On February 16, a study on converting blood types of donor’s lungs intended for transplantation was published in the Science Translational Medicine, the weekly online scientific research journal. Performed by a group of Canadian scientists from the University of British Columbia (UBC), the Latner Thoracic Research Laboratories, and Toronto’s University Health Network (UHN), the study demonstrated an innovative method of creating universal transplant lungs. With increased awareness of population aging and healthy life extension, new attempts of treating donor organs are rays of hope to patients and the medical community.

An important factor in finding a suitable organ for the patient is the compatibility of blood types between the donor and the recipient. Red blood cells have certain antigens that largely divide the cells into four different blood types: A, B, AB, and O. Organ transplantation only works between matching blood types. For example, a type A blood donor cannot donate an organ to a type B blood recipient because the receiving body’s immune system will reject the transplant. Unlike the A and B blood types, type O blood has neither A nor B antigens; thus, it is called a universal donor as it can be used in transfusions of any blood type. Given this, patients with type O blood may wait on average twice as long to receive a lung transplant compared to patients with other blood types, according to the author of the study, Dr. Aizhou Wang.

Overcoming the Barriers of Organ Transplants

Meeting the fundamental yet challenging condition for successful transplantation motivated the team to devise methods of getting rid of the antigens. The researchers conjugated the ex vivo lung perfusion (EVLP), a technique used for preserving and evaluating the lungs before transplantation, to create universal transplant lungs. During the study, the lungs of a type A blood donor were put into the EVLP circuit, with one lung being treated with enzymes that erase the antigens, while the other being left untreated. As a result, the treated lung did not show signs of rejection when type O blood was added to the circuit, while the untreated lung showed a sign of immunological rejection.

According to the UHN, Dr. Marcelo Cypel, a professor of surgery at the University of Toronto and a senior author of the study, reported that future universal blood type organs could “eliminate the blood-matching barrier and prioritize patients by medical urgency, saving more lives and wasting less organs.” Although organ transplantation between unmatching blood types has been feasible through plasmapheresis — the process of separating the liquid part of the blood from the blood cells — direct intervention on patient’s body accompanies risks of sensory abnormalities, muscle spasm, and change in blood pressure. With this study, EVLP has made it possible to treat the organ instead of the patient, which can be seen as a safer method.

However, the number of recipients on the waiting list continues to increase due to the limited supply of donor organs. The overall procedure of organ transplantation is complex as it requires examinations on biological suitability and bioethical considerations. To overcome this issue and find possible solutions for increasing the supply of donor organs, the medical community is investing in biotechnology and the development of transplantation methods such as xenotransplantation — the transplantation of organs from a nonhuman animal source. Although new methods of transplantation are yet to be generalized, these important findings including the universal blood type lung can be seen as milestones in organ transplantation.

The Remaining Ethical Considerations

Despite the ongoing efforts of technological development, discussions regarding ethical considerations and safety issues limit rapid transitions in organ transplantation. For example, deciding the order of recipients is a problem yet to be confronted since most patients who need transplantation are seriously injured and they frequently experience fluctuations of hopes and fears. Until now, the fundamental condition for deciding the order of receival has been immunological compatibility, including the matching of blood types. As Professor Jung Jae-Seung (Department of Thoracic and Cardiovascular Surgery) explains, “If blood type no longer matters, deciding the order of recipients becomes more complicated. For example, should the organ be given to a type O blood patient who typically waits longer than the other blood types, or to a type A blood patient who has been equally waiting for a long time? Since there is no definite answer to this, fair and just organ transplantations must be operated through multidisciplinary discussions regarding the safety and ethical considerations.”

Most importantly, Professor Jung states that ethical discussions and technological development should go together. “Currently we are at the limit, the point where we try to find the balance between technological development and ethical considerations. Societies differ in cultures, perceptions of death, and capital, thus complete unification or transitions regarding organ transplantations cannot happen at this point. However, scientific efforts, including the study of universal blood type lungs and xenotransplantation using pig hearts, are gradually contributing to the paradigm shift. Although it takes time, combined efforts to ensure safe and ethical organ transplantations can hopefully lead to remarkable changes in our society.”

For instance, the study on universal blood type lungs was a collaboration of different organizations in Canada, such as the UHN, UBC, University of Toronto, and University of Alberta. UBC biochemist Dr. Stephen Withers and his team first brought up the idea of using enzymes to treat lungs in 2018. Four years later, scientists from different organizations have gathered to apply this important finding to creating universal transplant organs. In an interview with the UHN, Dr. Wang expresses his appreciation for this collaboration: "By exchanging ideas across disciplines and across the country, we became one collaborative effort to tackle an important problem in organ transplantation.”

All in all, universal transplant lungs created through EVLP assist the development of future healthcare and organ transplantations. Although it takes time to justify its effects, the newly invented technique provides hope to people with physical deficiencies that are incurable through ordinary surgeries. To make every effort count, technological development must accompany active consultations and transparent information delivery among different individuals and communities, including the doctor, the patient, and his or her family members.