitoring single nucleotide polymorphisms that are specific to the donor's genome (and are not shared with the recipient's genome) one can measure the relative health of the transplanted organ. The investigators' preliminary studies show that cell-free donor DNA levels in the serum of heart transplant recipients increase prior to diagnosis of acute rejection by endomyocardial biopsy, but remain at stable low levels in the absence of acute rejection.