Current concepts in histocompatibility during heart transplant.

Sensitized candidates for heart transplant usually end up on a long waiting list and have an increased risk of rejection, graft loss, and incidence of cardiac allograft vasculopathy. An increasing number of studies have demonstrated the negative effect of preformed and posttransplant antibodies on graft survival. Thus, in sensitized patients, the combination of new, appropriate, desensitization protocols, and monitoring of posttransplant development of donor-specific antibodies may improve short-term and long-term outcomes. Introduction of more-sensitive and more-specific techniques for antibody detection provides a valid tool for assessing the degree of pretransplant HLA histocompatibility, and, therefore, predicting the results of crossmatch in sensitized patients, which are difficult to transplant. Currently, there are no accurate and standard methods to determine the functional characteristics of antibodies detected by solid-phase assay and, therefore, to predict their clinical relevance. Therefore, the future of heart transplantation requires a better understanding of tissue typing techniques and the effect of anti-HLA antibodies on clinical outcome to prevent discrimination against sensitized patients at the time of organ allocation.