There were recent landmark papers on how blood monocytes replace the microglia in the brain and promote inflammation, increasing risk of Alzheimer’s (AD)
Today, this has been reinforced
@NatureNeuro by the discovery of dysfunctional bone marrow blood cell production and its effect on the brain
"The present study supports the emerging understanding that AD is not solely a brain disease; especially at later stages, it also encompasses
a dysfunction of the peripheral immune system."