Patients are stratified by CD4 count: less than 200 cells/mm3 or 200 - 500 cells/mm3. BAL is performed and blood samples are collected prior to initiation of HAART and after 1 and 6 months of HAART. If a patient has detectable HIV in the lung after 6 months of HAART, the patient is asked to submit to an optional fourth BAL after 12 months of HAART. BAL fluid and cells are analyzed for HIV viral load, percent lymphocytes, and lymphocyte subsets. Responses in the lung are compared to simultaneous changes in these variables found in the peripheral blood. Each patient serves as his/her own control.