Predictive capacity of pre-donation GFR and renal reserve capacity for donor renal function after living kidney donation.
Rook M., Hofker HS., van Son WJ., Homan van der Heide JJ., Ploeg RJ., Navis GJ.
Kidney transplantation from living donors is important to reduce organ shortage. Reliable pre-operative estimation of post-donation renal function is essential. We evaluated the predictive potential of pre-donation glomerular filtration rate (GFR) (iothalamate) and renal reserve capacity for post-donation GFR in kidney donors. GFR was measured in 125 consecutive donors (age 49 +/- 11 years; 36% male) 119 +/- 99 days before baseline GFR (GFRb) and 57 +/- 16 days after donation (GFRpost). Reserve capacity was assessed as GFR during stimulation by low-dose dopamine (GFRdopa), amino acids (GFRAA) and both (GFRmax). GFRb was 112 +/- 18, GFRdopa 124 +/- 22, GFRAA 127 +/- 19 and GFRmax 138 +/- 22 mL/min. After donation, GFR remained 64 +/- 7%. GFRpost was predicted by GFRb(R2 = 0.54), GFRdopa(R2 = 0.35), GFRAA(R2 = 0.56), GFRmax(R2 = 0.55)and age (R2 = -0.22; p < 0.001 for all). Linear regression provided the equation GFRpost = 20.01 + (0.46*GFRb). Multivariate analysis predicted GFRpost by GFRb, age and GFRmax(R2 = 0.61, p < 0.001). Post-donation renal function impairment (GFR < or = 60 mL/min/1.73 m2) occurred in 31 donors. On logistic regression, GFRb, body mass index (BMI) and age were independent predictors for renal function impairment, without added value of reserve capacity. GFR allows a relatively reliable prediction of post-donation GFR, improving by taking age and stimulated GFR into account. Long-term studies are needed to further assess the prognostic value of pre-donation characteristics and to prospectively identify subjects with higher risk for renal function loss.