A person’s blood type might play an important role in contracting COVID-19 and the severity of infection.
According to a study, people with blood type A are more likely to test positive for the novel coronavirus.
Evidence shows that the COVID-19 virus, SARS-CoV-2, is highly attracted to the blood type A antigen expressed in the respiratory tract.
Researchers examined the SARS-CoV receptor-binding domain (RBD), a crucial part of the virus that binds to the cells and leads to infection.
The antigens on the surface of a red blood cell determine a person’s blood type: A, B, and O (ABO).
The immune system ignores our blood group antigens but antibodies will attack foreign antigens that enter the body.
The research team analysed the blood group antigens on respiratory and red blood cells (RBCs) to determine how the SARS-CoV-2 RBD interacts with each blood type.
They found that the SARS-CoV-2 RBD much preferred attaching to blood type A antigens found in the lungs.
Dr Sean Stowell, the study’s lead author, said:
“It is interesting that the viral RBD only really prefers the type of blood group A antigens that are on respiratory cells, which are presumably how the virus is entering most patients and infecting them.
Blood type is a challenge because it is inherited and not something we can change.
But if we can better understand how the virus interacts with blood groups in people, we may be able to find new medicines or methods of prevention.”
The authors pointed out this mechanism can’t fully explain or predict how coronaviruses would affect patients with different blood groups.
In other words, something else might affect the connection between blood types and coronavirus disease.
Dr Stowell said:
“Our observation is not the only mechanism responsible for what we are seeing clinically, but it could explain some of the influence of blood type on COVID-19 infection.”
The study was published in Blood Advances (Wu et al., 2021).