Type O blood seems to fight better the Covid 19 virus Preliminary data indicate those with Type A blood are at greater risk, while Type O may offe
Preliminary data indicate those with Type A blood are at greater risk, while Type O may offer some protection
Although not conclusive, the cases studied until now allow scholars to hint that there is a certain natural “resistance” in the Type O against Covid 19
The New England Journal of Medicine published a story on results from studies that follow the damages of the Covid 19 virus on people with different types of blood. Gto News reproduces this story by The New England Journal of Medicine as we consider it to be important to all
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Blood type may play a key role in determining who contracts Covid 19and how severe the illness becomes, according to a recent report published in The New England Journal of Medicine (NEJM).
“Our genetic data confirm that blood group O is associated with a risk of acquiring Covid-19 that was lower than that in non-O blood groups, whereas blood group A was associated with a higher risk than non-A blood groups”, researchers concluded in the story by Alexandra Becker for The New England Journal of Medicine.
In the midst of the pandemic
Study participants were spread throughout seven hospitals in the Italian and Spanish epicenters of the pandemic and each were defined as having “severe” respiratory disease; those patients were compared to approximately 2,000 healthy individuals.
Based on the early data and despite the relatively small sample size, the study corroborates other reports, including one from Wuhan, China, where the SARS-CoV-2 virus outbreak originated.
Yet inherent limitations of the NEJM study mean it’s too soon to definitively link blood type to Covid 19 outcomes.
Waitung for conclusive results
“I do believe there is likely a connection, and the question is: What does this word ‘outcome’ mean?” said Ang Li, M.D., an assistant professor of hematology and oncology at Baylor College of Medicine. “The cases are not a study of all Covid patients versus all non-Covid patients, and it’s not a study of all severe Covid patients versus all non-severe Covid patients. It’s comparing the severe Covid patients versus everyone else without Covid. So, it’s hard to know if it’s an increased susceptibility to infection or a severity question”, reveal Li in the story of The New England Journal of Medicine.
Still, Li said, the data suggests that a connection may exist. If it holds, he said, the conclusion would follow results from a 2005 study published in JAMA (the Journal of the American Medical Association) examining SARS-CoV-1—the “original” SARS virus that created an outbreak in 2003. That study also found an association between ABO blood groups and disease susceptibility, with individuals with Type O less susceptible to that virus, as well.
Biologic mechanisms and immune response
Scientists do not know exactly why blood type could influence a person’s susceptibility to these viruses, but authors of the NEJM paper suggest that variations in biologic mechanisms in ABO blood groups may play a role, specifically in their immune response.
“We have different antibody profiles based on our ABO blood type,” Li said. “Also, there are some theories about how some of these ABO genes, based on the protein they’re encoding, might affect some of the receptors where the virus binds and can alter how someone becomes more or less susceptible to the virus.”
Like an exchange
A person’s blood type is determined by the presence or absence of specific antigens—A and B—which are molecules on red blood cells that trigger an immune response. A person with Type A blood has the A antigen on red cells and a B antibody on their plasma; a person with Type B has the B antigen on red cells and A antibodies on their plasma. Individuals with Type AB have both A and B antigens on their red cells, but neither on their plasma, and those with Type O have neither A nor B antigens on their red cells, but both antibodies are present on their plasma.
One theory is that because the immune systems of people with Type O blood already have antibodies for both A and B, their bodies are more equipped to identify foreign proteins—including those on the surface of viruses.
“There are potentially some changes in the immunogenicity in the human host based on the ABO typing,” Li said.
Other symptoms
Some of the conditions observed in Covid 19 patients—including blood clots, strokes and thromboembolisms—may also vary in severity based on blood type, adding another possible explanation, Li added.
“In the ABO blood group, there is evidence that there is increased susceptibility in Type A versus Type O for increased risk for venous thromboembolism, such as pulmonary embolism and deep vein thrombosis,” Li said. “That … has been confirmed in multiple different studies.”
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