Do blood groups influence the severity of COVID-19?

Why do some people not even perceive that they have been infected, while others need medical treatment and mechanical respiration, and in the worst case they die? These very different evolutions make it difficult to determine how many people have actually been infected with the coronavirus and how many have developed antibodies. The hidden figure is high.

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Blood groups in focus

German and Norwegian researchers analyzed different blood groups in relation to the course of COVID-19 disease. And they reached surprising conclusions, although they are still provisional.

One reason for the very different way in which the disease develops may lie in the patient's blood group. The scientists investigated what influence it can have in the cases of patients of special gravity.

The track of blood

The researchers studied the cases of 1,610 COVID-19 patients with respiratory collapse. These are people from Italy and Spain: specifically, from Milan, Monza, Madrid, San Sebastián and Barcelona. All presented a very serious picture. Some did not survive.

Scientists analyzed material from the patients' DNA at certain points, where variants often occur. The genetic characteristics that were discovered were compared with blood samples from 2,250 healthy people.

A first result: people with group A blood seem to be at a particularly high risk of suffering a serious evolution. In Germany, 43 percent of the population has that blood group. In this segment, the risk of needing oxygen or mechanical respiration in case of falling ill with COVID-19 could double that of people with group "0".

The latter may feel lucky in the current situation, although they are also not free to become infected with the coronavirus. But, according to the study, in his case the danger of a serious evolution is less.

Blood group 0, which is 41 percent of the German population, also has other special characteristics: those who have it are universal donors.

Blood groups B and AB, corresponding to 11 and 5 percent of the population, respectively, are not as frequent and would be in an intermediate position when it comes to COVID-19, according to the study.

Blood groups and therapies

If the results of the study are confirmed, they could be useful for the development of pharmacological therapies.

There has already been similar research on the relationship of blood groups and other diseases. For example, malaria. Meanwhile, it is known that people with group 0 blood rarely become seriously ill with malaria and are better protected against an aggressive course of this disease. There are other diseases in which other blood groups protect their carriers better. For example, group A in the case of plague.

Scientists are now following this new blood trail, in their efforts to unravel the mysteries of COVID-19.

Source: Gudrun Heise for DW