SV2A & TSPO PET Imaging Measures to Reveal Mechanisms of HIV Neuropathogenesis During Antiretroviral Therapy

The purpose of this study is to longitudinally characterize and evaluate changes in synaptic density in the brain using novel positron-emission tomography (PET) scans; magnetic resonance imaging (MRI), and clinical laboratory markers associated with HIV-related injury in the central nervous system. This study will test hypotheses relating to the presence and mechanisms of aberrant brain structure at the synaptic level in living humans with virologically controlled HIV on antiretroviral therapy. To evaluate associations between PET imaging radiotracers \[11C\]UCB-J, a ligand for presynaptic vesicle protein 2A (SV2A), a vesicle membrane protein expressed in synapses, and PET \[11C\]PBR28 a measure of microglia function in the brain, the Yale PET center has developed an advanced approach of combining multiple distinct ligands in coordinated same-day PET imaging. Additionally, the study will evaluate the associations of this novel synaptic density marker with well-established clinical measures of neurocognitive performance and laboratory measures of blood and cerebrospinal fluid (CSF).