Funding outcome

Heart transplantation is a life-saving intervention for children with heart failure due to birth defects or heart muscle weakness. After transplant, the child's immune system recognizes the heart as foreign due to certain proteins on its surface called Human Leukocyte Antigens (HLA). This triggers the immune system to attack the new heart, leading to rejection. A serious form of rejection, known as antibody-mediated rejection (AMR), is caused by antibodies against HLA and can lead to poor outcomes like shorter survival and heart vessel damage. Children with previous surgeries are more likely to have HLA antibodies, making it harder to find a matching donor. Current guidelines for managing these antibodies are limited and not specific to children. In 2010, the University of Alberta developed a protocol to manage HLA antibodies in pediatric heart transplant recipients. This protocol involves treatments to lower antibodies before and after surgery, thus improving the chance of finding a suitable donor heart and treating AMR. It also reduces antibodies against blood groups, potentially allowing heart transplants from donors with different blood types. This study will assess if the protocol reduced HLA antibodies, helped to find a donor heart in time, and resolved AMR after transplant. It will compare outcomes such as survival, rejection, and side effects (such as infections), as well as why the protocol may have been unsuccessful in some patients. The study will also explore if the protocol reduced blood group antibodies, and how many children could thereafter receive heart transplants from different blood type donors. We will confirm if the Edmonton HLA management protocol improves results by reducing problems caused by antibodies, improving chances to find a donor heart, and helping children live longer after their transplant. The results of this study could change the global management of pediatric heart transplants in the future.