4 ms·

If you’re doing the calf exercises to ward off a DVT, (and not to just stretch your strained calf!) you may be barking up the wrong tree. The preliminary theor

If you’re doing the calf exercises to ward off a DVT, (and not to just stretch your strained calf!) you may be barking up the wrong tree. The preliminary theories (backed by the thrombocytopaenia) are that, if there’s a vaccine induced thrombosis with thrombocytopenia, it is probably immune-mediated (similar to HITT - heparin induced thrombocytopenia and thrombosis). And then there’s some weird thing that makes them form in your venous sinus. But there were also reports of more typical blood clots (ie DVTs), the first European Medicines Agency advisory (0) said that this was within the level of noise (im now talking AstraZeneca, so apologies for shifting vaccine as generally they should be considered separately until the evidence catches up, although everyone is quickly drawing parallels between them) (0) https://www.ema.europa.eu/en/news/covid-19-vaccine-astrazeneca-benefits-still-outweigh-risks-despite-possible-link-rare-blood-clots https://www.ema.europa.eu/en/news/covid-19-vaccine-astrazene... Ps apologies for not referencing around HITTs and theories around antibody-mediation for CVT. Basically it’s all pretty noisy anyway at the moment and so my here-say from the medical tea rooms is as good a gossip as any, as long as everyone is aware that no one really has any definitive idea what may be going on yet

davak 6y ago
Good take. Arterial clots with thrombocytopenia is incredibly rare. Additionally the PF4 activity in these patients is very abnormal and appears to be to immune mediated. Lots of science and focus going into the mechanism around this now. The other recent NEJM articles around clots associated with the other adenovirus COVID vaccines are likely a similar phenomena.
chemeng 6y ago
Agreed, I don't think anyone knows clearly what is happening. Some additional points that are related. Thrombocytopenia has been a known complication of adenovirus vectors that researchers have worked to overcome in recent decades. These incidents mirror HITT (women are at higher risk for HITT) and seem to be happening in the timeperiod where IgG titers spike post vaccination. To me this indicates it's not unlikely something with the adenovirus vectored vaccines (J&J, AZ) is causing this issue. And because this thread seems to have gone to hell, I'll add that I support doing subgroup specific risk calculations and allowing vaccinations to proceed where it makes sense. https://jvi.asm.org/content/81/9/4866 https://jvi.asm.org/content/81/9/4866 https://ashpublications.org/blood/article/109/7/2832/125650/Adenovirus-induced-thrombocytopenia-the-role-of https://ashpublications.org/blood/article/109/7/2832/125650/... https://pubmed.ncbi.nlm.nih.gov/17148587/ https://pubmed.ncbi.nlm.nih.gov/17148587/
- Pyramus 6y ago
  Just want to add that this is not a new theory and has been circulating in medical circles for roughly a month [1]. There is also the hope that when it happens it can be diagnosed and treated. [1] https://twitter.com/LJohnsdorf/status/1371721321336475651 https://twitter.com/LJohnsdorf/status/1371721321336475651 (in German)

davak 6y ago

Good take. Arterial clots with thrombocytopenia is incredibly rare. Additionally the PF4 activity in these patients is very abnormal and appears to be to immune mediated. Lots of science and focus going into the mechanism around this now. The other recent NEJM articles around clots associated with the other adenovirus COVID vaccines are likely a similar phenomena.

chemeng 6y ago

Agreed, I don't think anyone knows clearly what is happening. Some additional points that are related. Thrombocytopenia has been a known complication of adenovirus vectors that researchers have worked to overcome in recent decades. These incidents mirror HITT (women are at higher risk for HITT) and seem to be happening in the timeperiod where IgG titers spike post vaccination. To me this indicates it's not unlikely something with the adenovirus vectored vaccines (J&J, AZ) is causing this issue. And because this thread seems to have gone to hell, I'll add that I support doing subgroup specific risk calculations and allowing vaccinations to proceed where it makes sense. https://jvi.asm.org/content/81/9/4866 https://jvi.asm.org/content/81/9/4866 https://ashpublications.org/blood/article/109/7/2832/125650/Adenovirus-induced-thrombocytopenia-the-role-of https://ashpublications.org/blood/article/109/7/2832/125650/... https://pubmed.ncbi.nlm.nih.gov/17148587/ https://pubmed.ncbi.nlm.nih.gov/17148587/

Pyramus 6y ago
Just want to add that this is not a new theory and has been circulating in medical circles for roughly a month [1]. There is also the hope that when it happens it can be diagnosed and treated. [1] https://twitter.com/LJohnsdorf/status/1371721321336475651 https://twitter.com/LJohnsdorf/status/1371721321336475651 (in German)