Scientists at the University of British Columbia (UBC) in Canada have successfully performed the world’s first human transplant of a kidney converted from blood type A to the universal type O.
The experiment, which used special enzymes developed at UBC, was published on October 3 in the journal Nature Biomedical Engineering. The kidney was transplanted into a brain-dead patient, allowing doctors to study how the immune system reacts to a converted organ.
Scientists at UBC discovered unique enzymes that can remove the antigens that determine a person’s blood type. These enzymes work like “molecular scissors,” cutting away the blood-type A markers that usually cause rejection when an organ is transplanted into a patient with a different blood type. When these markers are removed, the organ becomes blood type O — a universal donor type that can match anyone.
Dr. Stephen Withers, a UBC professor of biochemistry and one of the study’s main authors, explained it in simple words. “It’s like taking off the name tag that causes trouble,” he said. “Once the antigens are gone, the immune system no longer sees the organ as foreign.”
By turning a type A kidney into type O, the scientists created what they call a universal transplant kidney — a discovery that could help thousands of patients who wait years for a compatible donor.
With permission from the donor’s family, the team transplanted the enzyme-converted kidney into a brain-dead patient who had many anti-A antibodies, which would normally attack a type A organ. This gave doctors a rare chance to observe what happens when a universal organ meets a real human immune system.
The converted kidney worked normally for two days, producing urine and showing no signs of rejection. On the third day, a few blood-type A markers began to reappear, causing a mild immune reaction. But unlike a typical transplant failure, this reaction was not severe, and the kidney continued to function.
“This is the first time we’ve seen this in a human model,” said Dr. Withers. “It gives us valuable insight into how to improve long-term results. We are very hopeful about what comes next.”
Blood type has always been a big challenge in organ transplants. Humans have four major blood types — A, B, AB, and O. The problem is that people with blood type O can only receive type O organs, while their organs can go to anyone. This makes type O the universal donor type but also the hardest blood group to match for patients.
Patients with blood type O often wait two to four years longer than others for a kidney transplant. Some never get one in time. In the United States alone, more than 90,000 people are currently waiting for kidney transplants, and around 11 people die every day while waiting. The new discovery from UBC could help end this long and painful wait.
To make the kidney universal, the research team used a machine called a perfusion device. This device keeps donated organs alive by circulating a special solution through them before transplantation. The scientists added their unique enzymes to this solution. Within just two hours, the enzymes removed the blood-type A antigens and converted the kidney into type O.
Dr. Jayachandran Kizhakkedathu, a co-author and professor of pathology at UBC, explained that the enzymes are very powerful and efficient. “These enzymes work even in very low amounts,” he said. “They are highly selective and can transform a donor kidney into a universal one in just a few hours.”
The same UBC team had previously used this enzyme method to convert lungs from type A to type O, but this was the first time they tried it in a human transplant.
Although the converted kidney only functioned for a few days, experts say it is a huge achievement for the medical world. The next goal is to test the process in living patients under clinical trials, where the kidneys will be combined with standard immunosuppressive therapy to prevent rejection.
Dr. Withers said, “In real clinical use, there are several procedures that can minimize rejection. If we use those with enzyme-converted organs, the chances of long-term success are very high.”
UBC’s spin-off company, Avivo Biomedical, is now preparing to bring this enzyme technology to hospitals. Their aim is to make enzyme-converted organs (ECO) available for use in transplants and to eventually create universal donor blood for transfusions.
“Our dream is that one day, every organ could be made compatible for every patient,” said Dr. Withers. “We’re getting closer to that dream.”
