BACK TO SCIENCEINSIDER
SCIENCEINSIDERHEALTH
Blood abnormalities found in people with Long Covid
Study implicates lack of key hormone, battle-weary immune cells, and reawakened viruses
16 AUG 202212:30 PMBYJENNIFER COUZIN-FRANKEL
Illustration of crowd of people and large looming Covid virus in foreground casting a shadow over some individuals
ROBERT NEUBECKER C/O THEISPOT
SHARE:
Linked In
issue cover image
A version of this story appeared in Science, Vol 377, Issue 6608.
Download PDF
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.
Other groups studying Long Covid patients have reported similar results this year, including in a January Cell paper that documented low cortisol in those with long-lived respiratory
Other groups studying Long Covid patients have reported similar results this year, including in a January Cell paper that documented low cortisol in those with long-lived respiratory symptoms, and reactivation of viruses in patients with neurological issues. Collectively, these data “make me think about what other drugs we can test,” such as virus-directed antibodies or targeted anti-inflammatories to tame the immune system, says Emma Wall at University College London and the Francis Crick Institute, who co-leads a large trial of potential Long Covid therapies.
The new Long Covid project began in late 2020, when Yale University immunologist Akiko Iwasaki teamed up with David Putrino, a neurophysiologist at the Icahn School of Medicine at Mount Sinai who was caring for affected patients. The pair wanted to compare those patients with people who had never been infected—and those who had recovered. To Putrino’s surprise, “It was quite challenging to find people who were fully recovered from COVID.” Many post–COVID-19 volunteers described themselves as healthy but then admitted, for example, that their once-normal gym workouts were too exhausting to resume. In the end, the team signed on 39 COVID-19–recovered volunteers among a total of 116 controls.
The low cortisol levels in the Long Covid patients, about half of normal levels, aren’t a total surprise: Symptoms such as fatigue and muscle weakness are associated with less of the hormone. The cause remains a mystery. ACTH, a hormone made by the pituitary gland that controls cortisol production, was at normal levels in the Long Covid group. Furthermore, note Putrino and others, some Long Covid patients outside the study have tried short courses of steroids, which can treat low cortisol, but say they haven’t helped. Next, the researchers plan to track cortisol levels throughout the day in Long Covid; the steroid rises and falls on a daily cycle, and the initial research only tested it in the morning.
You must be logged in to post a comment.