Mediators involved in HIV-related pulmonary arterial hypertension

HIV-related pulmonary arterial hypertension (PAH) is one of the long-term complications of HIV infection that has become increasingly apparent in recent years. The clinical presentation and underlying pathology of PAH in HIV is similar to that in other forms of the disease, although there are data to suggest subtle differences, such as a greater inflammatory component in the HIV-related form. Advances continue to be made in defining the underlying pathogenesis of PAH, but the overall processes leading to vascular dysfunction and remodeling remain unclear. It would appear that PAH has a multifactorial etiology, with various risk factors--probably acting on an underlying genetic predisposition--that lead to the pulmonary vascular dysfunction that characterizes the disease. A range of growth factors, chemokines, cytokines and other inflammatory mediators, together with mediators involved in vasoconstriction and dilation, have been implicated in the pulmonary vascular remodeling resulting from this dysfunction. An increased understanding of the processes and factors involved in PAH has led to the development of new therapeutic strategies that have improved the management of various forms of PAH, including PAH associated with HIV (HIV-PAH). Recent results from studies into other potential mediators of PAH offer the possibility of new targets for therapy in this progressive and serious condition.