Mild Neurocognitive Disorder in HIV Infection of the Brain

Study Summary

Background: \- Some people with human immunodeficiency virus (HIV) develop problems with thinking and concentration when the virus affects the brain. This is known as mild neurocognitive disorder (MND). Research has shown that some HIV medications do not get through the blood brain barrier very well. P-glycoprotein (P-gp) is a brain protein that is part of the blood brain barrier. Differences in the activity of P-gp may help explain why some people with HIV develop MND. It is also possible that MND is partly due to inflammation in the brain. Researchers want to study P-gp and its effect on MND and HIV infection. Objectives: \- To study P-gp and brain inflammation related to HIV infection. Eligibility: * Individuals between 18 and 60 years of age who have HIV and either do or do not have MND. * Healthy volunteers between 18 and 60 years of age. Design: * Participants will be screened with a medical history and physical exam. Blood and urine samples will be collected. * Participants will have one outpatient visit and one 3-day inpatient stay. * At the outpatient visit, participants will provide blood samples and have a lumbar puncture (spinal tap). The spinal tap will collect cerebrospinal fluid for study. * At the inpatient visit, participants will have two positron emission tomography (PET) scans of the brain. These scans will study brain activity and possible inflammation. One scan will involve a study drug called tariquidar, which blocks the activity of P-gp. A second lumbar puncture will be done before the first PET scan. Blood and urine samples will be collected daily.