We read about advances in the medical field every day, and it is surprising that one of the most precious and irreplaceable resources is still human blood. Yet, despite scientific advances, finding compatible blood donors remains a daily challenge for hospitals and patients around the globe. What if I told you that the solution could be found right within us (and be right, contrary to what 'That' would say)? Look at yourself in the mirror, uncover your belly. Somewhere in front of you is your gut: and this research (which I link to you) start right there.
A revolutionary discovery
A team of Danish and Swedish researchers has identified a mixture of enzymes produced by a species of bacteria present in our intestines, Akkermansia muciniphila. It is “special observation” bacteria, with many promising potentials. Now, also that of transforming red blood cells into universal blood group 0 with "remarkably high efficiency". This discovery improves an idea born 40 years ago, when scientists discovered another enzyme, this time extracted from coffee beans, capable of “stripping” type B cells of their surface sugar structures.
That enzymatic reaction, however, was very inefficient: and made large-scale use impractical. Despite promising initial results in clinical trials, safety concerns were raised. And with good reason. For reasons still unknown today, the blood obtained was sometimes still incompatible in the recipients, even though the blood donors' cells had been stripped of almost all their antigens.
Will all blood donors be universal donors?
What makes the newly discovered enzymes special? Mathias Jensen, Linn Stenfelt and colleagues at the Technical University of Denmark tested the enzymes on red blood cells from different blood donors, and various subtypes A and B. They incubated the enzymes at high concentrations of red blood cells, at room temperature and for just 30 minutes, improving conditions processing times that are longer and less efficient than previous candidates. Result? The chosen enzymes also removed all four known extensions of the group A and B antigens from red blood cells, as well as the shorter canonical A and B antigens of other blood subtypes.
Removal reduced the incompatibility of treated B-type cells with plasma samples less than 9%. And it made the reactions less severe in the cases where they occurred. Further studies will allow us to understand why a small fraction of apparently sugar-free red blood cells still reacts with group 0 plasmas, and to improve the conversion of group A blood cells. The path, in short, seems to be the right one.
New frontiers for transfusion medicine
The researchers are thrilled. They say they have found “a missing link” in the production of universal blood for transfusions, and potentially for organ transplants. In 2022, a similar strategy (with different enzymes) was used to convert donated lungs from blood type A to universal type 0 under laboratory conditions. This new work could improve those efforts enough to meet the safety standards required for human transplant trials.
In the not too distant future, thanks to these extraordinary "intestinal" enzymes, blood banks could have always-ready supplies of universal red blood cells. It would mean saving countless lives in medical emergencies, and saying goodbye to dependence on specific blood donors. An exciting prospect that opens new frontiers for transfusion medicine and transplants, bringing us closer to the goal of more universal and accessible healthcare for all.
