Risk factors such as low CD4+ (cell count, high viral load at baseline, low CD4+ nadir, HCV-coinfection, drug abuse, and metabolic comorbidities are also associated with a higher incidence of HIV-neurocognitive impairment (cited in the following paragraphs) [4,10,11,12,13,14,15,16,17,18]. Here, CD4 is linked to coinfection.