The kidney evaluation of living kidney donor candidates: US practices in 2017.

We surveyed US transplant programs to assess practices used to assess kidney health in living kidney donor candidates in 2017; the response rate was 31%. In this report, we focus on the kidney; a companion piece focuses on the metabolic and cardiovascular aspects of candidate evaluation. Compared to 2005, programs have become more stringent in accepting younger candidates and less stringent in accepting older candidates. The 24-hour creatinine clearance remains the mainstay for kidney function assessment, with 74% continuing to use a value below 80 mL/min/1.73 m2 for exclusion and 22% using age-based criteria. ApoL1 genotyping is obtained routinely or selectively by 45%, half of which use the high-risk genotype as an absolute exclusion criterion. For history of symptomatic stones, 49% accept if there is no current radiographic evidence of stones and urine profile is low risk, 80%-95% consider candidates with unilateral asymptomatic stones, but only 33%-48% consider if stones are bilateral. In addition, 14% use the risk assessment tool developed by Grams et al routinely for decision-making, and 42% use it sometimes. Also, 57% reported not having yet determined a risk threshold for acceptable postdonation risk above which candidates are excluded. Contemporary practice variation underscores the need for better evidence to guide the donor selection process.