It is the central hypothesis of the investigators study that HIV disease is a pro-inflammatory condition, and that years of inflammation result in premature "aging' of the immune system ("immunosenescence"). Just as these changes are thought be causally associated with heart disease in the very old,the investigators postulate that these changes will be associated with early heart disease in the untreated and perhaps treated HIV disease. To address this hypothesis, the investigators will measure immunosenescence in a large cohort of patients who span the entire disease process.