Autoimmune antibodies strongly linked to disease severity in COVID-19 patients

The presence of special immune system defense molecules called autoimmune antibodies has been strongly linked to the poverty of people hospitalized with COVID-19, according to a new study.

Led by researchers at NYU Grossman School of Medicine, the study detected autoimmune antibodies in the blood of more than a third of men and women upon admission to hospital and confirmed to have the disease. .

Among the new study findings, a subset of those autoimmune antibodies that bind to DNA or a particular type of fat molecule, a lipid called phosphatidylserine, was more often than twice as abundant at the start. coronavirus infection in those whose condition has worsened rapidly than in those whose health has not deteriorated. Patients with these high levels of autoimmune antibodies were five to seven times more likely to develop severe disease than those with stable antibody levels.

According to researchers, people hospitalized with life-threatening COVID-19 cases needed intensive care and a mechanical ventilator to help them breathe, while those with lower levels of these autoantibodies usually breathed through them. themselves and were largely recovering.

Publication in the journal Life Sciences Alliance Online September 9, the team’s latest work is based on the nature of antibodies, they say, immune proteins that target invading bacteria and viruses. In contrast, autoimmune antibodies instead attack an infected person’s own cells and molecules. This includes lipids and genetic material, or DNA, which are known to spread through the bloodstream when cells are killed by a disease, such as COVID-19.

The results of our study show that the initial blood levels of anti-DNA or anti-phosphatidylserine antibodies were directly related to the severity of the disease in people with COVID-19. “

Claudia Gomes, PhD, Study Co-Principal Investigator, NYU Langone Health Postdoctoral Fellow

“While further testing is needed, our results suggest that testing for the presence of anti-DNA and anti-phosphatidylserine antibodies could help identify hospital-admitted COVID-19 patients who are most at risk of need intensive care and need to be monitored more closely, ”says Marisol Zuniga, MS, also the study’s co-principal investigator at NYU Langone.

For the new study, researchers looked at the medical records and blood tests of 115 white, black, Asian and Hispanic men and women hospitalized with COVID-19 at NYU Langone hospitals between April and June 2020. Roughly numbered. equal had a serious illness from which they survived or died, or did not require intensive care and recovered quickly. Test results for more than 100 measurements, such as blood oxygen levels, liver enzymes, and kidney function, were compared to levels of autoimmune antibodies.

The researchers designed the scan to find out whether common autoimmune antibodies were present in COVID-19, as other studies of other infectious diseases had previously suggested, and whether changes in blood levels were related or no to the way people got sick.

Thirty-six percent of study participants had autoimmune antibodies upon admission to hospital. The levels of anti-DNA and anti-phosphatidylserine antibodies were then strongly related to the severity of the disease. Specifically, 86 and 93 percent of patients with high levels of anti-DNA and anti-phosphatidylserine antibodies, respectively, experienced severe COVID-19. Levels of anti-DNA antibodies were also linked to increases in blood clotting (thrombosis) and cell death (lysis), particularly in muscle tissue. Researchers say thrombosis, which can lead to life-threatening blood clots, and damage to muscle tissue, especially the heart, has been seen in the most severe cases of COVID-19.

“Our overall observations suggest that in severe cases of COVID-19, the production of autoimmune antibodies plays a key role in blood clotting and cell death,” says study principal investigator Ana Rodriguez, PhD , professor in the department of microbiology at NYU Langone. . “Our study adds evidence to the underlying premise of the disease that the erroneous response of the immune system does more damage than the viral infection itself.”

Rodriguez warns that more experiments will be needed to determine whether autoimmune antibodies are the “cause or effect” of the blood clotting and cell lysis seen in his team’s study.

If they are found to be responsible for cell damage, new COVID-19 treatments could include injections of antibodies from healthy donors to dilute the presence of autoimmune antibodies. Other experimental therapies under study involve biodegradable antigens that bind to and neutralize autoimmune antibodies, but do not lead to a lasting immune response of the antibodies.