Performance of 2021 Creatinine and Cystatin C Based Equations without Race in Living Kidney Transplant Donors
Cleveland Clinic, Cleveland, OH
Meeting: 2022 American Transplant Congress
Abstract number: 490
Keywords: African-American, Kidney transplantation, Living donor, Screening
Topic: Clinical Science » Kidney » 42 - Kidney Living Donor: Selection
Session Information
Session Name: Kidney Living Donor & Paired Exchange
Session Type: Rapid Fire Oral Abstract
Date: Tuesday, June 7, 2022
Session Time: 5:30pm-7:00pm
Presentation Time: 5:30pm-5:40pm
Location: Hynes Room 302
*Purpose: New 2021 Creatinine (Cr) and Cystatin C (CysC) based GFR equations without the race factor have been refitted to perform better than either 2009 Cr CKD-EPI (’09 Cr CKD-EPI) or ’12 CysC-Cr CKD-EPI (‘12 CysC-Cr CKD-EPI) equations which use the race factor. The performance of these new GFR estimation equations when compared to previous race-based equations in living kidney donors is yet to be determined.
*Methods: We studied the performance of ’09 Cr CKD-EPI, ’12 CysC-Cr CKD-EPI, ’21 CKD-EPI without race (’21 Cr CKD-EPI), 2021 CysC-Cr CKD-EPI without race (’21 CysC-Cr CKD EPI) equations against measured GFR by cold iothalamate clearance (iGFR) in 287 living kidney donors from 2015 to 2021. We calculated the bias (difference between eGFR and iGFR) and accuracy (percent within 30% of iGFR, P30%) for each of these equations.
*Results: The median (IQR) age of the population was 45 yo (36-54), 38.3% were male and 90.2% were non-blacks (AA). The median (IQR) serum Cr was 0.84 [0.73,0.95] mg/dl and the serum CysC was 0.80 [0.70,0.92] mg/dl. The median (IQR) for iGFR, ’09 Cr CKD-EPI, ’12 CysC-Cr CKD-EPI, ’21 Cr CKD-EPI and ’21 CysC-Cr CKD-EPI were 101 (88-115), 94 (83-105), 100 (90-111), 98 (87-107) and 103 (94-113) ml/min/1.73m2 respectively. Overall performance as measured by bias and accuracy was better for the ’21 CysC-Cr CKD-EPI equation (Bias 0.77 ml/min/1.73m2, P30% 93.7%) when compared to ’09 Cr CKD-EPI (Bias -0.74 ml/min/1.73m2, P30% 93.4%), ’12 CysC-Cr CKD-EPI (Bias -2.8 ml/min/1.73m2, P30% 94.1%) and ’21 Cr CKD-EPI (Bias -4.6 ml/min/1.73m2, P30% 94.4%). However performance is very variable across different age groups, gender and race. For non-AA donors, smallest bias was observed with the ’21 CysC Cr-CKD EPI while the other three equations underestimated the GFR. Accuracy was highest for AA using both the new 2021 equations (P30% 94%) but using ’21 Cr CKD-EPI led to underestimation of the GFR (Bias -7.4).
*Conclusions: The new 2021 CysC-Cr CKD-EPI equation performs better in regards to bias and accuracy for all living kidney donors. In AA living donors, both bias and accuracy was superior using the 2021 CysC-Cr based CKD-EPI equation. In conclusion, implementation of 2021 CysC-Cr CKD EPI would lead to better estimates of GFR for potential living kidney donor candidates.
| Subset | Overall N= 287 | ’09 Cr CKD-EPI – Bias / P30% | ‘12 CysC-Cr CKD-EPI – Bias / P30% | ’21 Cr CKD-EPI – Bias / P30% | ’21 CysC-Cr CKD-EPI – Bias / P30% |
| Age 18-35 | 74 | -0.73 [-11.5, 7.8] / 90.5 | 4.3 [-7.5, 12.8] / 93.2 | 0.98 [-10.0, 10.6] / 91.9 | 6.5 [-4.6, 13.8] / 93.2 |
| Age 36-45 | 78 | -8.0 [-17.2, 3.1] / 97.4 | -6.4 [-13.2, 11.0] / 94.9 | -5.0 [-16.0, 4.9] / 94.9 | -3.6 [-11.1, 13.7] / 94.9 |
| Age > 46 | 135 | -10.8 [-19.8, 0.02] / 92.6 | -4.6 [-12.5, 7.7] / 94.1 | -7.1 [-16.7, 2.7] / 95.6 | 0.34 [-9.1, 11.1] / 93.3 |
| Non-AA | 270 | -7.8 [-17.8, 3.5] / 93.7 | -3.6 [-12.4, 9.5] / 94.8 | -4.3 [-14.1, 7.0] / 94.4 | 0.23 [-9.0, 12.3] / 93.7 |
| AA | 17 | 2.2 [-1.9, 10.8] / 88.2 | 15.1 [6.5, 25.7] / 82.4 | -7.4 [-13.2, -2.1] / 94.1 | 6.6 [1.6, 20.2] / 94.1 |
| Male | 110 | -6.7 [-16.0, 5.0] / 92.7 | 1.8 [-9.8, 12.0] / 93.6 | -3.2 [-12.5, 7.5] / 94.5 | 5.0 [-6.9, 15.5] / 91.8 |
| Female | 177 | -7.7 [-19.2, 3.7] / 93.8 | -4.6 [-12.5, 9.5] / 94.4 | -5.4 [-16.0, 5.4] / 94.4 | -2.2 [-10.0, 10.2] / 94.9 |
To cite this abstract in AMA style:
Liaqat A, Sawaf H, Cholin L, Arrigain S, Wee A, Schold J, Augustine J, Poggio E. Performance of 2021 Creatinine and Cystatin C Based Equations without Race in Living Kidney Transplant Donors [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/performance-of-2021-creatinine-and-cystatin-c-based-equations-without-race-in-living-kidney-transplant-donors/. Accessed May 18, 2025.« Back to 2022 American Transplant Congress