Will tolerance become a clinical reality?

The goal of transplant physicians is to create a state of antigen-specific tolerance in the recipient, whereby the graft is not rejected and the patient will not need a lifetime of medical therapy. Although the immunosuppressive medications used are effective in lowering the incidence of rejection, they produce significant side effects and do not induce a state of transplantation tolerance. Progress toward inducing transplantation tolerance has been made in animal models, primarily by the exploitation of the natural mechanisms that vertebrates have to maintain self-tolerance. These same strategies are being employed in clinical trials and consequently are promising and challenging for the future.