Covid-19 patients with type A blood more likely to need ventilator

PEOPLE with blood type A may be more at risk of serious forms of the coronavirus, research has shown.

The study, by researchers in Germany and Norway but not yet published, is the latest to show that people with this particular blood type may be more susceptible to the disease.

The researchers found two points in the human genome that were associated with an increased risk of respiratory failure in patients with Covid-19.

One of these points is the gene that determines blood type.

Having type A blood was linked to a 50 per cent increase in the likelihood that a patient would need oxygen or go on a ventilator, the researchers found.

However, Andre Franke, professor of molecular medicine at the University of Kiel and lead author of the study, said it was not certain whether it was the blood group that determined whether someone would become more seriously ill, or the genetic marker. “We cannot disentangle yet whether actually the blood group is the risk or some genetic variants that are linked to the blood groups.

“Using the blood groups as proxies, we estimate a 50 per cent higher protection for [blood type] O and a 50 per cent higher risk for A,” said Prof Franke.

Researchers took blood samples from 1,610 patients in hospitals in Italy and Spain who needed oxygen or had to go on a ventilator. They extracted DNA and scanned it using a technique called genotyping.

They then compared these findings with 2,205 blood donors who did not have Covid-19.

Next they examined the DNA of the Covid-19 patients to determine if they shared any of the same genetic code. Separate studies from China and the US have also shown that people with blood type A are more susceptible to the disease than those with type O, the more common blood type.

During the 2002-03 epidemic of Sars, researchers also found that those with type A blood were more likely to contract the disease.

But researchers are still unsure why there is a link.