Influence of the recipient's size upon renal function following kidney transplantation. An experimental and clinical investigation.

The influence of the size of the recipient upon posttransplantation renal function was investigated in an experimental study of inbred rats as well as in a retrospective analysis of juvenile recipients of adult donor kidneys. The experimental study revealed either augmentation of the compensatory response, in case of a juvenile donor kidney transplanted into an adult recipient, or attenuation of this response, in case of an adult donor kidney transplanted into a juvenile recipient. Various workers have reported an augmentation of renal function in humans in case of adult recipients of juvenile donor kidneys. In contrast, attenuation of renal function in case of adult donor kidneys transplanted into juvenile recipients, has not been reported. This attenuation was substantiated in our retrospective clinical study. We found that 3 weeks after transplantation, the absolute creatinine clearance (mL/min) was lower in a group of recipients under 12 years old than in a group of recipients older than 12 years. The experimental as well as the clinical investigation indicated that the size of the recipient plays an important part in the functional outcome after renal transplantation. It appeared that the transplanted kidney behaves like a single organ pertaining to the recipient.