Apolipoprotein L1: role in the evaluation of kidney transplant donors

PURPOSE OF REVIEW: To summarize the current state of evidence regarding the role of apolipoprotein L1 (APOL1) genotyping in evaluating donors for kidney transplantation. RECENT FINDINGS: African ancestry is associated with an increased risk of kidney failure following living donation. Moreover, kidney transplants from African ancestry deceased donors have an increased risk of graft failure. Preliminary evidence suggests that APOL1 genotype may mediate at least a portion of this racial variation, with high-risk APOL1 genotypes defined by presence of two renal risk variants (RRVs). A pilot study 136 African ancestry living donors found that those with APOL1 high-risk genotypes had lower baseline kidney function and faster rates of kidney function decline after donation. To date, three retrospective studies identified a two-to-three times greater risk of allograft failure associated with kidneys from donors with high-risk APOL1 genotype. Active research initiatives seek to address unanswered questions, including reproducibility in large national samples, the role of 'second hits' injuries, and impact of recipient genotype, with a goal to build consensus on applications for policy and practice. SUMMARY: As evidence evolves, APOL1 genotyping may have applications for organ quality scoring in deceased donor kidney allocation, and for the evaluation and selection of living donor candidates.