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Abstract: SA-OR004

Clinical Utility and Interpretation of CKD Stages in Living Kidney Donors

Session Information

Category: Transplantation

  • 1802 Transplantation: Clinical

Authors

  • Massie, Allan, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
  • Thomas, Alvin G., UNC Chapel HIll, Chapel Hill, North Carolina, United States
  • Snyder, Jon J., Minneapolis Medical Research Foundation, Minneapolis, Minnesota, United States
  • Segev, Dorry L., Johns Hopkins University, Baltimore, Maryland, United States
Background

Current definitions of chronic kidney disease (CKD) staging define any individual with estimated glomerular filtration rate (eGFR)<60 as having stage 3 or higher CKD. Nearly half of living kidney donors (LKDs) have post-donation eGFR below this threshold, but the clinical interpretation of eGFR<60 in donors is unknown, and the "CKD" label may not be appropriate. Evidence of risk associated with decreased post-donation eGFR is needed to inform international guidelines and best practices for donor followup and care management.

Methods

Using national registry data, we studied end-stage renal disease (ESRD) risk in 67,571 LKDs 1999-2015 with at least one reported postdonation serum creatinine (SCr). eGFR was calculated via the CKD-EPI equation. Measurements with eGFR<15 were excluded from analysis. We modeled the association between eGFR category (≥60, 45-59, 30-44, 15-30, corresponding to no CKD, CKD stage 3, stage 4A, and stage 4B) using Cox regression with eGFR category as a time-varying exposure and adjusting for donor age, sex, race (black vs nonblack), BMI, and 1st-degree biological relationship to recipient.

Results

117,051 CKD measurements were reported at median (IQR) 11 (4-14) months post-donation (90th percentile 25m post-donation). Of these, 33.9% were in the range 45-59, 5.7% were in the range 30-45, and 0.8% were in the range 15-29. Lower eGFR categories were associated with greater ESRD risk: 5-fold higher risk for eGFR 30-45 (aHR = 5.3 (2.1-13.3)) and 54-fold higher risk for eGFR 15-29 (aHR=53.7 (4.8-421.3); both p<0.001). Donors with eGFR 45-60 had elevated risk but the association was not statistically significant (aHR=1.9 (0.9-3.8), p=0.08).

Conclusion

There is insufficient evidence to support the category eGFR 45-60 as clinically meaningful "CKD stage 3" among LKDs. Nevertheless, eGFR category is associated with ESRD risk among donors with eGFR<45, and our results support current guidelines recommending longitudinal followup of renal function in living kidney donors.

Funding

  • NIDDK Support