NPR: Unraveling long COVID: Here's what scientists who study the illness want to find out

[forestglip]

https://www.npr.org/sections/health-shots/2023/09/09/1198342040/long-covid-causes-treatment-research

I couldn't find if this NPR article about Long COVID research from September had been posted. I was looking for a not too complicated summary of the state of research, and this was pretty good.

Theories and other important bits:

Evidence of COVID viral persistence

Take the theory of viral persistence: There's now strong evidence that protein and genetic material from SARS-CoV-2 persist in the blood and tissue of some long COVID patients well after their initial illness. Scientists believe these "viral reservoirs" could be driving many of the problems in long COVID patients, although it isn't yet clear exactly how this is happening — and whether the virus itself is replicating.

High T cell levels

His lab has found activated T cells in the gut wall, lung tissue, certain lymph nodes, the bone marrow, the spinal cord and the brainstem, long after someone's initial infection.
...
Henrich says T cell activity could be evidence that the immune system is trying to purge the viral reservoirs, or that the immune response has gone awry, possibly in the form of an autoimmune response, and is "doing damage to people, even if the virus has been cleared or is not replicating in those tissues," he says.

COVID reactivates Epstein-Barr

Research shows that people with long COVID have high levels of Epstein-Barr antibodies and that an acute COVID infection can trigger reactivation of the virus. Akiko Iwasaki, a professor of immunobiology at Yale University, says it's well known that this herpesvirus can lead to a "long COVID-like syndrome," but whether or not the reactivation is driving long COVID symptoms — or just an indication of a dysregulated immune system — remains to be seen.

Microclots

Her research has focused on the role of tiny, harmful blood clots she's seeing in the blood of long COVID patients that appear to have "trapped inflammatory molecules that you might expect inside the blood if you have inflamed [or] damaged endothelial layers."
...
As the clots accumulate, they may choke off blood flow, preventing oxygen from reaching tissue.

In Santa Fe, Pretorius shared preliminary data from her team showing that so-called "triple therapy" — a combination of three medications — targeting clotting and platelet hyperactivation could benefit some long COVID patients. The preprint showed that this regime resolved symptoms in the majority of the 91 patients who were followed, although the results are not yet peer-reviewed and the study was not a clinical trial.

Hormone level differences between males and females

At the conference, she shared evidence of reduced cortisol levels in long COVID patients and shared a separate, unpublished finding that female long COVID patients tend to have reduced testosterone levels and that males have reduced estradiol levels.

Those who had lower testosterone (compared to the controls who don't have long COVID symptoms) also have higher activation of T cells, whether they're males or females, says Julio Silva, a graduate student in Iwasaki's lab who presented the new findings on testosterone. And this was "associated with higher neurological symptoms and overall higher symptom burden," says Silva.

The impetus to look at testosterone was, in part, because of "anecdotes from trans individuals who were informing us that while on testosterone therapy, their symptoms had improved dramatically," says Silva. While the results are preliminary and need to be replicated, he says they at least raise the question "could hormonal therapy help?"

Trials testing if viral persistence is a cause

In Santa Fe, UCSF's Peluso outlined how his team had just launched a small trial using monoclonal antibodies to target the coronavirus spike protein in long COVID patients — one vehicle for testing whether viral persistence is the underlying cause of at least some patients' symptoms. Meanwhile, Iwasaki and Krumholz, both at Yale, have started a clinical trial testing whether a 15-day course of Paxlovid can help alleviate symptoms.

 

[forestglip]

Oh, I realize this should have gone in research news. If a mod can move it, that'd be great.