Researchers have effectively altered the blood type of donor’s kidneys, a breakthrough that could expand the organs available for transplant.
The breakthrough has special ramifications for minority groups, for whom it is typically more difficult to find a suitable partner.
The kidney of a person with blood type A cannot be transplanted into a person with blood type B, and vice versa.
However, converting a kidney’s blood type to type O will allow it to be transplanted into any patient.
Because they are more likely to have the rarer B-type blood group, people of color and other ethnic minorities are often required to wait a year longer for a transplant than white patients.
In addition, organ donation rates are lower among these populations. In 2020/21, slightly more than 9% of all organ donations came from black and other minority ethnic donors, while 33% of kidney transplant candidates are from these populations.
Using a normothermic perfusion machine – a device designed to circulate oxygenated blood through a kidney to help preserve it – scientists at the University of Cambridge were able to flush blood laced with an enzyme through a donor’s kidney.
The enzyme eliminates the blood-type markers that line the organ’s blood arteries, effectively converting the organ’s blood type to type O. When the procedure was successfully conducted on three donor kidneys, it took only a few hours.
Serena MacMillan, a Ph.D. candidate who contributed to the study, remarked that it was “exciting to consider how this could affect so many lives.”
Before a kidney is transplanted into a patient, the next step is to evaluate how the kidneys behave when given a normal supply of blood from their new blood group. This can be done using a machine.
In the coming months, the Kidney Research UK-funded research will be published in the British Journal of Surgery.
Dr. Aisling McMahon, the charity’s executive director of research, described the discovery as “possibly game-changing.”
This is an intriguing and attractive concept, but its effect on organ transplantation remains unproven.
Concerns exist over the science and the extent to which it can expand the availability of organs for donation.
It will require additional testing to determine how these modified organs behave when exposed to previously mismatched blood. And to guarantee the procedure does not cause any harm to the kidneys.
This must be tested in the laboratory before being administered to a small number of patients.
Also, the blood group is only one of three ways kidneys are matched before transplant, and half of the population is already O positive or O negative, the types of blood that anyone can contribute.
Tissue matching and cross-matching (in which the blood of the donor and receiver is combined to test for a reaction) will continue to play a role, especially in ethnic groups.
The best strategy to increase the number of transplants that save lives is for more of us – from every community – to become donors.
