Donor gender plays a role in the outcome of renal transplantation, but
the mechanisms responsible for this effect are unclear. In this study
, actuarial graft survival in 1049 recipients transplanted at Montefio
re Medical Center between 1979 and 1994 was examined. It was found tha
t donor gender had no influence on graft survival in recipients treate
d with precyclosporine immunosuppressive agents. In contrast, graft su
rvival time was greater in cyclosporine-treated recipients of male don
or kidneys compared with female kidneys (P < 0.05). This survival time
difference was evident in the early post-transplant period and was en
tirely accounted for by the survival advantage of kidneys from white m
ale donors. There was no gender-related difference in graft survival t
ime among recipients of African-American donor kidneys. Recent attenti
on has focused on the hypothesis that a mismatch between female donor
kidney nephron supply and male recipient functional demand results in
hyperfiltration-mediated glomerular injury and that this is responsibl
e for reduced survival time of female allografts. Any hypothesis purpo
rting to explain gender-related differences in graft survival time mus
t take into account this study's observations that the donor-gender ef
fect was observed only in cyclosporine-treated recipients, was not see
n in African-American donors, appeared soon after renal transplantatio
n, and did not increase progressively with time, These observations ar
e most consistent with the hypothesis that gender-related differences
in graft survival time may reflect differences in susceptibility to cy
closporine nephrotoxicity or differences in the therapeutic response t
o cyclosporine.