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Female kidneys and kidneys from small donors have been suggested to perform worse after kidney transplantation. Here, we evaluate the impact of gender and body dimensions on posttransplantation GFR in living donor transplantation. Two hundred and ninety-three donor-recipient pairs, who were transplanted at our center were evaluated. All pairs had detailed renal function measurement ((125) I-iothalamate and (131) I-hippuran) 4 months predonation in the donor and 2.5 months posttransplantation in donor and recipient. For 88 pairs, 5 years of recipient follow-up was available. Delta GFR was calculated as (recipient GFR-donor single kidney GFR). Recipients of both male and female kidneys had similar renal function at early and long term after transplantation. Male recipients had higher ERPF, ΔGFR and ΔERPF at both time points. Kidneys of donors smaller than their recipient had higher ΔGFR and ΔERPF than kidneys of larger donors at both time points (p < 0.05). In multivariate analysis, ΔGFR was predicted by donor/recipient BSA-ratio together with transplantation related factors (R(2) 0.19), irrespective of donor and recipient gender. In conclusion, in living donor transplantation, female kidneys perform as well as male donor kidneys. Kidneys adapt to the recipient's body size and demands, independent of gender, without detrimental effects in renal function and outcome up to mid-long term., (©2011 The Authors Journal compilation©2011 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Renal functional reserve could be relevant for the maintenance of renal function after kidney donation. Low-dose dopamine induces renal vasodilation with a rise in glomerular filtration rate (GFR) in healthy subjects and is thought to be a reflection of reserve capacity (RC). Older age and higher body mass index (BMI) may be associated with reduced RC. We therefore investigated RC in 178 consecutive living kidney donors (39% males, age 48 +/- 11 years, BMI 25.5 +/- 4.1). RC was determined as the rise in GFR ((125)I-iothalamate), 4 months before and 2 months after donor nephrectomy. Before donor nephrectomy, GFR was 114 +/- 20 mL/min, with a reduction to 72 +/- 12 mL/min after donor nephrectomy. The dopamine-induced rise in GFR of 11 +/- 10% was reduced to 5 +/- 7% after donor nephrectomy (p < 0.001). Before donor nephrectomy, older age and higher BMI did not affect reserve capacity. After donor nephrectomy, the response of GFR to dopamine independently and negatively correlated with older age and higher BMI. Moreover, postdonation reserve capacity was absent in obese donors. The presence of overweight had more impact on loss of RC in younger donors. In conclusion, donor nephrectomy unmasked an age- and overweight-induced loss of reserve capacity. Younger donors with obesity should be carefully monitored.

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.