APOL1 Genotype and Renal Function of Black Living Donors

Abstract

Black living kidney donors are at higher risk of developing kidney disease than white donors. We examined the effect of the <i>APOL1</i> high-risk genotype on postdonation renal function in black living kidney donors and evaluated whether this genotype alters the association between donation and donor outcome. We grouped 136 black living kidney donors as <i>APOL1</i> high-risk (two risk alleles; <i>n</i>=19; 14%) or low-risk (one or zero risk alleles; <i>n</i>=117; 86%) genotype. Predonation characteristics were similar between groups, except for lower mean±SD baseline eGFR (CKD-EPI equation) in donors with the <i>APOL1</i> high-risk genotype (98±17 versus 108±20 ml/min per 1.73 m²; <i>P</i>=0.04). At a median of 12 years after donation, donors with the <i>APOL1</i> high-risk genotype had lower eGFR (57±18 versus 67±15 ml/min per 1.73 m²; <i>P</i>=0.02) and faster decline in eGFR after adjusting for predonation eGFR (1.19; 95% confidence interval, 0 to 2.3 versus 0.4; 95% confidence interval, 0.1 to 0.7 ml/min per 1.73 m² per year, <i>P</i>=0.02). Two donors developed ESRD; both carried the <i>APOL1</i> high-risk genotype. In a subgroup of 115 donors matched to 115 nondonors by <i>APOL1</i> genotype, we did not find a difference between groups in the rate of eGFR decline (<i>P</i>=0.39) or any statistical interaction by <i>APOL1</i> status (<i>P</i>=0.92). In conclusion, <i>APOL1</i> high-risk genotype in black living kidney donors associated with greater decline in postdonation kidney function. Trajectory of renal function was similar between donors and nondonors. The association between <i>APOL1</i> high-risk genotype and poor renal outcomes in kidney donors requires validation in a larger study.