Introduction: The relative donor kidney size is well-known factor to graft renal function, but there are still controversies about its effect on long-term graft survival. This study is aimed to evaluate the impact of the mismatch between donor kidney weight to recipient body weight(KW/BW) on long-term graft survival.
Materials and Methods: We retrospectively investigated 1255 consecutive adult living donor kidney transplantation cases from January 2000 to December 2013 in Severance hospital. According to KWBW quartile, the enrolled patients were divided into 4 groups, 1st quartile (KW/BW < 2.9; n=313), 2nd quartile (2.9≤KW/BW<3.5; n=314), 3rd quartile (3.5≤KW/BW<4.2; n=315), 4th quartile (4.2≤KWBW; n=313).



Results: In multivariate analysis, recipient age (p=0.017), donor age (p<0.001), HLA mismatch (p=0.039), KW/BW (p=0.020) were independent factors that affect the death-censored graft loss. The 1st quartile group showed lowest eGFR at postoperative 1, 6 months (p=0.005) but the renal function of this group improved steadily, the statistical difference was diminished compared to other groups after a year from surgery (p=0.163). From 5 years after transplantation, the eGFR of 1st quartile group declined significantly lower than other groups (p=0.000) and this phenomenon sustained up to 10 years after operation.



The KW/BW also effects on the death-censored graft survival at 10 years after operation (p=0.04).



Conclusions: The KW/BW ratio is the independent determinant for long-term renal graft function and graft survival.