Use of induction therapy with mTOR inhibitor maintenance immunosuppression to facilitate reduced calcineurin inhibitor (CNI) exposure in de novo kidney transplant patients has been explored in a series of randomized trials. These studies have typically employed interleukin-2 receptor antagonist (IL-2RA) induction, in low or standard immunological risk recipients. Although no study has directly compared mTOR inhibition plus reduced CNI exposure with or without induction, inclusion of IL-2RA induction appears to permit a substantial reduction in CNI exposure without the need for high mTOR inhibitor dosing. IL-2RA induction with an mTOR inhibitor and steroids has consistently shown similar efficacy to standard-exposure CNI with mycophenolic acid and steroids and may improve renal function among patients who remain on the mTOR inhibitor-based regimen. With modern mTOR inhibitor dosing, wound healing complications are of less concern and may be no more frequent than in mycophenolic acid-based regimens. The incidence of cytomegalovirus infection appears lower in patients receiving de novo mTOR inhibition. The available evidence demonstrates that IL-2RA induction with an mTOR inhibitor can successfully reduce CNI exposure by at least half without a penalty in terms of rejection in low- or moderate-risk de novo transplant recipients and may offer renal and antiviral benefits.
