There are always calls, sometimes almost desperate ones: blood donors urgently needed. Because donations have been decreasing in Germany for years. The German Red Cross regularly says that reserves are becoming scarce, especially in winter and during the holiday periods. To date, medicine has relied on whole blood or plasma donations; there are no alternatives. In the event of illness, things can become particularly difficult for people with rare blood groups.
Scientists have therefore long been looking for a way to obtain universal blood that can be used equally for all people, regardless of blood type. They primarily rely on methods that can be used to create group 0, which can be used by all recipients, from the two groups A and B, which are only suitable for people in the same group.
also read
A team from Denmark and Sweden may have now made the decisive difference: using a mix of enzymes, they managed to transform samples of the A or B type into type 0. This method makes it possible to ensure more donor blood and simplify the logistics for rare blood groups, they report. They published their results in the journal “Nature Microbiology”.
Human blood groups differ, among other things, in so-called antigens on the surface of the red blood cells, which are characterized by different sugar molecules. In 1900, Austrian pathologist and hematologist Karl Landsteiner discovered the ABO blood group system while experimenting with sera in the laboratory. He noticed that some blood samples clumped together when mixed. On the surface of the red blood cells, the erythrocytes, he found two different structures: antigen A and antigen B.
also read
Blood group A has antigen A, blood group B has antigen B; Group AB blood has both antigens. There are also other properties, including the so-called Rhesus factor. The two blood groups A Rhesus positive and 0 Rhesus positive are most common in the population (37 and 35 percent); the blood groups AB Rhesus negative (one percent) and B Rhesus negative (two percent) are rare.
also read
If you were to inject a person with blood from the A group with the blood of a B group donor, his body would recognize the different blood cells and react to them: Antibodies can then clump the blood – the donation could therefore be life-threatening.
However, things are different with group 0 blood: because special sugar residues are missing, the red blood cells are not perceived as foreign. There are no defensive reactions; in emergency situations it can be transmitted via transfusion without prior testing. In other words, a ‘universal blood’ that also carries Rhesus factor D negative is very popular. However, only six percent of German citizens would be eligible as donors.
also read
In their search for a universal serum, the Danish and Swedish researchers are now relying on the bacterium Akkermansia muciniphila. This protozoan is found in the human large intestine and helps to protect the mucous membrane. The bacterium achieves this by using enzymes to constantly break down certain sugar molecules in the mucus, thereby stimulating the regeneration of intestinal cells.
Some of these sugar molecules correspond to those of blood group antigens. Scientists have therefore suspected for several years that there could be intestinal microbes that could also use their enzymes to “cut” blood antigens. And it has now actually been shown that a combination of these enzymes can transform antigens on people’s red blood cells – and thus produce the generally tolerated group 0.
Especially for girls and women of childbearing age
Markus Müller, senior physician and head of the blood donation department at the Institute for Transfusion Medicine and Immunohematology at the University Hospital Frankfurt am Main, opposite the Science Media Center, calls this an “interesting idea from a scientific and health care perspective.” In an emergency, when the blood type is unknown, “universal blood” is needed, especially for girls and women of childbearing age. And that is always close.
According to Müller’s assessment, this approach could potentially double the supply of the sought-after erythrocyte concentrate in the future. However, he points out that there is still a long way to go before this happens and the samples can be used on patients.
Until now, researchers have only carried out their studies in test tubes filled with hundred microliters of erythrocytes. Tests on animals – and later clinical trials on humans – are still pending. It is therefore still unclear how well the blood cells treated in this way perform in the recipient’s body: how long they remain there, whether they can get into the smallest capillaries and transport oxygen just as well.
Here you will find content from third parties
In order to display embedded content, your revocable consent to the transmission and processing of personal data is necessary, as the providers of the embedded content require this consent as third party providers [In diesem Zusammenhang können auch Nutzungsprofile (u.a. auf Basis von Cookie-IDs) gebildet und angereichert werden, auch außerhalb des EWR]. By setting the switch to “on”, you agree to this (revocable at any time). This also includes your consent to the transfer of certain personal data to third countries, including the USA, in accordance with Art. 49 (1) (a) GDPR. You can find more information about this. You can revoke your consent at any time using the switch and privacy at the bottom of the page.
Thilo Bartolmäs, a specialist in transfusion medicine at the Charité Berlin, is more skeptical. For him, the results are “of a purely academic nature”. He considers “upscaling” to the 250 milliliters of erythrocyte concentrate required for a transfusion to be “very difficult”. The dangerous antigens would then possibly not be completely broken down and dangerous defense reactions would be triggered in the recipient.
In addition, says Bartolmäs, the envisaged universal blood does not even exist. Strictly speaking, there are currently 362 known blood groups in 45 blood group systems. It would be much easier and cheaper to do something about a lack of blood group 0: by recruiting donors in a much more targeted manner.