/dpa
Leipzig/Stockholm – A genetic risk variant for a severe course of COVID-19, which originally comes from the Neanderthals, apparently reduces the risk of becoming infected with HIV by 27 percent. This emerges from a report in the Proceedings of the National Academy of Sciences of the United States of America (DOI: 10.1073/pnas.2116435119).
In addition to risk factors such as older age, obesity and chronic diseases, the genetic make-up can also increase or reduce the individual risk of severe COVID-19 disease.
As early as autumn 2020, scientists from the Max Planck Institute for Evolutionary Anthropology in Leipzig and the Karolinska Institutet in Stockholm had shown that humans inherited a significant genetic risk factor for severe COVID-19 diseases from Neanderthals.
When Svante Pääbo and Hugo Zeberg carried out further studies on prehistoric human DNA, it was found that this gene variant has become increasingly common since the last ice age – unexpectedly common for a variant inherited by Neanderthals. The scientists therefore concluded that the gene variant must also have an advantage for its carrier.
“This genetic risk variant for COVID-19 is so common that I’ve started to wonder if it’s good for something, like if it could protect against other infectious diseases,” Zeberg said in a statement from the Max Planck Society. Institute cited.
The genetic risk variant is located on chromosome 3, near several genes that code for immune system receptors. One of these receptors – CCR5 – is used by the HI virus to infect leukocytes.
Zeberg discovered that people with this COVID-19 risk variant had fewer of these CCR5 receptors. And an analysis of three major blood banks in Finland, the United Kingdom and the US state of Michigan found that carriers of the gene variant had a 27 percent lower risk of contracting HIV.
“This shows how a gene variant can have both good and bad sides: Bad if the carrier becomes infected with SARS-CoV-2, good if they are confronted with HIV,” says Zeberg.
However: HIV only appeared in the 20th century, so protection against this infectious disease does not explain why this genetic risk variant spread so rapidly among humans 10,000 years ago.
“We now know that this COVID-19 risk variant can protect against HIV infection. But it was probably protection from yet another disease that caused their incidence to increase so much after the last ice age,” Zeberg explained. © nec / aerzteblatt.de