Recent Advances in Pulmonary Hypertension

1361 Pulmonary hypertension is broadly recognized as a group of disorders that share the common characteristic of an elevated mean pulmonary arterial pressure (≥25 mm Hg). Pulmonary arterial hypertension (PAH; Group 1) is a subset of the pulmonary hypertension disorders that is also characterized by pulmonary arterial remodeling, the formation of plexiform lesions, and poor clinical outcomes. When present, pulmonary hypertension is associated with a worse overall prognosis. Clinical evaluation of patients with human immunodeficiency virus (HIV) has indicated that there is a high prevalence of PAH in patients with HIV suggesting a relationship between HIV infection and the pathogenesis of PAH. Human immunodeficiency virus is a member of the genus Lentivirus of the family Retroviridae. The primary target of HIV is the immune system; destruction of lymphocytes (mainly CD4 T cells) by the virus induces severe damage to the host immune function, which increases patient risk for developing opportunistic infections. AIDS is a clinical syndrome representing the final stage of HIV infection and is often characterized by a CD4 T cell count <200 cells/μL. Even in the contemporary era of immune-modulating therapies, the prevalence of HIV infection continues to grow worldwide, devastating the health of individuals, communities, regions, and entire countries. Two major types of the virus are reported: HIV type 1 (HIV-1) is related to viruses originally endemic to West African primates and is primarily responsible for the AIDS pandemic, whereas HIV type 2 (HIV-2) is comparatively less virulent. HIV infection promotes a range of cardiovascular diseases, and is an independent risk factor for the development of pulmonary vascular diseases, including severe PAH, the latter of which is the subject of this review.