A new study that was just published in Nature used blood tests to gain new insight into what biological markers are connected with this collection of mystery ailments that have been reported by millions of Americans. While there is no precise test to assess if someone is having long-term COVID, the study did reveal new information about what biological markers are related to long-term COVID-19.
Researchers at Mount Sinai and Yale University analyzed the immunological markers and hormone levels of 273 adult participants and compared those with and without long COVID symptoms at least one year after receiving COVID-19. Machine learning was utilized to assist with the analysis of these immune markers and hormone levels.
Long COVID, which was defined in this study as persistent symptoms longer than 6 weeks after infection, was associated with lower levels of a hormone called cortisol and had some specific changes in some immune cells and inflammatory markers circulating in the blood. These findings were gleaned from a comparison of patients who had long COVID-19 to those who had short COVID.
Blood tests are used to determine these levels; however, this particular blood test does not explicitly test for long COVID.
“[These results] suggest several potential processes that might be responsible for extended COVID and that might be treatable. According to Dr. Alison Morris, who is the division chief of pulmonary, allergy, critical care, and sleep medicine at the University of Pittsburgh School of Medicine, who spoke with ABC News, the test “may also help in identifying patients with long COVID.”
“I think that one of the most important findings of the paper is that it validates the symptoms that people have by finding biological differences between them and healthy controls,” said Morris. “I think that’s probably one of the most important findings of the paper.”
According to Dr. Shari Barnett Brosnahan, M.D., M.Sc., an assistant professor in the division of pulmonary, critical care, and sleep medicine at New York University Langone Health System, “It is a truly remarkable study,” she said in an interview with ABC News. Brosnahan was a COVID-19 researcher who was not engaged in the study. Brosnahan does point out, though, that “it’s a limited analysis that they did, and I think that there’s still a lot more work to be done.”
Since this study was conducted on a relatively small number of participants, the researchers believe that additional research is required to better appreciate the importance of these results when applied to a wider population. Despite this, they claim that the study brings researchers one step closer to gaining a better understanding of long-term. If there are biological indicators that are unique to extended COVID, then this could help validate a diagnosis or assist in the targeting of therapy.
This research contributes to a larger effort to obtain a better knowledge of long-term COVID conditions and attempts to provide services to those who are afflicted by them. These efforts include those made by the Biden administration, which only recently announced the creation of a new Office of Long COVID Research.
According to the working definition developed by the United States Department of Health and Human Services, the phrase “long COVID” is used to identify indications, symptoms, and diseases that remain for at least 4 weeks after getting infected with COVID-19 and that may last months to years.
The severity of these symptoms might vary, and they can affect a number of the body’s organ systems. According to the CDC, the most common complaints are weariness, brain fog, problems sleeping, difficulty breathing or shortness of breath, dizziness upon standing, and stomach disorders.
Long COVID was recognized as a condition in July 2021 that could qualify as a disability under the Americans with Disabilities Act if it “substantially limits major life activities.” The phrase “substantially limits” was added to the definition of “disability” in July 2021. Research that can assist physicians in making a diagnosis may be critical for ensuring that individuals who are most seriously harmed get access to these essential services.
“I also hope that continuing to have these studies that show objective evidence will help validate people and increase their understanding [of] their long covid,” Brosnahan added. “And help us as a medical community validate the disease of long-term COVID a little bit more.”