Schistosomiasis-associated pulmonary hypertension

Abstract

Schistosomiasis, a parasite-borne disease, is highly prevalent in Africa and Asia; it is estimated that close to 20 million people worldwide have a severe form of the disease. The chronic form can affect the gastrointestinal system and lead to hepatosplenic disease, and it may cause cardiopulmonary complications, including pulmonary hypertension. The exact pathogenesis of schistosomiasis-associated pulmonary hypertension (Sch-PH) remains unclear, although several mechanisms, including parasitic arterial embolization, pulmonary arteriopathy, and portopulmonary hypertension-like pathophysiology, have been suggested. The immunopathology of the disease is also unclear, although there are similarities with the immunology of idiopathic pulmonary arterial hypertension (PAH). Finally, the treatment of Sch-PH has not been well studied. There is some evidence on treating the underlying infection, with unclear effect on Sch-PH, and advanced PAH therapies are now being suggested, but more studies are needed to confirm their efficacy.

Keywords: Sch-PH; chronic schistosomiasis; pathogenesis and treatment; pulmonary hypertension.

Figure 1

Schistosoma life cycle. Reproduced with permission from the Centers for Disease Control and Prevention (CDC: http://www.cdc.gov/dpdx/schistosomiasis/index.html).

Figure 2

Global distribution of schistosomiasis infection. Copyright Institute of Tropical Medicine (ITM), Antwerp, Belgium; reproduced with permission; previous version published in Lancet.

Figure 3

Schistosoma mansoni eggs (unstained wet mount). Reproduced with permission from Centers for Disease Control and Prevention (http://www.cdc.gov/dpdx/schistosomiasis/index.html).