VANCOUVER, Canada — In a landmark achievement for regenerative medicine, researchers have reported the first successful human transplant of a kidney chemically altered to function as a universal donor organ.
By utilizing specialized enzymes to convert a Type A kidney into Type O, the team aimed to eliminate the high risk of organ rejection typically associated with blood-type mismatches.
The study, led by scientists from the University of British Columbia (UBC), was recently published in the journal Nature Biomedical Engineering under the title, “Enzyme-converted O kidneys allow ABO-incompatible transplantation without hyperacute rejection in a human decedent model.”
The clinical trial and observations
The pioneering procedure involved transplanting an enzyme-converted kidney into a brain-dead recipient, with full consent provided by the family.
This model allowed researchers to observe the body’s immediate immune response in a real-world biological environment.
- Initial success: For the first 48 hours following the transplant, the kidney functioned effectively with no evidence of “hyperacute rejection”—the immediate and violent immune response that usually destroys mismatched organs.
- Long-term insights: By the third day, scientists noted the reappearance of some blood-type markers, which triggered a mild immune reaction. Crucially, however, the resulting damage was significantly less severe than what is observed in standard mismatched cases.
- Adaptation: The team observed encouraging signs that the recipient’s body was beginning to develop a tolerance for the modified organ.
‘Molecular Scissors’: How the conversion works
This breakthrough is the culmination of over a decade of research focused on “stripping away” the sugar molecules that define blood types.
These sugars act as biological “nametags” that the immune system uses to identify foreign tissue.
The UBC-developed enzymes act as molecular scissors, snipping off these markers to reveal the neutral Type O structure underneath. Stephen Withers, PhD, a UBC professor emeritus of chemistry, used a vivid analogy to describe the process:
“It’s like removing the red paint from a car and uncovering the neutral primer,” Withers explained. “Once that’s done, the immune system no longer sees the organ as foreign.”
[Image: Illustration of enzymes removing sugar markers from a cell surface]
Why this matters for patients
Currently, patients with Type O blood face the most significant challenges in organ transplantation.
While Type O kidneys can be given to almost anyone, Type O patients can only receive Type O organs.
This creates a massive imbalance, leading to significantly longer wait times for more than half of the individuals on kidney transplant lists.
Unlike traditional desensitization methods, which require days of aggressive, high-risk immunosuppressant treatments for the patient, this new technology focuses on modifying the organ itself.
The road to clinical application
The journey to this human trial began in 2019 when the team discovered the specific enzymes needed for the conversion. Since then, the technology has been successfully tested on blood, lungs, and kidneys outside the body.
Reflecting on the progress, Jayachandran Kizhakkedathu, PhD, a professor at UBC’s department of pathology and laboratory medicine, stated:
“Our collaborators showed me their data where, using our enzymes, they had converted a human kidney and transplanted it into a brain-dead recipient. It was working beautifully,” Regarding the next steps, Withers noted that the trial data “gives us invaluable insight into how to improve long-term outcomes.”
Also Read: Kenya opens inquiry into Mediheal Group of Hospitals kidney transplant allegations
The research will now move toward seeking regulatory approval for full clinical trials.
Avivo Biomedical, a UBC spin-off company, has been tasked with leading the commercial development of these enzymes for both organ transplants and the creation of universal donor blood for emergency transfusions.
