Epigenetic endowment of every person has an impact on COVID-19 severity

COVID-19, caused by the infection of the SARS-CoV-2 virus, has changed people's behavioral patterns since the moment it became a global pandemic. To date, more than 136 million people have suffered from this disease, and more than 2.9 of these have lost their lives. The symptoms of the infection are varied, ranging from people with no clinical symptomatology to those who need hospital admission in the intensive care unit with the help from emergency assisted ventilation.

At the moment, the factors responsible for this wide range of clinical pictures are still unknown. Now, an article in EBioMedicine -The Lancet's sister journal for laboratory findings- shows that the epigenetic endowment of every person has an impact on the severity of COVID-19.

The study was carried out by the teams led by Manel Esteller, professor at the Department of Physiological Sciences of the UB, director of the Josep Carreras Leukaemia Research Institute (IJC) and ICREA research professor, and Aurora Pujol, also ICREA professor and head of the IDIBELL Neurometabolic Diseases Group.

Given the high number of infected people that have saturated healthcare systems worldwide, we would need ways to predict whether the infection in a certain person will require hospital admission or whether it can be controlled on an outpatient basis.

For now, we know the advanced age and coexistence of other pathologies (cardiovascular diseases, obesity, diabetes, immune defects) are linked to a more severe infection. However, what happens to the rest of the population?

This was the question researchers raised: "To work on the research, we decided to study more than 400 patients who had tested positive for COVID-19 and did not belong to any risk group, and we analysed the genetic material depending on whether they had presented symptoms, or if these were mild, or if they required respiratory assistance and needed hospital admission", notes Manel Esteller.

"The results of the study -continues the researcher- show there are epigenetic variations in the chemical switches that regulate the DNA activity in virus-positive patients who developed severe COVID-19". These modifications occur mainly in genes associated with an excessive inflammatory response and in genes that reflect a general worse state of health.

Interestingly, the 13% of the world population presents this epigenetic signature (EPICOVID); thus, this is the group at maximum risk we must take special care of."

Manel Esteller, Professor, Department of Physiological Sciences, Universidad de Barcelona