Background: Some kidney donors have diabetes, and little of their natural course of diabetic nephropathy (DN) is known. The aim of this study was to analyze the changes in pathologic lesions in the diabetic donor kidney after KT by performing biopsy 2 weeks and 1 year after KT.

Methods: This retrospective study included 103 patients who underwent KT, with kidneys from donors with a history of diabetes mellitus (DM). Among these, 37 underwent biopsy 2 weeks and 1 year after KT, of which, data of 34 patients were reviewed. Biopsy specimens were reviewed using light microscopy and electron microscopy. Glomerular basement membrane (GBM) thickness at 2 weeks and 1 year was compared.

Results: Biopsy showed that DN occurred in 29 of the 34 patients. However, 17 of them (50%) were classified as having class I, a mild case with an increase in GBM thickness. Extremely small histological changes were observed in 22 patients (64.7%), including 5 patients who did not show DN. At 1 year after transplantation, there was no change in the DN histologic class in 26 patients (76.5%), and there was no statistically significant difference in the change in GBM thickness. This pattern was observed regardless of the recipient’s DM or glucose control status.

Conclusions: Donor DN was mostly stable for 1 year after KT, and this pattern did not depend on the recipient’s DM or glucose control status. With this understanding, clinicians can use kidneys from DM donors with more comfort, thereby reducing the kidney discard rate.