Transfer of IgG from Long COVID patients induces symptomology in mice

This seemed especially relevant to share given the Times article published today talking about how long COVID patients end up being thrown into psych wards.

Link to preprint if you just want the broad highlights: https://www.biorxiv.org/content/10.1101/2024.05.30.596590v1. Note that this has been out since June 2024, so might not be new to some of you. The key takeaway from there I think is: “These findings demonstrate that transfer of IgG from Long COVID patients to mice replicates disease symptoms, underscoring IgG’s causative role in Long COVID pathogenesis. This work proposes a murine model that mirrors Long COVID’s pathophysiological mechanisms, which may be used as a tool for screening and developing targeted therapeutics.”

And if you’d like to see a more in depth discussion, one of the lead investigators, Dr. Brent Appelman, just successfully defended and published his PhD thesis that discusses in much greater detail and depth the biological mechanisms thought to be affected in people with long covid. Link to his university’s website where you can download a pdf of the full thesis for anyone who wants to read it: https://dare.uva.nl/search?identifier=d465d8ed-7510-4261-b570-663f74729240.

A few things really stood out to me. First, I thought it was pretty extraordinary that they were able to induce long covid symptoms by injecting IgG antibodies from long covid patients into mice. I think that pretty conclusively refutes the unfortunately widely held idea that this is all just in people’s heads or that we’re all just anxious/depressed/malingering. And second, I thought it was really noteworthy when he explained, “What we saw is that the energy factories were not working as well and that the muscles themselves showed abnormalities” and that "The same picture applies to the immune cells, the energy factories do not work properly. Substances that should not actually be present, such as ido-2, can also cause a lot of damage in the long term."

Overall this seems like a big step forward in Long Covid research. If there’s an autoimmune component as many of us believe there to be, hopefully this will help open doors to additional research and funding on potentially using existing treatments for other auto immune diseases to treat long covid, building on existing research into things like plasmapheresis etc.