Bone Marrow as a Reservoir in Long Covid
Recent work from the Bomsel group in France
ICYMI the Bomsel group in a France recently presented data showing #longcovid viral persistence in megakaryocytes. These are the cells that make platelets, and they’re found in bone marrow.
30/30 subjects had platelets containing infectious viral RNA and microclots.
The team looked to see if it was possible the platelets were picking up the viral material from the bloodstream.
But they determined that, in fact, no- the platelets were in fact being PRODUCED with infectious virus inside of them.
“The presence of the virus could lead to abnormal platelet activation and the formation of microclots, which would contribute to the various symptoms observed” they wrote.
Interestingly, they researchers only found circulating spike protein in 30% of the subjects tested, meaning it might not be the best biomarker.
Unfortunately spike protein is one of the main biomarkers currently being used in our most promising clinical trials in the US.
To be clear, the study was conducted on megakaryocytes in the lungs, however these cells are a major component of bone marrow as well.
The authors provided an abstract of their work in the booklet for the Demystifying LC conference - it’s presentation 28, on p. 31.
I’m sharing this now in light of a second study which was just published by study from Dirajlal-Fargo et. al: Altered mitochondrial respiration in peripheral blood mononuclear cells of post-acute sequelae of SARS-CoV-2 infection.
Dirajlal-Fargo et. al is also strongly suggestive of a bone marrow viral reservoir -in this case leading to abnormal activity and increased oxygen demand in peripheral blood mononuclear cells.
To me it is seeming more and more like the bone marrow could be a very significant reservoir, possibly even more so than the GI tract.
Infectious virus in ALL subjects tested in Bomsel study is a pretty big deal. At least the GI tract isn’t producing poisoned platelets! 🤮
Luckily, we will be getting further study on bone marrow.
Tim Henrich recently mentioned the @UCSF LIINC team will be conducting bone marrow biopsies as part of their upcoming clinical trials, with support from the PolyBio Research Foundation.
You can learn more from this great interview with Dr. Henrich, from The Long Covid Sessions Podcast!
I’m grateful this is happening, but we need so much more!
It’s really looking like bone marrow is a HUGE reservoir and could be behind the clotting, white blood cell abnormalities, and even the altered oxygen usage that’s being found in our tissues.
We need MORE trials of antivirals, mAbs, and hopefully even immunotherapies like Tim Henrich mentioned to get it OUT!
The only good news is so much of our misery could be reversed if we can just remove it. Here’s hoping for the future!
For further info:
For more info, I was able to learn about the Bomsel group's methods from their paper on acute Covid, where they found the same phenomenon: infected megakaryocytes creating infected platelets.
They write, “Lung macrophages capture SARS-CoV-2-containing platelets in vivo. The virus contained by platelets is infectious.”
Infection of lung megakaryocytes and platelets by SARS-CoV-2 anticipate fatal COVID-19 - PubMedSARS-CoV-2, although not being a circulatory virus, spread from the respiratory tract resulting in multiorgan failures and thrombotic complications, the hallmarks of fatal COVID-19. A convergent contr…https://pubmed.ncbi.nlm.nih.gov/35708858/
In 2021, Bomsel and her team also found megakaryocytes to be a reservoir in #HIV, leading to the creation of infected platelets.
https://www.medecinesciences.org/en/articles/medsci/full_html/2021/03/msc200348/msc200348.html
They write,
"We then analyzed bone marrow samples from HIV-infected subjects under effective antiretroviral treatment, without detectable viremia, and with a low level of CD4 + T lymphocytes...and we detected HIV RNA and proviral DNA."
I know many peole with Long Covid are experiencing low CD4+ T cell counts. There is growing evidence for a similar reservoir as to what occurs in #HIV.
We need TREATMENTS for Long Covid!
This is not a matter for CBT or graded exercise therapy!
We need antivirals now.