Coding variants in the apolipoprotein L1 gene (APOL1) are strongly associated with nephropathy in African Americans (AAs). The effect of transplanting kidneys from AA donors with two APOL1 nephropathy risk variants is unknown. APOL1 risk variants were genotyped in 106 AA deceased organ donors and graft survival assessed in 136 resultant kidney transplants. Cox proportional-hazard models tested for association between time to graft failure and donor APOL1 genotypes. Mean follow-up was 26.4 ± 21.8 months. Twenty-two of 136 transplanted kidneys (16%) were from donors with two APOL1 nephropathy risk variants. Twenty five grafts failed; eight (32%) had two APOL1 risk variants. A multivariate model accounting for donor APOL1 genotype, overall African ancestry, expanded criteria donation, recipient age and gender, HLA mismatch, CIT, and PRA revealed that graft survival was significantly shorter in donor kidneys with two APOL1 risk variants (hazard ratio [HR] 3.84; p=0.008) and higher HLA mismatch (HR 1.52; p=0.03), but not for overall African ancestry excluding APOL1. Kidneys from AA deceased donors harboring two APOL1 risk variants failed more rapidly after renal transplantation than those with zero or one risk variants. If replicated, APOL1 genotyping could improve the donor selection process and maximize long term renal allograft survival.

BACKGROUND.: Alemtuzumab and rabbit antithymocyte globulin (rATG) are commonly used for induction of immunsuppression for kidney and pancreas transplantation, but the two agents have not been compared directly. METHODS.: We conducted a prospective randomized single-center trial comparing alemtuzumab and rATG induction in adult kidney and pancreas transplantation in patients treated with similar maintenance immunosuppression. RESULTS.: Between February 1, 2005, and September 1, 2007, 222 patients randomly received either alemtuzumab (n=113) or rATG (n=109) induction; 180 (81%) underwent kidney alone, 38 (17%) simultaneous pancreas-kidney, and 4 (2%) pancreas after kidney transplants. Of 180 kidney-alone transplants, 152 (84%) were from deceased donors, including 61 (34%) from expanded criteria donors. Retransplantation, human leukocyte antigen match, antibody titer, expanded criteria donors, race, cytomegalovirus status, delayed graft function, and immunologic risks were similar between the two induction groups. With a median follow-up of 2 years (minimum 1 year), overall patient, kidney, and pancreas graft survival rates were 96%, 89%, and 90%, respectively. Survival, initial length of stay, and maintenance immunosuppression (including early steroid elimination) were similar between alemtuzumab and rATG groups, but biopsy-proven acute rejection (BPAR) episodes occurred in 16 (14%) alemtuzumab patients compared with 28 (26%) rATG patients (P=0.02). Late BPAR (>12 months after transplant) occurred in 1 (8%) alemtuzumab patient and 3 (11%) rATG patients (P=NS). Infections and malignancy were similar between the two induction arms. CONCLUSION.: Alemtuzumab and rATG induction therapies were equally safe, but alemtuzumab was associated with less BPAR.

Apolipoprotein L1 gene (APOL1) nephropathy variants in African American deceased kidney donors were associated with shorter renal allograft survival in a prior single-center report. APOL1 G1 and G2 variants were genotyped in newly accrued DNA samples from African American deceased donors of kidneys recovered and/or transplanted in Alabama and North Carolina. APOL1 genotypes and allograft outcomes in subsequent transplants from 55 U.S. centers were linked, adjusting for age, sex and race/ethnicity of recipients, HLA match, cold ischemia time, panel reactive antibody levels, and donor type. For 221 transplantations from kidneys recovered in Alabama, there was a statistical trend toward shorter allograft survival in recipients of two-APOL1-nephropathy-variant kidneys (hazard ratio [HR] 2.71; p=0.06). For all 675 kidneys transplanted from donors at both centers, APOL1 genotype (HR 2.26; p=0.001) and African American recipient race/ethnicity (HR 1.60; p=0.03) were associated with allograft failure. Kidneys from African American deceased donors with two APOL1 nephropathy variants reproducibly associate with higher risk for allograft failure after transplantation. These findings warrant consideration of rapidly genotyping deceased African American kidney donors for APOL1 risk variants at organ recovery and incorporation of results into allocation and informed-consent processes.

Background Two apolipoprotein L1 gene (APOL1) renal-risk variants in donors and African American (AA) recipient race are associated with worse allograft survival in deceased-donor kidney transplantation (DDKT) from AA donors. To detect other factors impacting allograft survival from deceased AA kidney donors, APOL1 renal-risk variants were genotyped in additional AA kidney donors. Methods APOL1 genotypes were linked to outcomes in 478 newly analyzed DDKTs in the Scientific Registry of Transplant Recipients. Multivariate analyses accounting for recipient age, sex, race, panel reactive antibody level, HLA match, cold ischemia time, donor age, and expanded-criteria donation were performed. These 478 transplantations and 675 DDKTs from a prior report were jointly analyzed. Results Fully-adjusted analyses limited to the new 478 DDKTs replicated shorter renal allograft survival in recipients of APOL1-two-renal-risk-variant kidneys (HR 2.00; p=0.03). Combined analysis of 1153 DDKTs from AA donors revealed donor APOL1 high-risk genotype (HR 2.05; p=3×10−4), older donor age (HR 1.18; p=0.05), and younger recipient age (HR 0.70; p=0.001) adversely impacted allograft survival. Although prolonged allograft survival was seen in many recipients of APOL1-two-renal-risk-variant kidneys, follow-up serum creatinine concentrations were higher than in recipients of zero/one APOL1-renal-risk variant kidneys. A competing risk analysis revealed that APOL1 impacted renal allograft survival, but not recipient survival. Interactions between donor age and APOL1 genotype on renal allograft survival were non-significant. Conclusions Shorter renal allograft survival is reproducibly observed after DDKT from APOL1-two-renal-risk-variant donors. Younger recipient age and older donor age have independent adverse effects on renal allograft survival.

By appropriate donor and recipient profiling and the use of management algorithms to project and protect renal function, excellent intermediate-term outcomes can be achieved with ECD kidney transplants that are comparable to SCD kidney transplants.