Study implicates lack of key hormone, battle-weary immune cells, and reawakened viruses
An ambitious study of people with Long Covid, the mysterious, disabling symptoms that can trail a SARS-CoV-2 infection, has turned up a host of abnormalities in their blood. The clues add to a body of evidence hinting at drivers of the condition and potential treatments worth testing. They also suggest that, as many scientists and patients have suspected, Long Covid shares certain features with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), another condition thought to follow an infection.
The new study, posted as a preprint last week, was modest in size, examining just 99 people with Long Covid. “But it went very deep, it went into granular aspects of the T cells, the antibody response,” says Eric Topol, director of the Scripps Research Translational Institute, who was not involved in the work. “This is exploratory, but it’s the foundation for much bigger studies.”
The Long Covid patients, most of them struggling with intense fatigue, brain fog, and other symptoms, had low levels of cortisol, a stress hormone that helps the body control inflammation, glucose, sleep cycles, and more. Features of their T cells indicated their immune system was battling unidentified invaders, perhaps a reservoir of SARS-CoV-2 or a reactivated pathogen such as Epstein-Barr virus.