[Immunosuppression in kidney transplantation: a way between efficacy and toxicity].

Renal transplantation is the best treatment for patients with end-stage renal disease. Over the last decades, the introduction of new immunosuppressive agents resulted into the reduction of the incidence of acute rejection and early graft loss. Despite this progress, there has been little improvement in the average life of the transplant. The main reasons of late failure are patient's death due to several complications (e.g. cancer, infectious or metabolic), and progressive deterioration of renal function caused by immunological and non-immunological factors. The immunosuppressive therapy can be distinguished into two components: the induction therapy and the maintenance therapy. The former has the aim to implement intense and immediate immunosuppression. This therapy is mostly useful in transplant with high immunological risk, although it is correlated with an increased risk of cytopenias and viral infections. The latter offers the rationale to prevent organ rejection and minimize drug toxicity. This is generally constituted by the association of two or three drugs with different mechanism of action. The most common application of this scheme includes a calcineurin inhibitor in combination with an antimetabolite and a minimum dose of steroids. Immunosuppressive therapy is also associated to an increased risk of infections and cancer development. For instance, each class of drugs is related to a different profile of toxicity. The choice of treatment protocol should take into account the clinical characteristics of the donor and recipient. Furthermore, this treatment may change anytime when clinical conditions result into complications.