Lauren Dempsey, MS in Biomedicine and Law, RN, FISM News
A new proof of concept study that was released this month details how scientists are creating universal blood-type organs, in what could be a major breakthrough for those waiting for transplants.
In this experiment, researchers converted the blood-type of donor lungs from type A to type O, in what would allow the lungs to be universally accepted by transplant recipients. The research was published in Science Translational Medicine by researchers at the Latner Thoracic Surgery Research Laboratories, Toronto’s University Health Network and the University of British Columbia.
Researchers used the Ex Vivo Lung Perfusion (EVLP), a plastic domed device that is usually used to provide fluids to donor lungs to prepare them for transplantation. The EVLP has helped physicians to improve the viability of transplant organs by essentially restarting the metabolic process before transplant, allowing their function to be reassessed and any necessary medications to be administered. Dr. Marcelo Cypel, surgical director of the UHN Ajmera Transplant Centre and the senior author of the study said that “We put the lung back to life on this machine.”
In this study the device was used to deliver two enzymes from the gut, which worked to remove the antigens on the surface of the red blood cells, by cutting them off and leaving the core O type structure. One lung was treated with the enzymes to clear the blood type-determining antigens from its surface, while the other lung was left untreated. Then the team added type O blood to the EVLP and discovered that the treated lungs tolerated the type O blood well while the untreated lungs showed signs of rejection.
There are four blood types, A, B, AB, and O, each is identifiable by the antigens that are present on the surface of the cell. For an organ transplant to be successful, the donor and the recipient must be compatible or the recipient runs the risk of rejection, which can be deadly. People with type O blood are considered “universal donors” because their blood and tissue won’t set off an immune response for recipients of any other blood type. However, people with type O blood can only receive blood and tissue products from a donor with the same blood type.
This research may help to tackle one big hurdle that many face while waiting for an organ to become available. There are currently more than 100,000 people in the United States on the transplant waitlist, this experiment would give more people access to this life-saving treatment by increasing the number of universal donors.
According to Aizhou Want, a researcher and author involved with the study, patients with type O blood have to wait about two times longer than those with type A blood. She then explained, “This translates into mortality. Patients who are type O and need a lung transplant have a 20% higher risk of dying while waiting for a matched organ to become available.”
The team is currently looking for enzymes that will work on the B antigens, the research in the study focused on the A antigen and researchers need to determine if the body will reject the modified lung once transplanted or if the antigens could return and trigger an immune response that would attack the transplanted organ causing rejection. Researchers are working on a proposal for a clinical trial within the next 12 to 18 months.
Albert Rizzo, chief medical officer for the American Lung Association acknowledges this advancement while clarifying that this would be one of many factors physicians look at when considering transplant as an option to give patients the best possible outcomes, saying “You’re weighing the benefit of getting the lung sooner against the likelihood of rejection,” but added that “this is very promising research.”