Impact of graft kidney weight to recipient body weight ratio on long-term graft survival after living-donor kidney transplantation

Abstract Background The relative size of kidney allografts is well known to be associated with graft function, but controversies remain about its effect on long-term graft survival. This study aimed to evaluate the effect of mismatch between graft kidney weight and recipient body weight on long-term graft survival. Methods We retrospectively evaluated 1397 consecutive adults undergoing live donor kidney transplantation between January 2000 and May 2019 at Severance Hospital, Republic of Korea. The patients were divided into 4 groups according to graft kidney weight to recipient body weight ratio (KW/BW) quartile. The median follow-up duration was 145 months. Results Kidney transplant recipients with a high KW/BW had significantly higher death-censored graft survival rates up to 10 years after transplantation than patients with a low KW/BW. On Cox multivariable regression analysis, pre-transplantation diabetes, older donor age, and 1st and 2nd KW/BW quartiles were independent risk factors for death-censored graft failure. The 1st KW/BW quartile had the lowest mean estimated glomerular filtration rate throughout the follow-up period. Conclusions Higher KW/BW was associated with better long-term graft function and graft survival after living-donor kidney transplantation.