Schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH): A comprehensive review of diagnosis and management.

Schistosomiasis is the second most dangerous parasitic disease, affecting approximately 200 million people worldwide. Chronic Schistosomiasis, especially the hepatosplenic form, can lead to the development of pulmonary arterial hypertension and has been classified as a distinct entity referred to as "Schistosomiasis-associated pulmonary arterial hypertension" (Sch-PAH). Several mechanisms may play a role in the pathogenesis of Sch-PAH, which include peri-ovular granulomatous inflammation with subsequent vascular remodeling. Pro-inflammatory and pro-fibrotic cytokines with altered downstream signaling of bone morphogenic protein receptor 2 pathway (BMRP-2) have been hypothesized based on the mouse models. Diagnosis of Sch-PAH requires confirmation of pre-capillary pulmonary arterial hypertension by right heart catheter and further evaluation of etiology in those with risk factors for schistosomiasis with anti-schistosomal antibody levels. Although there is no robust evidence to suggest a specific management of Sch-PAH, Phosphodiesterase -5 inhibitors (PDE-i) have been shown to improve functional capacity, 6-min walk test, and an improvement in cardiac index. There is some evidence that treatment of underlying infection, if never been considered may have some benefit in the management of Sch-PAH.