Given that the Tau/Aβ42 ratio is associated with an elevated risk of aMCI/AD in the general population [22], the decreased CSF EV Aβ42 levels and increased CSF EV Tau/Aβ42 ratio we observed in some PWH with HAND raises the possibility that these markers identify a subgroup with “HAND” that is due to non-HIV-related etiologies [30,50]. Here, MAPT is linked to Alzheimer disease.