Transplant recipient renal function is donor renal mass- and recipient gender-dependent.

The effect of both donor renal mass and gender on renal function, in both gender recipients, was examined. Qualifying consecutive living-donor renal transplants (n = 730) were stratified into 4 donor-recipient groups: female-female (n = 177), male-female (n = 151), female-male (n = 240), male-male (n = 162). Groups were equivalent in age, race, body mass index (BMI), match, ischemia time, operative time, and estimated glomerular filtration rate (eGFR). Female recipients had lower serum creatinine (Cr(s)). Male recipients had higher Cr(s) wherever they received a female allograft. Male recipients of male kidneys had a higher eGFR than all other groups for 3 years. Renal function of the recipient correlated with the renal mass of the donor within each group. Male and female kidneys functioned equivalently in the female-recipient environment. Large nephron-mass male donor kidneys function more poorly in female recipients. The male kidney loses 15-20 ml/min eGFR in the female host. The diminished graft function may be related to androgen deprivation. Female and male donor kidneys function equivalently in the male recipient if adjusted for renal mass transplanted. Female kidneys improve eGFR by 7-10 ml/min by being transplanted into a male environment. Donor renal mass and gender affect recipient graft function Expectations of ultimate recipient renal function should take into account both the gender and mass disparity of the donor-recipient pair.