Delayed graft function (DGF) in renal transplant is associated with reduced graft survival and increased immunogenicity. The complement-driven inflammatory response after brain death (BD) and posttransplant reperfusion injury play significant roles in the pathogenesis of DGF. In a nonhuman primate model, we tested complement-blockade in BD donors to prevent DGF and improve graft survival.BD donors were maintained for 20 hours; kidneys were procured and stored at 4°C for 43-48 hours prior to implantation into ABO-compatible, nonsensitized, MHC-mismatched recipients. Animals were divided into 3 donor-treatment groups: G1 -vehicle, G2 -rhC1INH+heparin, and G3 -heparin. G2 donors showed significant reduction in classical complement pathway activation and decreased levels of tumor necrosis factor α and monocyte chemoattractant protein 1. DGF was diagnosed in 4/6 (67%) G1 recipients, 3/3 (100%) G3 recipients, and 0/6 (0%) G2 recipients (P = .008). In addition, G2 recipients showed superior renal function, reduced sC5b-9, and reduced urinary neutrophil gelatinase-associated lipocalin in the first week posttransplant. We observed no differences in incidence or severity of graft rejection between groups. Collectively, the data indicate that donor-management targeting complement activation prevents the development of DGF. Our results suggest a pivotal role for complement activation in BD-induced renal injury and postulate complement blockade as a promising strategy for the prevention of DGF after transplantation. 1514 | DANOBEITIA ET Al. K E Y W O R D S animal models: nonhuman primate, complement biology, delayed graft function (DGF), donors and donation: donation after brain death (DBD), immunosuppression/immune modulation, ischemia reperfusion injury (IRI), kidney transplantation/nephrology, translational research/ science 1 | INTRODUC TI ON Delayed graft function (DGF) manifests as a consequence of ischemia-reperfusion injury (IRI) and is characterized by acute kidney injury (AKI) within 7 days of transplant, requiring life-sustaining dialysis. 1 The incidence of DGF in kidney transplants from brain dead (BD) donors is approximately 26% in the United States, and this rate can reach as high as 37% in kidneys from older donors and those subjected to extended cold ischemia >36 hours. 2-4 In addition to complications related to AKI in the peritransplant period, development of DGF is an important risk factor for acute cellular rejection, antibody-mediated rejection (AMR), and reduced