Immunosuppressive minimization with mTOR inhibitors and belatacept

Immunosuppressive therapy after kidney transplantation consists of a calcineurin inhibitor (CNI)-based therapy in combination with mycophenolic acid and steroids in most cases. In spite of low acute rejection rates and excellent graft survival, it is associated with major long-term complications, such as cardiovascular events, malignancy, and nephrotoxicity, and does not favor tolerogenic processes. Mammalian target of rapamycin (mTOR) inhibitors in combination with low-dose CNI offer good rejection rates and acceptable allograft function; however, de novo mTOR inhitibor-based treatment in combination with mycophenolate is not widely used due to higher acute rejection rates. Early conversion from a CNI to an mTOR inhibitor is a feasible option in selected patients with a slightly higher acute rejection rate, but equal or better GFR. Costimulation blockade has been proven to facilitate antirejection prophylaxis without CNI-associated side effects. So far, belatacept has been approved in combination with mycophenolate and steroids with better graft function, however, a slightly higher acute rejection rate. Recently, the combination of an mTOR inhibitor and belatacept with lymphocyte-depleting antibody induction and without maintenance steroids has been explored in two pilot studies with very low acute rejection rates, very good graft function, and an acceptable side effect profile.