Current definitions of chronic kidney disease (CKD) staging define any individual with 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 SRTR 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. In an unadjusted model, eGFR 30-45 was associated with 3.9-fold higher risk of ESRD compared to donors with eGFR≥60 (HR=_1.80 3.94 _8.60, p<0.01) and eGFR 15-29 was associated with 40-fold higher risk (HR=_5.41 40.29 _299.77, p<0.001) (Table). After adjustment, these associations persisted with 5.3-fold higher risk for eGFR 30-45 and 54-fold higher risk for eGFR 15-29 (both p<0.001, Table). Donors with eGFR 45-60 had elevated risk but the association was not statistically significant (unadjusted HR=_0.81 1.50 _2.79, p=0.2; aHR=_0.92 1.86 _3.77, p=0.08).

CONCLUSIONS: The categorization of eGFR 45-60 as "CKD stage 3" may not be clinically meaningful among LKDs. Nevertheless, eGFR category is associated with ESRD risk among donors with eGFR<30, and our results support current guidelines recommending longitudinal followup of renal function in living kidney donors.

CITATION INFORMATION: Massie A., Henderson M., Al Ammary F., Snyder J., Segev D. Clinical Utility and Interpretation of CKD Stages in Living Kidney Donors Am J Transplant. 2017;17 (suppl 3).

« Back to 2018 American Transplant Congress