Summary of the International Society for Heart and Lung Transplantation consensus conference on emerging understanding of antibodies and antibody-mediated rejection in heart transplantation.

The understanding of circulating antibodies and their relationship to antibody-mediated rejection (AMR) has yet to be fully elucidated in heart transplantation. Circulating antibodies are important in both pretransplant and post-transplant. In the pretransplant period, the more antibodies detected in a patient awaiting heart transplantation often significantly reduces the chance of obtaining a compatible donor heart. In the post-transplant period, de novo antibody development against the donor heart remains a challenge to manage. In both pre- and post-transplant scenarios, it is not known what approach is optimal for treating these patients with circulating antibodies. To address these unmet needs, a consensus conference was organized on April 18, 2023, endorsed by the International Society for Heart and Lung Transplantation. The conference represented a collaborative multidisciplinary effort by experts in cardiothoracic transplantation from across the world to understand and discuss the optimum approach and treatment of circulating antibodies and AMR in heart transplant candidates and recipients. The conference served as a forum to better understand antibodies and AMR and their impact on transplant patients. The nature of this consensus is to prepare a platform and pave the way for further detailed studies. The findings and consensus statements are hereby presented.