INDUCTION OF TOLERANCE TO CARDIAC ALLOGRAFTS

The ability to induce tolerance to alloantigens, and in the future xen oantigens, in vivo is essential to progress in transplantation. The im munosuppressive drugs available for use in clinical transplantation at present are capable of preventing or reducing the incidence of acute rejection in the first few months after transplantation, but they appe ar less effective at preventing chronic graft loss. The induction of t olerance to the histocompatibility antigens of the organ donor in the long term after transplantation would eliminate the need for long-term administration of these nonspecific immunosuppressive drugs. This alo ne would have a major impact on the quality of life of patients with l ong-term surviving organ grafts by reducing the immunologic and nonimm unologic complications associated with long-term immunosuppressive the rapy. The strategies for the induction of tolerance in the long term a fter transplantation, and more ambitiously before transplantation, tha t are currently being explored in a variety of experimental models are the subject of this review.