On Oct. 3, 2025, scientists announced the first successful human transplant of a kidney converted from blood type A to universal type O used special enzymes developed at the University of British Columbia to help prevent a mismatch and rejection of the organ.

Published in Nature Biomedical Engineering, the achievement marks a major step toward helping thousands of patients get kidney transplants sooner.

In a first-in-human experiment, the enzyme-converted kidney was transplanted into a brain-dead recipient with consent from the family, allowing researchers to observe the immune response without risking a life.

For two days, the kidney functioned without signs of hyperacute rejection, the rapid immune reaction that can destroy an incompatible organ within minutes. By the third day, some blood-type markers reappeared, triggering a mild reaction, but the damage was far less severe than in a typical mismatch, and researchers saw signs that the body was beginning to tolerate the organ.

“This is the first time we’ve seen this play out in a human model,” said Dr. Stephen Withers, UBC professor emeritus of chemistry who co-led the enzyme development. “It gives us invaluable insight into how to improve long-term outcomes.”

The breakthrough is the result of more than a decade of work. In the early 2010s, Dr. Withers and colleague Dr. Jayachandran Kizhakkedathu, a UBC professor in the department of pathology and laboratory medicine and the Centre for Blood Research, were focused on making universal donor blood by stripping away the sugars that define blood types.

Regulatory approval for clinical trials is the next hurdle, and the partner UBC spin-off company Avivo Biomedical will lead development of these enzymes for transplant application and to enable the creation of universal donor blood on demand for transfusion medicine.