HEARTBiT: Multi-Marker Blood Test for Acute Cardiac Transplant Rejection

Heart transplantation is a life saving therapy for people with end stage heart failure. Acute rejection, a process where the immune system recognizes the transplanted heart as foreign and mounts a response against it, remains a clinical problem despite improvements in immunosuppressive drugs. Acute rejection occurs in 20-30% of patients within the first 3 months post-transplant, and is currently detected by highly invasive heart tissue biopsies that happen 12-15 times in the first year post-transplant. Replacing the biopsy with a simple blood test is of utmost value to patients and will reduce healthcare costs. The goal of our project is to develop a new blood test to monitor heart transplant rejection. Advances in biotechnology have enabled simultaneous measurement of many molecules (e.g., proteins, nucleic acids) in blood, driving the development of new diagnostics. Our team is a leader in using computational tools to combine information from numerous biological molecules and clinical data to generate "biomarker panels" that are more powerful than existing diagnostic tests. Our sophisticated analytic methods has recently derived HEARTBiT, a promising test of acute rejection comprising 9 RNA biomarkers, from the measurement of 30,000 blood molecules in 150 Canadian heart transplant patients. Our objective is to study a custom-built HEARTBiT test in a setting and on a technology that enable clinical adoption. We will evaluate the new test on 400 new patients from 5 North American transplant centres. We will also track patients' HEARTBiT scores over time to help predict future rejection, and explore use of proteins and micoRNAs to improve HEARTBiT. Our work will provide the basis for a future clinical trial. The significance of this work rests in that it will provide a tool to identify acute cardiac rejection in a fast, accurate, cost-effective and minimally invasive manner, allowing for facile long-term monitoring and therapy tailoring for heart transplant patients.