March 20, 2021
MISFOLDED PROTEINS MAY BE CAUSING A PROTEINOPATHY RESULTING IN COMPLEMENT ACTIVATION AND NEURONOPHAGY
A paper out recently shows hypoxic/ischemic changes in all brains, both global and focal; large and small infarcts, many of which appeared hemorrhagic; and microglial activation with microglial nodules accompanied by neuronophagia, most prominently in the brainstem.
SARS-CoV-2 has been hypothesized to be a conformational disease and proteinopathy has been considered to be a part of several aspects of the diseases pathogenesis. As the virus causes misfolded proteins they may aggregate and be responsible for the Anti-DNA autoantibodies being observed in the disease. In fact, seeding brain protein aggregation by SARS-CoV-2 is a possible long-term xomplication of COVID-19.
It may be that the COVID is causing aggregate protein misfolding, which is then activating complement and causing the microglia to engulf synapses (think Long COVID, as well). The neuronophagy paper also showed viral fragments in brain.
In short, the body is trained to "recognize" its own neurons as "invaders."
COVID-19 Neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital
Seeding Brain Protein Aggregation by SARS-CoV-2 as a Possible Long-Term Complication of COVID-19 Infection
Implications of the SARS-CoV-2 spike protein interaction with type-1 macrophages via α7-nAChR.
Pathological Aspects of COVID-19 as a Conformational Disease and the Use of Pharmacological Chaperones as a Potential Therapeutic Strategy