Peripheral Reservoir of HIV DNA in Monocytes Pivotal to Cognition in HIV

Inclusion Criteria: * HIV-infected individuals meeting MOPH criteria to initiate HAART and planning to initiate HAART within a month of screening. * Consequently, all participants will have plasma CD4 counts at less than 250 cells. Exclusion Criteria: * Head injury with loss of consciousness greater than 1 hour or cognitive sequela * Current/past illicit drug use or positive drug screen for methamphetamines, amphetamines, or cocaine at screening or entry. * Any of the following laboratory abnormalities: * PT/PTT \> the upper limit of normal (ULN) or INR \> 1.1 * Hemoglobin \< 9.0 mg/dL * ALT \> 5x ULN * serum creatinine \> 2x ULN or creatinine clearance \< 30 cc per min by Cockroft-Gault formula * Acute illness within 30 days prior, persistent and active AIDS-defining OI of any organ system or autoimmune disease. * Current or recent fevers or meningeal signs suggestive of CNS opportunistic infection * CNS opportunistic infection, past or present (Patients diagnosed with opportunistic infection after CSF examination will be excluded from further analysis. In such a situation, an additional patient will be enrolled) * History of pre-existing neurologic disease to include stroke, multiple sclerosis or psychiatric illness including schizophrenia, bipolar disorder, anxiety disorder, panic attacks, major depression, or post traumatic stress disorder. Patients with past depression that is controlled and patients with or minor depressive symptoms will be allowed to enroll. * Known learning disability including dyslexia or unable to read or write basic Thai * Positive Hepatitis C serology (Hepatitis C Ab) * Confusion or other signs and symptoms of metabolic encephalopathy or delirium * Other conditions that could explain neurocognitive decline in the opinion of the investigator such as hypothyroidism, vitamin B12 deficiency or neurosyphilis * Pregnancy or metal objects that would preclude MRI