The purpose of this study is to describe the epidemiology of pulmonary hypertension in individuals with HIV infection and to investigate its pathogenesis. We propose to conduct a prospective observational cohort study to determine the association between highly active antiretroviral therapy (HAART) and viral suppression in HIV-infected patients who have been identified to have pre-clinical pulmonary hypertension (Aim 1). In addition, we will investigate the mechanistic role of the HIV-1 Nef protein and HHV-8 infection in the development and progression of pulmonary hypertension in individuals with HIV (Aim 2). We will also investigate endothelial function in HIV-infected patients with pulmonary hypertension (Aim 3).

Inclusion Criteria:

1. Infection with HIV greater than 6 months in duration
2. Right heart catheterization showing PASP > 30mm Hg
3. Ability to provide reliable history of HIV medications or has received the majority of medical care from San Francisco General Hospital with available records of medical treatment.
4. Ability to participate in follow-up for the duration of the study.

Exclusion Criteria:

1. Known significant cardiovascular disease, including clinically significant valvular heart disease, congenital heart disease, current or prior symptomatic coronary disease, or known cardiomyopathy.

2. Any known pulmonary disease that could potentially cause pulmonary hypertension.

3. A pO2 by pulse oximetry below 90% on room air.

4. Obstructive sleep apnea.

5. Known collagen vascular disease.

6. History of anorexigen use

   • 7. Age less than 18 years old.
   • 8. Other co-morbidities for which the investigators, in conjunction with the primary care provider, believe render the participant with an expected survival of 6 months or less.

HIV infected individiuals with the clinical diagnosis of pulmonary hypertension or who have mildly elevated pulmonary arterial pressures