Race-Neutral 2021 CKD-EPI Creatinine eGFR and Iohexol-Measured GFR in Living Kidney Donor Candidates

Background: The race neutral 2021 CKD EPI creatinine (Cr) eGFR was approved by the OPTN to calculate kidney function for transplant candidates on the national waitlist to address disparities in kidney transplantation. The 2021 CKD EPI Cr equation estimates a lower GFR for Black patients and a higher GFR for non -Black patients for the same creatinine value. Hence the 2021 CKD EPI Cr eGFR may not provide an accurate estimate of kidney function of potential living kidney donors Methods: single center retrospective review of charts of potential kidney donors who had measured GFR by Iohexol clearance between January 1, 2021 and December 31, 2023. Data collected include demographics, eGFR calculated by race neutral 2021 CKD EPI Cr equation and Iohexol GFR test. Subjects were divided into 2 groups, Black and Non Black. Results: Iohexol clearance was done in 333 kidney donor candidates, 62.7% were female and 23.7% were black. The average BMI was 30.4 kg/ m 2 . There was a positive correlation between 2021 CKD EPI Cr eGFR and Iohexol GFR in both groups. Black donor candidates had lower eGFR calculated by 2021 CKD EPI Cr compared to non black, p=0.002. See table. There was no significant difference between Iohexol clearance between the 2 groups. The race neutral 2021 CKD EPI Cr eGFR overestimated GFR in non black compared to black individuals, p=0.02. Conclusion: 2021 CKD EPI Cr eGFR correlated with the Iohexol GFR in black kidney donor candidates, however it overestimated GFR in non black kidney donors.