July 15, 2026

Donor urine test may help predict kidney transplant outcomes

Most kidney transplants in Canada are made possible through deceased donor donation. However, some deceased donors have conditions such as diabetes that can damage the kidneys. This raises concerns about how well those kidneys may function after transplantation.  

New research suggests that protein in a donor's urine (proteinuria)—a common sign of kidney damage—may help predict long-term transplant outcomes and provide useful information to help patients and transplant teams plan post-transplant care.  

Researchers from the University of Toronto studied more than 9,000 people who received a kidney from a deceased donor with diabetes. They found that about 55 per cent of the donated kidneys came from donors with proteinuria before donation.  

Interestingly, the researchers found that donor proteinuria was linked to long-term graft outcomes rather than immediate transplant complications. It was not associated with graft failure (when the transplanted kidney stops working) during the first 2.5 years after transplantation. However, after 2.5 years, recipients whose donors had proteinuria had a 36 per cent higher risk of graft failure than those whose donors did not have proteinuria. The study also found that donor proteinuria identified signs of kidney damage that were not always detected through routine biopsies. 

Importantly, these findings should not be used to automatically reject kidneys from deceased donors with diabetes or proteinuria. Instead, the researchers suggest that standardized testing for proteinuria in deceased donors could help improve recipient risk assessment and guide follow-up care. This could help clinicians make more informed decisions while expanding access to life-saving transplants for people with kidney failure.  

Overall, this study highlights a simple, widely available test that could improve the evaluation of donor kidneys and support better long-term outcomes for kidney transplant recipients.  

This research was supported in part by The Kidney Foundation of Canada.