Organ transplantation is a life-saving medical procedure, but patients who need it may have to wait a long time to find a suitable donor. In Israel, an average of about 500 are performed Organ transplants Per year. Over 1,000 people Waiting for a transplant, and hundreds of people join the waiting list every year.
One of the obstacles to finding an organ for transplant is the need to match the blood type of the donor to that of the recipient of the donation. Nose That most humans There is one of four blood types: A, B, AB and O, sometimes it is difficult to find a good match, and this means not only long waiting times but also organs that go down the drain.
What is a blood type, and how can it be changed?
Blood type Ours is determined by the types of sugars displayed on the surface of the red blood cells in our body. There are two such types of sugars, which differ from each other: one is called antigen A, and a person whose sugar is displayed on their red blood cells has blood type A. The other is called antigen B, and a person whose sugar is displayed on his red blood cells has blood type B. A person whose two sugars are displayed on his red blood cells will have blood type AB, and a person whose neither is shown on his red blood cells will have blood type O.
The researchers were able to turn the lungs of blood type A donors into lungs with blood type O, using two enzymes called FpGalNAc-datastylase and Fp-galactosamineidase. These enzymes are able to remove antigen A from red blood cells, thus turning them into type O blood cells.
The researchers treated eight blood-type A lungs taken from donors but disqualified for transplantation. The lungs have been placed in a special system that maintains comfortable and stable conditions of the composition of gases, fluids and temperature, in order to preserve their functions. The researchers added the enzymes to the system and saw that within 4 hours, 97 percent of the healthy red blood cells had no more antigen A on the cell surface, and in fact they became type O blood cells. The researchers checked and found that the process did not impair lung function Significantly the rate of cell death, the inflammatory response or the degree of physical damage to the lung cells.
Prevent rejection of precious organs
Patients with blood type A, B and AB can receive an organ from a donor with blood type O, but not vice versa. This is because people with blood type O develop antibodies that detect antigen A or B, and exposure to these antigens (e.g. following an inappropriate blood donation) can cause a strong immune system response against foreign blood cells, ultimately leading to the transplant organ being rejected for incompatibility. Therefore the number of organs suitable for transplantation for people with blood type O is relatively small; in fact, Patients with blood type O have a 20 percent higher risk of dying while waiting for a donor Compared to patients with a different blood type.
Thus, the present experiment examined the possibility of removing antigen, at this stage only from type A, from red blood cells, and transplanting these lungs into patients with type O blood. Blood type O or A.
To make sure that the bodies of O-type transplant recipients would not reject the lungs that had undergone the enzyme treatment, the researchers performed an experiment designed to mimic a condition of transplantation. They first took three pairs of lungs from donors with blood type A, and divided them into two systems: the right lung in a system that included enzymes that remove antigen A and the left lung in the system without treatment. Next, the researchers added to the two systems antibodies taken from the blood of people with blood type O, who identify and bind to antigen A, and tested whether these antibodies bind to each of the two lungs: the patient and the untreated. The researchers found that very few antibodies were bound to the blood cells of the lungs that underwent enzyme treatment, meaning that the rate of antigen A on these healthy cells dropped significantly. In contrast, lungs that had not undergone antigen A treatment on the cells remained high and many antibodies were bound to them.
And what next?
Still, of course, further research is needed to confirm this process as safe for use in human transplants. But the initial results look very promising. Next, the researchers want to try to implant lungs treated with these enzymes in genetically engineered mice that express a human antigen A, to see if the rate of antigen A in lung cells increases again over time, check lung function in the body and monitor the long-term effects of treatment. The researchers estimate that the procedure may, in the end, increase the rate of lungs available for transplant for people with blood type O from 55 percent of all lungs available for transplant today to more than 80 percent in the future.