Post-transplant allograft outcomes according to mismatch between donor kidney volume and body size of recipients with pre-transplant diabetes mellitus

Abstract Aims The aim of this study was to investigate allograft outcomes when relatively small kidneys were donated to patients with pre-transplant diabetes mellitus (DM). Methods From January 2010 to December 2018, 788 cases of non-sensitized living donor kidney transplant recipient and donor pairs were enrolled. The subjects were divided into four groups according to the relative size of kidney and pre-transplant DM status: non-DM large kidney, non-DM small kidney, DM large kidney, and DM small kidney. We compared allograft outcomes between these four groups. Results The four groups did not show differences in the development of de novo donor-specific antibody and acute rejection. However, a significantly greater decline of allograft function and increased proteinuria were observed in the DM small kidney group. The highest death-censored graft loss rate (P = 0.008) was also observed in this group and the combination of relatively small kidney size and pre-transplant DM was an independent risk factor for death-censored graft loss. In addition, the relatively small kidney and pre-transplant DM showed significant interaction with each other. Conclusions The size mismatch between donated kidney volume and recipient body size should be considered in donor selection of patients with pre-transplant DM.