Imaging and Biopsy of People With HIV-1 Undergoing Analytic Treatment Interruption

Background: Human immunodeficiency virus (HIV) infects CD4 T cells. There is no cure for HIV. People with HIV need to take daily medications called antiretroviral therapy (ART) to control their infection. ART stops HIV from infecting cells, but HIV does not go away. Some infected cells remain. If ART is stopped, then HIV levels will rise and infect more cells. Objective: To compare changes in the amount of virus in blood and lymph nodes after a short treatment interruption. Eligibility: Adults aged 18 years or older who are undergoing ART for HIV infection. Design: Participants will be screened with a physical exam, including blood tests. They will be assigned to 1 of 2 groups: One group will stay on ART. They will have 2 study visits: the first 45 days after screening, and the second 12 to 16 weeks later. They will have a PET/CT scan at each visit. A substance called a tracer will be injected into their arm. They will lie still on a table that moves through a doughnut-shaped machine. This process takes up to 2 hours. The other group will stop ART for no more than 90 days. This group will have 3 PET/CT scans over 8 months. Once they stop ART, they will visit the clinic weekly for blood tests. After restarting ART, they will continue to visit the clinic weekly until their HIV level is safe. All participants will have small samples of tissue taken from lymph nodes. They may also opt to provide semen samples or vaginal fluid. They may have samples taken of bone marrow or the fluid inside their spinal column.