Induction of specific unresponsiveness to transplantation antigens.

Transplantation of tissue between non-identical human beings does normally require heavy, non-specific immunosuppressive treatment to be successful. Complications of severe nature are frequently induced by such therapy. Here, procedures allowing a selective immunosuppression of the recipient with regard to the donor's alloantigens would be of paramount importance as to reduce the need for non-specific immunosuppressive agents. Classical pathways to achieve specific reduction of reactivity against transplantation antigens include "transplantation tolerance" and "enhancement". Although occasional successful when using adult, immunocompetent individuals in experimental animal systems these approaches have so far failed to leave impressive impacts with regard to the human transplantation immunologists. In the present article an entirely new concept will be introduced, namely that of auto-anti-idiotypic immunity leading to specific lack of reactivity towards transplantation antigens. The principle and the underlying results supporting the concept wil be presented and the practical implications will be discussed.