Pre-donation recruitment of Renal functional Reserve is associated with early renal adaptation after living kidney donation.

N.R. Hessels, M. van Londen, N. Kasper, A.L. Messchendorp, J. van der Weijden, J.S.F. Sanders, S.P. Berger, S.J.L. Bakker, M.H. de Borst, G.J. Navis

Thursday 15 march 2018

16:35 - 16:45h at Van Rijck/Ruys Zaal

Categories: Coördinatiesessie, Session (parallel)

Parallel session: Parallel session 10: Transplant coordination

Background

Early renal adaptation after kidney donation commonly results in a post-donation GFR above 50% of the pre-donation value. This is likely due to early hemodynamic changes, whereas long-term renal adaptation, which may further increase GFR in the months thereafter is likely more structural in nature. Renal Functional Reserve assessed by the renal response to dopamine infusion (RFR) is considered to reflect functional reserve capacity, but it is unknown whether it predicts either short- or long-term renal adaptation or both.

Aim

In this study we investigated the association between pre-donation RFR and GFR changes after donation.

Methods

In 750 living kidney donors between 1984 and 2017, we prospectively measured mGFR (¹²⁵-Iothalamate clearance) and RFR. We performed multivariable linear regression analyses with short-term post-donation mGFR as dependent variable. In donors with 5 year follow-up after donation we assessed the association with long-term mGFR.

Results

Donor age was 52±11 years and 48% were male. Pre-donation mGFR and mGFR_Dopamine were 107±28 ml/min and 115±30 ml/min respectively, resulting in a RFR of 9±10 ml/min. Three months post-donation mGFR and mGFR_Dopamine were 73±15 ml/min and 76±15 ml/min respectively, indicating that donors still had RFR (2.7±5.8 ml/min, p<0.001). Pre-donation RFR was associated with post-donation mGFR, independent of age, pre-donation mGFR, blood pressure and BMI (st. β=0.12 for pre-donation RFR, p<0.001, final model R²=0.63). In the subgroup of donors of whom 5-year follow-up data was available (n=349), pre-donation RFR was neither associated with absolute mGFR at 5 years post-donation (st. β=0.02, p=0.78), nor with change in mGFR between 3 months and 5 year after donation (st. β=0.03, p=0.67).

Conclusions

Dopamine-recruited Renal Functional Reserve is independently associated with mGFR early after donation, but not with long-term mGFR. This indicates that RFR_Dopamine is a marker of early, hemodynamic adaptation to kidney donation, rather than long-term mGFR changes. More long-term follow-up data are needed to provide conclusive results about the use of dopamine in living kidney donors.