CD163 and AIDS dementia complex: While in neurologically normal postmortem human brain tissue, CD163 staining is limited to perivascular macrophages as seen in our results and observed in other studies, it has been shown to be upregulated in microglia in disease states such as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, HIV encephalitis, SIV encephalitis, and traumatic brain injury [61–63].