Assessing the role of peripheral CD8 T cells in neurocognitive impairment in HIV-infected men who have sex with men: data from the MSM Neurocog Study - Rawson,TM; Dubb,S; Pozniak,A; Kelleher,WP; Mandalia,S; Gazzard,B; Barber,TJ (INTERNATIONAL JOURNAL OF STD & AIDS, 2015)