The part of the story that irritates me is the implication that donating the kidney is the cause of Wang's failing kidney. This is implied and to the lay person it makes total sense. God gave you two kidneys. You better not donate one or you could end up needing a transplant yourself.
This is the wrong conclusion. Donating a kidney does not increase your risk of dialysis, transplant or poor quality of life. This is best illustrated in Ibrahim et al's retrospective study of 3,698 kidney donors from 1963 to 2007.
The study population was the entire cohort of living donors from the University of Minnesota. This population, prior to donating is free of diabetes, hypertension and had a GFR >80 mL/min. Additionally they had no albuminuria. Of course, many of them had a relative with ESRD.
Eleven of the 3,700 (0.3%) donors ultimately needed dialysis or transplantation. The average time from donation to ESRD was 22.5±10.4 years. Seven of the unfortunate, donated to a sibling and only three lost their kidneys due to the same etiology as their recipient.
...estimated incidence of ESRD in donors would appear to be 180 per million persons per year, as compared with the overall adjusted incidence rate of 268 per million persons per year in the white population of the United States.Idea: to lower the epidemic of ESRD, get everyone to donate a kidney and we can reduce the incidence of ESRD by a third.
The remainder of the article goes through the deep analysis of the 255 donors who were invited for further testing.
- Creatinine had gone from 0.9 at the time of donation to 1.1 an average of 12 years later
- GFR went from 84 to 63 mL/min
- 11.5% developed microalbuminuria
- 1.2% developed macroalbuminuria
Thirty-eight donors have returned for two iothalamate GFRs at least 3 years apart. The investigators found the average loss of GFR was 0.6 mL/min per year.
One of the reasons that donating a kidney is safe is that the remaining kidney undergoes hypertrophy to accommodate the increased work-load. The investigators were able to provide some insight into the variables which govern this. Increased compensation correlated with:
- younger age at donation
- higher renal function at donation
- longer time since donation
This final graph should be the take away for discussing kidney donation:
|Kidney donors report better physical and mental health than the US average.|
The image I try to paint is that losing renal function is like melting an ice cube, people start with two ice cubes. When the ice is gone the patient needs a transplant or dialysis. Poorly controlled blood sugars, high blood pressure and proteinuria turn up the ambient temperature so the ice melts faster, but it melts both the left and right cube at the same time. A nephrectomy removes one of the ice cubes but it does not necessarily reduce the time until all the ice is gone.
JAMA published a great article showing the typical experience in India a decade ago. It's still worth reading.
Thanks to Dr. El-Ghoroury for help with this post. Follow him on Twitter @melgho