Improving Evaluation and Follow-Up of Living Kidney Donors: Role of Radioisotopic Glomerular Filtration Rate and Renal Functional Reserve

V. Cantaluppi¹, G. Guglielmetti¹, U. M. Morosini¹, A. Nappo¹, G. Merlotti¹, A. Airoldi¹, M. Quaglia¹, C. Ronco²

¹Nephrology and Kidney Transplantation Unit, University of Piemonte Orientale (UPO), Novara, Italy, ²Nephrology, Dialysis and Kidney Transplantation Unit, University of Padova, Vicenza, Italy

Meeting: 2020 American Transplant Congress

Abstract number: 562

Keywords: Graft function, Kidney transplantation, Living donor, Renal failure

Session Information

Session Name: Kidney Living Donor: Other II

Session Type: Oral Abstract Session

Date: Saturday, May 30, 2020

Session Time: 3:15pm-4:45pm

Presentation Time: 3:27pm-3:39pm

Location: Virtual

*Purpose: After donation, living kidney donors (KD) develop an early and transient loss of kidney function (KF), defined as Acute Kidney Injury (AKI). Its recovery is due to the presence of Renal Functional Reserve (RFR), defined as the capacity to increase glomerular filtration rate (GFR). The aim of the study was to analyze KD KF before donation, immediately post-surgery and 1 year after, investigating the predictive performance of pre-donation RFR on AKI and 1 year KF.

*Methods: In 48 consecutive KD, we evaluated: pre-donation serum creatinine (sCr), radioisotopic GFR (rGFR) with 51Cr-EDTA and a sequential scintigraphy with 99mTc-MAG to determine split KF, in the immediate post-operative period (sCr) and 1 year after donation (rGFR): 16 KD underwent a kidney stress test with protein load to assess RFR before donation and 1 year after, respectively. Biomarkers of tubular injury (NGAL , Nephrocheck) were also performed.

*Results: Data before donation: mean sCr 0.7 mg/dL, rGFR 98 mL/min. By scintigraphy, mean KF of right kidney 47%. In the first 72 hrs after donation (all left nephrectomies), KD worsened KF: mean sCr 1.2 mg/dL (1.1-1.4): 7 days after surgery, renal recovery was observed in all patients. One year after donation, rGFR was measured and compared with the split rGFR of the remaining right kidney obtained before donation: 64 mL/min (44-87) vs 46 mL/min (38-65), respectively, with a mean compensatory increase of 18 mL/min (1-46) (35%). Pre-donation RFR was 21.5 mL/min. There was no correlation between pre-donation RFR and AKI after donation, whereas we observed a strong linear correlation between RFR and the compensatory GFR increase 1 year after (r=0.66). Of interest, KD preserved RFR 1 year after donation (16.5 mL/min). Moreover, biomarkers of tubular injury were negative at all time points considered, confirming the absence of AKI and progression toward chronic renal damage.

*Conclusions: Evaluation of rGFR is feasible and allows the precise determination of KF and compensatory GFR increase of the single kidney after donation. This is the first study demonstrating the validity and potential clinical efficacy of a dynamic kidney stress test pre-donation with prognostic information on KF 1 year after. RFR may represent a useful screening tool, providing more information about the quality of the kidney, thus increasing the number of KD.

To cite this abstract in AMA style:

Cantaluppi V, Guglielmetti G, Morosini UM, Nappo A, Merlotti G, Airoldi A, Quaglia M, Ronco C. Improving Evaluation and Follow-Up of Living Kidney Donors: Role of Radioisotopic Glomerular Filtration Rate and Renal Functional Reserve [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/improving-evaluation-and-follow-up-of-living-kidney-donors-role-of-radioisotopic-glomerular-filtration-rate-and-renal-functional-reserve/. Accessed May 11, 2025.

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