Older kidneys work fine (thank you for asking:)

Older Kidneys Work Fine for Transplants

"Using data from more than 50,000 living donor transplants from 1998 through 2003, researchers at the University of British Columbia concluded that the age of the donor made no difference to the eventual success of the transplant — except for recipients ages 18 to 39, who were more likely to succeed with a donor their own age. Patients in this group accounted for about a quarter of all the patients studied.

The scientists also analyzed lists of people waiting for a kidney from a deceased donor and found that the probability of becoming ineligible for donation within three years was high, varying from 21 percent to 66 percent, depending on age, blood group and severity of disease.

Waiting can be fatal, the authors contend, and an offer of a kidney should not be rejected simply because of the donor’s age."