The development could increase the supply of kidneys available for transplant, particularly in minority ethnic groups who are less likely to find a match, scientists say. A kidney from someone with blood type A cannot be transplanted into someone with blood type B, nor vice versa. But changing the blood type to universal O would allow more transplants to be carried out, as it can be used for people with any blood type. Cambridge University researchers used a normothermic perfusion machine – a device attached to a human kidney to pass oxygenated blood through the organ to better preserve it for future use – to flush blood by injecting an enzyme through the deceased donor’s kidney . The enzyme removed the blood type markers lining the kidney’s blood vessels, which led to the organ becoming type O. Serena MacMillan, a PhD student at the University of Cambridge, said: “Our confidence was really boosted after we applied the enzyme to a piece of human kidney tissue and saw very quickly that the antigens were removed. “After that, we knew the process was feasible, and we just had to scale up the project to apply the enzyme to full-sized human kidneys. “By taking human type B kidneys and pumping the enzyme through the organ using our normothermic perfusion machine, we saw within just a few hours that we had converted a type B kidney to a type O. “It’s very exciting to think how this could affect so many lives.” People from minority ethnic groups often wait a year longer for a transplant than white patients, so the study could have particular implications for them, experts say. Start your day with the top stories from the US, plus the day’s must-reads from across the Guardian Privacy Notice: Newsletters may contain information about charities, online advertising and content sponsored by external parties. For more information, see our Privacy Policy. We use Google reCaptcha to protect our website and Google’s Privacy Policy and Terms of Service apply. People from minority communities are more likely to have type B blood and with low donation rates from these populations there are not enough kidneys to go around. In 2020-21, just over 9% of total organ donations in the UK came from black and minority ethnic donors, while black and minority patients make up 33% of the kidney transplant waiting list. Now the researchers need to see how the newly changed type O kidney to a patient’s normal blood type will react to their normal blood supply. The machine allows them to do this before testing in humans, as they can take the kidneys that have been changed to type O and inject different types of blood to watch how the kidney might react. Professor Mike Nicholson, Professor of Transplant Surgery at the University of Cambridge, said: “One of the biggest restrictions on who a donated kidney can be transplanted into is the fact that you have to be blood type compatible. “The reason for this is that you have antigens and markers on your cells that can be either A or B. “Your body makes natural antibodies against the ones you don’t have. “Blood group classification is also determined through ethnicity, and ethnic minorities are more likely to have the rarer type B.” Dr Aisling McMahon, executive director of research at Kidney Research UK, said: “The research being undertaken by Mike and Serena could be a game changer.” After testing the reintroduction of other blood types, the team will look at how the approach can be used in a clinical setting. The research, which is funded by the charity Kidney Research UK, is due to be published in the British Journal of Surgery in the coming months.
