The Impact of Body Build Difference between Kidney Donor and Recipient on the Outcome of Renal Allograft

Within the four decades, transplantation of the kidney has become a unique and exciting treatment for patients with end stage renal disease. Reviewing the results of renal transplantation during that time, short term graft survival has irnproved, but long term result has not due to chronic rejection or chronic allograft dysfunction, namely chronic allo- graft injury. As one of the non-immunologic mecha- nism, chronic allograft dysfunction is known to be the damaging result of hyperfiltration being a burden to allograft. The postulation that this damage result from imbalance between nephron supplying and patients demand in renal allograft, some authors suggest that as the index of that imbalance, the ratio of kidney weight/recipient body weight (KW/BW) should be at least 2.0-2.5 if stable graft function can be maintained, meanwhile the ratio of donor body surface area/ recipient body surface area(D/RBSA) should be at least over 0.8. In the whole world a lot of studies have been on in this aspect which usually is subjected in cadaveric graft, but in our country it is totally lacking. We made checking the weight of donated kidney and reci- pient's body weight, and comparing the body sur- face areas between donor and recipient among living donor renal transplants. We tried to investigate whether this disparity of body build have influence on transplantation significantly, and whether KW/ BW or D/RBSA is proper as a predictor of renal allograft outcome or not. Between April 1979 and Dec 1993, 1126 renal transplantations were done in Severance hospital Yonsei University Colledge of Medicine, Seoul Korea, and among them 635 cases were selected through some criteria. Medical records of kidney donor and recipient were examined to check the ratio of body surface between donor and recipient(D/RBSA), and the weight of donated kidney was calculated throug- ht a formula, so as to check the ratio between it and recipient's body weight(KW/BW). All cases were classified as two groups using KW/BW, one group was 2.5 and less, another was above 2.5, then they were compared at the basis of development of chronic allograft dysfunction. All cases were also classified as two groups using D/RBSA at the point of 0.93. The occurrence of renal insufficiency and proteinuria, and their duration of onset after kidney transplantation were regard as the variables of chro- nic renal allograft dysfunction. And then multivariate analyses were tried finally including other variables which were already analyzed in other studies. The results were as follows' 1) The mean age of 635 cases was 35.2±11.2 years in donors, and was 35.6±10.1 years in reci- pients. Male versus female was 1.8:1 in donors, 2.1:1 in recipients. Donor's BSA was 1.69±0.14m, reci- pient's BSA was 1.60±0.13m' The mean estimated kidney weight was 146.2±13.7gm, mean KW/BW was 2.72±0.45, mean D/RBSA was 1.06± 0.12. The mean duration of onset of renal insufficiency was 40.5±23.1 rnonth and of proteinuria was 41.223.0 month. 2) There was no significant difference in the ratio of renal insufficiency between two groups in respect of the KW/HW and D/RBSA. Multivariate analysis also showed no significant difference between two groups. 3) There was no significant difference in the time of onset of renal insufficiency after graft between two groups with respect to the KW/BW and D/RBSA. 4) The occurrence rate of proteinuria after graft was significantly higher in group of KW/BW which was lower than 2.5, and also in group of D/RBSA lower than 0.93. 5) The onset of proteinuria after graft in group with smaller KW/BW or D/RBSA showed in short period than that with larger KW/BW or D/RBSA(in univariate analysis). But there was no statistical significance between them in multivariate analysis. In conclusion, the difference of body build bet- ween kidney donor and recipient can be seen closely correlated with the occurrence rate of proteinuria, and also with the time of its occurrence in some degree. So it seems to be mandate to follow up for a long time if the the patient shows proteinuria after transplantation. We also feel it would need further investigation in much more cases, especially in living donor transplantation and comparing analysis in many aspects such as ethnic differences. However, if cadaveric renal transplantation is increased, KW/BW or D/RBSA can be used as valuable predictor of long-term graft outcome.ope