Definition of chronic kidney disease after uninephrectomy in living donors: what are the implications?
BACKGROUND
Living kidney transplant donors generally have a favorable renal functional outcome postuninephrectomy, but concern remains that a reduced glomerular filtration rate (GFR) postuninephrectomy might have harmful effects. This study examines the short-term (3 months) effect of donor nephrectomy on GFR and the occurrence of stage 3 chronic kidney disease (CKD) postuninephrectomy.


METHODS
The prevalence of stage 3 CKD (Kidney Disease Quality Outcome Initiative [GFR<60 mL/min/1.73 m]) was examined in 196 living donors by comparing preuninephrectomy and 3-month postuninephrectomy values of GFR using I-iothalamate GFR (iGFR), modification of diet in renal disease estimated GFR (eGFR), Cockcroft-Gault estimated creatinine clearance, and endogenous 24-hr creatinine clearance. The accuracy of GFR estimations for predicting iGFR was also studied.


RESULTS
The mean GFR before and after donation were iGFR, 105+/-18 and 68+/-13 mL/min/1.73 m; eGFR, 98+/-19 and 63+/-12 mL/min/1.73 m; Cockcroft-Gault estimated creatinine clearance, 125+/-33 and 85+/-22 mL/min/1.73 m, and endogenous 24-hr creatinine clearance, 133+/-38 and 86+/-24 mL/min/1.73 m, respectively. Stage 3 CKD was found postuninephrectomy in 53 donors (27%) by iGFR and in 73 donors (38%) by eGFR. The prevalence of stage 3 CKD was greater with older age. GFR estimation equations did not accurately predict iGFR, particularly postuninephrectomy.


CONCLUSIONS
Stage 3 CKD is commonly observed after living kidney donation, particularly in older donors. The long-term impact of stage 3 CKD postuninephrectomy is poorly understood and may not have the same implications as stage 3 CKD in other conditions. eGFR is a poor predictor of true GFR in kidney donors.
Barri
Yousri M
YM
Baylor Transplant Institute, Dallas, TX 75246, USA. barriy@dneph.com
Parker
Tom
T
Daoud
Yahya
Y
Glassock
Richard J
RJ
D000328:Adult; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000453:epidemiology* / Q000503:physiopathology; D019520:Living Donors / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000009:adverse effects*; D011237:Predictive Value of Tests; D015995:Prevalence; D012189:Retrospective Studies