In patients with long-term COVID, hormonal and immune function are clearly different than in people without the condition, new research shows. This confirms that long COVID is in fact a biological disease and points the way to personalized treatments for patients.
The study, led by researchers from the Icahn School of Medicine at Mount Sinai and Yale School of Medicine and published Monday in the journal Nature, is the first to find specific blood biomarkers, or measurable traits, that can accurately identify patients with long COVID.
The findings clearly show that “the biology of people with long COVID is changed and observably different from that of people who do not have long COVID, so we know we are looking at a physiological condition,” David Putrino, co-author of the study and director of the Cohen Center for Recovery from Complex Chronic Illness at Mount Sinai, told MarketWatch.
Based on the findings, Putrino said, “we can give doctors treating long COVID a trail of breadcrumbs” that they can follow to identify individual differences in hormones, immune function and other factors and treat their patients more effectively.
Long COVID-19 refers to a broad group of health problems that last four weeks or more after an initial COVID infection, with common symptoms including severe fatigue, heart palpitations, thinking problems and shortness of breath. About 6% of U.S. adults had long-term COVID-19 in June, according to the Centers for Disease Control and Prevention.
The new research comes at a time when COVID hospitalizations are again on the rise, with a 7.7% increase in the week ending September 9, according to the CDC. Putrino, who runs a long COVID clinic at Mount Sinai, said his “entire team is drowning in long COVID cases,” with many of those cases caused by COVID infections from just this year. The clinic’s waiting list is months long, he said.
Since the disease was first recognized early in the pandemic, COVID’s long duration has sparked debate in some quarters about whether the disease could be largely caused by psychological factors. But “every day we are accumulating evidence that this is in fact a biological condition and a complex chronic disease, and not a psychosomatic disease,” Putrino said. “Finally, the good science is beginning to emerge that refutes the bad science that was published early in the pandemic that minimized or confused people with this terrible disease.”
That new evidence is crucial in part, Putrino said, because long-term patients with COVID-19 are often denied the opportunity to work remotely or reduce their work hours, which they are legally entitled to under the Americans with Disabilities Act. The research into long-COVID biomarkers, he said, could provide these patients with “hard evidence of their condition so they can access the accommodations they are owed, and even hold accountable people who have denied them in the past .”
According to a recent Urban Institute survey, one in 10 adults with long-term COVID-19 say they have stopped working because of their symptoms, and only about six in 10 long-term COVID patients reported having access to paid sick leave at work .
The Mount Sinai and Yale researchers studied more than 270 patients between January 2021 and June 2022, including those with no previous COVID infection, those who had fully recovered from COVID, and those with active long-term COVID symptoms that lasted four months or more. Each patient completed questionnaires about their symptoms, medical history and quality of life. Researchers analyzed the similarities and differences between the blood biomarkers between the groups and used machine learning to assess which biomarkers most effectively helped the algorithm identify patients with long COVID. Ultimately, the algorithm was 96% accurate in distinguishing patients with long COVID-19 from those without the condition.
The study provides new evidence on the possible causes of common symptoms of long-term COVID-19, and the researchers are working to correlate specific biomarkers with specific symptoms, Putrino said. For example, patients with a long COVID-19 bout often have lower morning cortisol levels, a hormone produced by the adrenal glands that is “potentially very relevant to fatigue,” Putrino said. That helps build evidence against long COVID being caused by psychological factors, he notes, because people with anxiety and depression often have higher, not lower, cortisol levels.
The research also illustrates how the long-term disease process of COVID-19 can vary greatly from person to person. “Your own medical history and genetic history matter when it comes to what goes wrong if you get long COVID,” Putrino said. While “there is no silver bullet, no magic cure for every individual patient who has been ill for a long time,” he said, the study provides guidance for doctors on what tests to perform so that they can correct the dysfunction they see in the individual. can treat. The research, he said, “is a stepping stone to therapies, a stepping stone to understanding and addressing the root cause of long COVID.”