Humoral Barrier to Preclinical and Clinical Xenotransplantation

Xenotransplantation is finally moving toward clinical application. Despite the progress in survival in preclinical models and the limited attempts at clinical heart transplantation, the initial problem of xenoreactive antibodies in human serum remains a proximal barrier to widespread success in preclinical and clinical settings. Detailed understanding of the pretransplant status of recipients in the preclinical as well as clinical setting is critical to moving the field forward. The differences in the pretransplant donor-specific antibody (DSA) levels in the preclinical and clinical models are outlined so that we can begin to think about the two scenarios in a complementary fashion and facilitate decision making for research priorities and movement into the clinical realm.