People with type A blood are more likely to contract the new coronavirus
According to a recent report published by the news portal LiveScience, SARS-CoV-2 can bind more easily to the cells of people who have type A blood - compared to those who have type B or O blood. New studies show that, during the pandemic, people with type A blood were not only those who contracted the virus the most but also those who developed the most severe symptoms of the disease.
Based on data and experiments carried out in laboratories, the scientists found that a part of the structure of the coronavirus called the “receptor binding domain” (RBD), connects more easily to molecules that are uniquely associated with type A blood. These molecules, known as antigens, appear in the cells that line the respiratory tract, including the lungs.
The results of the studies were published on Wednesday, 03/03, in the journal Blood Advances.
Why does blood type matter?
Since the early days of the pandemic, several studies conducted with patients who were infected with the new coronavirus have revealed certain trends between the disease and blood types.
“Many studies have found associations between the disease and blood groups. Some, for example, point out that people with type O blood have a lower risk of contracting COVID-19, ”said Torben Barington, a clinical immunologist at Odense University Hospital and the University of Southern Denmark. "In contrast, people who have type A blood are more likely to not only contract the disease but also develop severe symptoms."
"Several hypotheses have been proposed for these associations, but we still need to conduct further studies," said Barington. “This new study suggests a possible explanation for why SARS-CoV-2 can infect type A individuals more easily than those who have type O - although it does not explain why type B is also linked to more infections than type O, ”noted the expert.
The finding came to light when the researchers when analyzing different parts of the virus's structure, realized that the receptor-binding domain is very similar to an old group of proteins, called galectins.
Galectins are found in multicellular animals. In short, these proteins bind to carbohydrates, or sugar structures, known as glycans; in humans, galectins are present throughout the body and are essential in many processes, from muscle development to the metabolism and behavior of immune cells.
The presence or absence of these antigens, which are classified in A and B, determines a person's blood group - A, B, AB, who has both, or O, which has neither. "Given the molecular similarity between the part of the structure of the coronavirus and the galectins, we can see how the virus binds directly to blood type A antigens," said the specialist.
“If we are really right, blood group antigens can somehow influence the likelihood that the disease will infiltrate the cells more easily, triggering the infection ”, reveals Barington.
"Therefore, we believe that something similar could be happening with blood group type A antigens and SARS-CoV-2.