Clinical transplant immunosuppression aims not only to prevent host immune responses against antigens on the transplanted organ, thereby avoiding rejection, but to prevent undesirable complications of immunodeficiency (eg, infection and malignancy) and to minimize nonimmune toxicities (eg, nephrotoxicity, hyperlipidemia, bone marrow suppression, and cushingoid effects). While physical methods such as irradiation can be used, in practice, immunosuppression for solid organ transplantation is usually achieved by immunosuppressive drugs (ISDs). It is an interesting paradox that many of the currently used ISDs, while responsible for drastic improvement in short-term outcomes, potentially compromise long-term graft and patient survival through complex toxic mechanisms.
