Project Summary Genetic variants in APOL1 commonly found in people of Western Sub-Saharan Africa ancestry are associated with kidney diseases such as Focal Segmental Glomerulosclerosis, Hypertension Attributed-End Stage Kidney Disease, and HIV-Associated Nephropathy. The presence of 2 APOL1- renal risk variants (RRV) in deceased donors is associated with 2-to-4-times higher risk of renal graft loss in the recipient. Living donors with APOL1 risk alleles may be at risk for kidney disease. The NIH established the “APOL1 Long-term Kidney Transplantation Outcomes” (APOLLO) U01 Consortium in 2017. The APOLLO Consortium includes 13 clinical centers (CCs) with 4 paired core Centers to study the role of APOL1. The Johns Hopkins/Saint Louis University CC is CC3. The primary objectives of the APOLLO Consortium are to assess outcomes in patients across the entire United States who receive a kidney from an AA donor, or other individuals with recent African ancestry, and to evaluate the association of APOL1 genotype with renal allograft function-related outcomes. The primary outcome is time to graft failure in the recipients. Other outcomes include the rate of change of kidney function in recipients, rates of acute rejection of the kidney transplant, and proteinuria. The APOLLO Consortium also ascertains meaningful longitudinal outcomes in AA living donors (LDs), focusing on vital status and renal function, as well as proteinuria. While APOLLO enrolls LDs, their relative numbers have been limited, highlighting the need for additional studies designed to more thoroughly define the relationships of APOL1 genotype with long-term LD outcomes This application seeks to build on and extend the findings of the APOLLO study to inform clinical practice by a) providing data regarding the effects of APOL1 genotype on outcomes of the recipients of kidneys from AA donors, b) providing data regarding the effects of APOL1 genotype on long-term survival and renal functional outcomes of AA LDs and their recipients, and c) establishing a resource of clinical and genetic data and biological specimens for the APOLLO Consortium and other future researchers through the NIDDK Central Repository.