The deficit of antibodies against the coronavirus responsible for covid-19 increases the risk of death among the most critical patients, according to a team of Spanish researchers, who emphasize the importance of vaccination to protect those who, in the face of a natural infection, do not they have produced enough antibodies.
The researchers concluded that patients who have not produced antibodies against the protein "S" -the protein present on the surface of the coronavirus that facilitates its attachment and entry into cells- at the time of admission to intensive care units, they are up to seven times more likely to die during the first 30 days after admission.
The study, whose conclusions are published in the scientific journal Journal of Internal Medicine, is the result of the work carried out by a team of researchers within the framework of a project funded by the Spanish Instituto de Salud Carlos III through the Covid-19 Fund.
This deficit in the production of antibodies has also been associated with an escape of antigens and the genetic material of the virus into the blood, which also translates into a greater risk of death, the Carlos III Health Institute reported in a note released today .
“Anti-S antibodies are, therefore, essential to control the replication of SARS-CoV-2 in critical covid-19 patients,” said the lead researcher, Antoni Torres, and the microbiologist José María Eiros pointed out that this "escape" of virus material into the blood is a poor prognostic marker.
This is one of the largest studies to date dedicated to analyzing antibodies in critically ill patients with COVID-19.
In a sample of 92 patients, the study reveals that 40 percent of critically ill patients have insufficient levels of antibodies "anti-S" at the time of admission to the ICU, while up to 13 percent have a complete absence of these antibodies.
Antibody quantification could therefore help identify which patients would benefit from treatments with monoclonal antibodies directed against this protein (the "S").
The findings highlight the special importance of vaccination to protect those who, faced with an infection with the natural virus, are not capable of producing antibodies, as explained in the same note by immunologists Jesús Bermejo and David Kelvin, researchers from the Ciberes-UCI project -COVID and Dalhousie University (Canada), respectively.
These findings also raise several interesting options for further studies, according to the Carlos III Health Institute; On the one hand, measuring antibody levels after admission to the ICU could serve to personalize treatment with exogenous antibodies directed against the protein. "S" of the virus.
And quantifying viral load in plasma could be helpful in identifying which patients are at higher risk of death.