Assessment of Glomerular Filtration Rate and End-Stage Kidney Disease Risk in Living Kidney Donor Candidates: A Paradigm for Evaluation, Selection, and Counseling  Lesley A. Inker, Farrukh M. Koraishy, Nitender Goyal, Krista L. Lentine  Advances in Chronic Kidney Disease  Volume 25, Issue 1, Pages 21-30 (January 2018) DOI: 10.1053/j.ackd.2017.09.002 Copyright © 2017 National Kidney Foundation, Inc. Terms and Conditions

Figure 1 The KDIGO framework to accept or decline donor candidates based on a transplant program's threshold of acceptable postdonation lifetime risk of kidney failure. A donor candidate's projected estimated lifetime risk is based on their predonation demographic characteristics (blue bar) and health characteristics (orange bar), and their risk attributable to donation (brown bar). The decision by the transplant program to accept or decline a donor candidate can be grounded upon on whether an individual's estimated projected postdonation lifetime risk is above or below the threshold set by the transplant program (dotted line). Each transplant program may decide on its acceptable threshold for an important outcome, and this threshold may vary across transplant programs, but a transplant program should apply their same threshold to all donor candidates evaluated at that center. For example, candidate A would be acceptable because the estimated projected postdonation risk for an important outcome is far below the threshold. Candidate B could be accepted with caution because the estimated projected postdonation risk is close to the threshold, and candidate C would be declined because the estimated postdonation projected risk is far above the threshold. KDIGO, Kidney Disease: Improving Global Outcomes. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.) Reproduced with permission from KDIGO.11 Advances in Chronic Kidney Disease 2018 25, 21-30DOI: (10.1053/j.ackd.2017.09.002) Copyright © 2017 National Kidney Foundation, Inc. Terms and Conditions

Figure 2 KDIGO classification of GFR categories and use in decision-making for donor candidates. Colors are blended together to signify thresholds for decision-making are imprecise. GFR, glomerular filtration rate; KDIGO, Kidney Disease: Improving Global Outcome. Reproduced with permission from Levey and Inker, JASN.13 Advances in Chronic Kidney Disease 2018 25, 21-30DOI: (10.1053/j.ackd.2017.09.002) Copyright © 2017 National Kidney Foundation, Inc. Terms and Conditions

Figure 3 Assessment of GFR and application to donor candidate selection. Initial test: eGFRcr is the initial test in most donor candidates. eGFRcys may be the preferred initial test for candidates with variations in non-GFR determinants of eGFRcr, for example, variation in muscle mass or diet. Interpretation of eGFR should include consideration of the probability that mGFR is above or below thresholds for decision-making (http://ckdepi.org/equations/donor-candidate-gfr-calculator). Very high likelihood that mGFR is <60 mL/min/1.73 m2 is justification to decline without further evaluation. Confirmatory tests: mGFR or mCrCl is required in the United States. Elsewhere, eGFRcr-cys can be acceptable if mGFR or mCrCl is not available and eGFRcys was not used as the initial test. Repeat eGFRcr can be acceptable if none of the others confirmatory tests are available but is not preferred. Inconsistent test results suggest inaccuracy of one or more tests, which should be discarded or repeated. Very high likelihood that mGFR <60 mL/min/1.73 m2 is justification to decline without further evaluation. Using GFR to estimate long-term ESRD risk. Long-term estimated risk of ESRD is compared to the transplant program's threshold for acceptable risk. Long-term risk in the absence of donation can be estimated from demographic and health characteristics, including GFR (http://www.transplantmodels.com/esrdrisk). Additional risk attributable to donation is currently thought to be approximately 3.5-5.3 times higher than risk in the absence of donation, but there is substantial uncertainty, especially in younger donor candidates, and we suggest caution in decision-making. Postdonation ESRD risk above the program's acceptance threshold is justification to decline the candidate. Candidates with risk below the threshold are acceptable to the program, and make their own decision whether or not to proceed with donation. Colors are blended together to signify thresholds for decision-making are imprecise. GFR, glomerular filtration rate; mGFR, measured GFR. Reproduced with permission from Levey and Inker, JASN 2017.13 Advances in Chronic Kidney Disease 2018 25, 21-30DOI: (10.1053/j.ackd.2017.09.002) Copyright © 2017 National Kidney Foundation, Inc. Terms and Conditions

Figure 4 Perspectives of risk in living kidney donation. Framework for risk assessment and comparison relevant to the design of research studies, interpretation of observations, and patient communication. KDIGO, Kidney Disease: Improving Global Outcomes; LKD, living kidney donor. Reproduced with permission from KDIGO and JASN.11,31 Advances in Chronic Kidney Disease 2018 25, 21-30DOI: (10.1053/j.ackd.2017.09.002) Copyright © 2017 National Kidney Foundation, Inc. Terms and Conditions