An mTOR-inhibitor-based protocol and calcineurin inhibitor (CNI)-free treatment in kidney transplant recipients from donors after cardiac death: good renal function, but high incidence of conversion to CNI.

ABSTRACT

Donor after cardiac death (DCD) grafts have excellent survival despite the high incidence of delayed graft function (DGF). We assessed the feasibility of a mammalian target of rapamycin inhibitor (mTOR-I) protocol in uncontrolled DCD kidney transplantation and compared it with brain-dead donor (DBD) transplantation under calcineurin inhibitor (CNI) treatment. This retrospective study (2002-2011) included 109 Maastricht category II DCD patients and 218 standard-criteria DBD as controls. Immunosuppression consisted of polyclonal antibody induction, mycophenolate mofetil, prednisone, and mTOR-I (starting on day 6) in the DCD group and tacrolimus in the DBD group. DGF occurred in 72.5% of the DCD group vs. 26.1% of the DBD group (P = 0.001). Patient survival at 1 year was 99.1% vs. 95.9% (P = 0.112), and graft survival was 89% vs. 92.2% (P = 0.253). Patient survival at 5 years was 85.3% vs. 90.1% (P = 0.340) and graft survival was 85.5% vs. 78.8% (P = 0.166). During the first year, 46.8% (n = 51) of DCD patients were converted to CNI therapy. Serum creatinine at 1 year was 1.5(1.26-2) mg/dl vs. 1.4(1.16-1.8) mg/dl (P = 0.078). At 1 year, the acute rejection rate was 7.3% vs. 12.5% (P = 0.766). mTOR-I-based therapy was not associated with inferior graft function or higher rejection rates than standard CNI therapy. DCD kidney transplantation with an mTOR-I-based protocol is feasible but is associated with a high conversion rate to CNI-based therapy.