It is confirmed that the blood group influences the chances of being infected with the Sars CoV-2 coronavirus and that the A is the one with the highest risk.

As researchers around the world work to identify and address risk factors for severe Covid-19, researchers have found additional evidence that certain blood groups could be associated with an increased risk of contracting the disease.

A new work published in the magazine Blood Advances details one of the first laboratory studies to suggest that SARS-CoV-2, the virus that causes Covid-19, is felt particularly attracted to blood group antigen A found in respiratory cells.

In the study, the researchers evaluated a protein on the surface of the SARS-CoV-2 virus called domain receptor binding or RBD. RBD is the part of the virus that attaches itself to host cells, making it an important research target to understand how infection occurs.

The team evaluated synthetic blood group antigens on respiratory and red blood cells found in individuals of blood groups A, B, and O, and analyzed how SARS-CoV-2 RBD interacted with each unique blood type.

They discovered that the RBD had a strong preference for joining blood group A found in respiratory cells. He did not show a preference for red blood cells of blood group A or other blood groups found in red or respiratory blood cells.

“It is interesting that the viral RBD only really prefers the type of blood group A antigens that are found in respiratory cells, which is presumably the way the virus enters most patients and infects them, “says study author Sean R. Stowell, from Brigham and Women’s Hospital in the United States.

“Blood type is a challenge, because it is inherited and it is not something we can change. But if we can better understand how the virus interacts with people’s blood groups, we may be able to find new drugs or prevention methods, ”he continues.

Based on their observations, the team tried to determine if a similar binding preference existed for the RBD of SARS-CoV, the virus that causes severe acute respiratory syndrome. Although the composition of the virus differs, SARS-CoV RBD showed the same preference for binding to group A antigens on respiratory cells.

Stowell and his team emphasized that their findings alone could not fully describe or predict how coronaviruses such as SARS-CoV-2 and SARS-CoV would affect patients of various blood types. “Our observation is not the only mechanism responsible for what we are seeing clinically, but could explain part of the influence of blood type on Covid-19 infection“, Add.

While more research is needed to understand that influence, the document adds to the findings from previous studies also published in Blood Advances suggesting a possible link between blood type and Covid-19 susceptibility and severity.

These works established that the chances of contracting an infection by the Sars CoV-2 coronavirus and the disease it causes, Covid-19, can vary depending on the blood group: people with type O blood – 44% in Spain – may have the lowest risk, while those with A and AB could present a greater risk of severe clinical pictures.

It was not the first time that a study linked these blood groups with a greater or lesser vulnerability to contagion and a better or worse evolution of the disease.

Last June, an article published in New England Journal of Medicine pointed out that genes may determine that some people develop severe forms of Covid-19 and that having type A blood was associated with a 50% higher risk of the need for respiratory support, while group O conferred a “protective effect”.