THE ESSENTIAL
- The researchers demonstrated that the elimination of the blood group A antigen, thanks to two enzymes, was successful and that the health of the lungs was not impaired.
- This technique, which consists of using two enzymes to modify the blood group of an organ, could make it possible to improve the fairness of the allocation of organs.
“The allocation of donor organs is dependent on ABO compatibility, which limits the possibility of some patients receiving a life-saving transplant.” This is what researchers at the University Health Network, in Toronto (Canada), wrote in work published in the journal Science Translational Medicine February 16. These researchers would have found a solution to remedy this problem. Thanks to two enzymes, they managed to modify the blood group of a human donor lung from A to O. Thus, the organ can potentially be used for any recipient awaiting a transplant.
As a reminder, people belonging to group O, whose red blood cells and blood are compatible with all other blood groups, can donate to any recipient because they have no antigen. Clearly, the organs of these universal donors can be accepted by a patient belonging to another blood group. That’s why Canadian researchers changed the blood type of a lung.
More than 99% of type A antigens from red blood cells have been eliminated
To efficiently convert group A red blood cells to O, they used two enzymes, FpGalNAc deacetylase and FpGalactosaminidase. “This group of enzymes that we found in the human gut can cleave the A and B antigen sugars on red blood cells, thereby converting them into universal type O cells,” said Dr. Stephen Withers, a biochemist at the University of British Columbia in Vancouver, in a statement.
According to the study, the ability of these enzymes to eliminate the A antigen was examined on five samples of ABO-A1 human red blood cells and three human aortas. The enzymes removed more than 99 and 90% of type A antigens from red blood cells and aortas, respectively. According to the results, the ex vivo pulmonary perfusion system (EVLP) developed in Toronto, which contained the enzymes, eliminated more than 97% of type A antigens in four hours. “No treatment-related acute pulmonary toxicity was observed,” can we read in the works.
“This experiment paved the way for the creation of universal blood-type organs,” said Dr. Withers. “The existence of universal organs means that we could eliminate the barrier of blood compatibility and rank patients in order of medical urgency, which would save more lives and waste fewer organs,” reported Dr. Marcelo Cypel, lead author of the study.