Kidney blood type switched to ‘universal donor’ in transplant breakthrough

·4 min read
Prof Mike Nicholson putting blood through a kidney
Prof Mike Nicholson putting blood through a kidney

The blood type of a human kidney has been changed for the first time ever in a medical breakthrough that could allow people on transplant waiting lists to get an organ sooner.

A person in need of a kidney can spend several years on dialysis waiting for an organ if a living donor cannot be found, but ethnic minorities face an even longer wait because of a lack of donors.

One in every 11 organ donations from 2020 to 2021 came from BAME donors despite making up a third of the waiting list, data show.

But a team from the University of Cambridge have now found a way to make all kidneys, irrespective of their blood type, into type O, the “universal donor” blood group. This, the team believe, could allow for more equitable access to transplants in the future as the success of procedures would not be constrained by blood group.

Three kidneys from deceased individuals that were deemed unfit for transplantation were subjected to an experimental procedure and treated with a bespoke chemical cocktail for five hours.

The key ingredient is an enzyme called α-galactosidase (GH110B) which acts like a pair of “molecular scissors” and shears off the antigen markers that identify the organs as type B.

By clearing the organ of these markers, the enzyme reverts the organ back to its default state, akin to type O.

People who are type O are known as “universal donors” as they have no recognisable antigens on their red blood cells and therefore their blood – and organs – can be given to anybody, irrespective of the recipient’s blood type, and the recipient’s immune system will not reject it.

“One of the biggest restrictions to who a donated kidney can be transplanted to is the fact that you have to be blood group compatible,” said Prof Mike Nicholson, professor of transplant surgery at the University of Cambridge, who was involved in the study.

“The reason for this is that you have antigens and markers on your cells that can be either A or B. Your body naturally produces antibodies against the ones you don’t have.”

Pioneering project

The three kidneys were hooked up to a machine that keeps them functioning after the death of the host and researchers pumped the enzyme-containing liquid through it which, after five hours, turned from type B to type O.

The pioneering project has been peer-reviewed and accepted for publication in the British Journal of Surgery and will be published in the coming weeks.

Researchers working on the project are unable to say when the procedure can be widely adopted in practice, with several regulatory and ethical questions still to be resolved, but say this technological advancement will have seismic implications going forward.

“By taking B type human kidneys and pumping the enzyme through the organ using our normothermic prefusion machine, we saw in a matter of just a few hours that we had converted a B type kidney into an O type,” said study author Serena MacMillan, a PhD student at the University of Cambridge.

“It’s very exciting to think about how this could potentially impact so many lives.”

Ayesha, who suffers with chronic kidney disease, needs a transplant but was told by consultants she may have to wait three times as long as a white person, with a potential wait time of up to 10 years.

Ayesha
Ayesha

“They explained that because of my ethnicity my wait for a deceased donor will be longer than for a white person,” she said.

“The reason being my background – the Muslim community and other faiths and cultures often don’t agree to be organ donors.

“I feel sad at the thought of waiting so long for a transplant. I understand a transplant isn’t a cure, but it would make my body a lot stronger and give me a second chance at a healthy life.”

Dr Aisling McMahon, executive director of research at Kidney Research UK, said: “It is incredibly impressive to see the progress that the team has made in such a short space of time, and we are excited to see the next steps.

“As an organisation, we are committed to funding research that transforms treatments and tackles health inequalities. We know that people from minority ethnic groups can wait much longer for a transplant as they are less likely to be a blood-type match with the organs available.

“This research offers a glimmer of hope to over 1,000 people from minority ethnic groups who are waiting for a kidney.”