Global Courant
Although there is no specific test to determine whether someone suffers from long-term COVID, a new study shows published in Nature used blood tests to gain new insight into which biological markers are linked to this collection of mysterious conditions reported by millions of Americans.
Researchers used machine learning to help analyze immune markers and hormone levels in 273 adult participants at Mount Sinai and Yale University and compared those with and without long-term COVID symptoms at least a year after getting COVID-19.
Long COVID-19, defined in this study as persistent symptoms more than six weeks after infection, was associated with lower levels of a hormone called cortisol and had some clear differences in certain immune cells and inflammatory markers circulating in the blood.
These levels are determined through blood tests, but this is not a blood test that specifically tests for long-term COVID.
“(These results) suggest some potential mechanisms leading to a long COVID-19 period that may be amenable to treatment. It can also help identify patients with a long COVID-19 period,” says Dr. Alison Morris, division chief of pulmonary, allergy, critical care and sleep medicine at the University of Pittsburgh School of Medicine, told ABC News.
“I think one of the most important findings of the paper is that it validates people’s symptoms by finding biological differences between them and healthy controls,” Morris said.
“It’s really a remarkable study,” says Dr. Shari Barnett Brosnahan, M.D., M.Sc., a COVID-19 researcher not involved in the study and assistant professor in the department of pulmonary, critical care and sleep medicine at New York. York University Langone Health System, told ABC News. Brosnahan does note that “it’s a limited analysis that they’ve done, and I think there’s more work to be done.”
This study was conducted in relatively few people, so researchers say more studies are needed to better understand the significance of these results more broadly. Still, they say this study helps scientists get one step closer to more knowledge about long Covid. If there are biological markers specific to long COVID-19, this could help confirm a diagnosis or help target treatments.
This research joins a major movement to better understand long COVID conditions and efforts to provide services to those affected, including efforts by the Biden administration which recently launched a new Office of Long Covid Study announced.
Long Covid is a term used to characterize signs, symptoms and conditions that last at least four weeks after becoming infected with COVID-19 and can last for months to years, according to the working definition developed by the U.S. Department of Health and Human Services.
These symptoms can vary in severity and affect multiple organ systems in the body. Common complaints include fatigue, brain fog, sleep problems, difficulty breathing or shortness of breath, dizziness when standing up, and stomach upset. the CDC.
In July 2021, long Covid was recognized as a condition that could qualify as a disability under the Americans with Disabilities Act if it “substantially limits major life activities.” Research that can help doctors make a diagnosis could be critical for those most affected to receive these necessary services.
“I also hope that continuing these studies that show objective evidence will help validate people and understand their long Covid situation,” Brosnahan said. “And help us as a medical community validate long covid disease a little bit more.”
Dr. Jade A Cobern, MD, MPH is a licensed and practicing physician and member of the ABC News Medical Unit.
